Ball sleeve for use in the inner sliding rail of a hidden sliding track assembly

The present invention relates to a hidden sliding track assembly for drawer or the like and more specifically, to a ball sleeve for use in the inner sliding rail of a hidden sliding track assembly, which has a narrow thin wall portion on the middle of the top wall of the sleeve body thereof for easy installation, and recessed bearing portions for supporting balls in respective openings in the sleeve body.

A regular ball sleeve 6 for use in a hidden sliding track assembly (see FIG. 1 ) has a sleeve body 61 of substantially η-shaped cross section. The sleeve body has four longitudinal rows of openings 611 respectively arranged in four angles of the inside space. Balls 7 are respectively mounted in the openings 611 by means of the application of a special mold and a special machine. After installation of the balls 7 in the openings 611 , the ball sleeve 6 is coupled to the inner sliding rail 8 and the outer sliding rail 9 . This ball sleeve installation procedure is complicated. In order to prevent falling of balls 7 out of the openings 611 of the sleeve body 61 , the sleeve body 61 must be coupled to inner sliding rail 8 and the outer sliding rail 9 step by step each time a limited number of balls 7 have been installed in the openings 611 . Further, the mounting tools are expensive.

The present invention has been accomplished under the circumstances in view. It is therefore one object of the present invention to provide a ball sleeve for use in the inner sliding rail of a hidden sliding track assembly, which is easy to install. It is another object of the present invention to provide a ball sleeve for use in the inner sliding rail of a hidden sliding track assembly, which is inexpensive to manufacture.

According to one aspect of the present invention, the ball sleeve has a narrow thin wall portion longitudinally extended on the middle between the two ends of the top wall of the sleeve body thereof through which the user can expand the sleeve body for easy installation of balls in the openings and easy coupling of the ball sleeve to the inner sliding rail of a hidden sliding track. According to another aspect of the present invention, the sleeve body of the ball sleeve further has a plurality of recessed bearing portions respectively disposed at two sides of each opening for supporting the balls in the openings, keeping the balls rotatably in close contact between the inner sliding rail and outer sliding rail of the hidden sliding track assembly.

FIG. 1 is an exploded view of an inner sliding rail, a ball sleeve, and an outer sliding rail according to the prior art design.

FIG. 2 is a sectional assembly plain view of the prior art design.

FIG. 3 is an exploded view of the preferred embodiment of the present invention.

FIG. 4 is a perspective assembly view of the preferred embodiment of the present invention.

FIG. 5 is an exploded view showing the relationship between the ball sleeve and parts of a hidden sliding track assembly according to the present invention.

FIG. 6 is similar to FIG. 5 but showing the ball sleeve coupled to the inner sliding rail.

Referring to FIGS. 3˜6 , a ball sleeve 1 is shown comprising a sleeve body 11 of substantially η-shaped cross section, having four longitudinal rows of openings 111 ˜ 114 respectively arranged in four angles of the inside space, and a plurality of balls 2 respectively mounted in the openings 111 ˜ 114 . After coupling of the ball sleeve 1 to a hidden sliding track assembly's inner sliding rail 3 , the balls 2 in the four rows of openings 111 ˜ 114 are respectively maintained in contact between respective sliding grooves 31 ˜ 34 of the inner sliding rail 3 and respective sliding grooves 41 ˜ 44 of the sliding track assembly's outer sliding rail 4 to support the outer sliding rail 4 on the inner sliding rail 3 .

The main features of the present invention are outlined hereinafter. The sleeve body 11 of the ball sleeve 1 has a narrow thin wall portion 1101 longitudinally extended on the middle between the two ends of the top wall 110 thereof through which the user can expand the sleeve body 11 for easy installation of the balls 2 in the openings 111 ˜ 114 and easy coupling of the ball sleeve 1 to the inner sliding rail 3 , and a plurality of recessed bearing portions 1111 ˜ 1141 respectively disposed at two sides of each of the openings 111 ˜ 114 for supporting two sides 21 of each of the balls 2 in the openings 111 ˜ 114 , keeping the balls 2 in close contact between the inner sliding rail 3 and the outer sliding rail 4 .

Further, slots 1102 are formed in the narrow thin wall portion 1101 of the sleeve body 11 of the ball sleeve 1 , thereby making the narrow thin wall portion 1101 more flexible for expanding.

Further, recessed bearing portions 1111 ˜ 1141 are smoothly curved inwards to fit the spherical shape of the balls 2 so that the balls 2 can be rotated smoothly in the respective openings 1111 ˜ 1141 .

As indicated above, the invention has the following advantages:

1. The sleeve body 11 of the ball sleeve 1 has a narrow thin wall portion 1101 longitudinally extended on the middle between the two ends of the top wall 110 thereof through which the user can expand the sleeve body 11 for easy installation of the balls 2 in the openings 111 ˜ 14 and easy coupling of the ball sleeve 1 to the inner sliding rail 3 .

2. The sleeve body 11 of the ball sleeve 1 further has a plurality of recessed bearing portions 1111 ˜ 1141 respectively disposed at two sides of each of the openings 111 ˜ 114 for supporting two sides 21 of each of the balls 2 in the openings 111 ˜ 114 , keeping the balls 2 in close contact between the inner sliding rail 3 and the outer sliding rail 4 and preventing falling of the balls 2 out of the sleeve body 11 .