US3862772A

US3862772A - Safety stop lock

Info

Publication number: US3862772A
Application number: US423971A
Authority: US
Inventors: Ernest W Latham
Original assignee: BENTSON IND Inc
Current assignee: BENTSON IND Inc
Priority date: 1973-12-12
Filing date: 1973-12-12
Publication date: 1975-01-28
Anticipated expiration: 1992-01-28

Abstract

A safety stop lock for drawers and the like, having catches extending laterally beyond the periphery of the drawer to bear against the border surrounding the drawer opening. The catches are mounted inwardly from the front wall of the drawer to space the front wall from said border when the catches bear against the outer wall of the border to stop further inward movement, and to align the front wall of the drawer flush with the outer wall of the border when the catches bear against the inner wall of the border to lock against outward movement of the drawer. The catches are biased outward laterally under spring loading and are drawn inwardly to permit passage through the border surrounding the drawer opening by turning the arms of a lock handle, to which the catches are pivotally connected, from an aligned extended position to an unaligned withdrawn position.

Description

United States Patent 11 1 Latham Jan. 28, 1975 1 SAFETY STOP LOCK [75] lnventor: Ernest W. Latham, North Aurora,

[73] Assignee: Bentson Industries, Inc., Aurora, 111.

[22] Filed: Dec. 12, 1973 [21] Appl. No.: 423,971

Primary E.raminer .lames C. Mitchell Attorney, Agent, or Firm-Ernest S. Kettelson [57] ABSTRACT A safety stop lock for drawers and the like, having catches extending laterally beyond the periphery of the-drawer to bear against the border surrounding the drawer opening. The catches are mounted inwardly from the front wall of the drawer to space the front wall from said border when the catches bear against the outer wall of the border to stop further inward movement, and to align the front wall of the drawer flush with the outer wall of the border when the catches bear against the inner wall of the border to lock against outward movement of the drawer. The catches are biased outward laterally under spring loading and are drawn inwardly to permit passage through the border surrounding the drawer opening by turning the arms of a lock handle, to which the catches are pivotally connected, from an aligned extended posi-' tion to an unaligned withdrawn position.

3 Claims, 4 Drawing Figures SAFETY STOP LOCK BACKGROUND OF THE INVENTION This invention relates to a safety catch incorporated into a lock for drawers and the like to prevent accidental and abrupt closure which might result in injury to fingers or other members and objects caught between the drawer wall and border surrounding its opening. The invention is particularly desirable for drawers used as tub files for such items as tabulating cards, index cards and the like which become very heavy with large numbers of cards involved, creating a tendency for the drawer to slam shut unexpectedly and with substantial force. Since employees constantly work in such files to retrieve, tile and examine cards, their fingers are exposed to great danger of being caught and injured if the drawer slams shut unexpectedly. This invention is provided to protect against such unexpected closure, and to do so by incorporating the safety stop feature in a closure lock which is itself a desirable if not essential element of drawers for tab cards, index cards and other data cards of considerable operations value.

Other devices are known to stop or cushion a drawer against accidental abrupt closure, such as mating teeth between a fixed rack and a moveable unit on the drawer, arcuate recesses and other obstructions on tracks to catch drawer rollers, manually adjusted bumpers, cam and follower devices, reaction type bumpers, stops along telescope carriage tracks, spring cushions and the like. The objective of such devices is to slow down or stop abrupt movement of a drawer inwardly and in some cases outwardly as well, or abrupt closure of a door. It is not an objective to such devices to also function as a lock for the drawers or doors, and the structure of such devices accordingly differs substantially from the invention described herein.

It is an object of this invention to provide a safety stop lock which incorporates a safety catch into a lock for drawers and the like.

It is an object of this invention to provide a safety stop lock for drawers and the like having catches extending from the periphery to engage the border surrounding the drawer opening, on the outside to stop unintended closure and on the inside to lock against open- It is an object of this invention to provide a safety stop lo c k which automatically stops from complete closure when a drawer or door is open and automatically locks against opening when the drawer or door is closed.

It is an object of this invention to provide a safety stop lock for drawers and the like having peripherally extending catches spaced inwardly away from the closure wall of the drawer to provide a safety opening between the closure wall and the outer border surrounding the drawer opening when functioning as a safety stop and to align the closure wall flush with the outer border when functioning as a lock.

SUMMARY OF THE INVENTION A drawer or other closure member is provided with catches extending laterally beyond its periphery to engage the border surrounding its opening to prevent complete closure until the catches are withdrawn, and when the drawer is closed to prevent opening until the catches are withdrawn. The catches are biased toward their extended position and aligned with the radial arms of a twist handle to which they are pivotally attached. When the handle is turned bringing its arms out of alignment with the pivotally attached catches, they are drawn inwardly to clear the border opening either to open the drawer or fully close. Upon releasing the handle, spring loading returns its radial arms into alignment with the attached catches causing them to reextend beyond the periphery of the drawer or other closure member.

DETAILED DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view ofa cabinet having drawers which embody the safety stop lock in'accordance with this invention.

FIG. 2 is a plan view partially in section of a drawer and the safety stop lock in accordance with this invention.

FIG. 3 is a fragmented perspective view of the inner closure wall of a drawer embodying this invention.

FIG. 4 is an elevation view of a bullet catch for use in this invention shown seated in the collar keyed to the center shaft illustrated in cross section.

DESCRIPTION OF PREFERRED EMBODIMENTS A preferred embodiment of the safety stop lock in accordance with this invention is described herein and illustrated in the accompanying drawings. A catch assembly 1 includes bumper stops 2 mounted on the free ends of extension arms 3 which extend laterally beyond the periphery of side walls 4 of drawer 5. The opposite ends of extension arms 3 are pivotally linked at 6 to radial arms 7 to lock handle assembly 8.

The lock handle assembly 8 includes a center shaft 9 rotatably mounted through front closure wall 10 of drawer 5. Radial arms 7 are mounted to extend laterally from the end of center shaft 9 which is inward of closure wall 10, and lock handle 11 is provided at the opposite end of center shaft 9 outward of closure wall 10. Coil springs 12 are fastened between outward portions of radial arms 7 and the inside of closure wall 10 to bias raidal arms 7 in alignment with extension arms 3 whereby such extension arms 3 are fully extended. A collar 19 having a retention groove 13 is keyed ,to center shaft 9 inside of closure wall 10. A bullet catch 14 is mounted on the inner face of closure wall 10 positioned-to seat in retention groove 13 when radial arms 7 are aligned with extension arms 3, thereby serving to hold such arms in alignment and keeping bumper stops 2 fully extended until pressure is exerted to rotate center shaft 9 and collar 19 causing bullet catch 14 to unseat.

Extension arms 3 extend beyond the side walls 4 of drawer 5 through slots 15 formed in side walls 4 inwardly of front closure wall 10 at a point which (a) provides a safety space between closure wall 10 and border 16 surrounding the drawer opening when drawer 5 is opened and bumper stops 2 bear against the outside of border 16, and (b) permits catch assembly 1 to engage latch means 17 when closure wall 10 is aligned flush with the outside of border 16 to lock drawer 5 in closed position.

The safety space is selected of desired width to avoid injury to fingers and other members, or damage to property, which might be otherwise caught between closure wall 10 and border 16 if drawer 5 should fully close unexpectedly.

The latch means 17 may be a specially mounted catch appropriately spaced inward from border 16, or'

as shown in FIG. 2, the inner wall 17 of border 16 of a file cabinet against which the free end portions of extension arms 3 bear to lock drawer 5 in closed positin when the outer face of closure wall is aligned flush with the outside of border 16. I

Chrome abutment strips 18 may be provided along border 16 for contact with bumper stops 2. Such bumper stops are preferably of a resilient material such as rubber.

The safety stop lock of this invention operates as follows. When drawer 5 is closed, radial arms 7 and extension arms 3 carrying bumper stops 2 are aligned and fully extended bearing against the inner wall of border 16. Lock handle 11 is rotated causing radial arms 7 to rotate out of alignment with pivotally linked extension arms 3 thereby drawing them inward until bumper stops 2 clear border 16 permitting withdrawal of drawer 5 to an open position. Upon release of handle 11, coil springs 12 draw radial arms 7 back into an aligned position with extension arms 3 carrying bumper stops 2 to the fully extended position. At such point, bullet catch 14 seats in retention groove 13 thereby holding the assembly in such fully extended position. If the drawer 5 should be moved accidentlly or otherwise toward the closed position, bumper stops 2 would engage bumper strips 18 along border 16 and stop further movement of drawer 5 leaving a safety space for protection of fingers, hands or objects which might otherwise be caught and injured. To close drawer 5, lock handle 11 is again rotated as described to enable bumper stops 2 to clear border 16 until the outer face of closure wall 10 is aligned flush with the outside of border l6 and drawer 5 is fully closed. When handle 11 is released, coil springs 12 cause extension arms 3 to fully extend and engage the inner wall 17 of border 16 thereby locking drawer 5 in closed position.

The described invention is adapted for use with doors as well as drawers of a file cabinet, desk or other fixture. In fact, it may be used with any closure member which moves into and away from a frame or border that surrounds an opening to receive the closure member.

The particular form of the invention described herein and illustrated in the accompanying drawings are preferred embodiments, and various changes in the size, shape, materials and arrangement of parts may be made without departing from the spirit of the invention or the scope of the attached claims.

Having thus set forth my invention, what I claim is:

1. A safety stop lock for a closure member, said closure member having a front closure wall and a pair of spaced apart side walls extending inwardly from said front closure wall and normal thereto, border means surrounding an opening to receive said closure member, said border means having an outer surface in facing relationship with said front closure wall, slot means formed through said side walls at a first designated location, an extending arm movably mounted in association with said front closure wall adapted to extend laterally beyond the periphery of at least one of said side walls through said slot means and movable between a retracted and an engagement position, bumper means at the outer end of said extending arm having inward facing and an outward facing abutment means, said inward facing abutment means being positioned for abutment against said outer surface of said border means when said extending arm is in said engagement position and said front closure wall is spaced outwardly from said border means, said first designated location of said slot means being spaced apart inwardly from said front closure wall a distance to define a safety space extending between said front closure wall and said border means when said inward facing abutment means of said bumper means abuts said outer surface of said border means, said distance defining said safety space being greater than the corresponding dimension of a selected item said safety space is provided to protect.

2- A. afetzsto 9k, f9! 92 11 .95? m t s s t forth in claim 1, wherein said selected item is ''hum'n hand.

3. A safety stop lock for a closure member as set forth in claim 1, wherein said closure member is a drawer and said border means a wall portion of a fixture surrounding the drawer opening, latch means having an engagement surface at a second designated location for alignment with said bumper means when said extending arm is in said engagement position, said second designated locaton of the engagement surface of said latch means being spaced apart inwardly from the outer surface of said border means a sufficient distance for said engagement surface of said latch means to restrainingly bear against the outward facing abutment means of said bumper means when said extending arm is in said engagement position and when said drawer is closed with the outer surface of said front closure wall lying in the same plane as the outer surface of said border means, said latch means in engagement with said bumper means thereby retaining said drawer in closed position.

Claims

2. A safvety stop lock for a closure member as set forth in claim 1, wherein said selected item is a human hand.