Contact trip assembly for fastening tool

This application claims the benefit of Provision application Ser. Nos. 60/265,399, filed Jan. 31, 2001 and 60/338,896, filed Nov. 6, 2001.

The invention relates to fastening tools having contact trips and particularly to mechanisms for easily adjusting the contact trips.

Fastening tools are used for driving nails or staples into workpieces. It is well known in the art to provide such tools with a contact trip extending downwardly from the tool for contacting the workpiece and a separate trigger activated by the user's digits. Accordingly, the tool can be “programmed” to drive a nail only when the user has pushed the tool unto the workpiece and has activated the trigger.

At times, it is useful to adjust the length of the contact trip. Prior art solutions, such as the solution shown in U.S. Pat. No. 5,219,110, include providing a contact trip having an upper contact trip, a lower contact trip, and a rotatable element therebetween. As the element is rotated, the lower contact trip moves relative to the upper contact trip, thus adjusting the contact trip length.

It is an object of the invention to provide a contact trip that is easier to adjust than prior art contact trips.

In accordance with the present invention, an improved fastening tool is disclosed. The fastening tool includes a housing, a magazine connected to the housing for storing a fastener, a driving mechanism disposed within the housing for driving the fastener into a workpiece, a trigger assembly pivotally attached to the housing for activating the driving mechanism, the trigger assembly comprising a main trigger, pivotally attached to the housing and a supplemental trigger pivotally attached to the main trigger; and a contact trip assembly comprising an upper contact trip contacting the supplemental trigger, a lower contact trip connected to the upper contact trip, wherein the upper and lower contact trips have teeth that mesh together for locking the upper and lower contact trips.

Additional features and benefits of the present invention are described, and will be apparent from the accompanying drawings and the detailed description below.

The accompanying drawings illustrate preferred embodiments of the invention according to the practical application of the principles thereof, and in which:

FIG. 1 is a side view of a fastening tool including a first embodiment of a contact trip assembly according to the invention;

FIG. 2 is an exploded view of the contact trip assembly of FIG. 1;

FIG. 3 is a cross-sectional view of the contact trip assembly of FIG. 1, along line C—C as shown in FIG. 2;

FIG. 4 is a side view of a fastening tool including another embodiment of a contact trip assembly according to the invention;

FIG. 5 is an exploded rear perspective view of the contact trip assembly of FIG. 4;

FIG. 6 is an exploded front perspective view of the contact trip assembly of FIG. 4;

FIG. 7 is a cross-sectional view of the contact trip assembly of FIG. 4, along line A—A as shown in FIG. 4;

FIG. 8 is a partial cross-sectional view of the contact trip assembly of FIG. 4, along line B—B as shown in FIG. 7A;

FIG. 9 is a side view of a fastening tool including a further embodiment of a contact trip assembly according to the invention;

FIG. 10 is a side view of the contact trip assembly of FIG. 9;

FIG. 11 is a rear view of the upper contact trip of FIG. 9;

FIG. 12 is a side view of another contact trip assembly according to the invention;

FIG. 13 is a partial exploded view of the contact trip assembly of FIG. 12;

FIG. 14 illustrates a typical trigger assembly;

FIG. 15 is an exploded view of another embodiment of a contact trip assembly according to the invention;

FIG. 16 is a cross-sectional view of the contact trip assembly of FIG. 15, where FIGS. 16A-B show the engaged and disengaged contact trip assembly, respectively;

FIG. 17 is a cross-sectional view of a further embodiment of a contact trip assembly according to the invention, where FIGS. 17A-B show the engaged and disengaged contact trip assembly, respectively;

FIG. 18 illustrates another embodiment of a contact trip assembly according to the invention, where FIG. 18A is a partial exploded view, FIG. 18B is a partial assembled view, FIG. 18C is a perspective view of an adjuster and FIG. 18D is a perspective view of a detent spring;

FIG. 19 is an exploded view of a further embodiment of a contact trip assembly according to the invention;

FIG. 20 is a cross-sectional view of the contact trip assembly of FIG. 19, where FIGS. 20A-B show the engaged and disengaged contact trip assembly, respectively;

FIG. 21 is a cross-sectional view of another embodiment of a contact trip assembly according to the invention, where FIGS. 21A-B show the engaged and disengaged contact trip assembly, respectively;

FIG. 22 illustrates a further embodiment of a contact trip assembly according to the invention, where FIG. 22A shows a partially assembled contact trip, FIG. 22B shows a perspective view of the outside of the contact trip assembly, and FIG. 22C is a partial cross-section showing the interaction between the button and the cam rail;

FIG. 23 illustrates another embodiment of a contact trip assembly according to the invention, where FIGS. 23A-B show a perspective view of the contact trip assembly and a cross-sectional view of the contact trip assembly along line XXIII—XXIII of FIG. 23A, respectively;

FIG. 24 is a cross-sectional view of a further embodiment of a contact trip assembly according to the invention, where FIGS. 24A-B show the engaged and disengaged contact trip assembly, respectively;

FIG. 25 is a cross-sectional view of another embodiment of a contact trip assembly according to the invention, where the contact trip assembly is in the engaged position;

FIG. 26 illustrates a further embodiment of a contact trip assembly according to the invention, where FIGS. 26A-B show a partial exploded view of the contact trip assembly and a cross-sectional view of the assembled contact trip assembly, respectively; and

FIG. 27 is a front perspective view of another embodiment of a contact trip assembly according to the invention.

The invention is now described with reference to the accompanying figures, wherein like numerals designate like parts. FIG. 1 shows a fastening tool 10 comprising a main housing 15 which covers the driving mechanism (not shown) for driving a fastener, such as a nail or staple, and which includes a handle 11 , a nosepiece 13 below the housing 15 , a magazine 12 connected to the nosepiece 13 and the handle 11 , and a trigger assembly 14 disposed on the housing 15 and/or handle 11 for activating the driving mechanism as is well known in the art. Persons skilled in the art should recognize that the driving mechanism can be a pneumatic-based system, such as the ones shown in U.S. Pat. Nos. 3,673,922 or 5,181,450, or an electric system, such as the ones shown in U.S. Pat. No. 4,928,868. The teachings from those patents are wholly incorporated herein by reference.

Preferably, nosepiece 13 has rods 13 R (see FIG. 2) which are received within channels (not shown) in the magazine 12 . Fastening tool 10 also comprises a first embodiment of a contact trip 100 according to the invention.

Referring to FIG. 14, the trigger assembly 14 may have a main trigger 14 M pivotally attached to the housing 15 or handle 11 and a supplemental trigger 14 S pivotally attached to the main trigger 14 M. As discussed below, when main trigger 14 M and contact trip 100 are activated, supplemental trigger 14 S will move valve 14 V, thus activating the driving mechanism. Persons skilled in the art will recognize that valve 14 V will be a switch if the driving mechanism is an electric system, or an airflow-control valve if the driving mechanism is a pneumatic system. Persons skilled in the art will recognize that the operation of trigger assembly 14 in combination with contact trip assembly 100 is well known in the art, and is described in U.S. Pat. No. 5,785,228, which is wholly incorporated by reference herein.

Referring to FIGS. 1-3, the contact trip assembly 100 preferably has an upper contact trip 101 for contacting supplemental trigger 14 S and a lower contact trip 102 for contacting a workpiece W. The contact trip assembly 100 is preferably slidably attached to the housing 15 and/or nosepiece 13 so that it slides vertically when the lower contact trip 102 contacts a workpiece and the user pushes the fastening tool 10 unto the workpiece W. A spring 111 may be disposed between housing 15 and/or nosepiece 13 and contact trip assembly 100 to bias contact trip assembly 100 downwardly towards the workpiece W.

Upper contact trip 101 may carry an adjuster 105 . Preferably adjuster 105 has teeth 105 T for meshing with teeth 102 T disposed on lower contact trip 102 . This connection may be disposed within upper contact trip 101 as shown in FIG. 3 .

Upper contact trip 101 may also carry a cover 106 . Preferably cover 106 has hooks 106 H that latch onto upper contact trip 101 in a snap-fit manner. Cover 106 may retain adjuster 105 therewithin.

A button 103 is preferably disposed between upper contact trip 101 and cover 106 for moving adjuster 105 . Button 103 may be directly connected to adjuster 105 so that they move in conjunction, e.g., a press-fit junction or a friction junction. Alternatively, button 103 may receive adjuster 105 as shown in FIG. 3A to form a mechanical connection.

Button 103 may be kept within cover 106 by a flange 103 F, which prevents button 103 from escaping.

Alternatively, a spring 104 may be disposed between adjuster 105 and button 103 , and received within button 103 . Accordingly, the mechanical connection shown in FIG. 3A cannot be separated unless the spring 104 is separated from button 103 . The spring 104 contacts cover 106 and biases button 103 outwardly, thus biasing adjuster 105 towards the meshing position. Persons skilled in the art shall recognize that button 103 may be disposed directly on upper contact trip 101 or in any other place so long as it can move adjuster 105 .

Cover 106 may be alternatively held in place by the button/adjuster assembly. In other words, since adjuster 105 cannot escape from the upper contact trip 101 , the button 103 will maintain contact with cover 106 and thus preventing cover 106 from detaching. Alternatively, cover 106 may be held in place by rivets, screws or other fastening means.

FIG. 3A shows adjuster 105 meshing with lower contact trip 102 . If the user desires to change the overall length of the contact trip assembly 100 , the user would push button 103 as shown in FIG. 3 B. The button 103 moves adjuster 105 until its teeth 105 T do not engage with the teeth 102 T of lower contact trip 102 . The user can then move the lower contact trip 102 to the desired position and let go of button 103 . Spring 104 will move button 103 outwardly and adjuster 105 back to the meshing position.

Persons skilled in the art should recognize that it is preferred to move the adjuster 105 along a direction substantially parallel to the teeth 105 T and/or substantially perpendicular to the direction of movement for the contact trip assembly 100 . However, such persons will also recognize that the movement of adjuster 105 can be changed to meet other technical, ergonomic or preferential requirements. For example, teeth 105 T and 102 T may be inclined relative to the direction of movement of button 103 , in order to increase the contact area between teeth 105 T and 102 T. In such case, the adjuster 105 could move along a direction substantially perpendicular to the direction of movement for the contact trip assembly 100 , yet in a direction that is not parallel to the teeth 105 T.

Persons skilled in the art should realize that adjuster 105 may be disposed on lower contact trip 102 to engage the upper contact trip 101 .

It may also be useful to provide adjuster 105 with a protrusion 105 P that engages a notch 13 N in nosepiece 13 when adjuster 105 is moved to the disengaged position. In this manner, the upper contact trip 101 cannot move upwardly and unintendedly engage the trigger assembly 14 during adjustment. Persons skilled in the art will recognize that the same result will be achieved if adjuster 105 is provided with a notch that engages a protrusion on the nosepiece.

Referring to FIGS. 2-3, it may also be useful to provide lower contact trip 102 with a protrusion 102 P which is received within a slot (not shown) in upper contact trip 101 . Such protrusion 102 P will slide along the slot and limit the vertical movement of lower contact trip 102 when adjuster 105 is disengaged. Accordingly, the protrusion 102 P may also prevent the lower contact trip 102 from becoming disconnected from upper contact trip 101 . Persons skilled in the art will recognize that the same result will be achieved if lower contact trip 101 is provided with a slot that receives a protrusion on upper contact trip 101 .

FIG. 23 illustrates another embodiment of the invention, where like numerals refer to like parts. The teachings of the previous embodiments discussed above are fully incorporated herein.

In such embodiment, the contact trip assembly 120 preferably has an upper contact trip 121 for contacting supplemental trigger 14 S and a lower contact trip 122 for contacting a workpiece W. The contact trip assembly 120 is preferably slidably attached to the housing 15 and/or nosepiece 13 so that it slides vertically when the lower contact trip 122 contacts a workpiece and the user pushes the fastening tool 10 unto the workpiece W. A spring (not shown) may be disposed between housing 15 and/or nosepiece 13 and contact trip assembly 120 to bias contact trip assembly 120 downwardly towards the workpiece W.

Upper contact trip 121 may carry an adjuster 125 . Preferably adjuster 125 has teeth 125 T for meshing with teeth 122 T disposed on lower contact trip 122 . This connection may be disposed within upper contact trip 121 as shown in FIG. 23 B.

Upper contact trip 121 may also carry a cover 123 . Preferably cover 123 wraps around the front part of the upper contact trip 121 .

Preferably adjuster 125 extends through upper contact trip 121 and cover 123 .

FIG. 23B shows adjuster 125 meshing with lower contact trip 122 . If the user desires to change the overall length of the contact trip assembly 120 , the user would push adjuster 125 along direction F. The adjuster 125 would then move until its teeth 125 T do not engage with the teeth 122 T of lower contact trip 122 . The user can then move the lower contact trip 122 to the desired position. To lock the desired position, the user would pull adjuster 125 along the direction opposite to direction F, in order to engage teeth 122 T, 125 T.

Cover 123 may have a spring 123 S for maintaining adjuster 125 in an engaged position and a disengaged position. Adjuster 125 may have notches 125 D for receiving the spring 123 S. The notches 125 D and/or spring 123 S may have a curved profile so that they can disengage easily upon movement of adjuster 125 , rather than requiring the user to pull on the spring 123 S. Accordingly, as the user pushes adjuster 125 towards the disengaged position, spring 123 S pops out of notch 125 D, rides along the surface of adjuster 125 and springs back into a second notch 125 D, retaining the adjuster 125 in the disengaged position.

Adjuster 125 may have a cam ramp 125 C that contacts upper contact trip 121 . Such cam ramp 125 C is preferably arranged so that it takes up any clearance or gaps when adjuster 125 is in the engaged position.

Persons skilled in the art should recognize that it is preferred to move the adjuster 125 along a direction substantially parallel to the teeth 125 T and/or substantially perpendicular to the direction of movement for the contact trip assembly 120 . However, such persons will also recognize that the movement of adjuster 125 can be changed to meet other technical, ergonomic or preferential requirements. For example, teeth 125 T and 122 T may be inclined relative to the direction of movement of adjuster 125 , in order to increase the contact area between teeth 125 T and 122 T. In such case, the adjuster 125 could move along a direction substantially perpendicular to the direction of movement for the contact trip assembly 120 , yet in a direction that is not parallel to the teeth 125 T.

Persons skilled in the art should realize that adjuster 125 may be disposed on lower contact trip 122 to engage the upper contact trip 121 .

It may also be useful to provide adjuster 125 with a protrusion 125 P that engages a notch 13 N in nosepiece 13 when adjuster 125 is moved to the disengaged position. In this manner, the upper contact trip 121 cannot move upwardly and unintendedly engage the trigger assembly 14 during adjustment. Persons skilled in the art will recognize that the same result will be achieved if adjuster 125 is provided with a notch that engages a protrusion on the nosepiece.

It may also be useful to provide lower contact trip 122 with a protrusion (not shown) which is received within a slot (not shown) in upper contact trip 121 . Such protrusion will slide along the slot and limit the vertical movement of lower contact trip 122 when adjuster 125 is disengaged. Accordingly, the protrusion may also prevent the lower contact trip 122 from becoming disconnected from upper contact trip 121 . Persons skilled in the art will recognize that the same result will be achieved if lower contact trip 121 is provided with a slot that receives a protrusion on upper contact trip 121 .

Persons skilled in the art should recognize that the above-described elements may be rearranged and still obtain the same result. Referring to FIG. 25, a handle 125 H may be attached to adjuster 125 . Handle 125 H may have notches 125 N for receiving spring 123 S. Persons skilled in the art will recognize that spring 123 S is not integral with cover 123 in this arrangement, but captured by adjuster 125 T, cover 123 and upper contact trip 121 . Nevertheless, the method of operation remains the same.

FIG. 24 illustrates another embodiment of the invention, where like numerals refer to like parts. The teachings of the previous embodiments discussed above are fully incorporated herein.

In such embodiment, the contact trip assembly 130 preferably has an upper contact trip 131 for contacting supplemental trigger 14 S and a lower contact trip 132 for contacting a workpiece W. The contact trip assembly 130 is preferably slidably attached to the housing 15 and/or nosepiece 13 so that it slides vertically when the lower contact trip 132 contacts a workpiece and the user pushes the fastening tool 10 unto the workpiece W. A spring (not shown) may be disposed between housing 15 and/or nosepiece 13 and contact trip assembly 130 to bias contact trip assembly 130 downwardly towards the workpiece W.

Upper contact trip 131 may carry an adjuster 135 . Preferably adjuster 135 has teeth 135 T for meshing with teeth 132 T disposed on lower contact trip 132 . This connection may be disposed within upper contact trip 131 as shown in FIG. 24 .

Adjuster 135 maybe attached to a cover 135 C, which covers adjuster 135 and portions of upper and lower contact trips 131 , 132 . Cover 135 C may have a notch 135 N that receives one end of adjuster 135 . A pin 135 P and/or grommet 136 G may capture the other end of adjuster 135 within cover 135 C. Accordingly, adjuster 135 and cover 135 C will preferably move in unison.

FIG. 24A shows adjuster 135 meshing with lower contact trip 132 . If the user desires to change the overall length of the contact trip assembly 130 , the user would push adjuster 135 (and cover 135 C) along direction F. The adjuster 135 would then move until its teeth 135 T do not engage with the teeth 132 T of lower contact trip 132 , as shown in FIG. 24 B. The user can then move the lower contact trip 132 to the desired position. To lock the desired position, the user would pull adjuster 135 along the direction opposite to direction F, in order to engage teeth 132 T, 135 T.

Upper contact trip 131 may also carry a spring 133 S. Preferably spring 133 S wraps around the front part of the upper contact trip 131 . Spring 133 S may be disposed between adjuster 135 and cover 135 C.

Preferably, spring 133 S maintains adjuster 135 in an engaged position and/or a disengaged position. Contrary to the previous embodiment, adjuster 135 does not have notches for receiving the spring 133 S.

Instead, spring 133 S rests on a surface of adjuster 135 . To move to the disengaged position, the user would have to move spring 133 S onto teeth 135 T. A ramp 135 R is disposed on the teeth 135 T to facilitate such action. Persons skilled in the art will recognize that, even with the ramp 135 R, it should be difficult to move adjuster 135 unintentionally. This can be achieved by increasing spring force, increasing the ramp angle, etc.

Accordingly, as the user pushes adjuster 135 towards the disengaged position, spring 123 S rides along ramp 135 R onto teeth 135 T. The spring 133 S will then rest on teeth 135 T, preferably retaining the adjuster 125 in the disengaged position.

Adjuster 135 may have a cam ramp 135 CR that contacts upper contact trip 131 . Such cam ramp 135 CR is preferably arranged so that it takes up any clearance or gaps when adjuster 135 is in the engaged position.

Persons skilled in the art should recognize that it is preferred to move the adjuster 135 along a direction substantially parallel to the teeth 135 T and/or substantially perpendicular to the direction of movement for the contact trip assembly 130 . However, such persons will also recognize that the movement of adjuster 135 can be changed to meet other technical, ergonomic or preferential requirements. For example, teeth 135 T and 132 T may be inclined relative to the direction of movement of adjuster 135 , in order to increase the contact area between teeth 135 T and 132 T. In such case, the adjuster 135 could move along a direction substantially perpendicular to the direction of movement for the contact trip assembly 130 , yet in a direction that is not parallel to the teeth 135 T.

Persons skilled in the art should realize that adjuster 135 may be disposed on lower contact trip 132 to engage the upper contact trip 131 .

It may also be useful to provide adjuster 135 with a protrusion 135 P that engages a notch 13 N in nosepiece 13 when adjuster 135 is moved to the disengaged position. In this manner, the upper contact trip 131 cannot move upwardly and unintendedly engage the trigger assembly 14 during adjustment. Persons skilled in the art will recognize that the same result will be achieved if adjuster 135 is provided with a notch that engages a protrusion on the nosepiece.

It may also be useful to provide lower contact trip 132 with a protrusion (not shown) which is received within a slot (not shown) in upper contact trip 131 . Such protrusion will slide along the slot and limit the vertical movement of lower contact trip 132 when adjuster 135 is disengaged. Accordingly, the protrusion may also prevent the lower contact trip 132 from becoming disconnected from upper contact trip 131 . Persons skilled in the art will recognize that the same result will be achieved if lower contact trip 131 is provided with a slot that receives a protrusion on upper contact trip 131 .

FIG. 27 illustrates another embodiment of the invention, where like numerals refer to like parts. The teachings of the previous embodiments discussed above are fully incorporated herein.

In such embodiment, the contact trip assembly 140 preferably has an upper contact trip 141 for contacting supplemental trigger 14 S and a lower contact trip 142 for contacting a workpiece W. The contact trip assembly 140 is preferably slidably attached to the housing 15 and/or nosepiece 13 so that it slides vertically when the lower contact trip 142 contacts a workpiece and the user pushes the fastening tool 10 unto the workpiece W. A spring (not shown) may be disposed between housing 15 and/or nosepiece 13 and contact trip assembly 140 to bias contact trip assembly 140 downwardly towards the workpiece W.

Upper contact trip 141 may carry an adjuster 145 . Preferably adjuster 145 has teeth 145 T for meshing with teeth (not shown) disposed on lower contact trip 142 . This connection may be disposed within upper contact trip 141 . Preferably adjuster 145 extends through upper contact trip 141 .

Adjuster 145 may have a handle 145 K for moving adjuster 145 . Handle 145 K may in turn carry a screw 145 S, which may contact upper contact trip 141 .

If the user desires to change the overall length of the contact trip assembly 140 , the user would push adjuster 145 along direction F. The adjuster 145 would then move until its teeth 145 T do not engage with the teeth of lower contact trip 142 . The user can then move the lower contact trip 142 to the desired position. To lock the desired position, the user would (a) pull or push adjuster 145 along the direction F′ in order to engage the teeth. Alternatively, the user may rotate screw 145 S so that it contacts upper contact trip 141 , and moves adjuster 145 along direction F′.

As before, adjuster 145 may have a cam ramp (not shown) that contacts upper contact trip 141 . Such cam ramp is preferably arranged so that it takes up any clearance or gaps when adjuster 145 is in the engaged position.

Persons skilled in the art should recognize that it is preferred to move the adjuster 145 along a direction substantially parallel to the teeth 145 T and/or substantially perpendicular to the direction of movement for the contact trip assembly 140 . However, such persons will also recognize that the movement of adjuster 145 can be changed to meet other technical, ergonomic or preferential requirements. For example, teeth 145 T may be inclined relative to the direction of movement of adjuster 145 , in order to increase the contact area between the teeth. In such case, the adjuster 145 could move along a direction substantially perpendicular to the direction of movement for the contact trip assembly 140 , yet in a direction that is not parallel to the teeth 145 T.

Persons skilled in the art should realize that adjuster 145 may be disposed on lower contact trip 142 to engage the upper contact trip 141 .

As before, it may also be useful to provide adjuster 145 with a protrusion (not shown) that engages a notch 13 N in nosepiece 13 when adjuster 145 is moved to the disengaged position. In this manner, the upper contact trip 141 cannot move upwardly and unintendedly engage the trigger assembly 14 during adjustment. Persons skilled in the art will recognize that the same result will be achieved if adjuster 145 is provided with a notch that engages a protrusion on the nosepiece.

It may also be useful to provide lower contact trip 142 with a protrusion (not shown) which is received within a slot (not shown) in upper contact trip 141 . Such protrusion will slide along the slot and limit the vertical movement of lower contact trip 142 when adjuster 145 is disengaged. Accordingly, the protrusion may also prevent the lower contact trip 142 from becoming disconnected from upper contact trip 141 . Persons skilled in the art will recognize that the same result will be achieved if lower contact trip 141 is provided with a slot that receives a protrusion on upper contact trip 141 .

FIGS. 4-8 illustrate another embodiment of the invention, where like numerals refer to like parts. The teachings of the previous embodiments discussed above are fully incorporated herein. This embodiment may be especially useful when an adjustable wireform contact trip is desirable.

Referring to FIGS. 4-8, tool 10 is provided with an adjustable contact trip assembly 200 . The contact trip assembly 200 preferably has an upper contact trip 201 for engaging trigger assembly 14 and a lower contact trip 202 for contacting a workpiece. The contact trip assembly 200 is preferably slidably attached to the housing 15 and/or nosepiece 13 so that it slides vertically when the lower contact trip 202 contacts a workpiece W and the user pushes the fastening tool 10 unto the workpiece W.

Lower contact trip 202 may include a wire 202 W which contacts the workpiece as discussed above. Lower contact trip 202 is preferably disposed within upper contact trip 201 .

Upper contact trip 201 may carry an adjuster 205 . As shown in FIG. 8, upper contact trip 201 may have a lip 201 L that is received in a slot 205 SL in adjuster 205 . Upper contact trip 201 and adjuster 205 may have other features, such as the lip 201 L and slot 205 SL, for locking the vertical position of the adjuster 205 relative to the upper contact trip 201 , as shown in FIG. 8 . The lip/slot combination and the other features however should allow the adjuster 205 to move towards and away the upper contact trip 201 along a horizontal axis 205 A, which is preferably the longitudinal axis of adjuster 205 . Persons skilled in the art will know how to design the upper contact trip 201 and adjuster 205 to achieve such result.

Preferably adjuster 205 have teeth 205 T for meshing with teeth 202 T disposed on lower contact trip 202 . This connection may be disposed within upper contact trip 201 as shown in FIG. 8 .

Furthermore, a spring 204 may be disposed between upper contact trip 201 and adjuster 205 for biasing adjuster 205 away from upper contact trip 201 and preferably towards a meshing position. Adjuster 205 may have an inset boss 205 B for receiving spring 204 .

The upper contact trip 201 /lower contact trip 202 assembly may be disposed within a cover 206 , which is connected to the housing 15 . A button 203 is preferably disposed between upper contact trip 201 and cover 206 for moving adjuster 205 . Button 203 may be directly connected to adjuster 205 so that they move in conjunction, e.g., a press-fit junction or a friction junction. Preferably, button 203 is not mechanically connected to adjuster 205 .

Button 203 may be kept within cover 206 by a flange 203 F which prevents button 203 from escaping. Because adjuster 205 contacts button 203 , spring 204 in effect biases button 203 outwardly. Persons skilled in the art shall recognize that button 203 may be disposed directly on upper contact trip 201 or in any other place so long as it can move adjuster 205 .

Preferably cover 206 is connected to housing 15 via bolts 206 and stop bolt 206 SB.

FIG. 7A shows adjuster 205 meshing with lower contact trip 202 . If the user desires to change the overall length of the contact trip assembly 200 , the user would push button 203 as shown in FIG. 7 B. The button 203 moves adjuster 205 until its teeth 205 T do not engage with the teeth 202 T of lower contact trip 202 . The user can then move the lower contact trip 202 to the desired position and let go of button 203 . Spring 204 will move button 203 and adjuster 205 outwardly back to the meshing position.

Persons skilled in the art should realize that adjuster 205 may be disposed on lower contact trip 202 to engage the upper contact trip 201 .

It may be useful to provide lower contact trip 202 with a protrusion 202 P which is received within a slot 201 S in upper contact trip 201 . Such protrusion 202 P will slide along the slot and limit the vertical movement of lower contact trip 202 . Accordingly, the protrusion 202 P may also prevent the lower contact trip 202 from becoming disconnected from upper contact trip 201 . Persons skilled in the art will recognize that the same result will be achieved if lower contact trip 201 is provided with a slot that receives a protrusion on upper contact trip 201 .

It may also be useful to provide the cover 206 and upper contact trip 201 with protrusions 206 SP, 201 SP, respectively. A spring 207 can then be disposed therebetween. Spring 207 would thus bias upper contact trip (and thus contact trip assembly 200 ) downwardly towards the workpiece W.

In addition, it may be useful to provide upper contact trip 201 with protrusion 201 ST. Protrusion 201 ST would limit the downward movement of contact trip 200 by contacting stop bolt 206 SB when the contact trip assembly has moved to the downward limit.

It may also be useful to provide the lower contact trip 202 with a knob 202 K. The user could use knob 202 K to adjust lower contact trip 202 while pressing button 203 . Preferably knob 202 K can move vertically along a slot 201 KS of upper contact trip 201 and slot 206 S of cover 206 , when lower contact trip 201 is being vertically adjusted. Knob 202 K and cover 206 may have indicia 202 KI and 2061 , respectively, which indicate the relative length of the contact trip assembly 200 .

Preferably, button 203 engages lip 201 L when pushed towards the disengaged position. Such engagement prevents upper contact trip 201 from moving upwardly and unintendedly engaging the trigger assembly 14 during adjustment.

FIGS. 15-17 illustrate other embodiments of the invention, where like numerals refer to like parts. In particular, the embodiment of FIGS. 15-16 is very similar to the embodiment of FIGS. 4-8, and only vary slightly. Nevertheless, the teachings of the embodiments discussed above are fully incorporated herein.

One of the differences is that a button 207 is slidably attached to the adjuster 205 . Button 207 can move axially with adjuster 205 between the engaged and disengaged positions. However, button 207 is captured by cover 206 , so that button 207 remains stationary relative thereto while adjuster 205 move vertically along upper and lower contact trips 201 , 202 .

With such construction, FIG. 16A shows adjuster 205 meshing with lower contact trip 202 . If the user desires to change the overall length of the contact trip assembly 200 , the user would pull button 207 towards the position of FIG. 16 B. The button 207 moves adjuster 205 until its teeth 205 T do not engage with the teeth 202 T of lower contact trip 202 . The user can then move the lower contact trip 202 to the desired position.

To fix the desired length of contact trip assembly 200 , the user then needs to push button 207 (and adjuster 205 ) to the position shown in FIG. 16 A. Persons skilled in the art will recognize that this movement is necessary as no spring 204 is provided to move adjuster 205 outwardly back to the meshing position.

It may be desirable to provide a detent mechanism to maintain the adjuster 205 in the meshing and/or disengaged positions. Accordingly, adjuster 205 may be provided with a bore to receive detent 208 and spring 208 S, which biases detent 208 against a detent notch 202 N on lower contact trip 202 . Detent 208 may contact the teeth 202 T when in the adjuster 205 is in the disengaged position.

Persons skilled in the art shall recognize that the detent and notch combination may be disposed on any two continguous members that move relative to each other in the meshing and disengaged positions. For example, a detent mechanism may be provided between button 207 and cover 206 , as shown in FIG. 17 . Persons skilled in the art should recognize that the embodiment of FIG. 17 is very similar to the embodiment of FIGS. 15-16 and that like numerals refer to like parts. Nevertheless, the teachings of the embodiments discussed above are fully incorporated herein.

As shown in FIG. 17, cover 206 may have a detent 209 , which engages notches 209 DN disposed on button 207 . Preferably, button 207 and/or detent 209 are made of a resilient material, such as plastic, so that the detent mechanism does not bar all movement of button 207 relative to cover 206 . Persons skilled in the art should recognize that detent 209 D and detent notch 209 DN could have been placed on the button 207 and cover 206 , respectively.

FIGS. 19-20 illustrate another embodiment of the invention, where like numerals refer to like parts. In particular, the embodiment of FIGS. 19-20 is very similar to the embodiment of FIGS. 4-8, and only vary slightly. Nevertheless, the teachings of the embodiments discussed above are fully incorporated herein.

One of the differences is that two buttons 207 are slidably attached to the adjuster 205 via a pin 207 P. Buttons 207 have channels that slidably receive pin 207 P, so that pin 207 P can slide therein. Buttons 207 can move axially with adjuster 205 between the engaged and disengaged positions. However, buttons 207 are captured by cover 206 , so that buttons 207 remain stationary relative thereto while adjuster 205 move vertically along upper and lower contact trips 201 , 202 .

With such construction, FIG. 20A shows adjuster 205 meshing with lower contact trip 202 . If the user desires to change the overall length of the contact trip assembly 200 , the user would push disengaging button 207 D towards the position of FIG. 20 B. The button 207 D moves adjuster 205 until its teeth 205 T do not engage with the teeth 202 T of lower contact trip 202 . The user can then move the lower contact trip 202 to the desired position.

To fix the desired length of contact trip assembly 200 , the user then needs to push engaging button 207 E (and adjuster 205 ) to the position shown in FIG. 20 A. Persons skilled in the art will recognize that this movement is necessary as no spring 204 is provided to move adjuster 205 outwardly back to the meshing position.

As mentioned above, it may be desirable to provide a detent mechanism to maintain the adjuster 205 in the meshing and/or disengaged positions. Accordingly, detent 209 D can be placed on at least one button 207 . Detent 209 D would then engage a detent notch 209 DN placed on cover 206 .

FIG. 21 illustrates yet another embodiment of the invention, where like numerals refer to like parts. In particular, the embodiment of FIG. 21 is very similar to the embodiment of FIGS. 19-20, and only vary slightly. Nevertheless, the teachings of the embodiments discussed above are fully incorporated herein.

One of the differences is that two buttons 207 are not slidably attached to the adjuster 205 via a pin 207 P. Instead, buttons 207 just contact surfaces of adjuster 205 , so that buttons 207 can move adjuster 205 between the meshing and disengaged positions. However, buttons 207 are captured by cover 206 , so that buttons 207 remain stationary relative thereto while adjuster 205 move vertically along upper and lower contact trips 201 , 202 .

With such construction, FIG. 20A shows adjuster 205 meshing with lower contact trip 202 . If the user desires to change the overall length of the contact trip assembly 200 , the user would push disengaging button 207 D towards the position of FIG. 20 B. The button 207 D moves adjuster 205 until its teeth 205 T do not engage with the teeth 202 T of lower contact trip 202 . The user can then move the lower contact trip 202 to the desired position.

To fix the desired length of contact trip assembly 200 , the user then needs to push engaging button 207 E (and adjuster 205 ) to the position shown in FIG. 20 A. Persons skilled in the art will recognize that this movement is necessary as no spring 204 is provided to move adjuster 205 outwardly back to the meshing position.

FIG. 18 illustrates another embodiment of the invention, where like numerals refer to like parts. In particular, the embodiment of FIG. 18 is very similar to the embodiment of FIG. 21, and only vary slightly. Nevertheless, the teachings of the embodiments discussed above are fully incorporated herein.

One of the differences is that engaging button 207 E is fixedly attached (or integral with) adjuster 205 . In addition, disengaging button 207 D contacts a surface of adjuster 205 . Further, disengaging buttons 207 D is captured by cover 206 , so that it remains stationary relative thereto while adjuster 205 move vertically along upper and lower contact trips 201 , 202 . A spring 207 DS may be disposed between adjuster 205 and disengaging button 207 D to bias button 207 D outwardly of cover 206 .

With such construction, FIG. 18A shows adjuster 205 meshing with lower contact trip 202 . If the user desires to change the overall length of the contact trip assembly 200 , the user would push disengaging button 207 D. The button 207 D moves adjuster 205 until its teeth 205 T do not engage with the teeth 202 T of lower contact trip 202 . The user can then move the lower contact trip 202 to the desired position.

To fix the desired length of contact trip assembly 200 , the user then needs to push engaging button 207 E (and adjuster 205 ) to the position shown in FIG. 18 A. Persons skilled in the art will recognize that this movement is necessary as no spring 204 is provided to move adjuster 205 outwardly back to the meshing position.

As mentioned above, it may be desirable to provide a detent mechanism to maintain the adjuster 205 in the meshing and/or disengaged positions. Accordingly, a leaf spring 205 DS may be wrapped around adjuster 205 . One end of spring 205 DS may be folded to create a detent that engages notches 201 N formed on the upper contact trip 201 .

Spring 205 DS may also have a detent bump 205 DB. This bump 205 DB would not necessarily maintain the adjuster 205 in the meshing or disengaged positions. Bump 205 DB however would contact teeth 202 T when the adjuster 205 is being moved between positions, providing an audible and/or tactile signal to the user.

Persons skilled in the art should recognize that adjuster 205 may have a rail that slidably receives a button, so that the user can move adjuster 205 by pulling and pushing the button. FIG. 22 illustrates one such possible embodiment, where like numerals refer to like parts. Nevertheless, the teachings of the embodiments discussed above are fully incorporated herein.

Adjuster 205 may have a rail 205 R, which is slidably engaged a connector 210 . Rail 205 R may be shaped as a dovetail.

Preferably, connector 210 can remain stationary along a vertical axis when adjuster 205 moves along the vertical axis, but moves with adjuster 205 when adjuster 205 moves along a horizontal axis. This is achieved by the dovetail connection, which allows adjuster 205 to move along the vertical axis through connector 210 , without forcing vertical movement unto connector 210 . In addition, the dovetail connection requires adjuster 205 and connector 210 to move together along the horizontal axis between the engaged and disengaged positions.

Connector 210 has a post 210 P, which is in turn connected to a button 210 B. An activator 211 is used to move the button 210 B (and adjuster 205 ) between the engaged and disengaged positions.

Activator 211 is slidably attached to the cover 206 so that it can be moved along a vertical axis. In particular, activator 211 may have flanges 21 IF for capturing a cover rail 206 R therein, allowing activator 211 to slide along the rail 206 R. The range of movement may be limited at one end by a rail stop 206 RS, which may be engaged by a rail stop 211 RS. At the other end, activator 211 may be detented in two positions by detents 206 D on cover 206 . Activator 211 may have a handle 211 H for moving the activator 211 .

Activator 211 may also have an inclined rail 211 R that is captured between two flanges 210 BF of button 210 B. Accordingly, the linear motion of activator 211 as it slides along cover 206 is translated into a substantially perpendicular motion as button 210 B follows rail 211 R. Persons skilled in the art will recognize that adjuster 205 will move between the engaged and disengaged positions as button 210 B follows rail 211 R.

With such construction, if the user desires to change the overall length of the contact trip assembly 200 , the user would push activator 211 . Due to the interaction between rail 211 R and button 210 B, button 210 B will move adjuster 205 until its teeth 205 T do not engage with the teeth 202 T of lower contact trip 202 . The user can then move the lower contact trip 202 to the desired position. To fix the desired length of contact trip assembly 200 , the user then needs to move activator 211 to its original position. Persons skilled in the art will recognize that this movement is necessary as no spring 204 is provided to move adjuster 205 outwardly back to the engaged position.

FIG. 26 illustrates yet another embodiment of the invention, where like numerals refer to like parts. Nevertheless, the teachings of the embodiments discussed above are fully incorporated herein.

In this embodiment, an adjustment knob 216 is used to move adjuster 205 between the engaged, or meshing, and disengaged positions. Basically, knob 216 has a body 216 K, which is engaged to a housing 216 H. Preferably, housing 216 H is made of plastic. Body 216 K and housing 216 H may be engaged via a bolt 216 B. Body 216 K and/or housing 216 H preferably have a helical slot 216 S.

Slot 216 S is preferably engaged by one end of follower 215 . Follower 215 may be captured by housing 216 H. Upon rotation of knob 216 , follower 215 follows slot 216 S, thus moving along its longitudinal axis, rather than rotating about knob 216 . In other words, the rotational motion of knob 216 is converted into linear motion of follower 215 .

At its other end, follower 215 preferably has a hook 215 H, which may be disposed within slot 205 S of adjuster 205 . Preferably, hook 215 H is not captured by slot 205 S. As shown in FIG. 26B, it is preferable to provide enough clearance between adjuster 205 and hook 215 H so that adjuster 205 can move along vertical axis V without catching hook 215 H. Adjuster 205 however will catch hook 215 if knob 216 is rotated.

With such construction, if the user desires to change the overall length of the contact trip assembly 200 , the user would rotate knob 216 . Due to the interaction between slot 216 S and follower 215 , knob 216 will move follower 215 until it contacts adjuster 205 , then follower 215 and adjuster 205 will move jointly until its teeth 205 T do not engage with the teeth 202 T of lower contact trip 202 . The user can then move the lower contact trip 202 to the desired position. Persons skilled in the art will recognize that a user will not be able to move adjuster 205 and upper contact trip 201 along vertical axis V because of follower 215 .

To fix the desired length of contact trip assembly 200 , the user then needs to rotate knob 216 to its original position. Persons skilled in the art will recognize that such arrangement obviates the need for spring 204 . While spring 204 is not requires to move adjuster 205 outwardly back to the engaged position, it can still provide a force to maintain engagement between teeth 202 T, 205 T.

Persons skilled in the art will recognize that it may be desirable to provide a detent for knob 216 , which would maintain the knob 216 in the engaged and/or disengaged positions.

FIGS. 9-11 illustrate a further embodiment of the invention, where like numerals refer to like parts. The teachings of the embodiments discussed above are fully incorporated herein. Tool 10 is provided with an adjustable contact trip assembly 300 . The contact trip assembly 300 preferably has an upper contact trip 301 for engaging trigger assembly 14 and a lower contact trip 302 for contacting a workpiece W. The contact trip assembly 300 is preferably slidably attached to the housing 15 and/or nosepiece 13 so that it slides vertically when the lower contact trip 302 contacts a workpiece W and the user pushes the fastening tool 10 unto the workpiece W. A spring 311 may be disposed between housing 15 and/or nosepiece 13 and contact trip assembly 300 to bias contact trip assembly 300 downwardly towards the workpiece W.

Upper contact trip 301 and lower contact trip 302 preferably have teeth 301 T and 302 T, respectively, which mesh together.

A cam mechanism 320 may be used to force teeth 301 T and 302 T to mesh and/or lock upper contact trip 301 and lower contact trip 302 in place. Cam mechanism 320 may include a shaft 321 extending through upper contact trip 301 and lower contact trip 302 . The shaft 321 may have a head 321 H disposed on the side of lower contact trip 302 farthest from upper contact trip 301 . A cam 322 may be pivotally connected to shaft 321 and have a cam portion 322 C that contacts upper contact trip 301 .

With such arrangement, cam portion 322 C changes the distance between cam pivot 322 A and upper contact trip 301 when cam 322 is pivoted about an axis substantially perpendicular to the longitudinal axis of shaft 321 . If the user desires to change the overall length of the contact trip assembly 300 , the user would rotate the cam 322 , thus unmeshing teeth 301 T, 302 T, and move the lower contact trip 302 to the desired position. The user would then rotate cam 322 back to the locking position.

It may be useful to provide upper contact trip 301 with a slot 301 S to allow shaft 321 (and thus lower contact trip) to move vertically therein relative to upper contact trip 301 .

Persons skilled in the art will recognize that cam mechanism 322 may be disposed so that shaft 321 is captured by upper contact trip 301 , rather than lower contact trip 302 , and/or that cam 322 contact lower contact trip 302 , rather than upper contact trip 301 .

FIGS. 12-13 illustrate an alternative cam mechanism 340 , where like numerals refer to like parts. The teachings of the embodiments discussed above are fully incorporated herein.

A cam mechanism 340 may be used to force teeth 301 T and 302 T to mesh and/or lock upper contact trip 301 and lower contact trip 302 in place. Cam mechanism 340 may include a shaft 341 extending through upper contact trip 301 and lower contact trip 302 . The shaft 341 may have a head 341 H disposed on the side of lower contact trip 302 farthest from upper contact trip 301 . A cam 342 may be fixedly connected to shaft 341 so that shaft 341 and cam 342 rotate jointly about the longitudinal axis of shaft 341 . Cam 342 may have a cam portion 342 C that contacts cam portion 301 C of upper contact trip 301 .

With such arrangement, cam portion 342 C changes the distance between cam portion 342 C and lower contact trip 302 when cam 342 is pivoted. If the user desires to change the overall length of the contact trip assembly 300 , the user would rotate the cam 342 , thus unmeshing teeth 301 T, 302 T, and move the lower contact trip 302 to the desired position. The user would then rotate cam 342 back to the locking position.

It may be useful to provide contact trip 302 with a slot 302 S to allow shaft 341 (and thus lower contact trip 302 ) to move vertically therein relative to upper contact trip 301 .

Persons skilled in the art may recognize other alternatives to the means disclosed herein. However, all these additions and/or alterations are considered to be equivalents of the present invention.