US2546333A - Refrigerator door latch - Google Patents

Description

G. E. CURTISS, JR

REFRIGERATOR DOOR LATCH March 27, 1951 Filed May 25, 1948 2 Sheds-Sheet l ma; z.

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March 27, 1951 G. E. cUR-rlss, JR 2,546,333

A REFRIGERATOR DOOR LATCH Filed May 25, 1948 '2 Sheets-Sheet 2 F/cf. 5.

INVENTOR.

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Patented Mar. 27, 1951 UNITED STATES PATENT OFFICE REFRIGERATOR DOCR LATCH Application May 25, 1948, Serial N o. 28,987

This invention relates to latches of the type commonly used on refrigerator doors.

More particularly, the invention relates to an improved latch of the general type disclosed in my Patent No. 2,445,709, issued July 20, 1948, that is, a latch mechanism in which a progressively increasing latching force is exerted by the bolt as it approaches itsfully latched position, with the maximum available force being applied vat the time when the bolt member is fully the door is still open. When in the latter position, andthe door is swung to closed position, one of the particular advantages of the mechanism, is that the bolt is first urged into a retracted position from which it then moves into latching engagement with said keeper. Thus, the bolt will move into latching engagement with the keeper i whether the latch is in retracted or in advanced position, when the door is swung from open to closed position.

Inthe aforesaid latching mechanism it has been found necessary, when, they uncooked bolt isv moved toward latching engagement with the keeper, to overcome a, restraining force exerted by certain parts of the mechanism; This force*- was overcome by applying a greater force to the door when closing it. In general, it, was highly desirable to solve this problem in such a way as to reduce, insofar as possible, the force required to close the door under the abnormal condition above-noted and, in seeking such a solution, the present invention was conceived.

The invention has, therefore, as its primary object, theprovision of an improved latch mechanism of the` aforesaid' type.

More particularly, it is an object of the invention to provide a. latch mechanism characterized by itsV relative ease ofI operation and its prompt actuationto fully latched position, regardless of` the position of the, boltl when the. door is swung closed',

, These and other objects of the invention, hereV 4 Claims. (Cl. 292-332) inafter appearing, will be more readily understood by reference to the several views of the accompanying drawings, in which:

Figure 1 is a perspective View of a refrigerator embodying the present invention;

Figure 2 is a sectional view, on an enlarged scala, taken along the plane indicated by line 2 2, of Figure l, the latch mechanism being shown in its fully latched position; l

Figure 3 is a view similar to Figure 2, but on a smaller scale, and showing the mechanism in its normal unlatched and retracted condition, that is, with the bolt cocked, the door being shown in a position just prior to reaching its fully closed and latched condition;

Figure 4 is a view essentially similar to Figure 3, but illustrating the bolt in its uncooked position; and

Figure 5- is a sectional view on an enlarged scale, taken along the plan indicated by line 5-5 of Figure 1, the latch mechanism being shown in fully latched position.

Referring now to the drawings and more particularly to Figures 1 and 2, the numeral I0 designates a refrigerator comprising a cabinet II having a door I2. As seen in Figures 2 and 5 the door comprises an inner panel I3 and an outer panel I4 joined about their peripheries at I5 (Figure 5) as by screws Il, which serve also to fasten the customary resilient sealing gasket I3 to the door, at that juncture. Gasket I8 is adapted to impinge against the door jamb I9 of the cabinet and thereby provide an airtight seal between the door andA cabinet, when the door is closed. Mounted adjustably on the door jamb (Figure 2.) is a keeper which is provided with a strike having a cam face 23, the purpose of which will be explained hereinafter.

As more clearly shown in Figure 5 of the drawings, the latch includes a support or housing 24 having a bottom wall 25 and a pair of parallel side walls 26V and 2l. The inner end of sidev Wall 26 is provided with a flange 28 through the agency of which the housing is secured to juno-- ture I5 of the. inner and outer door panels, as`

secured by screws 29 to theperipheral flangel 30 of a support. member 3| welded, or otherwise suitablyV attached, to the outer door panel I4. Wthreference. to Figure 2, it is seen that a portion ofwall ZSeXtendsupwardlybeyond flange:

30 of member`3l. This extension is provided with inwardly turned ear portions 36 in which the ends of a pivot pin 31 are fixed. Pin 31 extends through a slot 38 in an elongated latch bolt 39, which latter is adapted for movement about said pin into and out of latching engagement with keeper 20 as hereinafter described.

Latch bolt 39 comprises a depending arm portion 40 which terminates at its lower end in a pair of spaced finger portions 4l and 42. Finger 42 provides the keeper-engaging portion of the latch bolt, engagement being facilitated by a. pair of rollers 43, one being provided on each side of its tip (see Figure `l Finger 4l is the trigger for moving the bolt from its retracted position, shown in Figure 3, into extended Aposition engaging the keeper, as is more fully described hereinafter. The force utilized to move the bolt into extended position is provided by a strong spring 44 positioned on arm 40, with one end impinging against shoulders 45 of the link and its other end adapted to react against pin 31.

Movement of the bolt between extended and retracted positions, when moving in its normal mode of operation, is guided by a pair of links 46. Each of the links is pivotally mounted at one end on a pin 4, the ends of the latter being secured in side walls 26 and 21 of the housing, while the portion intermediate the ends of the pin passes between the fingers 4l and 42 of the bolt.

A particular feature of the invention, as more fully described hereinafter, resides in the manner in which the other or free ends of the links engage the latch member to guide it in its normal latching movements, yet still permit free relative movement between said links and member during abnormal latching movement. This engagement takes place through a pin 48 which connects the free ends of the links and has its intermediate portion engaged in a slot 49 formed in the portion of the bolt which bridges the space between ngers 4l and 42.

Still with reference to Figures 2 and 5, it is seen that the left-hand end of pin 48 is provided with a roller 5l) positioned in the path of movement of an inwardly extending linger 5! of handle 52. The handle is pivotally mounted on a channelshaped member 54 welded or otherwise secured, as indicated at 55, to bottom wall 25 of housing 24. The handle is normally biased toward its rest position, as shown in Figure 2, by a spring 56.

The operation of the latch is as follows:

As viewed in Figure 2, roller 43 is in latching position behind the strike 22 of keeper 20. When it is desired to open the door the handle 52 isl grasped and rotated in a counterclockwise direction about its pivot This movement urges the contacting surface Elia of handle extension 5l against roller 55 on pin 48, thus rotating the links in a clockwise direction about their pivot 41.

Rotation of these links, as described, moves latching member 39, against the pressure of spring 44, in a direction determined by the arcuate movement of pin 48 about pin 41-as guided by engagement of pin 48 in slot -and to an extent withdrawing roller 43 from behind keeper 28, as seen in Figure 3, thereby permitting the door'to be swung open. This movement of latching member 39 continues until an extension 58 of one side edge of slot 49 contacts pin 41, at which position, as indicated in Figure 3, pin 48 has moved to or preferably slightly past a position of dead center with respect to pin 41 and the line of thrust of spring 44 against pin 31. As illustrated in Figure 3 this dead center position is reached when the straight line between pins 31 and 48 corresponds to a straight line 51 intersecting the axis of pins 31 and 41. Release of handle 52 by the operator permits spring 56 to return the handle to its normal position as illustrated in Figure 2, while the latch remains in its retracted or cocked p0- sition.

To close and latch the door the latter is merely swung toward closed position until trigger iinger 4I strikes the forward edge 22a of strike 22 (Fig. 3) which causes the latching member to move to the left, shifting pin 48 back past the aforesaid dead center position, so that the thrust of spring 44 may operate to urge the mechanism toward latched position. At the instant pin 48 passes the line of dead center (51), it is urged by the pressure of the spring 44 to move in a counter-clockwise direction toward the position illustrated in Fig. 2. This movement causes the latching member 39 to move downwardly, and to the leftl as viewed in Figure 2, guided by links 46 and pin 31, bringing roller 43 into contact with the keeper prior to completion of the link movement. Continued movement of the link draws the door forcibly into its fully closed position.

It is to be understood that, as the latching member approaches the fully latched position, the lateral component of movement of said member, that is, the component introduced by the strut-like action of links 46, becomes progressively smaller. Since, in a lever system of the kind here involved, the product of the input force and the distance through which the force is acting is always equal to the product of the output force and the distance through which the latter is acting, it will be evident that the aforesaid diminution of lateral movement is accompanied by a corresponding progressive increase in the lateral, or draw-in, force.

To a small degree, this increase in force is oiset by a progressive decrease in the thrust of spring 44, but this is a minor factor.

Movement of the latching member in its downward or counter-clockwise direction is terminated when the upper end of slot 38 contacts pin 31, as indicated at 31a. in Fig. 2, in which position pins 41 and 48 are in line with respect to the forces exerted against roller 43 so that rebound forces against the roller are exerted in a straight line against pin 41 and are thereby restrained.

Normal operation of the latch mechanism is as described above. However, when the mechanism is in the position illustrated in Fig. 3 and the door is opened to an extent permitting access to the refrigerator food storage compartment, it may readily be seen that the roller end of the bolt projects outwardly of the door structure in a position exposed to inadvertent actuation by forces great enough to move pin 48 over the dead center position, as described above. Such inadvertent actuation permits spring 44 to move the bolt to its latched position, while the door is still open.

In accordance with the foregoing statements of object and advantage, and as set forth in detail in what follows, the apparatus of the invention is such that the door may be moved to fully latched position even if the bolt or latching member be uncooked when the door is swung closed, the invention being particularly charactei-ized in that latching of the door, under such conditions, may be accomplished with considerably less closing force than was required with related mechanisms available heretofore. This feature may best be understood with reference to Figure 4.

When the door` is swung toward closed position-following inadvertent uncocking of the latch mechanism-roller 43 makes contact with cam face 23 of the strike 20, rolls upwardly along said face and thus forces the latch bolt 39 upwardly against the pressure of spring 44. This upward movement of the bolt or latching member takes place in a substantially straight line path determined both by pin 31 and slot 38, and by contact of the left hand edge 39a of bolt 39 against a guide member 26a fixed to side wall 26 of housing 24. The upward movement is of extent sufcient to permit the spring to move the roller 43 behind and into latching engagement with the keeper, as the door continues its closing movement. It is to be noted that the strike face 23 is provided with a sloped portion 23a, in order to facilitate entry of the roller 43 into latching position behind said strike.

Under the abnormal mode of operation just described, the upward movement of bolt or member 39 is independent of and relative to links 46 and said links are therefore not operative, as the roller 43 moves behind the keeper, to provide the lateral, or draw-in force, described above. Hence, under such condition of operation, the force applied to the door to effect closure thereof must be suicient both to raise the bolt 39 against the pressure of spring 44 and to provide compression of the door gasket. Accordingly it is of major importance that the total force which must be exerted against the door be kept as small as possible; In the apparatus of the presentinvention, substantially all of the force exerted by the roller 43 against the inclined face 23 of the strike 2 is available to eiect the necessary raising of the latch bolt.

To this end, and in contradistinction to related mechanisms heretofore available, the bolt is free to move with respect to the links 46, and it is therefore not necessary to overcome the restraining force which is present when the links 46 are pivotally secured to the latch bolt. Further, in the mechanism disclosed and claimed herein, the path of upward movement of the latch bolt is in general alignment with the direction of thrust reaction from the strike surface, thereby making such reaction fully effective in raising the latch bolt.

, In the apparatus of the present invention, and as will now be evident, the latch bolt retracts through an unrestricted, substantially straightline path aligned with the direction of thrust reaction from the strike surface and, therefore, retraction of the latch bolt is effected only against the force of spring 44, and such friction as exists in the mechanism. The spring, when thus loaded, then operates to move the bolt into latching engagement with the keeper, in the manner described.

From the foregoing, it will be understood that the invention herein disclosed and claimed provides apparatus which not only realizes the positive action and secure draw-in required for proper latching of large and heavy doors presently in commercial use but, further, is of such a nature as to effect an important reduction in the force which must be applied to the door to effect closure thereof when the latch bolt has been inadvertently tripped and moved to uncocked position.

I claim:

1. In a door latch, the combination with support structure of an elongated latch member adapted for interlocking engagement at one end with a keeper, means mounting the latch member for simultaneous oscillatory and longitudinal movement with respect to said structure, and means to control the oscillatory and longitudinal movements of said latch member so as to cause said latch member to move between a retracted position with respect to the keeper and an extended position in which said latch member is in interlocking engagement with the keeper, said control means comprising a spring exerting force tending to advance the latch member into the said extended position, and means guiding the movement of said latch member, said guide means comprising an element having a portionadapted to react against said support structure, and another portionspaced from the rst mentioned portion-normally engaging said latch member in a manner to effect arcuate movement of the latch member from said retracted position to said extended position With progressively amplied force under the influence of said spring, the engagement between said element and said latch member further being such as to permit substantially straight line movement of said latch member independently of said element, said straight line movement being from extended position out of latching engagement with said keeper to extended position in latching engagement with said keeper, and said guide means further including xed structure guiding said latch member in said straight line movement.

2. A door latch according to claim 1 wherein said guide element comprises a lever having one end thereof pivotally mounted for movement about an axis on said structure, and its other end releasably engaging said latch member adjacent its keeper-engaging end.

3. A door latch in accordance with claim 2 wherein the releasable engagement of said lever with said latch member is effected through a pin on said lever and a slot in the keeper-engaging end of said latch member, said pin normally passing through said slot.

4. A latch in accordance With claim 3 Wherein the latch member, the guide means, and the mounting means are so related with respect to each other that when the latch member is in retracted position, the point of engagement of said lever with said latch member will lie to one side of and closely adjacent to a straight line drawn between said axis and said mounting means, and when in extended position the point will lie at the other side of and relatively remote to said line, and wherein said latch additionally includes .stop means for stabilizing the member in said positions.

GEORGE E. CURTISS, JR.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 2,444,180 Anderson June 29, 1948 2,445,709 Curtiss July 20, 1948

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