US3086803A - Adjustable strength door latch - Google Patents

Description

April 23, 1963 H. C. WILSON ADJUSTABLE STRENGTH DOOR LATCH Filed July 18, 1960 IN V EN TOR. HARRY C. WILSON ATTORNEYS grates finite 3,686,803 ADJUSTABLE STRENGTH DGOR LATCH Barry C. Wilson, 15126 Rayneta Drive, Sherman ()aks, Calif. Fiied July 18, 1960, Ser. No. 43,678 1 Uaim. (Cl. 292-17) This invention relates to door latches and more particularly to a simple, inexpensive, button-type latch device featuring easily operable means by which the holding power of the resilient retainer may be varied at will over a Wide range.

The door latch of the present invention is commonly known as a button-type latch inasmuch as one of the two principal components comprises a contoured button which resiliently interlocks with the retainer assembly. A variety of designs embodying the operating principles of a button latch have been proposed heretofore. However, they have not been fully satisfactory in certain respects and have not enjoyed widespread use owing to certain shortcomings and disadvantages including the lack of simple, easily operated and reliable means for adjusting the holding strength to meet the needs of differing operating environments or the preferences of a particular user. Also lacking in prior constructions has been a desirable range of adaptability to differing environments or the change of conditions in a given environment due to shifting of the supporting walls or doors to which the latch parts are attached, shrinkage of the wood on which the parts are mounted and numerous other factors of a like character.

The present invention is provided to meet the above discussed and other shortcomings of prior latch devices and to provide a device that can be readily adjusted after installation to meet changing conditions both as respects the relative positions of the latch parts and in particular the holding power of the catch itself. To this end the latch comprises a cup-shaped retainer having a dished bottom through which the mounting screw or the like extends. Tightening or loosening of this mounting screw to change the degree of dish of the retainer bottom is eifective to change the normal position of the retainer fingers and thereby the holding power of these fingers relative to the detent button. It will therefore be appreciated that adjustment is obtained without need for special or additional parts and adjustment is accomplished by the aid of a screwdriver to turn the mounting screw.

A further feature is the use of a detent button formed of non-metallic noise-absorbing material and mounted on the shank of an attaching screw, The use of a non-metallic button in combination with the spring retainer renders the catch substantially noiseless in operation and has the additional advantage that it can be assembled to the mounting screw with a very firm frictional contact. By reason of this latter fact, the mounting screw can be adjusted axially thereof over a wide range with assurance that the button proper will remain firmly seated against the head of the mounting screw. In this manner the proper operating positions of the latch components can be maintained and changed as necessary to compensate for warpage of the door, sagging and the like changes.

Accordingly, it is a primary object of the present invention to provide an improved button-type latch device of simple, inexpensive construction and embodying highly desirable novel features.

Another object of the invention is the provision of a simple spring catch door latch having improved means for adjusting the holding power of the latch over a wid range.

Another object of the invention is the provision of an improved substantially noiseless spring detent latch device having several cooperating adjustable features.

These and other more specific objects will appear upon reading the following specification and claims and upon considering in connection therewith the attached drawing to which they relate.

Referring now to the drawing in which a preferred embodiment of the invention is illustrated:

FIGURE 1 is a fragmentary view in perspective showing a latch device according to this invention in operating position on a cupboard door;

FIGURE 2 is an enlarged cross-sectional view through the latch device in the closed position thereof;

FIGURE 3 is a cross-sectional view taken generally along the line 33 on FIGURE 2; and

FIGURE 4 is a view similar to FIGURE 2 but showing the retainer assembly adjusted for relatively low-power holding capability.

Referring to FIGURES 3 and 4, there is shown a button-type latch device designated generally 10 formed in two assemblies comprising a retainer assembly 11 and a detent assembly 12. As herein shown, retainer assembly 11 is shown secured to a cupboard shelf 13 by mounting screw 14 and detent assembly 12 is shown mounted on the interior side of a cupboard door 15 opposite assembly 1 1. It will be, of course, apparent that the two principal subassem'blies can be mounted in various other modes well known to those familiar with the latch art and the numerous modes of using such devices.

The principal parts of retainer assembly 11 comprise a one-piece cup-shaped member formed from resilient sheet material and having an inwardly dished bottom 17 and a plurality of spring fingers 18 arranged generally parallel with one another and spaced circum-ferentially of and integral with the rim of bottom 17. The free ends '19 of fingers 13 are preferably similarly curled, either inwardly or outwardly, and are arranged in a ring in the manner clearly illustrated in the several figures of the drawing.

Dished bottom 17 of the retainer is suitably apertured to receive the shank of a mounting screw 20. As herein shown the shank of this screw is engageable with a threaded opening 21 in the upright leg 22 of an L-shaped bracket member 23. The other leg 24 of the bracket has an opening 25 for receiving the shank of mounting screw 14. A further and important feature of the mounting bracket 23 is the provision of a pointed tang 26 extending generally perpendicularly from the rear face of leg 24. This tang is forced into the shelf 13 as the mounting screw 14 is tightened and cooperates with this screw in determining the orientation of the axis of retainer cup 18 in the installed position of retainer assembly 11. It is, of course, desirable that the axis of cup 18 and of screw 29 be in axial alignment with the axis of detent assembly 12. Once this position has been determined, anchor tang 26 is pressed into shelf 13 and. screw 14 and firmly tightened to lock retainer assembly 11 in this desired position.

Detent assembly 12 comprises a mounting screw 30 and a non-metallic detent button or ring 31; Button 31 is provided with a central axial opening of the diameter snugly fitting the slightly larger diameter inner end of the shank of screw 30. This fact together with the action of the screw threads in cutting a helical groove in the button assures that this button will have a very tight fit with the screw shank once it is fully assembled against the head of the screw. The exterior periphery of button 31 is provided with a detent groove 32 the inner rim edge of which merges with the 'base of a flange 33 and the exterior rim of which merges with a surface 34 which is suitably contoured to mate with the rounded head of screw 30.

The assembly of the parts is accomplished by first mounting the retainer assembly utilizing screw -14 for this purpose. This screw is driven into a shelf or a wall after first checking to determine that the curled free end 19 of the retainer member is spaced inwardly of the inner surface of the closure when closed. Once retainer assembly 11 has been secured in place, detent assembly 12 is inserted within the retainer leaving the pointed end of mounting screw 30 projecting forwardly. 'While the detent is so firmly held, the cupboard door 13 is closed against the pointed end of the screw to mark the place where the screw should be mounted. Marking of the mounting place having been accomplished, screw 30 is mounted in the door and checked for proper assembly. Desirably the parts are so mounted that in the installed position of the detent the base end of button 3-1 bears against the inner surface of door 15 and will then be properly positioned for the curled ends 19 of the retainer fingers to seat snugly within groove 32 of button 31.

After installation, it sometimes happens that the wood or shelf 13 shrinks. In this event the fingers will no longer have suflicient seating engagement with groove =32 to hold the door firmly closed. To correct for this change in conditions, the user merely inserts a screwdriver in the head ofrscrew 30 and turns it outwardly sufliciently for proper engagement of the latch parts. The presence of a narrow gap between the inner flanged end of ring 31 and the door is not objectionable.

Even with the parts properly adjusted for full seating of curled ends 19 of the fingers in retainer groove 32, the cupboard door may be sutficiently heavy that greater power of the latch parts is desirable. This requirement is easily and readily achieved by the simple expedient of using a screwdriver to turn retainer mounting screw inwardly thereby flattening somewhat the dish in bottom =17. When the dished bottom is partially flattened in this manner, it willbe understood that fingers 18 are deflected inwardly toward the axis of the cup and into firmer seating engagement with groove 32 of button 31. On the other hand, loosening of mounting screw 20 allows the dished bottom to move back toward its original and normal contour thereby moving fingers 18 away from the axis of the cup and out of strong engaging power with groove 32 of the button.

It is found that a retainer formed of light gauge strong spring metal having a bottom dishedinwardly by an "angle of 15 degrees is readily adjustable to vary the retaining power of the catch over a range of 3 to 14 pounds. Stated differently, the retainer is adjustable to provide a holding power from a minimum value of say 3 pounds to a maximum of more than four times the minimum. A greater range of adjustment is readily available by the proper selection of materials andv the use of a dished bottom having a greater angle of initial dish. Although spring metal is a preferred material from which to construct the retainer, it will be obvious that high-strength,

high res'iliency, non-metallic materials, such as plastic, maybe employed if desired.

While the particular adjustable strength door latch herein shown and disclosed in detail is fully capable of attaining the objects and providing the advantages hereinbefore stated, it is to be understood that it is merely illustrative of the presently preferred embodiments of the invention and that no limitations are intended to the details of construction or design herein shown other than as defined in the appended claim.

I claim:

A latch device for use in holding a swinging closure member releasably in closed position, and comprising as principal components a detent unit and a keeper unit, said keeper unit .comprising a cup-shaped resilient member formed from resilient sheet metal stock, said cupshaped member having a multiplicity of long narrow fingers of flat uniform thickness material integral with an inwardly-dished centrally-apertured bottom of said member, said fingers being arranged in a ring about the rim of saiddished bottom and each having similar inwardly-curled ends forming a ring of similarly-shaped similarly-disposed curls about the rim of said cup-shaped member and cooperating to provide an annular resilient pilot effective to 'guide the detent unit into holding engagement with the curled ends of each of said fingers, screw means receivable in the aperture of said inwardlydished bottom and eflective to mount said keeper memher, said screw means being adjustable to vary the curvature of saidinwardly dished bottom as and to the extent desired thereby to deflect said ring of fingers radially inwardly and outwardly to vary the circumference'of said ring of curls and to vary the holding power thereof, said detent means including a headed wood screw and an annularly grooved ring of plastic material surrounding the shank thereof and positioned adjacent the screw head and shaped to enter said keeper with the curled ends of said fingers seated in said annular groove, said plastic ring having a rounded rim edge merging with the exterior end surface of said wood screw and serving as a rounded pilot engageable with the curled ends of the keeper fingers to guide the same individually and noiselessly into and out of holding engagement with said keeper member, and said plastic ring having tight frictional engagement with the shank of said wood screw References Cited in the file of this patent UNITED STATES PATENTS 444,019 Richards Jan. 6, 1891 504,142 Wilburn Aug. 29, 1893 548,501 Barbarow Oct. 22, 1895 1,931,695 Hall Oct. 24, 1933 2,203,973 Walls June 11, 1940 2,694,592 Borchers et a1 Nov. 16, 1954 2,877,040 Curtiss et al Mar. 10, 1959

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