US2925297A - Latch mechanism - Google Patents

Description

Feb. 16, 1960 J. PICKLES LATCH MECHANISM 2 Sheets-Sheet 1 Filed Feb.v 7, 1955 NQE MS E ML K VG WP H P E S O J 17%; ATTORNEYS Feb. 16, 1960 J. PICKLES Q 5,297

LATCH MECHANISM Filed Feb. "7, 1955 2 Sheets-Sheet 2 INVENTOR. JOS-IEPH PICKLES Q 7 BY W ATTORNEY From an inspection of Figure 5 it will be apparent that the wedge portion 44 of the element 40 is effective to prevent counterclockwise rotation of the rotor 10. It will also be apparent that forces tending to rotate the rotor counterclockwise produce camming forces tending to swing the wedge cam element 40 in a counterclockwise direction. However, such movement ofthe wedge cam element 40 is frictionally opposed by the friction between the fixed abutment 56 and the ar'cuate surface 54, as well as the frictional forces existing between the lobe surface 32 and the camming surface 46 of the wedge cam element 40. Since both of these frictional forces oppose camming of the wedge cam element 40 in a direction to release the rotor 10, it will be apparent that the included angle between the surfaces Y46 and 54 considered as a wedge may have a value substantially twice as great as the angle of repose for the materials of which the abutment 56, surface 54, surface 46, and surface 32 are formed. This permits a relatively great cam rise on the cam surface 46 for a correspondingly small angular movement of the arm 42.

As previously indicated, the surface 34 of the lobe is shaped differently from the involute side 32 thereof. The wedge cam device 40 is provided with a surface portion 58 cooperable with the side 34 and particularly the tip 60 of the lobes so that upon rotation of the rotor 10 in the direction resulting from'movement of the, lobe into latched position, the lobe rocks the wedge cam element 40 out of latching position. 7

By properly selecting the angular orientation of the lobes 30 with reference to the teeth 12, an arrangement results in which the latch rotor 10 cams the wedge cam device out of blocking position as the teeth 12 roll over the teeth 22 of the keeper until the housing 14 reaches the positionillustrated in Figure 6. 'If the door is not completely closed so that the wall portion 24v of the housingis spaced from the end wall 26 of the recess in the keeper, the latch will operate to prevent opening movement of the door. If the door is thereafter caused to move by small increments, such for example as by vibration, further toward fully closed position, suitable spring means bearing against the wedge cam device 40 cause it to follow up so as to prevent return motion of the latch rotor from the furtherest latched position which it reaches.

Referring now to a practical embodiment of the invention, the construction comprises an angular support plate 62 having a wall 64 normally disposed at the free edge of a door, and a wall 66 disposed at one side of the door. Where the latch mechanism is used in conjunction with an automobile, the wall 66 is normally located at the inner surface of the door. The wall 64 includes a rearwardly extending flange portion 68 to which is secured suitable lock mechanism indicated generally at 70 and, includes an actuator 72 for release of the latch as will subsequently appear.

The toothed portion of the latch rotor including the teeth 12 is partially housed within the housing 14 previously referred to, which housing includes a mounting flange 74 welded or otherwise secured as. indicated at 76 to the outer surface of the plate 64. At the opposite side of the plate 64 from the toothed portion of the rotor 10 is provided the lobe portion thereof having the lobes 30, as best seen in Figure 1. Mounted in the plane of the portion of the rotor containing the lobes 30 is a lever or arm 78, this arm being mounted for rotation about a pin 80 and including an enlarged opening providing for some freedom of 'movement of the arm 78 in a direction perpendicular to the axis of the .pin 80. The arm 78 is provided with an arcuate slot 82 through which extends a fixed abutment pin 84. A spring 86 is provided surrounding the pinf80 and includes, an end portion 88 engageable with a laterally bent flange 90 on the arm 78, With the parts in the position illustrated in Figure 1, 1

the portion of the lever intermediate the lobe 30 and the fixed abutment 84. The camming surface 92 of the arm 78 engages the involute surface 94 of the lobe 30.

In order to free the rotor 10 for the free rotation required to move the door to open position, the arm 78 is rockedin a clockwise direction, as seen in Figure l for example by pressure applied against the flange 90. In the practical door construction the flange may be engaged by suitable actuating means such as a handle controlled lever or push button at the outside ofthe door.

The spring 88 is effective to cause the camming surface 92 of the wedge cam element 78 to follow up any movement of the lobes 30 of the rotor.

As is customary in automobile door latches, additional means are provided for actuating the latch release mechanism. This means comprises an actuating lever pivoted to the plate 66 as indicated at 102. The lever 100 includes a projection 104 movable into the path of a hook shaped portion 106 on the wedge cam arm 78 so as to blockmovement of the arm 78 to latch release position. The lever 100 is provided with an opening 108 receiving one end of the key actuated crank 72. The lever 100 includes a projecting arm 110 which overlies the hook portion 106 of the wedge cam arm 78 so that the wedge cam arm 78 may be moved to latch release position by swinging movement of the actuating lever 100. The lever 100 includes the elongated slot 112 forconnection with the usual push button actuator provided on automobile doors, by means of which the lever 100 may be moved into and out of position to block release movement of the wedge cam arm 78.

From the foregoing description it will be apparent that when mounted on the edge of a door as previously in dicated for coaction with the keeper plate as indicated in Figure 6, the door may be slammed shut which will result in rotation of the latch teeth 12 relative to the stationary rack teeth 22 of thekeeper plate. This rotationof the latch rotor 10 automatically shifts the wedge camv arm 78 out of wedging position, but the wedge cam arm. moves back to wedging position under the influence of the spring 86 as soon as the door is closed. The wedging action fo the wedge cam arm prevents any slight reverse rotation of the latching teeth and since the spring continues to'urge the wedge cam arm in wedging direction, it will follow up any further additional incremental movements in rotation of the latching teeth if the door moves slightly further toward latched position. In order to open the door it is necessary to release the wedge cam arm and this may be accomplished by swinging the wedge cam arm 78 in clockwise direction, as seen in Figure 1. This may be accomplished by pressing on the flange 90 of the aim through suitable outside handle mechanism or by inside remote control handle mechanism coupled to an opening indicated at 114 in the lever 100.

Referring now to Figures 6 and 7 there is illustrated an arrangement in which the latching teeth 12 are helical further be observed that due to the inclined relationship of the latch teeth 12 and the engaged tooth 22 of the keeper, movement of the tooth 12 (and hence of the entire latch mechanism) relative to the keeper in the direction of'the arrows 118 is effectively prevented, As a result of this construction the inter-engagement be tween the latching teeth of the latch rotor and keeper.

p es fi m n e ti e een h 49st and frame at.

the vehiclelongitudinally of rev-chat. r ass-mat of this the doorwhecome's a srtuctu l ;partj: f the vehicle frame a H Theexaet helix'angle 'ofth the, teeth 22 is not critical except that, in ,forder toretain a firm andieifect'ive' engagement, the angle should .be substarltial. It will of "sense be'apparlen'tj that if the teeth 1 12 of the latch rotor have'a helix angleof zero ,,de'grees, they will haveiio'elfect v'v'hatv'e door to take up longitudinalstresses,ibiitfwill be'perfectly effective to retain the doof'inlat'ched position. At the other' extreme, the helix angle of the teethtcannot be e [or an gnlarity of mean and one'of 'which' includes a fixea iacnag projecf rotor having 'a radially extending locking projection movablefover and engageable with the smear said fixed lock 7 ing projection at the closed inner end of said 'rec'essfthe too large since clo'singrnove'm'entof' the door isfrequir'ed I to produce rotationof the? 'latch ro tor For practical purposes the helix angle'of the teeth 12 on the rotor will normally be between 30 degrees and 60 degrees. Itwill of course be apparent that the hand of the teeth 12 and the direction of inclination of the teeth 22 are required to conform and will be in the direction such that engagement between a single tooth 12 and a single tooth 22 is effective to oppose both ope'ningmovement of the door and longitudinal separation between the free edgeof the door and the adjacent portion of the door opening.

The drawings and the foregoing specification constitute a description of the improved latch mechanism in such full, clear, concise and exact termsas to enable any person skilled in the art to practice the invention, the scope of which is indicated by the appended claims.

What I claim as my invention is': v

1.- Door latch mechanism for connecting the free edge of a swinging door and a door frame in which the door is pivotally mounted comprising a cooperating rotor and keeper releasably connecting the free edge of the door and the frame and including means for selectively preventing rotation of the rotor in the directionrequiredto permit opening movement of the door from latched posi-- tion, said rotor being disposedwith its axis generally parallel to the plane of the door when the door closed, said keeper comprising meansdefi ninga generally .hori-'- zontal recess extending in a direction transverse to the ra so nsagi c'surfa e 'o'n s h s e r u faces of said "locking projections, and the engaging'surfaces of said keeper at the closed inner end of its recess and the surface of said rotor housing at the side of said rotor, converging toward the free edge of the door to' l prevent separation between the free edge ofthe door and the adjacent edge of the door frame ina direction parallel to the plane of the door when closed.

3. Door'latch mechanism for connecting the free edge of a' swinging door and a door frame in which the door is pivotally mounted comprising a cooperating rotor and keeper releasably-connecting the freeedge of the door and the frame and including means for selectively preventing rotation of the'rotor in the direction required to permit opening movement of the door from latched position, said rotor being disposed with'its axis generally parallel to the plane of the door when the door is closed, said keeper comprising means defining a generally horizontal recess extending in a direction transverse to the plane of the door when the door is closed and having a pair of vertically separated surfaces one of which is smooth and one ofwhich includes a plurality of fixed locking projections plane of the door when'the door is closed and having 2 7 upper and lower surfaces, said .recess being open at one end to receive said rotor and closed at its other end to provide an abutment surface, said 'keeper havinginsaid recess a fixed locking projection, said rotor having a, housing having a generally horizontal wall engagingone of said-upper and lower surfaces of the recess in said keeper I and having at one side ofthe rotor a surface'engageable with the abutment surface of the recess in said keeper to limit closing movement'of the door, said rotor having a radially extending locking projection movable over and i engageable with the side of said fixed locking projection at the closed inner end of said recess, the pairs'of engaging surfaces consisting of the engaging surfaces of' a said locking projections, and the engaging surfaces of a said keeper at the closed inner end of itsrecess and the surface of said rotor housingat the side of said rotor, converging toward the free. edgeof the doorjto prevent separation between thefree edge of the demand the adjacent edge of the door frame in a direction parallel to the plane of the door when closed.

a I i 2. Door latch mechanism for. connecting thefree edge of a swinging door and a door frame in which the'door is pivotally mounted comprisingfa cooperating rotor and keeper releasably connecting the free edge of the door and the frame and including means for selectively pretion, said rotor being disposed with its axis generally parallel to the plane of the door when the door is closed,

ering said rotor and having a first wall providing a surface I slidable over the smooth surface of said'keepcr and a second wall providing an abutment surface engageable. with the abutment surface of said recess to limit closing movement of the door, said rotor having radially extending'locking projections movable over and engageable I with the side of said fixed locking projections at the closed inner end of said recess, the pairs of engaging surfaces consisting of the engaging surfaces of said locking projections, and the engaging surfaces of saidkeeper at the closed inner end of its recess and the surface of said rotor 'housingat the side of said rotor, converging toward the 1 free edge of the door to preventfseparationhetween the freeedge of the door and the adjacentedge of the door frame in a direction parallelto the plane of the door when a closed. 1

4. Door latch mechanism for connecting the free edge of a swinging door and a door frame in which the door is pivotally mounted comprising a cooperating rotor and keeper releasably connecting the free edge of the door and the frame and including means for selectively prer venting-rotation of'therotor in the direction required to permit opening movement of the door from latched p osition, said rotor being disposed with its axis generally parallelto the plane of the door when the door is closed, said '1 keeper comprising means defining a, generally horizontal recess extending in a direction transverseto the plane of, 'the'door when the door is closed and having upper and lower-surfaces, said recess being open at one end to resaid keeper comprising means defining a generally horipair of vertically separated surfaces one of which is ceive said rotor, abutment means acting between said door and door frame and having abutment surfaces disposed i generally-parallel'to the plane of the 'door when the door is closed, said keeper having in said recess a fixed locking projection, said rotor having a housing having a generally"? horizontal wall engaging one, ofsaid upper and lower 7 v surfaces of the recess in said keeper, said rotor having a j 1 a radially extending locking projection movable overand V engageable with the side of said fixed locking projection at the inner end ofsaid-recesgthe pairs of engaging SUI? faces consisting of the engaging surfaces of 'said' locking projections and the abutment surfaces of said abutment means converging toward the free edge of the door to provide wedge means operable to prevent separation between the free edge of the door and the adjacent edge of the doorframe in a direction parallel to the plane of the door. when closed, and manually releasable take-up mechanisn 'operatively connected to said rotor and operable to prevent unlatching rotation thereof from any position Withix'l a range of door-latched positions as determined by engagement between the abutment surfaces of said abut? {Hint means.

-Reei-encesite nin file .Q Ib s pa n UNI ED STATES PATENTS Spore V May 23, 1871 I Whitcbinb Feb. 24,1914 Benn tt-- J y 5 1916 Wells --V- Dec. 3, 1929 Marple Apr. 23, 1940 ,Marple May 27, 1941 -Marp,1e r r Nov. 10, 1942 Endter Mar. 23, 1943 Roethel V v Feb. 24, 1953

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