US2760804A

US2760804A - Door latch

Info

Publication number: US2760804A
Application number: US386035A
Authority: US
Inventors: Falk Harold Walter
Original assignee: Wright Products Inc
Current assignee: Wright Products Inc
Priority date: 1953-10-14
Filing date: 1953-10-14
Publication date: 1956-08-28
Anticipated expiration: 1973-08-28

Description

Aug. 28, 1956 H. w. FALK 2,760,804

DOOR LATCH Filed Oct. 14, 1953 INVENTOR 35' 32 M flara/d Wa/fm' Fa/A' 34 gbwmam 6 9 ATTORNEY DOOR LATCH Harold Walter Falk, Minneapolis, Minn assignor to Wright Products, Inc., Dakota County, Minn., a corporation of Minnesota- Application October 14, 1953, Serial- No.- 386,035-

11 Claims. (Cl. 292164) This invention relates to an improvement in door latch and deals particularly with a latch. of simple construction, particularly useful on screen doors, storm doors, combination doors and the like. p

In recent years, considerable stress has been placed upon the desirability of reducing the labor costs of applying door latches to doors. With the present cost of labor, any saving in time which may be effected by changing the door latch construction is extremely welcome to the purchaser. The present invention: resides in the provision of a door latch which. may be easily and quickly applied to the door with a minimum of tools andusing a minimum of time.

A feature of the present invention lies inthe provision of a latch having a slidable latch bolt which is so devised that the entire actuating mechanism is on the outside of the door with the exception of the slidable bolt and its actuating lever. Thus in attaching the latch to the door, it is only necessary to bore one or two holes transversely through the door from side to side thereof and to bore another hole into the edge of the door to communicate with the transverse apertures. The entire mechanism may then be attached to the door without additional tools,

. with the possible exception of a screw driver a'nd hammer.

A feature of the present invention resides in the provision of a mechanism housing which is of relatively small size and which accommodates the operating mechanism, the lock, and the biasing spring. This housing may be secured to a surface of the door and is sufii'ciently small so that it is not unsightly. In attaching the latch to the door, it is only necessary to extend the handle shank of the latch through one drilled opening, to extend the slidable latch bolt and its sliding support into the aperture in the edge of the door, and to insert the latch bolt actuating lever into a second transverse opening or into a portion of the first opening. Thus the attachment of the lock is so simple that it may be readil y applied by, anyone possessing a means of drilling the openings and screwing the housing in place.

A feature of the present invention lies in the provision of a mechanism housing which lies over one surface of the door and is provided with a latch bolt operating lever projecting therefrom. This lever is the only portion of the mechanism which is actually enclosed within the door, with the exception of the latch bolt and the handle shank. With this arrangement the requirement for unusual. tools is obviated, the holes through the door being of relatively small size and Within the range of auger bits, ordinarily found in the tool equipment of a home owner. The necessity for morti'cinginto the door edge or door 7 surfaces is obviated" and there is no need even for using nited States Patent 0.

r 2,760,804 Patented Aug. 28, 1956 Figure 1 is a perspective view of a portion of a door showing the latch in place thereupon.

Figure 2 is a diagrammatic view of the door before the latch is applied thereto showing the arrangement of apertures required for attachment of the latch.

Figure 3 is a cross sectional view through the door latch and its operating mechanism showing the relationship of the parts thereof.

Figure 4 is a sectional view through the mechanism housing, the position of the section being indicated by the line 4-4 of Figure 3.

Figure 5 is an elevation view of the mechanism housing, the position of the view being. indicated by the line 5-5 of Figure 3.

Figure 6 is a sectional view through a portion of the mechanism housing, the position of the view being. indicated by the line 6-6 of. Figure 4.

Figure7 is a sectional view through the latch bolt.

The manner in which the door is prepared to receive the present lock is best illustrated in Figure 2 of the drawings. The door isindicated in general by the letter A and numeral 10 designates one flat door surface. The edge of the door is designated by'the numeralll. Two holes 12 and 13 are bored through the door from one surface 10 to the opposite surface, these openings preferably intersecting as illustrated to form a cavity which is elongated in a direction normal to the door edge 11. A hole 14 is alsordrilled in the edge 11 of the door with its axis normal to the surface of the edge and intersecting the axes of the holes 12 and 13. When these three holes have been drilled, the door is completely prepared for the lock.

The lock is illustrated in: general by theletter B. The lock includes a knob 15 having a hub 16 detachabl'y'com nected to arectangular shank 17. The end oft-he shank 17 isequipped with a sleeve 1 9'. An elongated handle 20 is secured to the sleeve 19 to rotate in unison therewith. When attached the shank 17 may be oscillated ineither direction by the handle 20 or by the knob 15. A-n escutcheon plate 21' is provided adjacent to the hub 16 of the knob 15 and isof. sufficient size to conceal the ends of the holes 12 and 13. This escutcheon plate 21 is preferably provided with anv inturned marginal edge 22 which bears against the door surface 23 opposite the surface 11.

The slidable latch bolt issupported inthe aperture 14. A thimble like member 24 is provided with a closed end 25 and an outwardly flanged open end 26.' The closed end 25 is provided with anelongated rectangular opening 27 extending therethrough. A- pair of pointed ears 29 are struck from opposite sides of the sleeve 24 to extend outwardly beyond the periphery of the sleeve and toward the flanged end thereof. These ears 29 are intended to anchor the sleeve in the aperture 14 and prevent its accidental removal.

The latch bolt includes a plunger member formed of two parts. One part comprises a wedge shaped member 30 which is substantially triangular in cross section and circular in elevation. This 'wedge shaped member 30 is provided with a projecting: cylindrical sleeve 31 which terminates in an inturned rim 32. The other main art of the latch bolt comprisesan elongated strip 33 having outwardly projecting shoulders 34 at one end thereof and an elongated aperture 35 near the other end thereof. The sleeve 31 is provided with a slot 36 at its outer extremity of proper dimensions to accommodate the shouldered end of the strip- 33. The end of the strip 33 extends into the slot 36 and holds the wedge shaped part 30 from rotation about the axis of the sleeve 31.

p The strip 33 ,is of proper" dimensions to slidably fit through the slot or aperture: 27 in. the thimble 24. The strip is thus held from rotation by the thimble but may be arranged with 'its inclined face directed in either of two opposite directions. In other words, while the inclined surface is directed in one direction in Figure 3 of the drawings, the latch bolt could be removed from the aperture 14 upon disengagement of the remainder of the mechanism and could be rotated through 180 degrees and replaced so that the inclined surface would be on the opposite side.

The mechanism housing is shown in its outline form in Figure l of the drawings. As indicated in this figure, the housing 37 is circular in outline and is provided with a peripheral wall 39 which is directed toward the door surface. A portion of the housing 37 is relatively thick, this part comprising a generally rectangular portion having parallel side walls 40 which are of equal length so that the thicker portion of the housing extends through the center thereof. An outwardly projecting ring shaped bead 41 encircles the end of the sleeve 19 and the housing is centrally apertured at 42. to accommodate the knob shank 17.

As indicated in Figures 4 and of the drawings, the major portion of the mechanism is supported upon a mounting plate 43 which is enclosed within the marginal peripheral walls 39 of the housing 37. The surface of the plate 43 which is normally against the door surface is shown in Figure 5. The plate 43 is provided with an inwardly projecting sleeve 44 centrally thereof which is designed to encircle the shank 17. The plate is also provided with an elongated slot or aperture 45 through which the latch bolt actuating lever 46 extends. An additional elongated slot 47 is provided into which a portion of the latch bolt actuating spring 49 extends. This slot 47 acts to locate the spring 49 and to prevent its, movement laterally.

As seen in Figure 4 of the drawings a portion of the periphery of the mounting plate 43 is bent right angularly to form a flange 50. A slidable yoke 51 includes an apertured panel 52 which encircles the shank 17 and is provided with an aperture 53 of suflicient length to permit the plate 52 to slide. The plate 52 is provided with a flange 54 along one end thereof and a spring 55 is interposed between the

flanges

50 and 54 to urge the slide in one direction. The plate 52 is also provided with upwardly extending cars 56 which assist in holding the platein its proper location.

A cam 57 is mounted upon the shank 17 adjacent to the slide 51. This bar-extends in opposite directions from the shank and is engageable with the slide 51 to move the slide to 'its left hand position illustrated in Figure 4 of the drawings. The cam 57 normally extends parallel to the flange 54, the spring 55 expanding to push the slide toward the right from the position shown in Figure 4. Obviously rotation of the shank 17 in either direction from its normal position will act to engage one end of the cam against the flange 54 to move the slide 51.

As indicated in Figures 3 and 4 of the drawings, the lever 46 extends through the slot 45 and through a slot 57 in the slide 51. A cooperable housing member not illustrated in Figure 4 for the purpose of simplicity of showing, cooperates with the mounting plate 43 and is best shown in Figure 6. This cooperable mounting plate 59 is provided with a circular periphery 60 similar to that of the mounting plate 43 and is provided with an elongated central ofi-set portion 61 having parallel sides 62 and 63. The side walls 62 and 63 extend on opposite sides of the slide 51 and guide this slide in its movement. The mounting plate member 59 also acts to hold the spring 55 engaged in the recess 47 of the mounting plate 43.

The cooperable mounting plate 59 is shown in Figure 3 as including an aperture 64 into which the lever 46 extends. As the mounting plate 59 remains stationary, and as the aperture 64 snugly fits the end of the lever 46, this aperture acts as a fulcrum for the lever. Movement of the slide 51 acts to pivot the lever 46 from the position shown in full lines in Figure 3 to the position shown in dotted outline in this figure. As the end of the lever 46 extends through the latch bolt member 33, movement of the slide also acts to retract the latch bolt.

As indicated in Figure 6 of the drawings, a locking pin 65 is provided with a reduced diameter end 66 which extends through a slot 67 in the mounting plate 59 and through a registerable slot 69 in the housing member 31. A flat spring 70 has angularly bent ends 71 and 72 which extend into the spring aperture 47 and a spaced aperture 73 in the mounting plate 43. This flat spring is upwardly bowed from the mounting plate 43 and tends to hold the pin 65 either at one end of its movement or at the other. In one position of movement, the locking pin 65 is in the path or movement of a projection 74 on the slide 51. This projection is shown in Figures 4 and 6 of the drawings. In the other position of its movement the pin 65 is laterally spaced from the path of movement of the projection 74 and does not interfere with the movement of the slide.

The lever 46 is 'oddly shaped in order to act most effectively and to remain 'in proper position automatically. The fulcrumed end of the lever 76 is bent angularly from the central portion of the lever and the lever end 77 which extends through the latch bolt is also angularly bent so that the lever will hinge near or through right angular relation with respect to the parts engaged. This arrangement permits the apertures through which the lever extends to-fit rather snugly about the lever thus preventing excessive play which causes rattling or vibration of the parts.

The operation of the lock may now be described. The method of preparing the door and the lock has been described. Screws or bolts may extend through the escutcheon plates and into the door to lock the parts of the structure together and to hold the escutcheon plate and mechanism housing from rotation relative to the door. Figure 1 illustrates screws 79 extending into the door through the mechanism housing for this purpose. The screws 79 also pass through the mounting

plates

43 and 59. Similar screws can be employed for the escutcheon plate 21.

When the knob or handle is rotated in either direction from a former position, one end or the other of the cam 46 is urged againstthe flange 54 of the slide 51. This causes the slide to slide across the surface of the mounting plate 43, compressing the spring 55. The flange 54 and the cars 56 extend into contact with the offset portion 61 of the mounting plate 59, thus holding the slide panel 52 in surface contact with the mounting plate 43. Slidable movement of the slide 51 acts to exert a pullingforce upon the lever 46 intermediate its ends. This action swings the end 77 of the lever 46 in a counterclockwise direction as viewed in Figure 3, thereby retracting the latch bolt.

I When the force is removed from the door handles the spring urges the slide 51 back into its normal position, thus swinging the lever 46 in a clockwise direction and projecting the latch bolt. This action also rotates the cam 46 to its central starting position.

In order to lock the door, the reduced diameter end 66 of the locking pin is moved upwardly in the slot 69 so that the body of the pin extends in the path of movement of the projection 74 on the slide 51. Thus rotative movement of the cam forces the projection 74 against the pin 65 which is held from lateral movement by engagement in the slot 67 and also by peripheral engagement with the fixed flange 50. Thus the cam 46 cannot rotate to move the slide sufliciently to retract the latch bolt. In unlocking the door the pin 66 is moved downwardly to move thepin 65 out of the path of the projection 74;

In accordance with the patent statutes, I have described the principles of construction and operation of my door latch, and while I have endeavored to set forth the best embodiment thereof, I desire to have it understood that obvious changes may be made within the scope of the following claims without departing from the spirit of my invention.

I claim:

1. A door latch including in combination a mechanism housing designed to overlie the surface of a door, a shank rotatably supported by said mechanism housing and-designed to extend through an opening in the door normal to the surface thereof, a slide within said mechanism housing, cooperable means on said shank engageable with said slide to slide the same upon rotation of said shank, and lever means mounted in said housing and projecting therefrom into an opening in said door, and latch bolt means mounted on said door externally of said mechanism housing and arranged to move on an axis parallel to said surface of the door cooperably connected with said lever for actuation thereby.

2. The structure described in claim 1 and in which said slide is provided with an aperture therethrough through which said lever extends.

3. A latch including in combination a mechanism housing including a slide, means supporting said slide for recoprocatory movement, a rotatable shank extending through said mechanism housing and including means cooperable with said slide to move the same in one direction, a lever pivotally supported by said mechanism housing and having an end extending therefrom, a latch bolt positioned externally of said housing and slidably supported for movement by said extending end of said lever, and locking means extending into and out of the path of movement of said slide and locking said slide from movement in one position thereof.

4. The structure described in claim 3 and including resilient means for urging said locking means selectively toward locked or unlocked position.

5. A look including in combination a mechanism housing designed to overlie a surface of a door, said housing having a number of apertures therein, a rotatable shank extending through an aligned pair of said apertures in said mechanism. housing normal to said surface of the door, a lever projecting through another of said apertures in said mechanism housing and designed to extend into an opening in the door in spaced relation to the shank, associated leverage means in said housing cooperable with said shank and said lever to pivot said lever upon rotative movement of said shank, and latch means operatively connected to said lever externally of said mechanism housing.

6. The structure of claim 5 including with said latch means, a latch bolt slidable on a plane parallel to the surface of the door and latch engaging means on said lever cooperable with said latch bolt to accommodate the same.

7. A door latch including in combination a mechanism housing designed to overlie the surface of a door, a shank rotatably supported by said mechanism housing and designed to extend through an opening in the door normal to the surface thereof, a slide within said mechanism housing, cooperable means on said shank engageable with said slide to slide the same upon rotation of said shank, and lever means mounted in said housing and projecting therefrom into an opening in said door, latch bolt means mounted on said door externally of said mechanism housing and arranged to move on an axis parallel to said surface of the door cooperably connected with said lever for actuation thereby, and fulcrum means at one end of said lever, said slide engaging said lever within said housing mechanism intermediate said fulcrum means and said latch bolt.

8. A door latch including in combination a mechanism housing designed to overlie the surface of a door, a shank rotatably supported by said mechanism housing and designed to extend through an opening in the door normal to the surface thereof, a slide within said mechanism housing, cooperable means on said shank engageable with said slide to slide the same upon rotation of said shank, said slide including a flange against which said cooperable means on said shank may engage to move said slide, lever means mounted in said housing and projecting therefrom into an opening in said door, and latch bolt means mounted on said door externally of said mechanism housing and arranged to move on an axis parallel to said surface of the door cooperably connected with said lever for actuation thereby.

9. A door latch including in combination a mechanism housing designed to overlie the surface of a door, a shank rotatably supported by said mechanism housing and desi ned to extend through an opening in the door normal to the surface thereof, a slide within said mechanism housing, cooperable means on said shank engageable with said slide to slide the same upon rotation of said shank, said slide including a flange, and a cooperable means on said shank and slide including a cam engageable with said flange to move said slide upon rotation of said shank, lever means mounted in said housing and projecting therefrom to an opening in said door, and latch bolt means mounted on said door externally of said mechanism housing and arranged to move on an axis parallel to said surface of the door cooperably connected with said lever for actuation thereby.

10. A door latch including in combination a mechanism housing designed to overlie the surface of a door, a shank rotatably supported by said mechanism housing and designed to extend through an opening in the door normal to the surface thereof, a slide within said mechanism housing, cooperable means on said shank engageable with said slide to slide the same upon rotation of said shank, lever means mounted in said housing and projecting therefrom into an opening in said door, said slide being provided with an aperture therethrough through which said lever extends, latch bolt means mounted on said door externally of said mechanism housing and arranged to move on an axis parallel to said surface of the door cooperably connected with said lever for actuation thereby.

11. A door latch including in combination a mechanism housing designed to overlie the surface of a door, a shank rotatably supported by said mechanism housing and designed to extend through an opening in the door normal to the surface thereof, a slide within said mechanism housing, cooperable means on said shank engageable with said slide to slide the same upon rotation of said shank, spring means for urging said slide in one direction, lever means mounted in said housing and projecting therefrom into an opening in said door and latch bolt means mounted on said door externally of said mechanism housing and arranged to move on an axis parallel to said surface of the door cooperably connected with said lever for actuation thereby.

References Cited in the file of this patent UNITED STATES PATENTS 991,018 Powers May 2, 1911 1,473,378 Moore Nov. 6, 1923 2,401,559 Falk June 4, 1946