US2637576A - Automatic latch for two relatively movable members - Google Patents

Description

y 1953 R. K. NOTTINGHAM 2,637,576

AUTOMATIC LATCH FOR TWO RELATIVELY MOVABLE MEMBERS Filed July 25, 1949 4 Sheets-Sheet 1 6 66 Egg 42. {3 1 Z6 INVENTOR. H. 7 [P b K A/oizl'njbam y 5, 1953 R. K. NOTTINGHAM 37,576

' AUTOMATIC LATCH FOR TWO RELATIVELY MOVABLE mans Filed July 25, 1949 4 Sheets-Sheet 2 INVENTOR.

Pal 0k K. Noftz'ng/mm %,.AL,, 6%

y 1953 R. K. NOTTINGHAM 2,637,576

AUTOMATIC LATCH FOR TWO RELATIVELY MOVABLE mans Filed July 25, 1949 4 Sheets-Sheet 3 IN V EN TOR. Fry/ 0, K /Vo tiny/7am y 5, 3 R. K. NOTTINGHAM 2,637,576

AUTOMATIC LATCH FOR TWOERELATIVELY MOVABLE MEMBERS Filed July 25, 1949 4 Sheets-Sheet 4 IN VEN TOR. Ra lph K. Na Hz'nyham BY Y 1 flaw, 10am...

#3 I 4ffur'nE- /s Patented May 5, 1953 omrsosrrss PATENT OFFICE,

AUTQMATIC LATCH FOR TWO RELATIVELY MOVABLE MEMBERS (Cl. seas-9.9)

.-Claims.

The present application is a "continuation-inpart of my prior application, Serial l\lo. 46,653, filed August 28, 1948, now abandoned.

The present invention comprises an automatic latching-device to hold one of two relatively movable members in latchedrelationship to each other, such members-being, for example, a doorand a cabinet, a-door into a room and its casing;

or a'desk and a'drawer; The invention isof particular utility in the manufacturing oisheet metalcabinetssuch as wall or floor cabinets for kitchen,-bedroom-or-bathroom use. The principal object of the present invention is to provide asimplifiedlorm of latching device for accomplishing the latching function, and one which may be easily fabricated and easily assembled with the members.

A further object of the present invention is to provide a latching unit for a latching device of the above type having the desirable characteristics outlined above and whichmay be entirely concealed within a cabinet or other structure so that no unsightly or dangerous projections protrude from the outer surface of the cabinet or The only projection is a catch other structure. member on the other of the relativelymovable members, which is concealed from View when in latched position.

pressed or moved, in order to operate the device. The device is so constructed that the members will be retainedin closed position upon being brought into the closed position. Thereafter the members may be serarated upon being pressed slightly together. The provisionof the latching means of my invention permits a busy housewife with both hands full to approach a closed cabinet and open it by simply pressing against the door with her shoulder, elbow or knee.

A further object of the present invention is to provide an automatic latching device for two relatively movable members in which resilient means are incorporated to provide the force to separate the two members when the latching de vice is unlatched, thus eliminating the separate spring pusher heretofore found necessary inconstructions of this character.

The foregoing and other objects and advantages of the present invention will be more-readi- 1y ascertained from-inspection of the--iollowingspecificationitaken .in. connection with the-ac-. companying drawing wherein like numerals: refer-.1

2 to like-parts throughout, while the features ofnovelty will be more distinctlypointed out in the appended claims.

In the drawing,

Fig. 1 is a partial, isometric view of a cabinet: having a door held in closedpositionby; ,a modification of the present invention;

Fig.2 is a partial, horizontal section, onan enlarged scale, taken substantially-along line 2-'-2 1 of Fig. 1;

Fig. 3 is aviewin -elevation of the forward suriace'of a portionof a cabinet in which the latchingunit is adapted to be mounted;-

Fig; 4. is a front view of the housing of the latching unit with the operating parts removed;-

Fig. 5 is a plan view of the housing;

Fig. 6 is a side elevation of the'latch of the present invention;

Fig. 7 is a plan view of the latch;

Fig. 8 is a plan view of the resettingplunger of the present invention;

Fig. 9 is aside elevation of the plunger;

Fig- 10 is a longitudinal vertical section. through the latching unit and a portion of a door at the moment when the door is about to reach closed position; the latching unit being in normal condition with the latch in V cocked position;

Fig. 11 is a similar view showing the catch in, the process of .raising:the.hook portionof the; latch during the closing movement or" the door;

Fig. 12'is a similar view showing the parts at the moment whenthe *door has moved inwardly to the fullest extent possible andthe, latch is, in catch engaging position;

Fig. 13 is asimilar view showing all parts at, rest with the latch in latching position retaining the separable members in latched. relationship;

Fig. 14 is asimilar view showing the latchv in the releasing position automatically assumed upon pressing the. door inwardly to initiateopening thereof;

Fig-.15 shows axsubsequent stagein the operation of. thedevice when the door has been re-. leased from inwardspressure and is being propelled toward itslopen position by the resilient. means of the latching device Fig. 16 is a view similar to Fig. 2 showing a second modification oi. the present invention;

Fig. 17 is a plan View of the housing of the second modification;

Fig. i8 is: aside elevation of thehous-ingot the second modification;

Fig. l9 is; a plan; -view of the resetting plungerr. iorthe second modification;

Fig. 20 is a side elevation of the plunger for the second modification;

Fig. 21 is a side elevation of the latch of the second modification;

Fig. 22 is a bottom view of the latch of the second modification;

Fig. 23 is a longitudinal, vertical section of the second modification and a portion of a door when the latch is in normal, cocked position, the view being similar to Fig. 10;

Fig. 24 is a similar view showing the parts when the door has been pushed as far closed as possible, and the latch is in catch engaging position. the View being similar to Fig. 12;

Fig. 25 is a similar view showing the parts when the door is being retained in closed position and the latch is in latching position, the view being similar to Fig. 13;

Fig. 26 is a similar view showing the parts when the door has been pushed inwardly to initiate opening thereof and the latch is in releasing position, the view being similar to Fig. 14; and

Fig. 27 is a horizontal section through a cabinet having a third modification of the present invention thereon.

Description of first modification In Figs. 1, 2 and 3, a cabinet comprising a side wall In is shown as having a door hinged thereto by hinges l2. As is common in sheet metal cabinet construction, the forward edges of the side walls are reinforced by bending a portion inwardly and then rearwardly to form a flange M'around the door opening. In order to mount the latching unit in the cabinet the flange I4 is preferably provided with a rectangular opening l5 having a pair of rectangular notches [6 in the vertical edges thereof. The latching device preferably comprises an elongated, troughshaped housing including a bottom wall I! and opposed side walls l8 of slightly less height than the vertical edges of opening IS. The corners of the trough are slit rearwardly from the front end for a substantial distance and the side walls are sprung outwardly, the material of the troughshaped member being resilient so that the separated forward portions of the side walls tend to remain spread open as seen in Fig. 5, but may be sprung inwardly. Each side wall I8 is provided with a tongue |9 which extends forwardly and then laterally outward. As seen in dotted lines in Fig. 3, the housing may be slid longitudinally through the opening l5 until the tongues 9 snap into the notches IS. The remaining portions of the end edges of the side walls l8 and the end edge of the bottom wall I"! will underlie the surface of the flange l4 and the housing will thus be retaned in position. If it is desired to remove the latching unit, the tongues l9 may be pressed toward each other until the housing may be raised slightly and withdrawn through the opening l5. The housing mounts a pair of spaced-apart latch pivots, which are preferably in the form of longitudinally and vertically spaced crossbars 2| and 22, which not only pivotally cooperate with the latch but hold the walls I8 from spreading. The bottom wall I! is provided with a pair of longitudinally extending slots 23 at its sides below the pivots 2| and 22.

The working parts of the latching device comprise an elongated latch 25 seen in Figs. 6 and 7 and an elongated plunger 35 seenin Figs. 8 and 9. The latch comprises a U-shaped member having a pair of vertical side portions 26 so spaced as to slide within the side walls l8 of the housing and a rearwardly inclined bight portion 21 at the forward end thereof which provides the latch hook. Each side portion 26 is provided with an upwardly facing, rearwardly inclined notch 28 adjacent its rear end and a downwardly facing, rearwardly inclined notch 29 spaced forwardly therefrom. A forward portion of one of the side portions 26 is slit longitudinally and the tongue 30 so formed is bent laterally to provide an anchoring crosspiece which is provided with a notch 3| in which one end of a tension spring 32 may be anchored. The spring extends diagonally downward and rearward between the pivots 2| and 22 and its rear end is suitably anchored so that the spring is always tensioned. The rear edges of the side portions 26 are in-- clined upwardly and rearwardly to provide cam surfaces 33 for a purpose to be explained.

The plunger 35 comprises a flat bar having an upwardly and rearwardly extending striker portion 36 at its forward end. The bar is of such width as to slidably fit between the side walls l8 of the housing throughout the greater portion of its length. A central portion 31 is reduced in width and bent upwardly from the plane of the remainder thereof so as to provide a guiding surface engaging the lower surface of the lower crossbar 22 to retain the plunger in sliding contact with the bottom wall H. The portion 31 is defined by a pair of edge notches 38 having a function to be described later. Immediatel to the rear thereof a small tongue 39 is struck upwardly from the central portion of the plunger, the side edges thereof being provided with notches 49 in which to anchor the opposite end of the latch spring 32. Immediately to the rear thereof a pair of cam tongues 4| are struck upwardly from the side edge portions of the plunger for a purpose to be described. The plunger is of greater length than the housing and the extreme rear end thereof is bent upwardly to provide a terminal flange 42 which is provided with a central opening 43 (Fig. 10) in which one end of an auxiliary tension spring 44 is retained. The opposite end of spring 44 is hooked over the central portion of the upper crossbar 2|. The spring 32 is initially tensioned and is placed under greater tension at various times during the operaticn of the device, as will appear, and the spring 44 is tensioned at least when the plunger is rearwardly within the housing.

The other part with which the latching unit cooperates to retain the door in closed position is a catch member which in the present illustration comprises a stem 50 having a head 5| provided with a rounded forward surface, the rear surface of the head providing an abutment to retain the hook 2"! of the latch. The stem 50 may be attached to the door H in any suitable fashion as, for example, by threading the inner end thereof and screwing it into a nut 52 (Pig. 2) fastened to the inner surface of the inner panel of a hollow door.

It is to be appreciated that the present invention may assume other shapes and forms and may have various details thereof modified. For example, the catch member may comprise a screw or stud which may be screwed into or otherwise fastened to a solid door member. The angle at which the striker tongue 36 extends rearwardly and the extent to which it extends may be varied in accordance with changes in the shape of the head 5|.

fore, spring 44 provides an auxiliary force to move the latch and the plunger forwardly in unison to the extent required to withdraw the overhanging forward edge of notches 28 from engagement with the upper pivot 21 to condition the latch for subsequent resetting action.

Description of second modification A number of refinements have been incorporated in the modification of the invention disclosed in Figs. 16- to 25 inclusive whereby the sizes of the various parts are reduced, various parts are made sturdier, the action of the latching device is made more positive, and other advantages achieved. In this modification a channel-shaped housing Bil is employed, the housing having a bottom wall 6|, a pair of spaced side walls 82, and a rear wall 63. The forward edges of the side walls and of the bottom wall are provided with flanges G l adapted to engage the edges of an opening in a surface portion 65 of a structure such as a sheet metal cabinet 65, behind which are provided stamped-out tongues 61 which snap behind the surface portion 65 to hold the housing in position as illustrated in Fig. 16. The side walls 62 are preferably provided with a pair of inwardly embossed, vertical ribs it; located near the upper and lower pivots, 59 and 70 respectively, which span the interior of the housing, the upper pivot being located rearwardly of the lower pivot as in the previous modification.

A latch H is floatingly mounted in the housing, the latch comprising a sheet metal member including an elongated body portion 12 terminating at its front end in a rounded, inwardly extending latch hook #3. At its rear portion the latch is provided with a pair of side portions l i, each of which is provided with an upwardly facing notch F for engagement with the upper pivot 69 and a downwardly facing notch S6 for engagement with the lower pivot 78. The notches 4E have their forward edges terminating adjacent the rear edge ll of the body portion "i2. The for ward edge of each of the notches i5 inclines rearwardly as indicated at E8, then forwardly to provide a pivot recess it, the upper edge of the recess '29 and the sloping surface 73 defining a nose 8%. The rear wall 8! of each notch is substantially normal to the plane of the body 72. The front wall of each notch '56 is defined by a rounded lower corner 82 above which is a small, substantially vertical portion, and the rear wall 83 of the notch I6 is rearwardly inclined. From the rear limit of notches 16 the portions is are upwardly rounded to provide cam surfaces 84. A pin 85 is riveted to the body portion '52 and projects downwardly therefrom. being provided with a spring-retaining groove 86 which is substantially in line with the tip of the hook "i3 and the bottoms of the recesses '55 and "i6. The outer surfaces of the portions 74 are spaced so as to slidably engage the inner surfaces of the ridges 58, friction between the latch and the housing being thus reduced to a minimum.

A resetting plunger 92 is slidably mounted in the housing and rests upon the bottom wall 6i. The plunger is of substantially the same width as the width of the interior of the housing and is provided with a raised portion 92 which bears against the lower pivot it! to retain the plunger in sliding contact with the bottom wall. The forward end of the plunger is bent upward at right angles to provide a striker surface 53, and then bent rearwardly at right angles to provide a. striker tongue 94 which normally underlies the hook 13 as seen in Fig. 23. The rearward portion of the actuator plunger is bent upwardly to provide a pair of laterally spaced cam-engaging tongues 95 adapted to engage the cam surfaces 84 of the latch when the latch is cooked as seen in Fig. 23. A central spring anchor 96 is provided between the tongues 95, the same comprising a tab which is bent upwardly, then rearwardly. The portion 92 is defined by longitudinally extending edge notches 91 into which the lower portions of the cam surfaces 84 may project when the latch is in releasing position as seen in Fig, 26. In this modification the lower wall of the housing is not slotted and the portions 74 of the latch cannot project through the lower wall, thus permitting the mounting of the housing closely adjacent a portion of a cabinet or the like on the three sides defined by the side walls 62 and the bottom wall 6|. The striker tongue 84 is centrally notched at 93 to provide an opening into which the tip of the pin may project when the plunger is forced inwardly as seen in Figs. 24 and 25.

A latch spring I00 is tensioned between the tip of pin 85 on the forward end of the latch ll and the anchor 85 on the rear end of the plunger 90, the spring being always under tension and extending rearwardly from a forward part of the latch between the pivots 68 and 10 to a rearward portion of the plunger. The rearward end of the spring N30 is tightly coiled about the spring anchor Q6 for several turns and then continues to provide a conical auxiliary spring Illl projecting rearwardly from the rear end of the plunger, the spring normally projecting loosely into the clear space of the housing. The parts are so proportioned that when the plunger is forced rearwardly to the positions shown in Figs. 24 and 25 the spring I0! is compressed between the upright portion of the spring anchor 9-5 and the rear wall 63 of the housing. The auxiliary spring functions to provide a forward thrust against the plunger and latch to disengage the recesses it? from the upper pivot in order to condition the latch for subsequent opening movement. The auxiliary spring in this modification exerts a forward force on the plunger only when the plunger is near the inner limit of its movement, thereby permitting the use of less sturdy cabinet and door parts since less force is required to cause the catch to force the plunger rearwardly during most of its travel.

The latch in housing 5t cooperates with a catch mounted upon the other of the two separable members in any convenient manner, the same being illustrated in Fig. 16 as comprising a mounting member I82 conveniently associated with the inner wall of a hollow door m3. The catch itself comprises a fiat stem portion I94 having a notch in its upper edge, the forward edge of the notch being normal to the direction of movement of the door to provide a hook-engaging abutment. The forward tip of the catch is rounded so that in the event the door should slightly the catch will lift the door upwardly as the lower edge thereof cammed upwardly by the bottom wall 65, or so that it may raise the hoot: '1 ii the parts are misaligned in the other direction. The height of the catch is substantially the same as that of the striker surface 333 so that as the plunger moved inwardiy the tip of hook it will rest upon the upper edge of the catch under the downward tension of spring we.

A: vfeature o;1 f minor importance: is that the tip. of the-hook 13; is in longitudinal alignmentwith the g-rooyelie in; the pin 85 and the tip of the nose Bllgatthe forward edge of the upper notch 15. It is in order to make certain that the 5 spring anchoring groove 1351s held in this position of alignment that the separate pin 85 is utilized, since the distance between the shoulder of the pin and the'groove 86 may oehelclwithin very close tolerances. It is by reason of thisalignment that a function-oi the device occurs as will appear in the description of the opera. tion.

Operation of second modification In order to assemble-the latching unit with. 1511 and held in a position intermediate betweenthc positions illustrated. in Figs. and 26 .so thatv the. housing may he slid longitudinally into an opening until. the portions file snap into. position, whereupon the latch maybereleased: from man:- ual confinement" and theplunger permitted: to slip forwardly under the. tensionof spring Hill until the ,partscome to rest with the. latch being. heldhinucocked position bytheplunger, as.illus-:.- trated in Fig. 23-.

When. the latching. mechanism is coclnedaand at-rest; as seen in Fig 23;. the tongues lit-and. cam surfaces 84 are infirm engagement, forcing. the rear? end of. thehook latchrupwardly. with the pivot 69-. engaged in the; bottoms of notches '16; The spring Hid forces thehook latch rearwardly. with the pivot t-Qrengagedin the pivot recesses it; beneath the nosestfiz.

When the dooror other movable-part has been. pushed inwardly. beyond. a certain point near itsxlimit; ofclosing movement, thehook 1.3 is. snapped -.do.wnw.ard1y into-the notch .l by spring ltB-..unti1;its. rests. upon the-stem .i tdxof. the catch, thelatch now. be ng. in catch ensi einepo ition as seenin Fig. 2.4. Thespring we is. further tensiolled during this-movement andtoward the 61361301: the movementtthe auxiliary spring.- lfizl iscompressed. It. will. be 3 noted; that-Uthetpln 35.. projects into; the, notch. 93;- inthe: striker tongue M this construction enabling the housing. to be;

slightly; shorter than would. otherwise ,be nee:

essaryi;

When inward pressure is released. the; spring Wt o est h plun er and-t e; ca h oupwa v 1y; Sincethe hook- 'lt is engagedith theabut-.-

mentface of the; catch, the heel; latch ll is- 60..

drawn forwardly to the slight extent required to; Withdraw the upper pivot, from theplvot-recesses l9 and; conditlonthe latch hook for pivoting about lower pivot it}. Due to the transfer oi the;

fulcrum. point of the. hook latchto; its forward;

end, the rearend 01?; the hooklatch. is drawinslig'htly' downwardly-so that the noses till; are oppositeor slis'htly belowthe uppenpivot 6-9;, as seen in Fig. 25., and; the rearvertical wallsSl of.

the upper note-hes.- are drawn against the upper inwardly, thus releasing the hook from the catch 7 portion. 72. of thelatch, or by'thecam surlaces 84015 the latch resting against the. bottom wall Ell. of the housing, or by both of such actions occurring, depending upon slight. differences in inanuia cturihgtolerances.

At. t '5 point the spring I09 is tensionedto themagii um and the'spring lei compressed to 2 the mum so that, upon release of inward- Lressure from the. oor, the door is propelled outwardly by the plunger forcing the catch'outwardlyunder the iorce of both springs. A-iter delivering its initial; thrust the; compression spring ml is merely carr ed along With the plunger ancl all force is eszertedyby spring loll. Asth'e plunger nears the end of itsoutward movement the rear edges of 'thenotches 91 therein engagethecam surfacestl of the latch and begin to raise therear end-oi the'latch" iroin the position illustrated in Fig. 2 6; toa point-such that the tongues Qfijmay engage-thecaro surfaces to continuecammihg the rear end of the latch upwardly, thus shifting the pivotpOintfrom the lower notches to the upper notches, as seen in- Fig. 23. During this upward camming action the verticeltcomponent 0f ior exer e by. h spring Itdyontl; ront; endv;ot:the latch -ts from. an. upward direction ;to a; downward direction. so as lJQt dIELW' the; hook; l3; downwardly behind the receding catch and-hold itagainst the striker tongues 94-..- The parts'arenowtat-restin cocked posit n il'lli readines u om ic ly; to e: the catch; .upon;-the;;-next inwardmovement of;

the door,

ec m ete ole of e at he latching.

ly-mOvable partssince the noses-.thwill slide: baokoverthe rear. pivot-$95 it the latch is rapidlyretracted-as-would=be the case.;.-wit h a, door rebounding upon; being; slammed; shut. The door will therefore remain closed regardless of theforce andspeed-iwithiwhich it is moved toward itsclosed ppsition uponthe first. closing movement, but, it will. open after the. second closing movement only ifthe closing pressurelis gently applied, The. spring I ill isofh suincient forcev toprev'entthe door. from. rattling open. asa result ofany vibrations such, ascreated b z-nearby machinery, or from, beinsmoved bygusts ,of wind or. the like. The, latching. deviceis thereforeincapableotj being released. except by the application of an intentionally applied gentle pressure.

Description of third: modification InFig. 2.7. there isillustrated. a portion-of acab inet. having a. modificationof thepresent invention incorporated therein. In this modification 11 a cabinet including a fiange 85 has a housing 68 associated therewith as illustrated in Fig. 16. A latch and plunger are mounted in the housing 66 and interconnected by a spring lill), all parts of the latching unit being identical with the parts illustrated in 16, with the exception that the spring lllil terminates at the end of the plunger 90 and there is no auxiliary spring in the housing 60. A cabinet door 103, as illustrated in Fig. I6, has a catch I04 associated therewith for cooperation with the latching device as previously described. The function of the auxiliary spring is performed by external means such as a springurged buifer HG mounted in a barrel HI adapted to be mounted upon the wall H2 of the cabinet on which the door is mounted as by means of hinges H3. When the door is in closed position a spring I M mounted in the cylinder H I between the rear wall of the cylinder and a flange H5 on the buffer I lit is compressed, the spring I 14 thereby exerting an outward thrust tending to open the door. This thrust is transmitted through the abutment face [65 to the hook 73 to pull the floating latch forwardly and unseat the upper pivot 69 from the pivot recesses l9 in the upper notches when the door and cabinet are being held in latched position, as seen in Fig. 25. This action, as previously explained, conditions the latch so that the spring I00 may shift the pivot point of the latch hook from the upper to the lower pivot when the door is subsequently pressed inwardly, thereby permitting the latch hook to be swung upwardly by spring I913, as seen in Fig. 26.

Summary In all three modifications there is provided a latching device for automatically latching and releasing two relatively movable members, each form comprising a latching unit adapted to be mounted upon one of the relatively movable members and a cooperating catch adapted to be mounted upon the other. The latching unit comprises a housing having an upper and a lower pivot therein and in which are mounted a floating latch and a reciprocating resetting plunger. The latch in all cases is restrained against substantial longitudinal movement by the upper and lower pivots engaging upper and lower notches respectively in the latch. First spring means are provided in the housing tending to force the latch rearwardly and the plunger forwardly. When the parts are at rest the upper pivot is seated in the upper notch and the first spring means exerts a downward pull on the forward end of the latch, causing it to rest against the forward end of the plunger in cocked position. The plunger is moved rearwardly by the catch when the movable members are brought together, and the first spring means thereupon snaps the hook end of the latch downwardly to engage the catch. Upon the first release of closing pressure against the relatively movable members, auxiliary spring means aids the first spring means in forcing the plunger forwardly and the auxiliary spring means at this instant is in eifect to move the plunger and the latch forwardly in unison to a slight extent sufficient to release the upper notches from engagement with the upper pivot and condition the hook latch for openin movement. Upon subsequent closing pressure upon the relatively movable members, the first spring means snaps the hook latch to releasing position whereupon the first spring means, either with or without aid from the auxiliary spring means, may return the plunger to its initial position, thereby propelling the catch from the housing and thus separating the relatively movable members. At the termination of the forward movement of the plunger, cooperating cam means on the plunger and the rear end of the latch shift the rear end of the latch from engagement with the lower pivot to engagement with the upper pivot, thereby causing the first spring means to return the latch to its cocked initial position. In each modification there is an auxiliary spring exerting outward force on the latch when the parts are latched together to shift the latch longitudinally forward to the slight amount permitted by the pivots and notches in order to condition the latch for opening movement upon subsequent closing of the relatively movable members. In the first case the auxiliary spring means comprises a tension spring connected between the plunger 35 and a relatively stationary part represented by the upper pivot 2 I. This arrangement causes the auxiliary spring means to forwardly shift the latch through the medium of the plunger 35 and the interengaged abutment face of the catch head 5| and the hook 2?. In the second modification the auxiliary spring means comprises the compression spring iill which is adapted to be compressed between the anchoring tongue 96 on the plunger 9i! and the rear wall 63 of the housing. The 1ongitudinal forward shifting of the latch is accomplished by this spring exerting forward pressure through the plunger and the interengaged abutment face of the catch and of the cooperating hook 73. In the third modification the auxiliary spring means comprises the spring-urged buffer H2 which exerts an outward pull on the latch H through the intervening door I03 and the engaged catch. In this third modification the auxiliary spring means does not pull or push the plunger forwardly, but the plunger and the latch move forwardly as a unit due to the tension of spring ltd holding the two parts together just as in the previous modifications. In the first two modifications the plunger is acted on by the auxiliary spring to cause the latch to move forwardly, and in the third modification the latch is acted upon by the auxiliary spring and the plunger moves forwardly therewith. In all three modifications movement of the plunger and latch forwardly as a unit is accomplished since the first spring means holds the tip of the catch against the striker face of the plunger and the tip of the hook against the abutment face of the catch, the entire longitudinal force of the first spring means being so exerted in holding the three members firmly together and the force of the auxiliary spring being brought into play to shift the three interlocked members forwardly to condition the latch for subsequent opening movement.

In all three modifications the relatively movable members are capable of movement toward each other to a limit relationship and are held slightly apart by the auxiliary spring when in latched relationship. The latch moves from its normal cocked position to a catch engaging position upon first closing movement of said members to a relationship between said limit relationship and said latched relationship whereupon the auxiliary spring forces the latch to its latching position. The latch moves to releasing position upon subsequent movement of said members toward said limit relationship, and is reset upon separation of the members.

ed any construction wherein tworelativer -t adrawer in a cable net, armthe auxiliary spring may be, so pro:

port-icned as to e} c" the drawer to any; desired extent after it hasloeen pushed slightlyinward and released.

ving illustrated described; preferred em;-

o cut to tho latching unit including an elongated housing having opposed side. walls, an elongated latch clement housing, said latchelement'being slidably guided between said opposed side walls, said la n clement comprising means defining a shoulder adapted to engage said catch element to retain said members in latched relationship spaced slightly apart from said limit relationship upon a movement of said members relatively together toward said limit relationship beyond latched relationship, a plunger slidably mounted in said housing in position to be moved rearvvardly therein by said catch element upon movement of said members to said limit relationship, first pivot means on said housing, second pivot means on said housing, cooperative means on said plunger and said latch element normally holding said latch element in a cocked position, first spring means operatively engaged with said latch element and said plunger normally to hold said latch element in pivotal engagement with said first pivot means and said plunger in a normal position forwardly in said housing, said first spring means being biased when said latch element is so engaged with said first pivot means to urge said shoulder toward said plunger whereby said latch element pivots about said first pivot means to a catch engaging position upon a first relative movemen of said members to said limit relationship, other spring means operatively associated with said members to urge said members apart to said latched relationship, cooperative means on said catch element and said latch element to shift said latch element from pivotal engagement with said first pivot means into pivotal engagement with said second pivot means and thus assume a latching position upon such movement of the members to said latched relationship, said first spring means being thereby relatively shifted to a position in which it biases said shoulder away from said plunger whereby upon a second relative movement of said members to said limit relationship said latch element pivots about said second pivot means to a releasing position, and cooperative means on said latch element and said plunger effective upon return of said plunger to its normal position by said first spring means to shift said latch element back into pivotal engagement with said first pivot means whereupon said first spring means may return said latch element to its cocked position.

iicnts of the invention, it, should-be apparskilled in the art 1 that, the; invention inits modification in arrangement and de tail. 1 claim my invention all such modificae.

ia lat ibingg device for a-pair; of; relatively; movable-members,whichdevice is of the-typewherein the; latched members are held in a slight ly spaced apart condition andunlatching iseffected by a slight further movement o-f said members tcseth b o at d position, sa device in udms a atch. elementa edto e mounted; on one of said members having forw rdly-exten n d d a s v ewins abutme ti. a at hi e 1 -tinc ud s a c an-- sated ho s n sa d; tc i g: t; ap d o be men ed; on the other: of; said members for co r ra re nsas m nt y sai catc e n n ounted in long udi l lignme with epa of trave he ee ii aid atchi g t udi an, elonsated -at h e hav nsa o end portion ad a ent: the orwars end f ai ho s ng p d for coop v y m said atch a u m nt. meanspi ot lr mountmssaid atc m n in saidvhousi sier I creme ta he hookrend. po e tio 'tow i fr m. sa dre-th 0f t eli. an, elon ate con rolrnlunse or nt ollin said latch means mounted for slidable movement long-i-tudinally in said housing and having a forward nd-portion,normal v x endine adj cent th or: Ward end-of said: housin tor n a e n y; the head of; said cat h element; and mea s i l din aspiring nerativc vnterconne tin a d: plun erand said latch-means whereby longitudinal sliding movements of said plunger by said catch element control latching and unlatching movements of said latch means.

3. A latching device for a pair of relatively movable members, said device being of the type wherein the members are latched in a slightly spaced apart condition upon closure of said mernbers and unlatched upon a slight further movement of said members together beyond the latched position, said device including a catch element adapted to be mounted on one of said members and having a forwardly extending head and a rearwardly facing abutment, a latching unit including an elongated housing, said latching unit adapted to be mounted on the other of said members, said latching unit including an elongated latch element having a hook end portion adjacent the forward end of said housing adapted for cooperatively engaging said catch abutment, an elongated control plunger for controlling said latch element mounted for slidable movement longitudinally in said housing, the forward end of said plunger normally extending adjacent the forward end or" said housing for engagement by the head of said catch element to effect longitudinal sliding movement of said plunger, means pivotally mounting said latch element in said housing for movement of said hook end portion thereof toward and away from a catch abutment engaging position in front of the forward end portion of said plunger, and means including a spring operatively interconnecting said plunger and said latch element whereby longitudinal sliding movements of said plunger by said catch element control latching and unlatching movements of said latch element.

4. In a latching device for a pair of relatively movable members, which device is of the type wherein the latched members are held in a slightly spaced apart condition and unlatching is effected by a slight further movement of said members together beyond the latched position, said device ncluding an elongated catch element adapted to be mounted on one of said members and having a forwardly extending head and a rearwardly facing abutment behind said head, a

latching unit including an elongated housing, said latching unit adapted to be mounted on the other of said members for cooperative engagement by said catch element, said latching unit including an elongated latch means pivotally mounted in said housing and having a hook end portion adjacent the forward end of said housing for cooperatively engaging said catch abutment, an elongated plunger means for controlling said latch means slidably mounted within said housing, means interconnecting said plunger and said latch means whereby latching and unlatching movements of said latch means are effected in response to corresponding movements of said plunger means, the forward end of said plunger mean extending adjacent the forward end of said housing for engagement and actuation by the head of said catch element.

5. In a latching device for a pair of relatively movable members, said device including a catch element adapted to be mounted on one of said members and having a forwardly extending head and a rearwardly facing abutment behind said head, a latching unit including an elongated housing, said latching unit adapted to be mounted on the other of said members for cooperative engagement by said catch element, said latching unit including an elongated latch means pivotally mounted in said housing and having a hook end portion adjacent the forward end of said housing for cooperatively engaging said catch element abutment, an elongated plunger means slidably mounted within said housing immedi-- ately adjacent said latch means, mean including a spring interconnecting said plunger means and said latch means for controlling latching and unlatching movements of said latch means in response to movements of said plunger means, said hook end portion normally engaging and supported by the forward end portion of said plunger means out of the path of travel of said catch element, said hook end portion engaging said catch element abutment upon depression of said plunger means within said housing a predetermined distance by engagement of the forward end thereof by the head of said catch element.

RALPH K. NOTTINGHAM.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,509,780 Robertson Sept. 23, 1924 1,775,392 Hagstrom et a1 Apr. 22, 1930 1,934,105 Totty Nov. 7, 1933

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