US2347468A - Door latch - Google Patents

Description

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DOOR LATCH Original Filed Nov. 13, 1939 3 Sheets-Sheet 2 April 25, 1944.

Original Filed Nov. 13, 1939 j r l Ill/A9 '1, Pf/ g; ff g A. DIEMER DOOR LATCH 3 Sheets-Sheet 5 Patented Apr'. 25, 1944 DOOR LATCH Anton Diemer, Stuttgart, Germany; vested in the Alien Property Custodian Original application November 13, 1939,` Serial No.. 303,977. Divided and this application 0ctober 10, 1940, Serial No. 360,523. In Germany May 12, 1938 13' Claims.

This application is a division of application Serial No. 303,977, filed November 13, 1939.

This invention relates to door latches, especially for doors of motor vehicles and for other doors which when closed are under spring tension, the bolt of such-latches carrying out, in addition to its forward motion, also a transverse one or a cross motion. An object of such double motion is to secure an easyv entering of the head of the latch -bolt into the striker plate or behind the lockingwedge, despite the door being distorted orv being under spring tension when in closed position. This should occur prior to the door being completely introduced into the body frame, so that such doors need not be slammed. However, since with latches ofknown structure the bolt performs both these movements simultaneously, the results aimed at are not always secure- 1y attained. This is dueto the fact thatespeciallywith bolts having their forward moticnfdepending upon spring action only t-may occur thatY the head of the bolt will not enter sufficiently deep into the striker plate opening or behind the locking wedge, being thereon jammed in the attained position on account of great friction or pressure. In such a condition the door may open accidentally upon the occurrence of the slightest concussion or distortion.

The present invention has for its object to remove Vthis drawback, :this beingv achieved by a suitable connection between the door handle and the latch bolt providing for both said movements being carried out consecutively only. In this way when alatch is to be unlocked, the bolt performs at first a cross motion only, whilst it is retracted into the vlatch casing after said cross motion is terminated. In locking operation, on the contrary,.the bolt executes first its forward motion, whereafter when this latter is terminated, it ,carries out its cross motion providing for a complementary drawing of the door into the door frame.

Another object is to provide two separate independently.operatingA doorv handles on opposite sides of the door.

With these objects in View, in a preferred embodiment of this invention, I provide a slider betweenthe latch bolt and a lever connected to the door handle, said slider being .adapted to bear on thelatch bolt and .on the latch casing. When the door handle performs an unlocking movement said slider first slides along a Wedge surface whereafter it causes the latch bolt to perform its inwardmovement. Thejust mentioned wedge surface may be arrangedeither `on' the bolt or on the door casing or ontheslider proper.

When this door latch, is used with motor vehicles it is desirablel that the outer vdoor handle be able to .be moved independently ofthe inner one, so that, e. g., the inner door handle vremains stationary when the latch is. o.pened by means of the outer door handle and vice versa. In order that such a mutualindependence ofboth vdoor handles be obtained with` the above ydescribed new door latch, I provide, laccording to a further, improved-feature of this my invention between the latch bolt yand the displaced doorhandles or respectively betweena slider acting yon the latch bolt and said doorhandles, a .swinging lever transferring themotionbf the door handleeither to thelatch bolt, or tothe. slider. By this means when one of the door handles isrotated,.the point of. engagement .between the other door handle and .the swinging lever ,servesv always asstationary fulcrum for said lever.

vOther featuresV and objects 4of the invention will more fully appear fromthe vfollowing description of a number of exemplary lembodiments rthereof with reference to the appended drawings.

In the drawings:

Figures 1 to 5Villustrate one form of embodiment of a latch constructed ,according to this my invention, wherein both .door handles operate independently of one another.

Figures 6 to 9 illustrate a further exemplar embodiment of a latch having mutually independent door handles, and

. Figures`10 to 13 illustrate another exemplary embodiment of a structure analogous to the above mentioned ones.

In the exemplary embodiment represented on Figs. l to 5fboth door handles', 65, 66 the axles whereof are Amutually'displaced may be operated independently one from another. 5 are views of the latch having the cover plate of its easing removed. v Fig. 1 illustrates the parts of the latch in their position of rest, Fig. 3 the same parts in an unlocking position obtained by a depression of the inner door handle B5, Yand Fig. 5 represents the parts of the 'latch in-their unlocked position due to'a depression of the outer door handlel. Figs. 2 and 4 are sectional views taken on lines 2-2 and 4-4 respectively of Figs. 1 and 3.

In this embodiment the bolt 30 is mounted shiftably in longitudinal direction in4 a chamber 35 of vthe latch casing and'it is arrangedy swingably about its reinforced-portion 36. The bolt 39 is held against movement in downward direc- Figs. l, 3 and` tion by means of its head 34 sliding in an aperture 11 of the latch casing as well as by means of a lug 19 of the cylindrical portion 36 sliding in a slit 18 of the base plate 33 of said latch casing. The leaf spring 43 presses the bolt 38, when no other greater forces are acting thereon, toward the base plate 33 of the latch casing. In this instance the roller 58 is mounted in the latch bolt and the inclined surface 1| causing the bolt to move in transverse direction is arranged on the slider 55. This latter is guided by a rectangular projection 54 engaging in the slit 18 of the base plate 33 of the latch casing in parallelism to the direction of movement of the latch bolt 38. Said slider carries on its inner bifurcated end 88 a swinging lever 82 pivotally mounted on a pin 8|. A contraction spring 84 attached to the base plate of the latch casing by means of a pin 83 urges the latch bolt into its locked position. The cut-out 14 of the latch bolt wherein the slider 55 moves has its aperture directed downwards. The purpose of such arrangement is to enable the swinging lever 82 to pass through said cut-out. Therefore, the latch bolt head 34 is connected in that case with the cylindrical portion 36 of the bolt by means of an upper arm 31 only.

A hub 85 mounted rotatably in the latch casing is positively connected to the outer door handle 65'by means of a square shank 86 of said handle being inserted into the hub. Said latter carries rigidly connected thereto and arranged in the latch casing a lever 81 also pivotally connected by means of a link 98 mounted on pins 88, 89 with the bottom end of the swinging lever 82. A contraction spring 92 attached to the latch casing by means of a pin 9| causes an extension 93 of the lever 81 to bear upon a striker stud 94 secured in the latch casing. An inner door handle 66 is positively connected by means of a square shank 96 to a second hub 95 also rotatably mounted in the latch casing. Said inner door handle is connected by means of a link 98 and a lever 91 attached to the hub 95 with a point lying between the ends of the swinging lever 82. This connection is of a similar linked nature as that of the outer door handle 65 with the bottom end of said swinging lever. The lever 91 is drawn in its position of rest towards a stationary abutment pin |8| by means of a contraction spring |88 engaging with its extension 99.

If lever 61 is now moved upwardly by depressing the inner door handle 66, it draws first the slider 55 by means of a link 98 and of a swinging lever 82 so far in backward direction that the inclined surface 1| of said slider moves through beneath the roller 58 of the latch bolt. The latch bolt is thereby swung due to the action of leaf spring 43, about its cylindrical portion 36, towards the base plate 33 of the latch casing. In this motion the pivot 89 of the link serves as fulcrum for the swinging lever 82, so that the link 98 and the lever 81 form nearly a straight line when -in position of rest. On the other hand, the traction forces transferred on the system 81, 98 when the inner door handle 66 is depressed the extension 93 of lever 81 with a greater force towards the striker stud 94, so that the outer door handle 65 remains in its position of rest when the latch is acted on by the inner door handle 66. When the slider, as it has been explained above, is drawn back by lever 91 so far that its inclined surface 1| has entirely cleared the roller 58 of the latch bolt, said slider abuts by its bifurcated inner end 88 on the cylindrical movement it draws the latch bolt into the latch casing up to the unlocking position represented in Figs. 3 and 4. When the latch is unlocked by the outer door handle 65, the movements of the slider and of the latch bolt 38 are carried out in the same sequence as above,.with the only dierence that in said latter case the swinging lever 82 is turned by means of lever 81 and link 98 in clockwise direction. Hereby also the pivotal connection |82 of the link 98 serves as relatively stationary fulcrum for the swinging lever 82 (see Fig. 5).

During the locking operation of the latch, both of the door handles and 66 are also operated independently one from another so that any time when a door handle depressed prior to the door being closed performs an ascendent movement it operates a tilt of the swinging lever 82 in counterclockwise direction. Simultaneously also the pivot pin of the other door handle engaging with the swinging lever acts as a fulcrum for said latter. By this means first of all the latch bolt is shifted outwardly together with the slider by the assistance of contraction springs 84, 92 and |88 until said bolt strikes onto a pin |83 secured in the lock casing whereafterV the slider 55 continues its outward movement alone until it reaches the position represented on Figs. 1 and 2. Following to this the inclined surface 1| of the slider enters between the casing base plate 33 and the roller 58 of the latch bolt swinging thereby said bolt about its cylindrical portion 36. The head 34 of the latch bolt is thereby forced against the abutment 18 of the locking wedge 52, the inner surface 62 of the door being thus pressed to the yielding sealing strip 58. The force applied for this purpose on the door handle is relatively small, because the parts 91, 98 and 81, 98 respectively act as toggle links which are nearly straight at the end of the closing movement of the latch bolt. It may be clearly seen from the drawings that this embodiment of the latch maybe used for enabling the door to be closed by a mere slamming. In this case when the latch bolt gets in contact with the inclined surface 15 of the locking wedge, it is shifted inwardly and on having passed said inclined surportion as of the latch boit and at its further face it snaps back outwards again under the action of spring 84, without thereby setting into movement the slider 55 and hence also the door handles 65, 66.

In the second exemplary embodiment provided with independently operated door handles as shown in Figs. 6 to 9 the latch is represented in locked position on Figs. 6 and 7. Fig. 7 represents a section of Fig. 6 taken on the line 1 1. Fig. 8 represents the latch unlocked by a depression of the inner door handle 66 whilst in Fig. 9 the same position of the latch bolt is shown after the outer door handle has been depressed. In all of the Figures 6, 8 and 9 each of which represents the latch in elevation the cover plate 42 of the latch casing has been removed.

Broadly speaking, the details and the operation of this latch are similar to those of the above mentioned exemplary embodiment. But in this case the levers 81, 91 moved by the door handles are not connected to the swinging lever by links, such connection being made by means of pins |88, |01 carried by levers 81, 91 respectively and engaging into preferably arcuate slots |88, |89 of the swinging lever. Thus when lever 81 is moved downwardly or lever 91 upwardly the swinging lever |85 is always tilted in clockwise direction, a pin |86 or |81 of that amarres ofthe levers S1, 91 which is not moved, serving thereby as a fulcrum for said swinging lever. A further difference vbetween this exemplary embodiment and-the preceding one resides therein that in this case the roller-58 is arranged on the outer end of the slider 55, whilst the cambered vinclined surface 1| istformed on the head 34 of the latch bolt.

Another form of door latch according to this invention having lhandles acting independently from .one another is represented in Figs. l0 to 13 ci which`l'ig`. ilshowsagain the latch in locked position with the coverplate 42 of the latch casing having been removed; Fig. '12,.is a section of Fig. l0 taken on the line l2-l2, whilst Fig. l1 represents in-.elevation a latch unlocked by the depression ofthe inner door handle Sii and Fig. 13 :is a similar view of a latch having .been unlockedby a .depression of the outer door handle B5.

In'this exemplary. embodiment the swinging lever |1537' engages by means of a cut-out provided on its upper end with a pin 8| ofthe slider. '55. On the bottom end of a Surface of the swinging lever` facing the base plate 33 of the latch .casing a block ||2 is attached provided on. two of its .sides with .gearing teeth. The upper` teeth ||3 of this block engage with a segment i4 provided with corresponding teeth and;mounted to rotate on a stub shaft H5 secured in the base plate 33 of the latch casing. In the same way the bottom teeth l I6 of part H2 are in engagement with ya, .toothed segment vrotatably.mounted on a stub shaft V| I8 also attached to the base plate .33.

TheY teeth H3 `and ||6 of the block H2 are formed .on curves facing one another. with their concavesides, the center of curvature ||9 of the arcoi- ,teeth H3 lying inthe point of contact ofthe pitch circle of Vteeth H5 ofthe block ||2 with the #pitch circle ofY the teeth of segment H1. `On the; contrary, the center of curvature |20 of the arcV of teeth HE of part |:|2 is located inthe point of contact of the Vpitch circle of the-teeth H3 3f-part |12 with the pitchcircle of :the teeth of segment |14. Therefore, the swingingv lever l| Id `will rotateV about the center of curvature H8 as-about a X'ed vfulcrurn in clockwise vdirection when the toothed segment H4 is rotated. in counterclockwise direction.

Furthermore, Ythere will be also a clockwise rotationpfthe swinging lever H0, but this rotation is carried out` about the center of curvature liiil as aboutva xedfulcrum, when the toothed segment il-is'turned in counterclockwise direction. Thetoothed segment i i4 is also in operative engagement Awith another segment |2| rigidly mounted on `the rotary tumbler 95 of the inner dcorhandle 65, Whilst the toothed segment. ,li'i engages with a further segment 22 rigidly mounted on the rotary tumbler 85 of the outer door handle 5. Owing-.to the above disclosed arrangement, rwhen the inner door handle 66 is depressedthe swinging-lever i I U is turned about the center cf curvature ||9 in clockwise direction. By'this motion, in the same way as has been described in connection with the precedent embodiments it retract-s primarily into the latch casing the slider and thereafter also the latch bolt 3e. A similar unlocking operation is also present when on account of depressing the outer door handle'the rswinging-lever Il@ is rotated about the center of curvature |20 in clockwise direction. On vthe other hand, when both of the door handles are moved in upward' direction;

the parts of the latching mechanism move in opposite directions. When both segments |2| and |22 are in their position of rest they are drawn respectively by contraction springs |23 and |24 towards abutment pins |25 and |26 xed on the base plate of the casing. When the latch is unlocked by means of one of the door handles B5, Bt, the segment belonging to the other door handle is more strongly pressed against its abutment pin by reaction forces acting thereon. In this way, the position of one of the door handles is not inuenced by a depression of the other one, both vdoor handles being thus adapted to operate quite independently from one another.

Having described several illustrative embodiments of the invention it is pointed out that various changes and modificatonstherein may be made without departing from the invention, it being intended that `the patent shall cover, by suitable expression inthe appended claims, all features of patentable novelty existing in the invention disclosed, as illustrated by the embodiments described.

I claim:

l. A door latch of the kind described, comprising a casing adapted to be secured in a door, a latch bolt mounted slidably in said latch casing and adapted to be swung about its inner end in a direction transverse to the plane of the door, a slider adapted to perform forward and backward movements along a base plate of said `casing between said plate and said latch bolt, a swinging lever pivotallyv connected with said slider and attached by link means to levers rigidly connected with hubs journalled in said latch casing and carrying spaced door handles adapted to be operated independently from one another, each of said levers and its respective link being disposed substantially in a straight line when in position of rest, and spring means adapted to urge said bolt into its locking position and to press the head of said bolt towards a base plate or said latch casing.

2. A door latch of the kind described, kcornprising a casing adapted to be secured in a door, a latch boit mounted slidably in said latch casing and adapted to be swung .about its inner end in a direction transverse to thefplane of the door, a slider adapted to perform forward and backward movements along a base plate of said casing between said plate and said latch bolt, a swinging lever pivotally connected with said slider and attached by link means -to levers rigidly connected with hubs' journalled in said latch casing and carrying spaced door handles adapted to be operated independently from one another, each of said levers and its, respective link being disposed substantially in a straight line when in position of rest, spring means adapted to urge said bolt into its locking position and to press the head or" said bolt towards a base plate of said latch casing, said levers attached to hubs being connected in such way with two spaced points of said swinging lever that when one of said hub carried levers is swung by its door handle, said lever is rotated about the point of its pivotal connection with the lever carried by the other hub. v

3. A door .latch of the kind described, corn prising c ng adapted to be secured in a door, a latch bo mounted slidably in said latch casing and adapted to be swung about inner end in a direction transverse to the plane of the door, springrneans adapted to urge said bolt into its locking position and to press the head ci said bolt towardsa base plate of said latch casing, a slider adapted to perform forward and backward movements along a base plate of said casing between said plate and said latch bolt, and adapted to retract said bolt into its unlocking position, a swinging lever pivotally connected with said slider and provided with oppositely curved slits engaged by pins carried on levers connected with two diiferent hubs journalled in said latch casing and carrying door handles, the curvature of said slits being preferably directed in opposition to the curvature of the arcuate paths followed by said pins.

4. A door latch of the kind described, ccmprising a casing adapted to be secured in a door, a latch bolt mounted slidably in said latch casing and adapted to be swung about its inner end in a direction transverse to the plane of the door, a slider adapted to perform forward and backward movements along a base plate of said casing between said plate and said latch bolt, a swinging lever having on one of its ends a pin and slot connection with said slider and carrying on its other end two opposite' convexly arched toothed gear portions each of which is positively connected by the intermediation of toothed gear members with one of the door handles, the centre of curvature of each one of said arcs of teeth lying in the point of contact of the pitch circle of the opposite arc of teeth with that of the intermediary toothed member engaging with said opposite arc of teeth.

5. A door latch of the kind described, comprising a casing adapted to be secured in a door, a latch bolt mounted slidably in said latch casing and adapted to be swung about its inner end in a direction transverse to the plane of the door, a slider adapted to perform forward and backward movements along a base plate of said casing between said plate and said latch bolt, a swinging lever movably connected with said slider, two hubs journalled in said latch casing and each carrying door handles, spring means adapted to urge said bolt into its locking position and to press the head of said bolt towards a base plate of said latch casing parallel with the plane of the door, and means operated by either hub for actuating said lever.

6. A door latch of the kind described, comprising a casing adapted to be secured in a door, a latch bolt mounted slidably in said latch casing and adapted to be swung about its inner end in a direction transverse to the plane of the door, a slider adapted to perform forward and backward movements along a base plate of said casing between said plate and said latch bolt, spring means adapted to urge said bolt toward its locking position, spaced door handles and connections between said door handles and said slider for operating said slider either with or against the action of said spring, upon operation of either door handle.

7. A door latch of the kind described, comprising a casing adapted to be secured in a door, a latch bolt mounted slidably in said latch casing and adapted to be swung about its inner end in a direction transverse to the plane of the door, a slider adapted to perform forward and backward movements along a base plate of said casing between said plate and said latch bolt, spring means adap-ted to urge said bolt toward its locking position, spaced door handles and connections between said door handles and said slider for operating said slider either with or against Cab the action of said spring upon operation of either door handle, said connections each including a toggle linkage arranged to be substantially straight when the bolt is in elective position.

8. A door latch of the kind described, comprising a casing adapted to be secured in a door, a latch bolt mounted slidably in said latch casing and adapted to be swung about its inner end in a direction transverse to the plane of the door, a slider adapted to perform forward and backward movements along a base plate of said casing between said plate and said latch bolt, spring means adapted to urge said bolt toward its 1ocking position, spaced door handles and connections between said door handles and said slider for operating said slider either with or against the action of said spring upon operation of either door handle, said connections each including a toggle linkage arranged to be substantially straight when the bolt is in effective position, and each serving as an abutment for the reaction forces set up by operation of the other toggle linkage.

9. A door latch of the kind described, comprising a casing adapted to be secured in a door, a. latch bolt mounted slidably in said latch casing and adapted to be swung about its inner end in a direction transverse to the plane of the door, a slider adapted to perform forward and backward movements along a base plate of said casing between said plate and said latch bolt, spring means adapted to urge said bolt toward its locking position, a rockable lever adapted to move said slider, spaced door handles and a connection between each door handle and said lever, each connection being adapted to rock said lever when actuated by its handle, and to provide a fulcrum for said lever when the other connection is actuated.

10. A door latch of the kind described, comprising a casing adapted to be secured in a door, a latch bolt mounted slidably in said latch casing and adapted to be swung about its inner end in a direction transverse to the plane of the door, a slider adapted to perform forward and backward movements along a base plate of said casing between said plate and said latch bolt, a swinging lever pivotally connected with said slider and attached by toggle linkages to spaced door handles adapted to be operated independently from one another, each of said linkages being disposed substantially in a straight line when in position of rest, and spring means adapted to urge said bolt into its locking position and to press the head of said bolt towards a base plate of said latch casing, said linkages being connected in such a way to two spaced points of said swinging lever that when one of said handle operated levers is swung by its door handle, said swinging lever is rotated about the point of its connection with the linkage connected with the other handle.

11. A door latch of the kind described, comprising a casing adapted to be secured in a door, a latch bolt mounted slidably in said latch casing and adapted to be swung about its inner end in a direction transverse to the plane of the door, a slider adapted to perform forward and backward movements along a base plate of said casing between said plate and said latch bolt, and arranged to force said latch to locking position, a swinging lever pivotally connected with said slider and provided with oppositely curved slots engaged by pins carried on levers connected with two different door handles, the curvature of said slots being preferably directed in opposition to portions each of which is positively connected by the intermediation of toothed gear members with one of two door handles, the center of curvature of each one of said gear portions lying in the point of contact of the pitch circle of the opposite gear portion with that of the intermediary toothed member engaging with said opposite arc of teeth.

13. A door latch of the kind described, com@ prising a casing adapted to be secured in a door, a latch bolt mounted slidably in said latch casing, a swinging lever having on one of its ends a pin and slot connection for sliding said latch bolt and carrying on its other end two opposite convexly arched arcs of teeth each of which is positively connected by the intermediation of toothed gear members with one of two door handles, the center of curvature of each one of said arcs of teeth lying in the point of contact of the pitch circle of t-he opposite arc of teeth with that of the intermediary toothed member engaging with said opposite arc of teeth.

ANTON DIEMER.

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