US2528864A - Door latch - Google Patents

Description

Nov. 7, 1950 a. E. CURTISS, JR 2,523,354

DOOR LATCH Original Filed Oct. 27, 1943 2 Sheets-Sheet 1 F cai IN V. EN TOR.

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BY flaw, M v

,1950 e. E. CURTISS, JR 2,528,864

DOOR LATCH Original Filed Oct. 27, 1943 2 Sheets-Sheet 2 IN V EN TOR.

Patented Nov. 7, 1950 UNITED STATES PATENT OFFICE toPh ilco Corporation, Philadelphia, Pa., a corporation of Pennsylvania Original application October 27, 1943, Serial No.

507,839, now Patent No. 2,451,380, dated October 12, 1948. Divided and this application Decamber 7, 1946, Serial No. 714,883

2 Claims.

This invention relates to latches. particularly to latches of the type adapted for use with reirigerator doors, and is a division of my co-pending application, Serial No. 507,839, filed October 27, 1943, now Patent No. 2,451,380, issued October 12, 1948. Although not limited thereto, the latch of the present invention is particularly useful in refrigerator construction and, accordingly, the following description is illustrative of such use.

Proper latching of refrigerator doors, to prevent leakage of cold air from the cooling cornpartments thereof, has received much consideration by refrigerating engineers since the operating efliciency of a refrigerator depends largely upon an air tight condition of the cabinet. When leakage does occur, there is an increase in the frequency or duration of the operating cycle of the compressor and a consequent undesirable increase in operational expense.

Many latches already known in the refrigerator art, and purporting to provide a positive seal between the door and cabinet of a refrigerator. have employed mechanisms such as spring pressed pivotally mounted latch bolts having either flat or hooked faces adapted for engagement with correspondingly shaped strikes and usually having their pivotal mounting adjacent the latch strike when the door is in a closed position. Others have cam faces on either or both the bolt and the strike. Experience has shown these mechanisms to be sensitive to rebound, that is, when the refrigerator door is swung closed, it often strikes the door jam}: with sufiicient force to bounce or rebound to an open position. These known latch mechanisms offer little resistance to such rebound forces, as the rebound force need overcome only the spring pressure against the bolt. In latch mechanisms using cam faced bolts and strikes, rebound forces are altered little or no resistance in overcoming the spring pressure, as the bolt is assisted in its reverse rotation by the cam action of its cam face against the strike. Rebound is, of course, highly undesirable because the refrigerator door often has to be swung to'a closed position more often than necess'ary, thereby not only causing undue wear on the latch mechanism, but also representing a source of annoyance to the operator. Many times the door does not rebound sufliciently to be noticed and remains slightly ajar, with a consequent los of refrigeration, Some known latches have made use of mechanisms of various types operating in conjunction with springs, but the constructions thereof have been such that the tendency to rebound has not been successfully overcome.

With these premises in mind, the present invention has for its principal object the provision of a latch mechanism designed to amplify the main source of latchin power in such a manner that an unusually large draw-in of the door to its closed position is achieved and the maximum force available in the mechanism is applied to the bolt at the time when it is fully home" and the door fully closed.

More particularly, it is an object of the invention to provide a latch mechanism havin its main pivot point so located as to cause the latch bolt to approach the latch strike angularly from behind, in an extended substantially straightline path, or a substantially flat arc.

Another object of the invention is to provide a latch of the type described which operates absolutely to prevent any rebound of the refrigerator door when it is swun to a closed position, and which positively secures the door in closed position. v

A still further object of the invention is the provision of a latch of sturdy, compact, inexpensive, and simplified construction, which is adapted to be concealed within the door structure, and which requires a minimum of effort to operate.

These and other objects of the invention and the construction and advantages thereof are fully set forth in the following description and in the drawings, in which:

Figure l is a perspective view of a refrigerator embodying the invention;

Figure 2 is a sectional view, on an enlarged scale, taken in the horizontal plane indicated by the line 2-2 of Figure 1 and showing the mechanism in its latched position; and

Figure 3 is a view similar to Figure 2, but with parts broken away and showing the mechanism in its unlatched position.

Referrin now in more detail to the drawings, and more particularly to Figures 1 and 2 thereof, numeral l0 designates a domestic type refrigerator comprising a cabinet ll and a door 52 having an inner panel i3 and an outer panel i4 joined about their peripheries at 55 as by screws it which serve also as a means for fastening a resilient sealing gasket It to the door at this juncture. A suitable door handle 20 is pivotally mounted upon a pin 2| which is journaled in lugs 22 of a substantially flat member 23 secured to the exterior of the outer panel Id of door l2 by screws or the like 26 and provided with outward- 3 ly turned lugs which serve to secure a round face plate 25 about the base of the handle 29. The resilient sealing gasket I9 is adapted to close against a door iamb 28 of cabinet ii. and thus provide an airtight seal between the door and the cabinet when the door is closed. The door lamb 28-is equipped with an adjustably mounted keeper 29, having an external strike face cooperable with a trigger mechanism to be later described.

The latch includes a substantially channelshaped support or housing 35, comprising a bottom wall 3| and a pair of parallel side walls 32, 32, it being understood that one of said side walls appears in Figure 2, and the other in the sectional showing of Figure 3. Each of these side walls has, at the forward end thereof, a slotted ear portion 3 turned outwardly at right angles therefrom. As shown in Figure 2, screws 34 pass through these slotted ear portions 33 and are threaded into a member 35 which extends outwardly from juncture it of the outer and inner door panels and is secured to the door at this juncture by screw l8, thereby providing for fastening of the forward end of housing to the door i2. The right or rearward end of this housing is fastened, through its bottom wall 3|, to the inside of outer door panel ll by the same screw 24 which secures flat member 23 to the outside of said panel ll.

Between the parallel walls 32, 32 of housing 30 is latch bolt 85 preferably comprising a pair of spaced substantially Z- shaped bolt arms 38, 38 each of which has its bottom end 39 Journaled to said wall 32, 82 by a pivot pin 40 located toward the rear of said walls and at a point sufliciently oif-set to the right, from keeper 29, to

provide angular rotational movement of the free I The mechanism 58 preferably comprises a pair of spaced links 5|, 5| (Figure 3) having their lower ends journaled on the aforesaid bolt arms 38, 38 by .a pivot pin 52, and their upper ends iournaled on a pin 53. The ends of pin 53 extend through arcuate slots 55, 55 in the side walls 32, 32 of housing 30. In particular accordance with the present invention, these slots 55, 55 serve to constrain and guide movement of the pin 53 and its associated links 5|, 5| between advanced and retracted terminal positions. Pivotally attached to pin 53 between links 5|, Si is a rearwardly extending link 59 having its rearward end slotted as at 60 to receive therethrough the pivot pin 40, which latter serves guidingly to support that end of the link 59 above the bottom wall 3| of housing 30, slot 59 restricting forward motion of pin 53 to the desired advanced position, when the latch is fully locked, and serving also to restrict rearward movement thereof to the desired retracted position.

Depending from the forward end of the link 59, and extending'rearwardly thereof, is an arm I! having a portion 52 turned outwardly at right angles thereto and arranged for engagement with the end of a lever 51 on door handle 20. Lever .4 88 extends inwardly through an opening 84 in outer shell ll of the door, and between walls I2,- 82 of housing 30, to impinge against the left or forward face of the outwardly turned portion 92 of arm 8|. Surrounding link 59 and carried thereby is a coil spring 55 having its ends enclosed by slotted washers GI and 59 through which the link passes, the rearward end of spring 65 being anchored against pin 40 while the forward end thereof presses against a pair of abutments I5, III on link 59 disposed closely adjacent pin 52 and, in effect, impinges directly against said pin.

It is to be understood that by the term advanced position" is meant the left terminal position of links 5|, 5| and the term "retracted position," designates the position reached whensaid links have been moved to the right terminal position as defined by the ends of the aforesaid slots- Adjacent roller II is a trigger mechanism" having side flanges (one of which appears at 18 in Figure 3) extending upwardly to form arms I8 which serve as bearings for pivotally supporting the said trigger mechanism 11 on a pivot pin 99 secured to the upper end portions of the bolt arms 38. 38 and slightly spaced from roller 4|. A flat faced portion 8| of trigger mechanism I1 is normally urged, by one end of a light spring 82, in a clockwise direction about pivot against a pin 83 (Figure 2), which pin preferably has a flat surface 84. Pin 83 is secured to the housing 1 walls 32, 32 at the forward end thereof, and the main body of spring 82 is wrapped around said pin 80 and has its other end extending upwardly and over one of bolt arms 38 (shown in Figure 3) to provide an anchor and reaction point for spring 82. At approximately the mid-point of the trigger mechanism 11, at the upper edge of the flat face portion 8l thereof and adjacent the roller ll, is an outwardly turned portion 55 positioned so as to contact the strike face of keeper 29 when door i2 is swung to a closed position. Provided on the opposite or lower edge of the trigger mechanism is .an inwardly turned shoulder portion 88 arranged to move into engagement with the flat surface 84 of pin 83 and thereby hold the latch in a cocked or ready position, upon such actuation of the link mechanism 50 by the handle 25 as to open the door. Each of the side flanges '18 has a downwardly extending lug 89 formed adjacent the shoulder portion 88, these lugs being provided for properly aligning said trigger 11 on flat face 84 of the pin 83.

In operation, and assuming the device to be in the latched position illustrated in Figure 2, and that it is desired to open the door, the door handle is grasped'and pivoted in a clockwise direction to actuate lever 63 against the outwardly turned portion'52 of arm 5i and move link 59 to the right, thus moving the link mechanism to its retracted positionand at the same time compressing .the coil spring against pivot pin 40. This movement of link 59 to the right is limited by pin 45 striking the left end 50a of slot 60, (Figure 3). This retraction moves pin 52 in the path defined by slot 54,- and causes links 5|, 5| to draw bolt arms 38, 38 upwardly, rotating about pivot pin 40 in a clockwise directiomand thus moving roller 4| in a substantially flat arc angularly away from keeper 29, until said roller will just clear the edge of keeper 29 and permit movement of door l2 to its open position. At the same time the flat face 8! of trigger mechanism I1 rides against pin 83 until the left end "a of slot 80 strikes pin 40, at which time the trigger swings freely in a clockwise direction until lugs 83 strike pin 83 and properly align trigger 11 with pin 83, with the shoulder portion 88 on the flat surface 84 of pin 83 where it is releasably held by the counter clockwise urge of the now loaded coil spring 65.

The latch is now in the cocked position (Figure 3) ready to snap to a closed position (Figure 2) upon contact of portion 85 of the trigger with the strike face of keeper 29. The latch mechanism remains in this cocked position until door i2 is swung to a closed position, whereupon the outwardly turned port on 85 of trigger mechanism I1 contacts the strike face of keeper 29, to disengage the trigger from pin 83 and free spring 65 to urge pin 5| to its extended position, shown in Figure 2. At the instant of trigger disengagement, bolt arms 38, 38 are rotationally urged in a counter clockwise direction by the link mechanism, thereby moving roller 4| angularly from behind in a substantially flat arc, into contact with the underside of keeper 29 and, because of the toggle-like arrangement of the link and pin with the arcuate slot in the housing, an everincreasing force will be exerted to draw the door into its closed position.

It can be seen that a gentle pressure of the outwardly turned portion 85 of trigger mechanism '71 against the strike face of the keeper 29 is sufllcient to overcome the light pressure exerted by the spring 82, and cause shoulder 88 to move off the flat surface 84 of pin 83, thus releasing the spring 65 against the pin 53 and forcing the link mechanism to its extended position, as illustrated in Figure 2.

By reason of the novel arrangement of spring as impinging against pin 53 of mechanism 50. and the olTset location of pivot 40 of the bolt arms 38, 3B,the force tending to rotate said arms in a counter clockwise direction effects engagement of the roller 4i against the underside of strike 29 immediately upon release of the trigger mechanism, thus urging the door 12 in a closing direction. An increasingly amplified draw-in force is exerted upon the mechanism as the linkage approaches its fully extended position, at which time the greatest force is delivered and the door is secured in its fully closed position. The sealing strip i9 will thus be drawn against the jamb 28 in a slightly compressed and airtight or leakproof condition.- The nature of the linkage prevents any rebounding of the door because the rebound force is directed against the side of slot 555 and is thus effectively restrained.

It should be understood that pivot pin 40 may be moved some distance, either to the right or the left, without interfering with the function of the bolt mounted thereon. Its present location, however, has been found desirable.

To provide adiustment of the pressure exerted against the sealing strip I 9. when the door is closed against jamb 28, keeper 29 is provided with a slot 99 through which bolt 9! is passed and threaded into a nut 92, for securing the strike to the jamb. By loosening nut 92, the strike may be moved inwardly or outwardly to adjust its position with relation to the jamb. Most of the latch parts may be made by simple stamping methods and the mechanism may be less expensively manufactured than latches having parts that must be accurately machined.

From the foregoing, it will be evident that the present invention provides a novel type of latch that has an unusually large draw-in capacity,

and wherein an ordinarily decreasing spring force is utilized in such manner that instead of its decreasing force being used to pivot the bolt against the strike to draw-in" the door to its closed position (as is customary in most prior latches) the force is directly applied to the pin of the link mechanism wherein, because 01 the arc of slot 55, it is substantially and continuously amplified until the bolt has reached its fully home position and the door is drawn-in" to a fully closed position. Furthermore, the invention provides a sturdy and compact latch mechanism that absolutely prevents the door 01' a cabinet from bouncing or rebounding to an open position, and positively holds the door in its closed position by so arranging the mechanism that, when the door is fully closed, the link mechanism is in an extended position wherein the rebound force is directed therethrough to the housing and thereby restrained.

It is also evident that the present invention provides a latch which eliminates the necessity of slamming the cabinet door, since relatively slight force is required to uncock the trigger mechanism and release the spring force. Moreover, the individual parts thereof are of inexpensive and simple design, thus lending themselves well to mass production methods at comparatively low cost.

I claim:

1. In door latching apparatus, the combination with support structure, of a latch member having a portion adapted for interlocking engagement with a keeper, means mounting the latch member upon said support structure for oscillation with respect thereto, means to control the oscillatory movements of said latch member and cause said member to move between a retracted position with respect to the keeper and an extended position in which said member is in interlocking engagement with the keeper, said control means comprising a slot formed in the support structure and a follower'pin. said pin being associated with said latch member and engageable with said slot at a position spaced from said mounting means. a spring exerting force tending to advance the latch member into said extended position in interlocking engagement with the keeper, means effective to hold said member in retracted position and releasable in response to closing of the door, the said slot being inclined with respect to the path of movement of the latch member and operable in cooperation with the said follower pin and under the influence of said spring to effect movement of the latch member with progressively amplified force into said extended position in interlocking engagement with the keeper.

2. In door latching apparatus, the combination with support structure, of a latch member having a portion adapted for interlocking engagement with a keeper, means mounting the latch member upon said support structure for oscillation with respect thereto, means to control the oscillatory movements of said latch member and cause said member to move between a retracted position with respect to the keeper and an extended position in which said member is in interlocking engagement with the keeper, said control means comprising an arcuate slot formed in the support structure and a link pivotally connected to said latch member and having a follower portion disposed in engagement with said slot at a position spaced from said mounting means, a spring exerting force tending to advance the latch member into said extended position in interlocking some 7 i 3 enzezement with the Keeper, means elective to i muons cum mm member m retracted M The following references are of record in the ieassble in response to closing or the door, the p said arcuate slot being inclined with respect to this went the path or movement oi. the latch member and UNITED TATES PATENTS operable in cooperation with said follower portion Number Name Date and under the influence or said spr n to effect 2,029,197 Roedding Jan. 2a 1929 movement or the latch member w th n os eu lr 2,210,495 North Aug. 6' 1940 amplified force into sai extended p n n Y 2,259,136 Ho g Oct. 14,1941 terlocking engagem nt w h the keeper- 10 2,359,150 Peglow Sept. 26, 1944 GEORGE E. CURTISS. J8.

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