One directional movement catch device

March 8, 1966

C. E. MURCOTT

3,239,255

ONE DIRECTIONAL MOVEMENT CATCH DEVICE

Filed April 6, 1964

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ATTORNEY

United States Patent Office

3,239,255

Patented Mar. 8, 1966

3,239,255

ONE DIRECTIONAL MOVEMENT CATCH DEVICE Charles E. Murcott, Huntington, N.Y.

(Valley Drive, Bay Crest, Long Island, N.Y.) Filed Apr. 6,1964, Ser. No. 357,586 5

Claims. (CI. 287—58)

This invention relates to catch devices for automatically checking movement of two telescoping tubular members in one direction of movement of the tubes with re- iq spect to each other while permitting free movement of the tubes in the opposed direction. More particularly, the invention deals with a catch device in the form of a generally wedge-shaped block mounted in an aperture of an inner tube with spring means arranged within said tube 15 for urging the block into operative position at all times.

Still more particularly, the invention deals with a structure of the character defined, wherein the block includes, at its ends, extended portions, one of which is bevelled for operative engagement with the inner surface 20 of the tube in which the block is mounted in checking movement of the block into operative position.

The novel features of the invention will be best understood from the following description, when taken together with the accompanying drawing, in which certain embodi- 25 ments of the invention are disclosed and, in which, the separate parts are designated by suitable reference characters in each of the views and, in which:

FIG. 1 is an enlarged diagrammatic plan view showing part of a footrest frame having parallel side tubes operat- 30 ing in frame tubes of a chair and showing my improved devices mounted in connection with the tubular sides of said frame, with parts of the construction broken away.

FIG. 2 is a partial section on the line 2—2 of FIG. 1.

FIG. 3 is a side view of the catch device detached; 35 and

FIG. 4 is a side view of the spring employed in its normal untensioned position.

In illustrating one adaptation and use of my invention, I have shown, in part in FIG. 1 of the drawing, a foot- 40 rest frame 1®, part of the front crosshead of the frame being shown at 11 and at 12 I have shown the tubular sides of the frame. In this connection, it will be apparent that the frame is generally U-shaped in form. Mounted on and extending between the tubular sides 12 is a foot supporting plate shown, in part, at 13. By way of illustration, the frame 10 can be similar to the footrest frame as shown and described in my Patent Number 3,123,397 issued March 3, 1964.

In FIGS. 1 and 2 of the drawing, I have shown for- ₅θ ward end portions of tubular chair frames 14 and, adjacent said forward ends, the upper surface of the frames 14 have apertures 15. In FIG. 2 of the drawing, I have shown a sectional view through one of the frames 14, as well as one of the sides 12 of the footrest frame 10. The _rrsides 12 have elongated apertures 16 in upper surfaces ⁰⁰thereof, in which operate catch devices 17, generally wedge-shaped in form. The inner portion of the device 17 has an extended straight end 18 and a tapered or bevelled end 19, the upper bevelled surface 20 of which is arranged parallel to and lower than the upper bevelled ⁶⁰surface 21 of the block 17 and these surfaces are joined by a slight undercut shoulder, as at 22. The shoulder 22 is equal in height to the thickness of the wall of the tube 12, as noted in FIG. 2. The lower surface of the block _rhas substantially centrally thereof a spring engaging chan- ⁰⁵nel 23, in which an angularly offset end 24 of a flat spring 25 operates. The offset end 24 has a bearing engagement upon the side wall of the channel 23 adjacent the shoulder 22 in constantly maintaining the shoulder 22 in pivotal engagement with the adjacent wall of the aperture 16, as ¹⁰clearly indicated in FIG. 2 of the drawing. The block, adjacent the straight end 18, has a perpendicular stop wall 26 which is adapted to engage the wall 15' of the apertures 15 in checking outward movement of the frame 1® with respect to the supports 14. The length of the offset end 24 is greater than that part of the stop wall 26 which projects above the tube 12 when the device is in the projected position shown in FIG. 2.

Considering FIG. 2 of the drawing, it will appear that the end 27 of the spring bears against the wall of the tube 12 opposed to the aperture 16 and the spring is bowed when under tension, the spring 25, adjacent the end 24, engages the end 18 in aiding support of the device 17 in operative position, as clearly illustrated diagrammatically in FIG. 2 of the drawing. This tension supports the ends 18 and 19 in engagement with the inner surface of the tube 12. Considering FIG. 2 of the drawing, it will appear that the body portion of the block between the undercut 22 and the stop wall 26 is less in dimensions than the overall length of the aperture 16, so as to provide freedom of movement of the block or device 17 in the tube 12, particularly in moving 12 from the extended checked position, where the wall 26 strikes the end 15' of the apertures 15, to an inward movement or, in other words, to the right, as seen in FIG. 2. In this last named movement, the wall of the support 14 rides over the upper bevelled surface 21 of the catch device or block 17 and moves the same into the bore of the tube 14. In the last named movement, the bevelled surface 2® facilitates the pivotal or rocking movement of the device 17. It will, thus, be apparent that, in the outward movement, the minute that the catch device or block 17 registers with the aperture 15, the same is forced outwardly by the spring and definitely checks this outward movement, thus preventing accidental displacement of the frame 10. It is here pointed out that these frames are quite often operated by the foot of the person occupying the chair and, in the outward movement, if there wasn’t a positive check, the entire frame could be displaced from the chair.

My improved device provides a simple and economical means to accomplish the desired end result and, while I have illustrated one adaptation and use of my invention, it will be apparent that devices of the type and kind under consideration can be utilized in conjunction with telescoping tubes of any type and kind, wherein it is desirable to automatically check movement of one tube with respect to the other in one directional movement of the tubes with respect to each other. One important point in connection with the device in question lies in the fact that, in movement, for example, of 12 to the right in FIG. 2, the action is all automatic by simply urging the frame 10 in this particular direction.

It will be apparent that, from a consideration of FIG. 2 of the drawing, the block has freedom of movement on the end 24 of the spring and the undercut shoulder 22 facilitates rocking movement of the block on the end 24 when the block 17 is moved into inoperative position. However, at all times, the block 17 is contained within the environment of the aperture 16 to definitely key the block against displacement from the tube 12.