US2232628A - Latch - Google Patents

Description

Feb. 18, 1941. E. w. NORTH ETAL LATCH Filed May 5, 1959 lvl/Tl/l/g fda; Milian 0. 5am/ie 12/ W/Orfl/ INVENTORS Patented eb. 18, 1941 'UNITED STATES PATENT OFI-lcs LATCH Edwin W. North and 0. Burke, Rockford, Ill., assignors to National Lock Co., Rockford, Ill., a corporation of Delaware Application May 5,1939, Serial No. 271,853

4 Claims.

'I'his invention relates to improvements in latches, one of the principal objects being the provision of intermediate lever and linking mechanism providing an operative connection between the operating handle and the latch bolt in a latch of the slam-shut variety such as is co'mmonly employed on refrigerators and the like.

A further object is the provision ofA improvements in the mounting and operative connection or association of an operating plunger with the latch handle and an intermediate lever mechanism for operating the bolt.

A further object is the provision of improved handle means in which a handle and mounting therefor Vconstitutes a. unit with an operating plunger associated as a part of the unit and A of construction as well as the arrangement and operation of the parts in the illustrative embodiment described hereinafter in viewvof the annexed drawing, in which:

Fig. 1 is a horizontal section through a latch structure. and operating handle mounted on a refrigerator door;

Fig. 2 is a vertical section along line 2-2 of Fig. 1;

Fig. 3 is a vertical section along line 3 3 of Fig. 1 through the latch bolt;

Fig. 4 is a rear perspective of the latch with portions of the mounting frame cut away;

Fig. 5 is a fragmentary rear perspective of the4 handle unit. i

Latches of the slam-shut variety, that is to say, whichI employ spring-urged bolts normally disposed in latching position for camming engagement with a keeper when .the door is slammed shut, are subject to a great deal of mechanical stressdue to the impact of the bolt with the keeper, and in order to make an economical latch from1 the standpoint of production cost, a yproblemarises in providing an operating leverage or mechanism which is simple, inexpensive, of high mechanical advantage, and withal rugged and freey from reasonable likelihood -of mechanical breakdown due to abuse or wear. Such latches are commonly employed with refrigerators and other utility devices of this class,`and the arrangement is commonly such that the operating handle for the latch is impositively associated with the latch-operating mechanism; that is to say, the latch' bolt and associated operating means is movable independently of the handle so that the door may be slammed shut without moving the handle.

' It is practically possible to manufacture a latch of this class which will be adequately rugged and free from mechanical trouble, but the problems arise in constructing such a latch along economical lines for production purposes. The

present invention provides an operating mechanism which is sim-ple and inexpensive and overcomes the diiiiculties heretofore experienced in constructing this type of latch.

In its preferred embodiment, the new latch consists of a mounting bracket l5 (Figs. 2, 3 and 4) formed by bending a heavy metal strap back upon itself to provide a channel having a bottom portion I6 and opposite side walls I1. At one end, the strap. has upset flanges I8 for mounting purposes. Near an opposite end of the channel there is an inturned tongue I9 (Figs. 1 and 2) embossed toprovide a seat for one end of a coil spring 20. The opposite end of this spring engages a knobular seat on the inner end of a latch bolt 2| which slides in the channel -part of the bracket against the inner surface of the bottom Wall I6 and side walls I1. A roller 2 2 is mountedon a pin 2,3, seated in the opposite side walls Il, in spaced relation to the bottom of the channel i6 so as to guide the bolt in its reciprocable movement into and out of latched position, that is, in a direction into and out of the channel part of the bracket. The spring 20 normally urges the bolt into latched position as seen in Fig. 1, and the bolt is provided with a cammed nose portion 24 which is engageable with a keeper 25 and which, upon striking the latter, coacts with the eammed surface of the keeper to force the bolt toward unlatched position for movement into the latching part of the keeper by reaction of the spring 20 when the door or other closure is closed.

The bolt is provided with an operating mechanism which includes a. vpair of parallel straps 26 (Fig. 4 particularly) riveted thereto as at 21 and extending inwardly into the channel on opposite sides of the spring 20. The rearward or inner end portions of each of these straps are provided with elongated slots 28 through which extends a ystationary guide pin 29 secured in the opposite wall portions I1 of the mounting bracket. Thus, the bolt proper is guided at its forward end 'between the bottom wall I6 of the channel part of the bracket and the roller22, and at its rear the bolt structure is guided by the pin 29.

An intermediate operating lever 30 is pivotally mounted on a pin 3| between opposite wall portions I'I of the bracket, and this lever is of peculiar shape and formed by bending a piece of metal back upon itself so that there will be spaced opposite side walls joined b y an intermediate wall portion 32 (Figs. 1, 2 and 4). This latter intermediate wall portion is curved inwardly and is disposed at one side of the pivot 3| for engagement with the operating plunger 33 of a handle unit. The inner end of this plunger works in the inwardly or concavely curved part of the intermediate wall portion 32 when a handle member 50 is suitably rocked, and as a result, the intermediate lever is pivoted so as to displace the far end portion 35 toward the right in the` general direction of retractive movement of the bolt. This intermediate operating lever may preferably be of the construction described and claimed in our copending application, Serial No. 271,854, iiled May 5, 1939.

Means for providing a connection of great mechanical advantage and simplicity includes a link strap 36 having opposite end portions turned back upon itself to provide eyes 31 and 38, the

former of which pivotally engages a pin 39 bend straightening out or even loosening.

mounted in the opposite wall portions of the lever 30 near the end 35 thereof, and the latter eye 38 pivotally engaging a pin 40 mounted between projections 4I on the parallel straps 26.

The pivotal connections between the bolt structure and the intermediate operating lever 30 through the agency of the link 36 are such that when the lever 38 is displaced toward the right (Fig. 1), by inward movement of the plunger 33, the movement of the link means 35 will be almost rectilinear in the direction of movement of the bolt. Effort of the spring 20 restores the bolt, the operating mechanism and the plunger to the normal position shown in Fig. 1.

It will be apparent that the bolt and its associated operating mechanism 30-38 is capable of movement independently of the plunger 33. The lever 30 may be conveniently and inexpensively constructed as a simple stamping which is additionally strengthenedby the provision of the pin means 39 connecting it with the link, and the link 36 may likewise be manufactured as a simple stamping.

The nearly rectilinear movement of the link 36 with respect to the line of reciprocation of the bolt, brings an appreciable part of the load on the eye portions 31 and 38 very close to the initial bends at the ends of the link and which constitute the eye portions, so that unusually heavy stock need -not be employed in anticipation of the possibility of the bight or eye portions of the In addition, the momentary shock which the eye portions of the link 36 must withstand at the time of impact of the bolt with the keeper, is adequately withstood as a result of the construction and arrangement of the link as aforesaid.

A further consideration of importance is the fact that fby arranging the pivots of the inter-` almost in a straight line parallel with the move-l ment of the bolt so that the pull on the bolt is largely in a straight line therewith and thereis no wasted torque or turning effort as a result of excessive pivotal movement which would cause the pivotal' centers to shift relative to each other during retraction of the bolt. For example, in Fig. 1 the pivot 39 is closer to the axis of the bolt than pivot 49 and lies at one side of a. line through pivot 40 and nearer to the bolt than pivot Ill. This arrangement ,not only reduces wear on the parts. but takes maximum advantage of the leverages involved in a manner such that the effort applied to the handle may be more uniform throughout the retractive movement of the bolt and not, as in the case of some older latches, easy at first but increasingly resistant until the bolt is nally fully withdrawn. To the same end, the pivot of the link on the intermediate lever and the pivotal axis of the latter lie along'a line making a small angle with the length of the plunger. These small angles are as small as possible for any similar disposition oi' parts with respect to relative location and dimension, and which ywill also prevent the pivoting members from getting into dead centers" and thus jamming.

Another feature of importance is the construction of the handle mechanism as a unit, as illustrated particularly in Figs. 2 and 5, wherein the handle member 50 is a hollow formed-up stamping which rocks on a pintle 5i mounted on opposite side wall flanges 52 of a channel-shaped mounting bracket, a bottom portion 53 of which is adapted to t against the door. A plate 54 is welded or otherwise secured to small upset flanges 55 (Fig. 4) on the latch bracket and fits against the inside oi' the door face opposite the handle part 58. Means such as the screws 56 passing through holes 51 punched in the bottom of the handle bracket, are employed to attach the handle bracket to the plate 54.

The handle is provided with the usual spring.

58 for maintaining the same in a normal position. In the arrangement illustrated, the handle is mounted in an upside-down position compared with the conventional mounting, so that the handle must be pulled down away from the door structure upon which it is mounted.

A bearing plate 59, moving with the handle, is provided near the open end portion at one side of the pintle 5I so as to bear against the head 60 of the operating plunger 33. 'I'he plunger is slidable in a bushing 5| seated in the bottom portion 53 oi' the handle mounting bracket. Thus, the handle structure is an independent unit which may be associated with a latch structure such as shown in Fig. 1, or with some other type of lock adapted to coact with the plunger 33 and adapted to have the bracket portion 53 mounted therewith so that the plunger will be disposed in operative position relative vto the latch mechanism.

The specic recitation of certain details of construction and operation of the preferred embodiment hereinbefore described is not to be construed as a limitation upon the invention except to the extent that may be provided in the appended claims.

Having thus described our invention, what we claim as new and desire to protect by Letters Patent is: Y

1. In a latch of the type adapted to be actuated by a reciprocable plunger, a plunger and handle structure comprising a mounting plate, a handle pivoted on said plate to rock about an axis parallel with the plane of the plate, a bushf ter and actuate ing seated in the plate at one side of the rocking axis oi.' the handle, a plunger reciprocable in said a bearing surface, and'stop means preventing the plunger from working out handle having a hollow of the bushing, said portion opposite the headed end of the plunger,l a bearing elementmounted in said hollow portion to rock coaxially with said handle and having a surface portion disposed to bear againstl the headed part of the plunger and another portion bearing against an eccentric part oi' the handle whereby rocking of the handle toward the plunger will move the latthe latch, and spring means interposed between said mounting plate and said bearing element and urging the latter against the handle, whereby the handle and bearing element are moved into a normal position in a direction away from the plunger.

2. In a latch oi' the otype includinga rocking handle adapted to engage a latch-operating plunger to move the latter in a direction normally of the rocking axis of the handle, the combination of: a plunger, a handle structure including a mounting, a handle on said mounting to rock toward the latte a bushing in the mounting disposed at a point eccentric of the rocking axis of the handle, a plunger in said bushing, said handle having a hollow end portion opposite an end of said plunger, a bearing element mounted torock coaxially with the handle in the hollow portion thereof and having a part engaged by the handle when the latter is rocked toward the plunger and a part engaging theend of the plunger when the handle is rocked as aforesaid to constitute a slidable bearing conneclfign between the handle and plunger, andspring means interposed between said mounting and bearing element to urge able with said plunger and l formed up to provide a handle portion with an enlarged open end portion, a mounting member, and means including a pintle extended through said enlarged open end portion mounting the vharidlefor rocking movement away from said mouting member, and a thrust element in the form of a plate member with offsets constituting mounting-ears which are means at said open end said thrust element may rock independently of the handle but coaxially therewith, said thrust element having a thrust-receiving portion offset from said pintle' means and disposed to engage a marginal portion of said open end of the handle for movement by the latter in a direction toward said mounting member, spring means interposed between said mounting member and thrust element, normally urging the latter against said end portion of the handle to dispose the latter in a normal position, said thrust-receiving portion of the element being adapted to engage the end of a latch operating plunger for movement in a direction transversely of said pintle means. v`

4. In combination with a pivoted latch operating handle having a hollow end portion and adapted to move a reciprocable plunger opposite said end portion, a thrust-receiving element pivoted coaxially with said handle in said hollow end portion and having a surface part engagea part engaged by said handle, whereby movement of the latter toward said plunger will cause said thrustreceiving part to bear against the plunger for the purpose set forth.

EDWIN W. NORTH.

O. BURKE.

of the handle whereby engaged with said pintle

Images