US2242385A - Latch - Google Patents

Description

May 20, 1941. K. BEYRODT 2,242,385

LATCH Filed Jan; 28, 1939 Z SheetS-Sheet 2 fig. 1]

. mfg w KURT 5524200? Patented May 2c, 1941 4 Claims.

The present invention relates to latches and more particularly to a latch for doors or other type closures.

An aim of the present invention is the provision of a latch which is particularly suitable for use on the closures of devices wherein a fluid or gas seal must be maintained or is highly desirable, such as in refrigerators Or as in the toilet seat sterilizer disclosed in Patent No. 1,877,689 to R. E. Peterson, and also on devices wherein there is a tendency of the closure to rattle or unlatch due to vibration, as, for example, in automobile doors.

An object of the invention is the provision of a latch for such use, which latch, upon being released, is self-closing and maintains a constant tension, tending to urge the closure to closed position.

A still further object is a latch having a bolt which is normally urged to closed position and wherein means are provided, upon the bolt being retracted, to automatically hold it in retracted position, and thus no parts project beyond the edge of the closure.

A still further object is a latch having switch means associated therewith, which means are operable upon movement of the bolt towards open and closed. position.

A still further object is a latch of this type having a minimum number of parts, which latch may be readily manufactured and is adapted to a wide variety of uses.

Other objects will be in part obvious and in part pointed out more in detail hereinafter.

The invention accordingly consists in the features of construction, combination of elements, and arrangement of parts which will be exemplified in the construction hereafter set forth and the scope of the application of which will be indicated in the appended claims.

In the accompanying drawings:

. Figure 1 is a front View of the latch as seen when mounted on a closure;

Fig. 2 is a side view partly in section showing the latch in latching position and. wherein a cam follower is associated with the bolt drawback;

Fig. 3 is a side sectional View showing the latch in retracted position and moving towards closed position;

Fig. 4 is an end view of retracted position;

Fig. 5 is a perspective fragmentary view showing the details of the bolt;

Fig. 6 is a front view of the cooperating latch the latch as seen in striker plate;

Fig. 7 is a perspective view of the plate shown in Fig. 6;

Fig. 8 is a rear view of the latch showing the cooperating switch means; v

Fig. 9 is a side view partly in section of another modification of the latch shown in its latching position;

Fig. l0 is a sectional view of the latch shown in Fig. 9 with the bolt in retracted position;

Fig. 11 is a front view of the latch shown in Figs. 9 and 10 with part of the casing removed;

Fig. 12 is an end view of the latch shown in Fig. 11;

Fig. 13 is a perspective ,view showing the details of the bolt and cooperating holding means therefor; and

Fig. 14 is a perspective view of a modified form of striker.

Referring to the drawings, and more particularly to Figs. 1 .to 8, the latch A is shown mounted on a surface B which may be a door hinged to swing into and out of engagement with adoor jamb C carrying a cooperating striker plate D; the latch and striker being equally efficient and operative if mounted on the opposite members.

The latch A comprises a casing having a front wall 20, side walls 22, a rear wall 24, and an end wall 26. As indicated, the rear, side, and

end walls may be stamped from a single piece of metal, and the side walls may be provided with outwardly projecting flanges 25 adapted to be spot welded to the front wall 20 to provide a substantially rectangular bolt casing adapted to be securedto a door or the like by suitable screws 32 extending through aligned openings in the front wall 20 and side flanges 25. The front wall 20 may also be provided with inwardly extending lugs 33 adapted to extend behind the end wall 26 to position and reinforce same.

The bolt housing or casing has positioned therein a latching bolt 34 comprising a rectangular body portion 35 and a latching pawl 3'! having one end pivotally connected to the body portion and its other end free to swing in the arc of a circle. The bolt body portion 35 comprises a one-piece rectangular member having a longitudinally extending bore 36 open at its inner end thereof and in which there is positioned a spring 38 which, bearing against the forward wall 35 of the bore and against the end wall 26 of the casing, normally urges the bolt outwardly to latching position. In order to withdraw the bolt, there may be provided an operating member 40 secured in the bolt and projecting from the casing through an elongated slot 42 in the front plate 20, as shown in Figs. 1, 3, and 4, or as shown in Fig. 2, a cam follower 44 may be utilized if the latch is to be mechanically operated.

The outer end of the body portion 34 carries two forwardly extending arm or wing members 46 having substantially the shape of a right angle triangle, with the smaller leg thereof adjacent the front wall 20 of the latch casing. The wing members 45 are provided at the apex with aligned apertures 48 adapted to receive a transverse pin 50 to provide a support for the latching or bolt pawl 31.

The pawl 31 comprises a substantially U- shaped member having a base 53 and two forwardly extending spaced parallel arms 54. The base 53 is provided with a transverse bore adapted to receive the transverse pawl supporting pin-- 50 and thus pivotally mount the pawl 31 on the end or wing member 46 of the bolt body 35. The two forwardly extending parallel arms 54 are also provided with aligned apertures Bit-arranged on the center line 51 of the pawl arms and adapted to receive a pin 58 having-rotatably mounted thereon intermediate of the arms a latching pawl roller 50. As best seen in Fig. 5, the ends of the pin 58 extend to either side of the arms 54 and serve to properly position the pawl and roller when the bolt has been retracted, as hereinafter described.

In the present invention, the bolt not only latches the door in closed position, but is selfholding within its casing when in retracted position, whereby no parts project from the edges of the closure when it is in open position. This 3 is accomplished by providing the pawl 3! with means for normally pivoting the free end thereof about the pin 50; said means comprising a spring 62 and having one end 64 abutting the forward end of the latch bolt and its other end 65 hooked over the upper surface of one of the latch'arms 54. The spring is coiled about pin 50 in a direction to normally pivot the pawl against rear wall 24 and position it behind suitable retaining means 10 carried thereon.

In the embodiment illustrated, the retainer 10 1 comprises a cross bar defining the forward edge of a rectangular opening 58 provided in wall 24 and having a width slightly greater than the width of the latching pawl but less than that of the pawl positioning pin 58. Thus when the latch bolt is drawn rearwardly, the spring 62 will automatically rotate the pawl to urge the pawl roller 60 into-the opening 68 behind the retainthat the releasing plate thereof will lie parallel to the front plate 20 of the latch casing when the closure has been moved to its closed position. There is mounted on the plate 14 a releasing lug 19 adapted to project into plate opening 68 and abut one of the arms 54 of latching pawl 31 and lift the free end thereof from behind retainer 70.

The amount of force necessary to release the pawl 31 from behind the retainer 10 is relatively small inasmuch as it is merely necessary to raise the pawl sufficiently to raise the forward end of a center line 5'! extending through the center of pins and 58 (see Fig. 3) above the upper edge H of the retainer; it being apparent that by changing the line of centers of the two pins relative to the retainer 10 the amount of force necessary may be increased or decreased.

As the bolt is urged forwardly by the spring 38, the pawl roller will engage the centrally arranged cam seat 18 of the plate 16 and, due

tothe forward motion ofthe latching bolt, be guided thereby into the retaining seat 82 with the free end of the pawl pivoting about thepin 50 as a center.' The retaining seat is so located "that when the roller 60- is seated therein, the

centerthereofwill be in a plane above the center of the pin 50; whereupon a toggle action results with both pin 50 and pin 58 acting as pivot centers. With the toggle created, the tendency of the body portion of the bolt will be .to continue to move forwardly in the direction of the arrow, as seen in Fig. 2, and carry the pin 50 towards vertical alignment with the pin 58. A continuous force is thus exerted .by the bolt against the striker plate seat 82; maintaining a continuous self-closing action, constantly urging the door ing cross member 10, with the pivot centerthereof beneath that of the pin 50 and the center line through the pivots intersecting retainer 10 beneath the upper edge 1 I.

The pawl roller 60 is prevented from passing completely through the opening 68 by the ex-' tending ends of positioningpin 58 which rest on the flanges 13 which define the side edges of the opening 68, and thus the bolt is restrained in retracted position against the normal tendency of spring 38 to urge it to its latching position.

There is further provided a strike plate D adapted, when the latch moves'to latching position, to cooperate therewith, whereupon the latch will exert and maintain-a constant tension tending to move the door towards closed position at all times after the latch has-zbeen released. To accomplish this, the strike plate D comprises a releasing plate 14 and a cam carrying plate 16 arranged at right angles to-the releasing plate. i The strike plate is so-mounted towards closed position, and likewise preventing any rattling thereof.

The construction shown in the foregoing figures' is particularly advantageous in structures wherein a gasor liquid-tight seal is essential. It has been found to be highly emcient and effective when used in closing and maintaining closed the sterilizer compartment doors 54 of the toilet seat sterilizer shown in the above-mentioned patent to Peterson No'.-1,87'7,689. When so used the spring member 38 is heavily loaded and mechanically operable cam means are providedfor withdrawing the bolt, and the latch is also so positioned that it cannot be accidentally released. 7

When used in conjunction with said patent, it is also desirable to provide switch means actuated by the bolt to open and. close a suitable safety circuit. As-bes't seen in Fig. 8, the switch arms may be mountedbetween suitable insulating blocks 8| mounted-on one of the side plates 22. The switch comprises a lower spring contact carrying arm 83 having a normal tendency to spring downwardly .and'adapted to be urged upwardly into engagement with a second contact carrying. arm 84. The arm 84 likewise has a normal .tendency to move downwardly, but is maintained in upper position by a suitable holding leaf 86. The arm 83 is controlledby a ball 88 positioned in an opening 92 in the sidewall of the casing and adapted, when the bolt is in retracted position, to drop into a suitable conical recess 90 provided therein. As is apparent; when the bolt is urged forwardly the ball will roll up onto the flat side surface of the bolt, carrying spring action of the contact arms 83 and 84. Due to the rapid action of the bolt, a fast make and break of the contact results, making the switch particularly suitable for many uses.

There is shown in Figs. 9 to 13 an embodiment which is particularly suitable for use such as on refrigerators or the like. As in the first embodiment, there is provided a casing having a front plate 94, a rear plate 96,'side channel members 98, and an end wall 99. The plates may be metal stampings or extruded shapes and, when assembled, secured as by spot welding to provide a rectangular casing for receiving the bolt I00. The bolt I may likewise be stamped and bent or cut from extruded stock to provide a rectangular open-ended body portion It provided with forwardly extending wing members I02 on which there is pivotally mounted a latching pawl I 04, as in the prior embodiment.

For retaining the spring I06 within the bolt, there is provided a suitable U-shaped member I08 positioned within the bolt with the base I09 thereof closing the forward end of the bolt body portion NH. The legs of member I08 may have outwardly projecting lugs IIO positioned within suitable recesses I I2 in the rear side edges of the bolt body portion IOI to further assist in positioning same.

Inasmuch as the embodiment illustrated is intended for use such as on household refrigerators, the rear plate 96 thereof has a relatively small opening II3 cut therein, and the forward cross bar is stamped upwardly to provide a pair of spaced apart latch retainers I I4.

With this construction, the pawl roller, when in retracted position, is held above the plane of the rear plate and, therefore, cannot be released by accidentally striking it or intentionally pushing it out with a finger. In order to release the pawl I04, the cam member II6 of the striker is provided with a forwardly extending portion II8 adapted to enter between the retaining members I I4 and engage the pawl roller just prior to the time that the closure reaches closed position, whereupon the retainers will move away from the roll and thus release the bolt.

As the pawl has come in contact with the striker plate cam while the relative velocity between the pawl roller and the striker plate issmall or practically zero, the pawl roller will continue to ride along the cam until it is positioned in the cam seat I05. Thus no contact between the metal parts is established while the relative motion between them is of a high degree and the latch for all practical purposes is silent in its operation.

It will also be noted that the pawl I04 is made substantially longer than in the prior embodiment, thus giving a greater toggle action after the latching pawl has become seated, permitting the use of a relatively light spring, which is desirable when the latch is to be manually operated.

There is also provided a handle member I20 mounted on the outer end of a shaft I22 suitably pivoted in the front and rear plates 9d and 96. Extending from the inner end of the shaft is rollback I24 having its inner end positioned in a suitable slot provided therefor in the rear wall I26 of the bolt body portion IOI. As best seen in Fig. 11, the inner end of shaft I22 is provided with a pin I2I positioned within an angular slot I23 in rollback I24 to provide an angular lost motion therebetween equal to the angular motion of the handle. Mounted on the shaft is a disturbed.

spring I25 having one end secured in the front plate 94 and the other secured to the shaft and so coiled as to normally tend to rotate the handle I20 in a counterclockwise position, as seen in Fig. 11. As in previous embodiments, a suitable switch might be mounted thereon; it being com.- mon practice in domestic refrigerators to have a light operated upon the opening of the door, and the switch could readily be utilized for the control of said light.

Thus when the bolt is in retracted position, the pin IZI will be positioned against the forward shoulder I230. of the slot I23, andupon the release of the latch the rollback will move relative to the shaft and the handle I20 will not be In latching position, the shoulder 2312 will be adjacent the pin I2I, where, upon rotation of the handle, the bolt will be retracted, and, upon releasing of the handle, the spring I25 will return the handle to the normal position shown in Fig. 11.

There is shown in Fig. 14 a modified striker plate comprising a cam I28 made of a. suitable resilient material bent to provide a latching seat I30 spaced downwardly from the upper rigid wall member I3I by a rearwardly and upwardly extending tongue I32. The tongue I32 tenninates in a T I34 slidably positioned in a suitable recess I36 in the rigid wall member I3. Positioned forwardly of the recess is an adjustment screw I38 vertically arranged in the rigid wall member I3I and adapted to engage the tongue I32 above the latch-receiving seat I30. The screw I38 permits the seat to be adjusted in a plane perpendicular to that of theclosure, whereby a maximum sealing tension between the closure and jamb may be obtained. Due also to the natural resiliency of the striker, the noise of closing may be greatly reduced, and likewise when the latching pawl is positioned in the seat I30 and tends to force the tongue I32 upwardly, there is a natural tendency of the cam to act against the pawl, thus increasing the tension for maintaining the door in closed position.

As many changes could be made in the above construction and many apparently widely different embodiments of this invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

It is also to be understood that the language used in the following claims is intended to cover all of the generic and specific features of the invention herein described and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.

I claim as my invention:

1. In a latch of the character described, a casing, a bolt positioned in said casing, a pivoted latching pawl carried by the bolt, a light spring normally urging said latching pawl in one direction, heavy spring means normally urging said bolt and pawl to latching position, a keeper against which said latching pawl is adapted to strike, said keeper including a cam terminating in a seat located above the pivot of said latching pawl, said heavy spring means for urging said bolt forwardly being of sufficient strength to pivotally carried by said bolt, and spring means normally urging said bolt in one direction, a keeper against which said pawl is adapted to strike, and second spring means normally urging said bolt to latching position and of such strength that it will overcome said first spring means and causesaid latching pawl to pivot on said strike into latching position.

4. In a latch of the character described, a casing, a bolt slidablypositioned in said casing, spring means normally urging said bolt to latching position, bolt retaining means within said casing, a latching pawl pivoted to said bolt, spring means normally urging said pawl in a direction to engage behind said retainer means and maintain said bolt and pawl in retracted position, a keeper-against which said pawl is adapted to strike, said keeper including a cam and a latching seat positioned above the pivot of said latching pawl, means carried by said keeper for urging said pawl from behind said retaining means, whereby said bolt springmeans will urge said pawl into engagement with said keeper and pivot it into said seat to establish a toggle link under constant spring pressure.

KURT BEYRODT.

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