US2676480A

US2676480A - Night latch

Info

Publication number: US2676480A
Application number: US276600A
Authority: US
Inventors: Mathias M Check
Original assignee: Yale and Towne Manufacturing Co
Current assignee: Yale and Towne Manufacturing Co
Priority date: 1952-03-14
Filing date: 1952-03-14
Publication date: 1954-04-27
Anticipated expiration: 1971-04-27

Description

M. M. CHECK Apr-H 27, 1954 NIGHT LAME 2 Sheets-Sheet 1 Filed March 14, 1952 INVENTOR w- 4 BY ATTORNEY April 27, 1954 M. M. CHECK 2,676,480 NIGHT LATCH File d March 14, 1952 2 Sheets-Sheet 2 l VEN OR 'oRNEY Patented Apr. 27, 1954 UNITED STATE OFFICE NIGHT LATCH Connecticut Application March 14, 1952, Serial N 0. 276,600

7 Claims.

This invention relates to a night latch in which a spring pressed latchbolt is adapted to interlock with a strike when an attempt is made to jimmy the bolt. A night latch of this general class is shown in the Spain Patent No. 2,350,306, and my invention has as its object to provide a night latch of this type that will have certain improved operating characteristics and that can be made available at a low cost.

As one feature of my invention, I utilize for my latchbolt a novel unitary sheet metal construction that, because of its particular distribution of material, is easily formed and can be depended upon to accept the forces to which it is subjected. In this construction, the flat portion of the latchbolt that coacts with the strike is formed as a continuation of the plane of the latchbolt, and has at its upper and lower edges flanges that extend at right angles to the flat portion. These flanges continue along the edges of the latchbolt away from the head of the latch bolt and diverge so that the part of the bolt that extends away from the head is considerably wider than the head. Preferably, the flanges are formed with further flanges that are parallel to the plane of the latchbolt and that extend away from each other, thereby providing a construction that is simple to manufacture and imports great strength to the latchbolt.

As a further feature of the invention, I form that part of the latchbolt that coacts with a retracting cam as a flange that is turned laterally from the plane of the latchbolt. Through this arrangement, the retracting cam may be situated to engage the latchbolt approximately upon its longitudinal axis, and when two cams are provided in side by side relation so as to enable operation of the lock from either the inside or the outside of the door, the action of both cams will still be close to the axis of the bolt. As a further part of this feature, I utilize a single relatively short latchbolt spring that presses against the rear face of the retracting flange at a central location that is preferably upon the axis of the bolt. Directly opposite this spring in the flange is a depression whereby one of the cams may latch the bolt in retracted position.

As another feature of the invention, I form the locking dog that is pivoted on the latchbolt so that, when the dog is at the point of entering the strike, substantially the entire front edge of the dog will be in camming engagement with the strike. In the patent above referred to, this camming is accomplished solely through the action of inclined side flanges of the dog. Now,

however, I secure the camming action by bevelling the edge of the strike, this bevelled portion being arranged to coact with the front edge of the face of the dog. This makes it possible to use a very narrow interlocking head on the strike rather than the relatively wide bead of the prior art, and contributes better and more extended interlooking.

I have thus outlined rather broadly the more important features of my invention in order that the detailed description thereof that follows may be better understood, and in order that my contribution to the art may be better appreciated. There are, of course, additional features of my invention that will be described hereinafter and which will form the subject of the claims appended hereto. Those skilled in the art will appreciate that the conception on which my disclosure is based may readily be utilized as a basis for the designing of other structures for carrying out the several purposes of my invention. It is important, therefore, that the claims be regarded as including such equivalent constructions as do not depart from the spirit and scope of my invent, in order to prevent the appropriation of my invention by those skilled in the art.

Referring now to the drawings, Fig. 1 is a sectional plan view showing a preferred form of my invention taken on line l! of Fig. 2. Fig. 2 is a longitudinal sectional view taken on the line 2-2 of Fig. 1. Fig. 3 is a view similar to a portion of Fig. 1, but showing the dog as it would appear when pressed into interlocking position by a jimmying tool. Fig. 4 is a crosssectional view taken on the line 4- of Fig. 1. Fig. 5 is an exploded view showing my novel sheet metal latchbolt and its associated dog and pivot pin.

Referring now more particularly to the drawings, a latchbolt ii! slides in a casing ll so as to coact with a strike 12, and the retracting movement of the latchbolt may be accomplished either from the inside of the door through a knob I3 having a cam it, or from the outside of the door through a key operated lock having a cam i6.

Latchbolt H3 is an integral sheet metal stamping having a main body portion that I have designated by the numeral It. This body portion is flat and conforms to a plane that I shall term in this application the plane of the latchbolt. The body portion it may be channeled for purposes of stiffness, as I have indicated at it, although this formation is not essential. In order to coact with the strike 12, the forward end of the latchbolt it has a relatively narrow fiat portion 20 that is a continuation of the body portion l8, and that forms a part of the head of the latchbolt. At the upper and lower edges of the flat portion 2?! a pair of spaced flanges 2! are bent at right angles to the plane of the latchbolt so that the head of the bolt is U-shaped in cross section. The edges of the flat portion l8 diverge rearwardly away from the head of the bolt, and the flanges 2| are continued along these edges so that they are also divergent and impart great rigidity to the head of the latchbolt. The spaced flanges 2! in turn have a pair of flanges 22 extending away from each other in a plane parallel to the plane of the latchbolt. These flanges 22 extend along a part of the flanges 2| of the relatively narrow latchbolt head and also along the diverging parts of the flanges 2!, so as to accept forces that result from pressure of the head portion 20 against the strike.

A dog ll overlies the head of the latchbolt l9 and includes a pair of side flanges 23 that extend outside the latchbolt flanges 2i and are pivoted thereto by a pivot pin 24. The pivot pin 24 is so located in the flanges 2i as to be disposed a considerable distance inwardly of the casing i i when the latchbolt is in its projected position, and the flanges 2! are so formed as to allow a certain movement of the dog i"! about the pin 2d, this arrangement being important for reasons that will appear.

The forward face of the dog II is designated by reference numeral 25 and is inclined so that the strike through face 25 will earn the latchbolt i8 towards its retracted position during closing movement of the door, as will be understood by those acquainted with the art. On the dog I! is a detent portion 26 that is adapted to interlock with an inner lip 2'! or bead on the strike :2 whereby to prevent retraction of the latchbolt it. As will be understood, this interlocking action is normally avoided through the action of a spring 28 that presses the dog about its pivot to the position shown in Fig. 1. When an attempt is made to jimmy the look through the camming action of a tool T against the dog, as is indicated in Fig. 3, the spring 28 will yield to the inward pressure of the tool '1, and the dog I? will swing so as to place the detent portion 26 behind the lip or bead 21 of the strike, thereby preventing retraction of the latchbolt l0.

It will be observed that in the closing of a door carrying my night latch, the detent portion 26 of the dog I! will hit the outer edge of the strike, and that since the spring 28 holds the dog il in its normal non-dogging position'with but relatively light pressure, the strike will move the dog ll to its dogging position in which it will be incapable of entering the strike. In order that the dog ll shall enter the strike easily, I therefore form the lip or bead 2? of the strike with an outer bevelled surface 29 that earns the dog to its normal non-dogging position for the particular purpose. Because of this construction, the bead 2'! may be made quite narrow, thereby setting up a considerable space for the action of the dog, this space being much greater than in the Spain patent to which I have alluded.

The novel construction of my sheet metal latchbolt it also provides an improved relationship between the latchbolt and the cams I4 and I6 through which it is retracted. The rear end portion of the latchbolt is turned laterally so as to form a retractor flange 30 rearwardly of the cams M, 6 at one side of the plane of the latchbolt. The cams M and is are mounted relatively close to each other in such a way as to engage along central portions of the retractor flange 3G and, because of this arrangement, the retracting force that is applied by the cams is substantially aligned with the longitudinal axis of the head of the bolt. The latchbolt spring that I utilize is a relatively short coil spring of large diameter engaged between the retractor flange S8 and the rear end of the casing I I. Because this latchbolt spring 3| is so located as to press against a central part of the retractor flange 3B, the force of the spring also will be along the longitudinal of the latchbolt.

The central portion of the retractor flange 353 I form with a depression 32 that is adapted to receive the ends of the cams l4, l5 so as to latch the latchbolt [0 in its retracted position. Thus, if one of the cams [4, i6 is turned clockwise in Fig. 2 far enough to bring one end into the depression 32, the parts will mutually hold each other in this position through the pressure of the spring 3| and. the dead center relation of the parts. On the other hand, counterclockwise rotation of cams l4, I6 is limited by lug 33 to a degree preventing the cams from holding the latchbolt retracted.

Having thus described my invention, I believe that the operation and the advantages of my novel latch construction will now be apparent.

I new claim:

1. In a lock of the class described, a unitary sheet metal latchbolt having its rear end turned from the plane of said latchbolt whereby to form a retractor flange, a strike, a head at the front end of said latchbolt having a flat portion integral with said latchbolt whereby said latchbolt coacts with said strike, a pair of spaced flanges forming part of said head and tapering relatively to each other on said latchbolt whereby to accept forces incidental to the coaction of said head with said strike, a dog having a face overlying parts of said spaced flanges for camming said latchbolt through engagement with said strike, flanges on said dog, a pivot pin extending transversely through said flanges of said dog and said spaced flanges in said latchbolt head whereby said dog is adapted for pivotal movement relatively to said latchbolt, a detent portion on said dog adapted to interlock with said strike when said dog is moved about said pivot pin relatively to said sheet metal latchbolt as by pressure of a jimmying tool against said face of said dog, and means for pressing said dog whereby to move its detent portion out of interlocking relation to the strike.

2. In a lock of the class described, a unitary sheet metal latchbolt, a strike, a relatively narrow head at the front end or" said latchbolt having a flat portion integral with said latchbolt whereby said latchbolt coacts with said strike, a pair of spaced flanges on said latchbolt forming part of said head and diverging from said head rearwardly of said latchbolt, flanges extending outwardly from said spaced flanges parallel to the plane of said latchbolt and coacting with said spaced flanges whereby to accept forces incidental to the coaction of said head with said strike, a, dog having a face overlying parts of said spaced flanges for camming said latchbolt through engagement with said strike, flanges on said dog, a pivot pin extending transversely through said flanges of said dog and said spaced flanges of said latchbolt head whereby said dog is adapted for pivotal movement relatively to said latchbolt, a detent portion on said dog adapted to interlock with said strike when said dog is moved about said pivot pin relatively to said sheet metal latchbolt as by pressure of a jimmying tool against said face of said dog, and means for pressing said dog whereby to move its detent portion out of interlocking relation to the strike.

3. In a lock of the class described, a unitary sheet metal latchbolt having its rear end turned to one side of the plane of said latch bolt whereby to form a retractor flange, a strike, a spring pressing said latchbolt to projected position, a head at the front end of said latchbolt having a flat portion integral with said latchbolt and coacting with said strike when said latchbolt is in projected position, a pair of spaced flanges forming part of said latchbolt head and tapering relatively to each other on said latchbolt from said head whereby to accept forces incidental to the coaction of said head with said strike, a dog having a face overlying parts of said spaced flanges for camming said latchbolt against the pressure of said spring through engagement with said strike, flanges on said dog, a pivot pin extending transversely through said flanges on said dog and said spaced flanges of said latchbolt head Whereby said dog is adapted for pivotal movement relatively to said latchbolt, a detent portion on said dog adapted to interlock with said strike when said dog is moved about said pivot pin relatively to said sheet metal latchbolt as by pressure of a jimmying tool against said face of said dog, and means for pressing said dog whereby to move its detent portion out of interlocking relation to the strike, a pair of cams for engaging the forward face of said retractor flange whereby to retract said latchbolt from said strike through movement of either of said cams selectively when said detent portion is free from interlocking engagement with said strike, and a depression in said retractor flange for receiving said cams whereby to latch said latchbolt in retracted position against the force of said spring.

4. In a lock of the class described, a unitary sheet metal latchbolt having its rear end turned from the plane of said latchbolt whereby to form a retractor flange, a relatively short coil spring of large diameter pressing centrally against the rear face of said retractor flange, a strike, a head at the front end of said latchbolt having a flat portion integral with said latchbolt and entering said strike through pressure of said spring to coact with said strike, a pair of spaced flanges forming part of said head and tapering relatively to each other on said latchbolt from said head rearwardly of said latchbolt whereby to accept forces incidental to the coaction of said head with said strike, a dog having a face overlying parts of said spaced flanges for camming said latchbolt against the force of said spring through engagement with said strike, flanges on said dog, a pivot pin extending transversely through said flanges of said dog and said spaced flanges of said latchbolt head whereby said dog is adapted for pivotal movement relatively to said latchbolt, a detent portion on said dog adapted to interlock with said strike when said dog is moved about said pivot pin relatively to said sheet metal latchbolt as by pressure of a jimmying tool against said face of said dog, and means for pressing said dog whereby to move its detent portion out of interlocking relation to the strike, a cam for engaging said retractor flange whereby to retract said latchbolt from said strike when said detent portion is free from interlooking with said strike, and a depression formed opposite said coil spring in the front face of said retractor flange for receiving said cam to latch said latchbolt in retracted position.

5. In a lock of the class described, a unitary sheet metal latchbolt having its rear end turned from the plane of said latchbolt whereby to form a retractor flange, a strike, a relatively narrow head at the front end of said latchbolt having a flat portion integral with said latchbolt whereby said latchbolt coacts with said strike, a pair of spaced flanges on said latchbolt forming part of said head and diverging from said head rearwardly of said latchbolt whereby to accept forces incidental to the coaction of said head with said strike, a dog having a face overlying parts of said flanges for camming said latchbolt to retracted position through engagement with said strike, flanges on said dog, a pivot pin extending transversely through said flanges of said dog and said spaced flanges in said latchbolt head whereby said dog is adapted for pivotal movement relatively to said latchbolt, a bevelled portion of said strike engaging the edge of said face of said dog and rotating said dog about said pivot pin through camrning action when said head enters said strike, a detent portion on the edge of said face of said dog adapted to interlock with said strike when said dog is moved about said pivot pin relatively to said sheet metal latchbolt as by pressure of a jimmying tool against said face when said head is in said strike, and means for pressing said dog whereby to move its detent portion out of interlocking relation to the strike.

6. In a lock of the class described, a unitary sheet metal latchbolt having its rear end turned to one side to the plane of said latchbolt whereby to form a retractor flange, a relatively short coil spring of large diameter pressing centrally against the rear face of said retractor flange whereby to move said latchbolt to projected position, a strike, a relatively narrow head at the front end of said latchbolt having a flat portion integral with said latchbolt and coacting with said strike when said latchbolt is in projected position, a pair of spaced flanges on said latchbolt forming part of said head and diverging from said head rearwardly of said latchbolt, a pair of flanges extending outwardly from said spaced flanges parallel to the plane of said latchbolt and coacting with said spaced flanges whereby to accept forces incidental to the coaction of said head with said strike, a dog having a face overlying parts of said spaced flanges for camming said latchbolt to retracted position against the force of said spring through engagement with said strike, flanges on said dog, a pivot pin extending transversely through said flanges of said dog and said spaced flanges of said latchbolt head whereby said dog is adapted for pivotal movement relatively to said latchbolt, a detent portion on said dog adapted to interlock with said strike when said dog is moved about said pivot pin relatively to said sheet metal latchbolt as by pressure of a jimmying tool against said face of said dog, and means for pressing said dog whereby to move its detent portion out of interlocking relation to the strike, a pair of cams for engaging the front face of said retraotor flange whereby to retract said latchbolt head from said strike through movement of either of said cams selectively when said detent portion is free from interlocking engagement with said strike, and a depression formed opposite said spring in the front face of said retractor flange for receiving one of said cams whereby to latch said latchbolt in retracted position.

7. In a lock of the class described, a unitary sheet metal latch bolt having a body portion, a

part of said body portion at the rear end of said latch bolt turned transversely whereby to form a retractor flange, a head at the front end of said latch bolt having a flat portion for coacting with a strike, said body portion tapering from said head outwardly toward the rear of the latch bolt, a pair of spaced flanges integral with said fiat portion of said head and the said tapering portion of the latch bolt, and flanges extending from said spaced flanges parallel to the plane of the latch bolt along a part of said head and the tapering portions of the latch bolt whereby to coact with the spaced flanges for accepting forces incidental to the coaction of the latch bolt head with a strike.

References Cited in the file of this patent Number UNITED STATES PATENTS