US2240690A - Door latch - Google Patents

Description

A. DIEMER Dooa LATCH original Filed Nov. 1:5, 19:59

May 6, 1941.`

ATTO N EY Patented May 6, 1941 DOOR LATCH Anton Diemer, Stuttgart, Germany Original application November 13, 1939, Serial many May 12, 1938 Divided and October 10, 1940, Serial No.

this applicatlon 360,571. In Gers claims. (c1. 292-264) 'Ihis application is a division of application Serial No. 303,977, Jed November 13th, 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 easy entering of the head of the latch bolt in i the striker plate or behind the locking wedge, despite the door being distorted yor 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 of known structure the bolt performs both these movements simultaneously, rthe results aimed at are not always securely attained. This is due to the fact that especially withA bolts having their forward motion depending upon spring action only it may occur that the head of the bolrt will not enter sufciently 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 this drawback, this being 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 a latch is to be unlocked, the bolt performs at rst a cross motion only, whilst it is retracted into the latch casing after said cross motion is terminated. 11i-locking operation, on the contrary, thev bolt executes first its forward motion, whereafter when this latter is terminated, it carries out its cross motion providing for a compleinentary drawing of the door into the door frame.

Another object ofthe invention is to provide a slider between the'latch bolt and a lever operated by the door handle, said slider being adapted to bear both on the latch bolt and on the latch casing through antifriction means. When the door handle performs an unlocking movement said slider first slides relative to a wedge surface whereafter it causes the latch bolt to perform its inwardA movement. The just mentioned wedge surface may be yarranged either on the bolt or on the door casing or on the slider proper.

Other features and objects of the invention motor vehicle in a will more fully appear from the following description of several exemplary embodiments thereof with reference to the appended drawing.

In the drawing:

Figure 1 illustrates in elevation a door lock constructed in accordance with this invention and applicable to motor Vehicles one wall' thereof being removed.

Figure 2 is a cross-section on the line 2-2 of Fig. 1. 1

Figure 3 is -a cross-sectional view similar to Fig. 2 but showing a modification.

In the form illustrated in Figs. 1 and 2 the latch bolt 30 is guided slidably between Walls 3| and 32 of the latch casing. The bolt proper consists of a head 34 biased towards the baseplate 33 of the latch casing, of a cylindrical part 36 shiftable in a chamber of said casing and of two arms 31, 38 connecting the said cylindrical part with 'the bolt head. Guided in grooves 40, 4| of the walls 3l and 32 respectively is a pin 39 projecting upwardly and downwardly from the cylindrical part 36, In this way the latch bolt 30 is adapted to be moved not only in its longitudinal direction but also in a direction transverse to the plane of the latch when oscillated about the pin 39. A leaf spring 43 att-ached to a partition 42 of the latch casing tends steadily to urge the head 34 of the latch bolt towards the base plate 33 of the latch casing, whilst a coiled spring 44 which bears by one against the cross wall 46 of the latch casing and -by its other end, at 41, against the cylindrical part 36 of the latch bolt is adapted steadily tov urge said latch bolt 30 outwardly in the direction of its length.

The latch casing is mounted in a door 49 of a known manner by means of screws 49. When the door is closed, its inner edge is applied, also under a. relatively great pressure onto a yieldable sealing strip 50 provided on the rigid motor vehicle body frame 5| surrounding the door opening. The head 34 of the latch bolt bears under a suitable pressure onrto the rear face of a locking wedge 52 also arranged on the frame.

A slider 55 guided by its lateral lugs 54 in a slot 53 of .the casing base-plate 33 is adapted to develop a pressure necessary for the'closing of the door. Said slide carries on its bifurcated outer end 56 a roller |36 rotatable on a pin 51. Said roller bears, in closed position of the door, on the cambered surface 1| of the latch bolt head 34. A second roller |35 bears upon a suitable abutment such as the base plate 33 and of its ends, at 45,

in a manner known per se,`

- of thedoor handle, l means of its cylindrical head 60 in outward diserves to eliminate sliding friction of the slider upon the base plate.

A cylindrically shaped end 80 of a lever 6| is engaged in a cavity 59 o f the slider 55, Said lever passes downwardly between the arm 38 of the latch bolt and rthe casing base plate 33, its other end being iixed on a. tumbler 62 journalled both 'ln the said casing base plate and in the cover plate 63 of the latch casing.

A longitudinal bore of square cross-section is formed in the tumbler wherein shank is inserted having attached to both its ends respectively .the outer and the inner door handles 65 and 66. A contraction spring 61 havto a hook-shaped i ing one of its ends attached extension 68 of lever 6| and connected by'its other end to a pin 69 xed in the laltch casing is adapted to prevent any rattling of the upper cylinder-shaped end 60 of lever 6| in the cavity 59 of the slider 55. Y.

When the door is firmly closed as shown in the drawing, lever 6| takes the position shown in Fig. 1. The roller |36 of slider 55 presses the latch bolt head 34 against the abutment 10 of locking Wedge 52 and the roller |35 transfers the reaction force to the base plate 33 of thelatch and thereby the entire door is pressed against .the yieldable sealing strip 50 of the door frame. In this way the door is closed ltightly and secured against rattling, being simultaneously pressed onto the edges of the said door opening. The cambered conformation of the latch bolt head 34 is such that the roller |36, when in locking position, lies upon a surface nearly parallel to the base plate133 so that the latch device has non-reversing eiiect. In other words, no forces acting in longitudinal direction of the latch bolt may be created by a pressure acting transversely door, i. e, no forces acting to the plane of the both on the laltch'bolt proper may be created thereby. Y

When the lever 6| is swung. by depressing the outer or inner Vdoor handle 65 or 66, it rst withdraws roller |36 from the surface 1I permitting spring 43 to swing the latch inwardly and thereafter lthe cylindrical head 60 of the slider 55 shifts the latch bolt in its longitudinal direction until it clears the keeper 52. 'I'he door may be now entirely opened.

When a closing movement of the door is carried out the above recited operative steps follow in opposite order. So when one of the door handles 65, 6 6 has been depressed, the door is primarily closed so far only but slightly. on the yielding sealing strip 50. By moving the door handle upwards, the bolt is shifted out of the latch casing until it takes a and on the slider position behind keeper 52. Such outward mo` tion of the bolt is assisted by springs 44 and 61. Should now the lever 6| be brought back into the position of Fig. 1 by a further upward movement it will move the slider by rection, whereas the latch bolt 30 isno longer moving outwardly for the reason that its guiding pin 39 has been already brought to contact with the outer end Aof the-guiding slots 40, 4|. There- |36 of the slider now moves along fore the roller the surface '1| of the bolt head 34 andat the same time it turns' the latch bolt 34 about the pin 39 up to the moment when the bolt reaches again its closing position represented on Fig. 2.

The locking operation may be also carried out without acting on the` door handle byv merely slamming the door. In the latter caseth'el latch that its inner surface 12 bears' a squareshaped invention wherein a number `ing a casing adapted to latch bolt mounted slidably and swingably in said Thereby neither the slider 55 latch bolt 30 is retracted into the latch casing when its head 34 strikes on the inclined surface 15 ofthelocking wedge in opposition to spring 44. nor the door handles 65, 66 change their position. As soon as the inner surface of the door gets in contact with the sealing strip 50 and said latter is sufficiently compressed by the momentum of the slammed door, the bolt head 34 snaps behind the abutment 10 of the locking wedge under the action of spring 44 whereon thedoor is securely latched.

It is naturally an object of this invention to have doors closed noiselessly by operating a door handle. However an additional advantage of this my invention, 'as it will be seen from a further description of itsembodiments, resides therein that doors provided with latches made on the basis of this invention may be also'closedin the way heretofore practicable. where such operation would not be troublesome.-v

Fig. 3 illustrates a modified embodiment of the of rollers |31, |38 of different diameter are arranged on a common axle |39 carried by the slider 55. The rollers |38 of smaller diameter roll on the cambered surface 1| only of the latch bolt head 34, while the rollers |31 of greater diameter contact only with the base plate 33 of the latch casing. For this purpose there is provided in the inclined surface 1| a depression |40 having its breadth and depth corresponding to the roller |31 having a greater diameter. By this means also sliding friction between the rollers on the one hand the base plate of the latch casing or the inclined surface of the head bolt on the other hand is avoided.

Having described several illustrative embodiments o1' the invention it is pointed out that various changes and modifications therein may be made without departing from vthe invention, it being intended that the patent shall cover, by suitable expression in the appended claims, all features of patentable novelty existing in the invention disclosed, as illustrated by the embodiments described.

I claim:

1. A door latch of the kind-described, comprising a casing adapted to be secured in a door, a bolt mounted slidably and swingably in said a slider shiftably guided in said casing and adapted to be moved between a wall thereof and said latch bolt in parallelism to the sliding vmovement of saidI latch bolt, a vswinging lever movably connected to said slider and being directly or indirectly attached to rotary tumbler means having door handles operatively connected therewith, spring means secured in the said lock casing being adapted to urge said bolt into its locking position, there being provided on said slider a number of rollers mutually displaced in such a way that one of said rollers engages with a base plate only of said casing, whilst another one is in engagement with an inclined surface arranged on said door latch only.

2: A door latch of the kind described, comprisbe secured in a door, a

casing, a slider shiftably and adapted to be moved d said latch bolt in guided in said casing between a W'all thereof parallelism to the sliding means having door handles operatively connected therewith, spring means secured in the said lock acts as any conventional door latch wherein the .with said abutment, whilst another one is in casing being adapted to urge seid boit misas llocking position, there being provided on the outer end of said slider a number of rollers of different diameter mounted on a common pin axle, whereby either the base plate of said latch casing or the inclined surface of said latch bolt has a depression in a place opposing the rollers' lof maximum diameter and being of such depth that said rollers are bearing either on the latch bolt alone or only on the base plate of said latch casing.

3. A door latch of the kind described, comprising a casing adapted to be secured in a door, a latch bolt mounted slidably and swingably in said casing, a slider shiftably guided in said casing and adapted to be moved between a wall thereof and said latch bolt, spring means secured in the said lock casing being adapted to urge said bolt into its locking position, manually operated means for operating said slider, there being pro vided on said slider a number of rollers mutually displaced in such a way that one of said rollers engages with a base plate only of said cas.

ing, whilst another one is in engagement with an inclined surface arranged on said door latch only.

4. A door latch of the kind described, comprising a casing adapted to be secured in a door,

a latch bolt mounted slidably and swingably in said casing, a slider shiftably guided in said casengagement with said door latch only.

5. A door latch of the kind described, comprising a casing adapted to -be secured in a door,

a latch bolt mounted slidably `and swingably in said casing, a slider shiftably guided in said casing and adapted to .be moved between a wall thereof and said latch bolt, spring means secured 'in the said lock casing being adapted to urge said bolt into its locking position, manual means for operating said slider, an said abutment having surfaces converging in the direction of the bolt locking position, a plurality of rollers of different diameter mounted on said slider on a common axle, one of said converging surfaces having a depression opposite the rollers of maximum diameter and being of such depth that said rollers bear either on the latch bolt alone or only on said abutment.

6. A` door .latch of the kind described comprising a casing adapted to be secured in a door said casing being formed with an inwardly facing surface, a latch bolt mounted slidably and swingably in said casing, said bolt being formed with a surface facing saidsurface on the casing, a

' slider shiftably guided in said casing and adapting" and adapted to be moved between a wall thereof and said latch bolt, spring means secured in the said lock casing being adapted to urge said bolt into its locking position, manual means for operating said slider, an abutment, said bolt and said abutment having surfaces converging in the direction of the bolt locking position, a plurality of rollers on said slider mutually displaced in such a way that one of said rollers engages only ed to be moved between a wall thereof and said latch' bolt, spring means secured in the said lock casing -being adapted to urge said bolt into its locking position, manually operated means for operating said slider, there being provided on the outer end of said slider a number of rollers of different diameter mountedon a common axis, each adapted for engaging one of said surfaces, one of said-surfaces having depressions opposite the rollers of maximum diameter which are of such depth that some of said rollers bear on the latch bolt alone and the others only on the base plate of said latch casing.-

. ANTON DIEMER.

abutment, said bolt and l

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