US3514979A - Thin spring locks and unlocking means therefor - Google Patents

Description

June 2, 1970 HERBERT'LUDWIG WIESMANN THIN SPRING LOCKS AND UNLOCKING MEANS THEREFOR Filed Dec. 18, 1967 3 SheetsSheet 1 11/21/11,: 'I/II IIII.

ATTORNEY lNVENTOR HERBERT LUDWIG WIESMANN June 1970 HERBERT-LUDWIG WIESMANN 3,514,979

THIN SPRING LOCKS AND UNLOCKING MEANS THEREFOR Filed Dec. 18, 1967 3 Sheets-Sheet 8 FIG. 4

FIG.5

INVENTOR HERBERT LUDWIG WIESMANN ATTORNEY HERBERT-LUDWIG WIESMANN 3,51

June 2, 1970 THIN SPRING LOCKS AND UNLOCKING MEANS THEREFOR Filed Dec. 18, 1957 3 Sheets-Sheet 3 FIG.6

ATTORN EY United States Patent 0,

Int. Cl. Eb 65744; E05c 1/12 US. CI. 70-81 9 Claims ABSTRACT OF THE DISCLOSURE A flat, thin spring lock for use in narrow confined Spaces, as in a thin cabinet door or similar closure, particularly adapted for airplanes or other vehicles where protruding handles or knobs are undesirable. The lock and door are operated by a bell crank lever pivoted on the lock casing having one lever arm within the lock casing and attached to the latch actuating mechanism, and the other lever arm outside and overlying the casing and adjacent thereto so that it does not protrude when the door is locked. To unlock, the outside lever arm is moved first by a finger to an unlocking position where it is angularly related to the door and thereafter it may be grasped by several fingers, to exert a dooropening force thereon. In another embodiment, the lever arm is biased by a spring in an unlocking direction but is prevented from moving therein by a trip means. A push button disables the trip means whereby the spring moves the lever arm into its projected position where it may be used as the door handle.

This invention relates to spring locks, particularly of the flat thin type.

In certain eviron-ments, such as in airplanes, land vehicles and similar locations, locks for doors, windows and similar closures or for drawers and the like must be of special dimensional design to fit within the narrow confines of a closure or wall space. For safety reasons, no parts of the lock, such as handles or knobs, may protrude from or above the lock casing closure or the wall, that is, the entire lock unit should be flush with the surface of the closure or wall. The lock should also effectively maintain the closure in its locked position against all forces tending to disturb it, such as, for example, centrifugal forces in airplanes, but still be so constructed as to be easily operated to its unlocked position.

An object of this invention is to provide a lock having all its elements within a flat, thin casing so that it fits within the available limited space provided by the closure or wall structure of the cabinet or vehicle.

Another object is to provide a lock with a latch biased by a sufliciently strong spring to retain it in its locked position against all undesired forces tending to move it in the opposite direction.

Another object is to provide a lock with a spring urged latch and a handle to move it against the spring, the handle, when in the normal inoperative position, lying flush against the lock casing. The handle is provided with an accessible grip portion whereby it can be gripped by a finger and moved to overcome the latch spring and to withdraw the latch. In the final position, the handle may be grabbed by several fingers and used as a pull to open the door, drawer, or any movable device to which the lock is attached.

A further object is to provide a trans-mission means between the handle and the latch whereby the latch can bemoved easily and quickly with no undue force exerted by the finger of the operator.

3,514,979 Patented June 2, 1970 Another object is to provide a lock as described above wherein the handle is spring operated and controlled by a push button.

A further object is to provide a locking device to prevent latch withdrawing movement and thereby effectively lock the closure.

Other objects and advantages of this invention will become apparent upon consideration of the following specification and the attached drawing wherein:

FIG. 1 shows a top view of a spring lock according to the invention;

FIG. 2 shows a section according to line II-'II in FIG. 1;

FIG. 3 shows a section according to line l-IIIII in FIG. 1;

FIG. 4 shows a top view of a different embodiment of the spring lock;

FIG. 5 shows a section according to line VV in FIG. 4;

FIG. 6 shows a further modification in which the spring lock is opened by means of a push button; and

FIGS. 7 and 8 show in two views and on an enlarged scale the safety device shown in FIG. 1.

FIGS. 1 to 3 show a lock housing which consists of a lock box 1 and a cover plate 2 which is fastened thereto by means of screws 3 threaded into sockets 5 of the lock welded to bottom 4 of the lock box. The side walls of the lock box 1 have bent extensions 6 to which threaded sockets 7 are welded. The lock casing may be fastened to the desired structure by means of screws threaded into sockets 7. In the disclosed embodiment, numeral 8 designates the rear wall of a door panel to which the lock is secured. The front wall 9 of the door panel is cut out and overlaps somewhat the ends of the bent extensions 6 which are once more bent at an angle. The lock box 1, furthermore, is formed in one piece with a cuff 10 in which an opening has been provided for the passage and guidance of the catch or latch 11 of the lock.

Latch 11 is biased by a relatively strong spring 12 to its outward position and is guided in its slidable motion by formations 13, 14 and 15 struck from or otherwise formed in the lock box. Latch 11 comprises an elongated members having the usual bevel or cam surface at its front or outward end to cooperate with a keeper element (not shown), and having an inward end 16 in the form of a toothed rack which meshes with a gear segment 17 journaled around a pivot 18 suitably secured within the lock box. As shown, pivot 18 may be in the form of a rivet. An element 19, which may be a struck-up portion, of gear segment 17, or a separate element secured to the gear segment, is located on gear segment '17 on the side of pivot 18 remote from the gear teeth of segment 17. Thus, as shown in FIG. 1, a force applied to element 19 to move it to the right causes clockwise movement of gear segment 17 around pivot 18 with the resulting withdrawal movement of latch 11 to the left against the bias of spring 12.

The withdrawal movement of gear segment means 17, 19 is accomplished by means of a bell crank lever 20 which pivots on a shaft 21 supported in the side walls of lock box 1. Bell crank lever 20 has a short arm 22 directed toward the inside of the lock adjacent element 19, and a longer lever arm 23 which normally lies flat on the cover plate 2 and terminates over a portion of recess 24 provided approximately in the middle in the cover plate 2. Lever arm 23, lying on the outside, is about the width of the lock and covers up the heads of the screws 3.

To open the closure or device to which the lock is secured, a finger is placed within recess 24 below lever arm 23 and lever arm 23 is moved upwardly. As bell crank pivots around shaft 21, its other end 22 engages element 19 on gear segment 17 and moves it to the right, as viewed in FIGS. 1 and 2. As explained above, such movement causes gear segment 17 to move clockwise and thereby move rack portion 16 and latch 11 to the left to release it from its keeper. In the fully withdrawn position of latch 11, lever arm 23 of hell crank 20 is in a position generally perpendicular, or angularly related, to the closure and therefore it can be grasped by other fingers and utilized as a pull handle to pull the closure to open position. Thus, bell crank lever acts as a latch withdrawing or unlocking means and. thereafter as a closure pull handle.

Upon release of lever arm 23, spring 12 forces latch 11 and thereby transmission means 16, 17, 19 and bell crank 20 to their normal position (FIG. 1). If the closure is not fully closed, any vibration of the support mounting the lock will cause bell crank 20 to audibly rattle around its shaft 21 and thereby call attention to the fact that latch 11 is not fully engaged by its keeper, that is, the

closure is not completely locked.

In the embodiment shown in FIGS. 4-5, spring 12 is eliminated, and thereby the overall length of the lock casing is reduced. As shown in FIG. 4, a tension spring 12a is secured to a socket 3a and to gear segment 17a, whereby spring 12a biases latch 11 to its locked position. Gear segment 17a is provided with a plurality of holes or bores 25. Element 19a is in the form of a pin, and by placing it in a selected bore 25, the radial distance between pin 12a and pivot 18 may be varied, and thereby the throw or withdrawal movement of latch 11 may be varied. The location of the line on which the centers of bores are located is defined by a line passing through pivot 18 and through the point of engagement of the teeth of gear segment 17:: and rack portion 16, when latch 11 is in a half pulled-back position. Such location of bores 25 gives a maximum travel of latch 11 for a minimum travel of lever arm 22 along pin 19a, for a given position of pin 19a in a selected bore 25.

As shown in FIGS. 4 and 5, in order to reduce the size of the lock, sockets 7a are located within lock box 1. One of these sockets, designated as 712, acts as a stop to limit the movement of gear segment 17a and thereby limit the withdrawal movements of latch 11 and bell crank lever 20.

To further guide latch 11 in its movement, it is provided with an extension 11a slidable in a suitable opening formed in the wall of lock box 1.

In the embodiment of FIG. 6, hairpin type spring 26 is pivoted around shaft 21, with one arm engaging the bottom of the lock box and the other arm engaging lever arm 23 of hell crank 20 to move it in the latch withdrawal direction. Movement in such direction is prevented by a trip 27 engaging a nose portion on lever arm 22. Trip 27 may be in the form of a resilient member riveted to the bottom of the lock box, as shown in FIG. 6.

To unlock the closure, a push button 28 which overlies trip 27, or which is otherwise connected to depress trip 27, is operated. Movement of push button 28 actuates the trip out of engagement with lever arm 22 and permits pivotal movement of bell crank lever 20 under the influence of spring 26 to assume its position wherein it can be grasped and used as a handle to fully withdraw the latch and to open the closure. The dotted lines in FIG. 6 show the positions of the movable elements in their projected position so that lever arm 23 may be grasped and operated. It is apparent that in this embodiment, recess 24 may be eliminated.

Spring 26 may be made stronger than holding spring 12. In the event when push button 28 is actuated, spring 26 will move bell crank lever 20 to its final position wherein the latch is fully withdrawn and lever arm 23 may serve as the closure handle.

FIGS. 7 and 8 show the details of safety and locking means designated as 30 in FIG. 1. Means 30 comprises a member 31 fixed to the lock box 1. A locking plug 32, carrying a locking finger 34, is mounted in a bore of member 31. Plug 32 has a key slot formed therein which may be of a varied shape so that only a key of a mating shape would fit therein. Plug 32 and its key slot 33 are merely a diagrammatic representation of a locking device and may assume any form, such as a tumbler type locking means or a plain key type. Member 31 houses a spring pressed detent 35 which may interengage with either of recesses 36 or 37 formed in plug 32, whereby the detent 35 maintains plug 32 in either of its two positions.

FIG. 1 shows in solid lines plug 32 and its finger 34 in a position which permits latch withdrawing movement of gear segment 17. If it is desired to lock the closure, plug 32 is turned by means of a mating key to bring finger 34 in the path of movement of gear segment 17 to thereby block its movement. The blocking position of finger 34- is shown by the dotted lines in FIG. 1. Plug 32 and finger 34 are thereafter retained in blocking position by detent 35 engaging recess 37, and the closure will stay locked until plug 32 is returned to unlocked position.

While the forms of the invention herein described constitute preferred embodiments, it is to be understood that the invention is not limited to the precise structures disclosed, and that changes may be made therein without departing from the scope of the invention which is defined in the following claims.

What is claimed is:

1. A spring lock comprising a thin, fiat lock casing with main walls and smaller side walls adapted to be secured to the element to be locked, a latch slidable within said casing having a locking position wherein its end protrudes from said casing, spring means biasing said latch to its locking position, a unitary plate member to initially withdraw the latch and thereafter serve as a handle means, said plate member being in the form of a bell crank lever with a short lever arm and a relatively longer lever arm and being pivotable about an axis which extends perpendicularly to the sliding direction of the latch and parallel to saidunitary plate member, said short lever arm extending within the casing and the longer arm closely overlying a portion of said casing when said latch is in its locking position, means to support said plate member for pivotal movement, motion transmitting means directly activated by said short arm to transmit unlocking motion from said member to said latch, said motion transmitting means being pivotable about an axis which extends perpendicularly to the sliding direction of the latch and also perpendicularly to the axis of the plate member, said motion transmitting means engaging the slidable latch at a side facing the smaller side wall of the casing, a depression providing a finger recess struck in the wall of the casing adjacent the overlying longer lever arm to permit the insertion of a finger below said longer arm for applying a pivoting force to the plate member to move it in a direction to cause an initial movement of the short lever arm and the motion transmitting means in a direction to withdraw the latch against its spring bias and thereafter bring the long lever arm into a position wherein it is substantially angularly related to the casing to serve as a handle.

2. A spring lock in accordance with claim 1, wherein the motion transmitting means comprise a pivoted gear segment oscillated by movement of said short lever arm and a rack means interconnecting said gear segment and latch.

3. A spring lock in accordance with claim 2, wherein said gear segment has a series of bores, the centers of which are located on a line passing through the center of the gear segment pivot and the point of engagement of the teeth of the gear segment with the teeth of the rack when the earth are in the position corresponding to a half unlocking movement of the latch, and a pin insertable in a preselected bore, said first lever arm abutting said pin to transmit movement to said gear segment.

4. A spring lock in accordance with claim 1, said lock casing having means for securing the lock casing to the desired element, said securing means being within the area defined by the overlying portion of the long lever arm.

5. A spring lock in accordance with claim 1, second spring means biasing said plate member in the latch withdrawal direction against said first claimed spring means, trip means to prevent movement of said plate member by said second spring means, and push button means operatively connected to said trip means to disable it and thereby permit movement of the plate member in the latch withdrawal direction.

6. A spring lock in accordance with claim 1, and locking means located adjacent the motion transmitting means to prevent movement thereof in a latch withdrawing direction.

7. A spring lock in accordance with claim 6, said locking means comprising a mounting means secured to said lock casing adjacent said motion transmitting means, and key operated means supported by said mounting means and operable to a first position wherein it is in the path of movement of the motion transmitting means to prevent movement thereof, and operable to a second position lying out of said path.

8. A spring lock in accordance with claim 7, wherein said key operated means comprise a keyed plug rotatable 6 in said mounting, a member secured to said plug to be moved thereby into and out of the path of said motion transmitting means, and detent means for maintaining said plug in either of its positions.

9. A spring lock in accordance with claim 1, wherein the lock casing includes side walls, angular extensions on said side walls, and threaded socket means secured to said extension for reception of fastening screws therein.

References Cited UNITED STATES PATENTS 1,199,849 10/1916 Willoughby 105-434 1,557,581 10/1925 Harrington 292173 X 2,075,948 4/1937 Kuszmaul 292173 X 2,642,300 6/1953 Pelcin 292173 2,934,370 4/ 1960 Love 292142 2,900,204 8/1959 Pelcin 292173 3,055,204 9/1962 Pelcin 153 3,159,415 12/1964 Sandor 2923363 3,250,558 5/1966 McClintock 292229 1,964,066 6/1934 Kuszmaul 292172 X 3,044,815 7/1962 Soss 292173 3,209,563 10/1965 Pelcin 292173 X RICHARD E. MOORE, Primary Examiner E. J. MCCARTHY, Assistant Examiner US. Cl. X.R. 292172

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