US3334935A

US3334935A - Door latch

Info

Publication number: US3334935A
Application number: US469219A
Authority: US
Inventors: James W Eddy
Original assignee: Chrysler Corp
Current assignee: Old Carco LLC
Priority date: 1965-07-02
Filing date: 1965-07-02
Publication date: 1967-08-08
Anticipated expiration: 1984-08-08
Also published as: DE1553317A1; DE1951435U; DE1553317C3; DE1553317B2

Description

J. w. EDDY Aug. 8, 1967 DOOR LATCH I 4 Sheets-Sheet 1 Filed July 2, 1965 INVENTOR. Jim; fiJy BY Hm M HM FTTORNEYJ Aug. 8, 1967 w, EDDY 3,334,935

DOOR LATCH Filed July 2, 1965 4 Sheets-Sheet 2 FTTOPNEXJ.

J. W. EDDY DOOR LATCH Aug. 8, 1967 4 Sheets-Sheet 3 Filed July 2, 1965 INVENTOR. Jams W57,

HTTORME'KS.

J. W. EDDY DOOR LATCH Aug. 8, 1967 4 Sheets-Sheet 4 Filed July 2, 1965 INVENTOR. Jaime; 50 BY y I'll FTTORNEX I United States Patent Delaware Filed July 2, 1965, Ser. No. 469,219 Claims. (Cl. 292216) This invention relates to a mechanism for latching a movable member to a fixed member; more particularly, it relates to a door latch for an automobile.

In a typical automobile door latch, a bolt is moved in response to closing of the door and a detent coacts with a ratchet tooth on the bolt to prevent return movement of the latter. Means are also provided to lock the door in its closed or latched position. These locking means may typically comprise a key cylinder lock on the outside of the door and a push button or locking handle on the inside of the door.

Most latches today are of the safety type in which two ratchet teeth are provided serially on the bolt so that if the detent shakes loose from one tooth, as for example in an accident, it may still be engaged by the second or safety tooth to prevent opening of the door.

This double tooth arrangement, while an improvement from a safety standpoint over the single tooth latch, does offer certain disadvantages. In a copending United States patent application, Ser. No. 422,459, filed Dec. 30, 1964 and assigned to the assignee of this application, several of these disadvantages are discussed and a latch mechanism is disclosed which effectively overcomes the enumerated disadvantages.

In addition to the disadvantages discussed in this copending application, prior art door latches of the above described safety type have allowed the locking mechanisms associated with the latch to be actuated by the operator even with the door in its safety rather than its fully latched position.

Specifically, with the door in its safety position, the appropriate key when inserted in the key cylinder lock associated with the latch will readily turn to lock the door. Since the fact that the door is in its safety rather than its fully latched position is not readily sensed, either visually or tactually, and since the key turns readily in the key cylinder to lock the door, the operator may leave his car thinking it to be securely locked when in fact the door is only in its safety position. In this condition, the car may be readily entered since a moderate inward 'push on the door trips the locking mechanism and unlocks the door.

Similarly, with the door in its safety position, a downward force on the push button lock on the inside of the door will depress that button to lock the door, Since the fact that the door is in its 'safety rather its fully latched position is not readily sensed, either visually or tactually, by an operator situated within the car, and since the push button lock readily depresses, the operator may be fooled into thinking that the door is locked in its fully latched position. If the operator thereafter exits by another door and securely locks the latter, the first door will provide ready entry into the car, in the manner described above. Perhaps more importantly, the partially latched door, even though locked, presents a safety hazard to occupants since it may be shaken open in an accident and may even pop open in the course of normal movement of the vehicle.

Accordingly, it is an object of the present invention to provide an improved latching mechanism for latching a movable member to a fixed member.

Another object is to provide an improved latching mechanism for an automobile door.

3 ,334,935- Pa tented Aug. 8, 1967 A more specific object is to provide an automobile door latch of the safety type which cannot be locked with the door in its safety position.

A yet more specific object is to provide a safety type automobile door latch, including a key cylinder lock, in which a key inserted in the lock cannot be turned with the door in its safety position.

Another object is to provide a safety type automobile door latch, including an inside locking mechanism such for example as a push button, in which the inside locking mechanism cannot be moved to its locking position with the door in its safety position.

According to the invention, the door latch includes means which sense the position of the detent means and operate to prevent operation of the various locking devices when the detent means is sensed to be in its safety rather than its fully latched position.

More specifically, the door latch of the invention in-,

cludes two separate detents. These detents are arranged so that, as the bolt is moved in response to closing of the door, the first or safety detent moves from its rest position into a position of coaction with the safety tooth on the bolt whereafter, with continued movement of the bolt, the second or fully latched detent moves from its rest position into a position of coaction with the fully latched tooth on the bolt. A locking member is provided which, when moved into its operative position as by depression of the inside push button or turning of a key in the key lock cylinder, locks the detents in their latching position so that manipulation of the outside or inside door handles will be ineffective to release the detents. This locking member, when moving between its rest and operative positions, 'follows a path which is blocked by a portion of the second or fully latched detent with the latter in its rest position. Thus, if the door is swung toward its closed position but fails to fully latch, stopping instead in its safety position, neither the inside push button nor the key lock cylinder will be effective to lock the door since the locking member will be prevented from moving to its locking position by the second or fully latched detent lying across its path.

These and other objects, features and advantages of the invention will be apparent from the following detailed description of a preferred embodiment of the invention and from the accompanying drawings wherein:

FIGURE 1 is a fragmentary view of an automobile with the right front door shown in an open position to reveal the mounting in the door of a door latch constructed according to the present invention;

FIGURE 2 is a fragmentary side elevational view on an enlarged scale of the door latch of FIGURE 1 showing the latch in its unlatched or rest position;

FIGURE 3 is a view similar to FIGURE 2 but showing the latch in its partially latched or safety position;

FIGURE 4 is a view similar to FIGURES 2 and 3 but showing the latch in its fully latched position; and

FIGURE 5 is an end elevational view of the latch of FIGURES 1 to 4.

Referring first to FIGURE 1, the latch of the invention, broadly considered, comprises a striker 10 rigidly extending from door post 12 and an assembly 14 mounted within door 16 and exposed, by a tapered slot 18 in door panel 19, for coaction with striker 10 upon closing of the door.

Striker 10 includes a cylindrical shank portion 20 and a cylindrical flange portion 22.

Referring now to FIGURES 2 to 5, door assembly 14, includes a bolt or rotor 24 mounted for pivotal movement on 'a' pin 26 secured to the latch frame. Bolt or rotor 24 is shaped to define a latch arm 28 and a throw- As door 16 is closed, shank portion 20 of striker 10 is out arm 30 defining therebetween a slot or throat 32. guided by slot 18 into engagement with throwout arm 30, whereby to pivot rotor 24 about the axis of pin 26 and move latch arm 28 around shank portion 20, as seen in FIGURES 3 and 4, to trap shank portion within throat 32. A spring (not shown) resists such pivotal movement of rotor 24.

During this closing operation, flange portion 22 of striker 10 slides along the inclined upper face of the usual spring loaded wedge block 34.

Rotor or bolt 24 includes a first or safety tooth 36 and a second or fully latched tooth 38.

Teeth

36, 38 respectively present substantially radial tooth faces 40, 42 for coaction with first and

second detents

44, 46. Upon rotation of rotor 24 in response to closing of door 16, detent 44 is moved into the trace of face 40, whereby to block return rotation of rotor 24, and thereafter detent 46 is moved into the trace of face 42, whereby to further block return rotation of rotor 24.

In the embodiment shown, and as best seen in FIG- URE 5, rotor 24 is a laminated structure comprised of two

plates

48 and 50 held in face to face relation as by rivets 52.

Plate 48, the foremost plate as viewed in FIGURES 2 to 4, in addition to providing the above-described arms 28 and and throat 32, also provides radial face 42. Plate 50, the rearmost plate as viewed in FIGURES 2 to 4 provides radial face 40. Faces 40 and 42 are thus disposed in different planes so that detents 44 and 46 may pivot side by side about a common pin 54 secured to the latch frame.

With the latch in the unlatched condition of FIGURE 2, follower arm 43 of detent 44 is urged by a spring (not shown) against a follower surface 60 provided by an arcuate peripheral portion of plate adjoining face 40, and follower arm 45 of detent 46 is urged by a spring (not shown) against a follower surface 64 provided by an arcuate peripheral portion of plate 48 adjoining face 42.

When door 16 is closed to rotate rotor or bolt 24, the follower arm 43 of detent 44 rides along follower surface and follower arm 45 of detent 46 simultaneously rides along follower surface 64. After a predetermined amount of angular movement of rotor 24, follower arm 43 runs off of surface 60 and is moved by its spring into the trace of face 40. This partially latched, or safety, condition at the rotor is shown in FIGURE 3.

After a predetermined amount of further angular movement of rotor 24, during which time follower arm 43 moves to a position spaced circumferentially from face 40, follower arm 45 runs off of surface 64 and is moved by its spring into the trace of face 42 where it coacts with that face to latch the rotor and prevent return rotation of the latter.

This fully latched condition of the rotor is shown in FIGURE 4. As seen in that figure, the detent arm 43, since it has been moved well beyond face 40, cannot be hung up on that face but rather must of necessity be firmly planted in the peripheral trace of that face. Thus, even if arm 45 should hang up on face 42 upon closing of the door and thereafter be shaken loose from that tooth to release rotor 24, the rotor will be positively caught by the subsequent firm abutment of the butt end of detent arm 43 against face 40.

Each

detent

44, 46 includes a

radial brake arm

72, 73. A pad 74, formed of any suitable cushioning material such for example as sponge rubber, is suitably secured to the latch frame in a position in the path of pivotal movement of

brake arms

72, 73. As follower arm 43 drops off the end of follower surface 60 and is propelled by its spring radially inwardly into the trace of face 40, brake arm 72 is moved against cushion 74 to prevent arm 43 from slapping noisily against the adjacent underlying peripheral surface 76 of rotor plate 50. Similarly, as follower arm 45 drops off the end of follower surface 64 and is propelled by its spring radially inwardly into the trace of face 42, brake arm 73 is moved against cushion 74 to prevent arm 45 from slapping noisily against the adjacent underlying peripheral surface 78 of plate 48.

Rotor 24 may be released for movement from its fully latched position of FIGURE 4 to the unlatched position of FIGURE 2 either by depression of the usual outside door handle push button 80 or by operation of the usual inside door handle (not shown).

Depression of push button 80 pivots a bell crank 82 about a fixed pivot pin 83 to depress a rod 84. Rod 84 is pivotally connected at its upper end to crank 82 and at its lower end to a T-shaped lever 85 pivotally mounted on pin 54 behind

detents

44, 46. Lever 85 is connected by a screw 86 to one arm 87 of a three-armed lever 88 pivoted on pin 54 behind lever 85. Another arm 89 of lever 88 carries a tab 90 for coaction with tabs 91, 92 carried on

brake arms

72, 73 of

detents

44, 46. As button 80 is initially depressed, rod 84 is depressed to pivot

levers

85, 88 clockwise about the axis of pin 54 and bring tab 90 into engagement with tabs 91, 92. Further depression of button 80 causes tab 90 to pick up tabs 91, 92 and thereby pivot

detents

44, 46 clockwise about the axis of pin 54 and

lift follower arms

43, 45 clear of radial faces 40, 42 to allow the door to be opened. A slot 93 in lever 85 coacts with screw 86 to allow the relative angular position of

levers

85, 88 to be adjusted to achieve the desired amount of free play in the outside door handle release linkage.

Operation of the inside door handle slides (by a linkage not shown) a slotted lever 96 upwardly on a pin 68 carried on the latch frame. Lover 96 has a transversely extending end portion 98 (best seen in FIG. 5) which, as the lever is moved upwardly, engages the undersides of radial arms 66, 67 of

detents

44, 46 to pivot

follower arms

43, 45 upwardly and thereby release rotor 24 for return movement.

Means are also provided to lock the door in its latched position. These means include a locking lever 100 pivotally mounted on pin 26 behind rotor 24. One end of lever 100 is forked to provide

arms

102, 104 and each such arm has its free end bent over to form

tabs

106, 108, respectively. Lever 100 is movable between an unlocked position, as seen in FIGURES 2 and 3, and a locked position, as seen in FIGURE 4.

With lever 100 in its locked position, tab 106 on arm 102 lies in the arcuate path of the tip end of an arm 110 formed as an integral part of lever 88 and tab 108 on arm 104 lies in the arcuate path of the tip end of an arm 111 formed as an integral part of detent 46. Lever 100 is thus operative to render the outside door handle release means inoperative to release the detents, since as push button 80 is depressed, arm 110 on lever '88 is quickly rotated into abutment with tab 106 on locking lever 110 to block further releasing movement of the outside door handle release assembly. In the illustrated latch, the inside release mechanism overrides the locking lever so that, as is customary with a front automobile door, the door may be opened by the inside door handle even though the door is locked. This overriding is accomplished by a dog or tang 112 on lever 96 which engages a tab 114 on lever 100 has lever 96 slides upwardly on pin 68 in response to actuation of the inside door handle. Tang 112. pivots lever 100 to its unlocked position before lever portion 98 picks up the detents so that the detents may be thereafter lifted up to release the rotor for return movement. It will be understood that, for a rear door latch, tang 112 is omitted so that as lever portion 98 picks up the detents in response to actuation of the inside door handle, arm 111 on detent 46 is quickly rotated into abutment with tab 108 to block further releasing movement of the inside door handle release assembly.

With locking lever 100 in its unlocked position as seen in FIGURES 2 and 3, tab 106 lies below the arcuate path of the tip end of arm 110 and tab 108 lies below the arcuate path of the tip end of arm 111 so that the detents may be released by actuation of either the outside or the inside door handle. The locking lever 100 may be moved to its locked position by actuation of the usual push button 115 projecting upwardly above garnish molding 116 or by actuation of the usual key cylinder lock 117.

Push button 115 connects to one end of lever 100 by a rod 118 so that depression of push button 115 pivots lever 100 counterclockwise to its locked position and raising of push button 115 pivots lever 100 clockwise to its unlocked position. The push button is shown in its raised or unlocked position in FIGURES 2 and 3 and in its depressed or locked position in FIGURE 4.

A rod 120 connects the other end of lever 100 to the free end of the crank arm 122 of lock 117. When the appropriate key is inserted in keyway 124 and the key turned in a given direction, crank arm 122 is pivoted upwardly to pivot lever 100 counterclockwise to its locked position; turning of the key in the opposite direction pivots crank arm downwardly to pivot lever 100 clockwise to its unlocked position. An overcenter spring 126 enables locking lever 100 to move with a snap action between its locked and unlocked position and maintains the locking lever in the position to which it is moved by the push button or by the key cylinder lock.

However, the locking lever cannot be moved into its aforesaid locked position by either the push button or the key cylinder lock unless the door is in its fully latched position since, with detent 46 in its rest or unlatched position, the tip end of arm 111 lies in the arcuate path of tab 108 on locking lever 100. Thus, if an attempt is made to depress push button 115 with the door in its safety of partially latched position, the tab 108 will move quickly into abutment with the tip end of arm 111 to block movement of lever 100 into its locked position. Similarly, if an attempt is made to lock the door by insertion of the appropriate key in cylinder lock 117, abutment of tab 108 with arm 111 will block movement of lever 100. In either case, the operator, having attempted and failed to lock the door, will be thereby apprised that the door is in its safety rather than its fully latched position.

Specifically, if an operator or passenger seated Within the car attempts to close the door but succeeds only in latching it in the safety position when he thereafter attempts and fails to depress the push button lock 'he will be thereby apprised of the partially latched condition of the door. If the door is thereafter reopened and then fully closed, follower arm 45 will pivot downwardly about pin 54 to raise the tip end of arm 111 clear of the arcuate path of tab 108; the door may thereafter be locked by either the push button or the key cylinder lock.

While a preferred embodiment of the invention has been illustrated and described in detail, it is to be understood that various changes may be made in the disclosed embodiment without departing from the scope or spirit of the invention as defined by the appended claims.

I claim:

1. A mechanism for latching a movable member to a fixed member comprising (A) a bolt assembly on one of said members defining a safety tooth and a fully latched tooth;

(B) coacting means on said fixed and movable members operative in response to closing of said movable member on said fixed member to move said bolt to a position blocking return movement of said movable member;

(C) detent means on said one member operative in response to the aforesaid movement of said bolt to move (1) first into a position of engagement with said safety tooth and thereafter, with continued movement of said bolt,

(2) into a position of engagement with said fully 6 latched tooth, whereby to block return move ment of said bolt;

(D) release means on said one member operative to move said detent means out of engagement with said teeth, whereby to allow return movement of said bolt and thereby allow said movable member to be opened;

(E) lock means on said one member operative to render said release means inoperative, whereby to prevent release of said detent means; and

(F) means operative with said detent means in its said first position to prevent operation of said lock means, whereby an operator attempting and failing to operate said lock means will be thereby apprised that said movable member is in its safety rather than its fully latched position.

2. A mechanism for latching a movable member to a fixed member comprising (A) a bolt assembly on one of said members defining a safety tooth and a fully latched tooth;

.(C) detent means on said one member operative in response to the aforesaid movement of said bolt to move (1) first into a position of engagement with said safety tooth and thereafter, with continued movement of said bolt,

(2) into a position of engagement with said fully latched tooth, whereby to block return movement of said bolt;

(D) release means on said one member operative to move said detent means out of engagement with said teeth, whereby to allow return movement of said :bolt and thereby allow said movable member to be opened;

(E) lock means, including a key cylinder lock, normally operative in response to turning movement of the appropriate key in said lock to render said release means inoperative, whereby to prevent release of said detent means; and

(F) means operative with said detent means in its said first position to prevent operation of said lock means, whereby an operator attempting and failing to operate said lock means with said key will be thereby apprised that said movable member is in its safety rather than its fully latched position.

3. A mechanism for latching a movable member to a fixed member comprising (A) a bolt assembly on one of said members defining a safety tooth and a fully latched tooth;

(C) detent means on said one member operative in response to the aforesaid movement of said bolt to move (1) first into a position of engagement with said safety tooth and thereafter, with continued movement of said bolt;

(2) into a position of engagement with said fully latched tooth, whereby to block return movement of said bolt; (D) release means on said one member (1) accessible, with said movable member in its closed position, only from one side of said movable member and (2) operative to move said detent means out of engagement with said teeth, whereby to allow return movement of said bolt and thereby allow said movable member to be opened;

(E) lock means (1) including a manually operable member accessible, with said movable member in its closed position, only from the other side of said movable member and (2) operative to render said release means inoperative, whereby to prevent release of said detent means and (F) means operative with said detent means in its said first position to prevent operation of said lock means, whereby an operator attempting and failing to operate said lock means by manipulation of said manually operable member will be thereby apprised that said movable member is in its safety rather than its fully latched position.

4. A mechanism for latching a movable mem-berto a fixed member comprising (A) a bolt assembly on one of said members defining a safety tooth and a fully latched tooth;

(E) a lock assembly, including a manually operable member movable between a rest position and a locking position, operative in response to movement of said manually operable member to its locking position to render said release means inoperative, whereby to prevent release of said detent means; and

(F) means operative with said detent means in its said first position to block movement of said operabtle member to its locking position, whereby an operator attempting and failing to move said operable member will be thereby apprised that said movable member is in its safety rather than its fully latched position.

5. A mechanism for latching a movable member to a fixed member comprising (A) a bolt assembly on one of said members defining a safety tooth and a fully latched tooth;

(E) a lock assembly, including a key cylinder lock, operative in response to turning movement of the appropriate key in said lock to render said release means inoperative, whereby to prevent release of said detent means; and

(F) means operative with said detent means in its said first position to prevent turning of said key in said lock, whereby an operator attempting and failing to operate said lock means with said key will be thereby apprised that said movable member is in its safety rather than its fully latched position.

6. A mechanism for latching a movable member to a fixed member comprising (A) a bolt on one of said members presenting first and second faces each having a substantial extent in a direction transverse to the path of movement of said bolt;

(B) first and second detents normally positioned adjacent said path;

(C) coacting means on said movable and fixed members operative in response to closing of said movable member on said fixed member to move said bolt from a rest position through a distance sufficient to move said first and second faces past said first and second detents, respectively,

(1) said detents and faces being arranged so that said first face is moved past said first detent before said second face is moved past said second detent;

(D) means operative (l) in response to the aforesaid movement of said first face past said first detent to move the latter to a position within the trace of said first face, whereby to block return movement of said bolt and define a partially latched position of said movable member, and

(2) in response to the aforesaid movement of said second face past said second detent, to move the latter to a position within the trace of said second face, whereby to further block return movement of said bolt and define the fully latched position of said movable member;

(E) release means on said one member operative to move said detents out of the trace of said faces, whereby to release said bolt for return movement to its rest position and thereby allow said movable member to be opened;

(F) lock means on said one member operative to render said release means inoperative, whereby to prevent releasing movement of said detent means; and

(G) means operative with said first detent in its bolt blocking position and said second detent in its normal position to block operation of said lock means, whereby an operator attempting and failing to operate said lock means will be thereby apprised that said movable member is in its partially rather than its fully latched position.

7. A mechanism for latching a movable member to a fixed member comprising (A) a bolt on one of said members presenting first and second faces each having a substantial extent in a direction transverse to the path of movement of said bolt;

(B) first and second detents normally positioned adjacent said path;

(C) coacting means on said movable and fixed members operative in response to closing of said movable members on said fixed member to move said bolt from a rest position through a distance sufiicient to move said first and second faces past said first and second detents, respectively,

(D) means operative (1) in response to the aforesaid movement of said first face past said first detent to move the latter from its normal position to a position within the trace of said first face, whereby to block return movement .of said bolt and define a partially latched position of said movable member, and

'(2) in response to the aforesaid movement of said second face past said second detent, to move the latter from its normal position to a position within the trace of said second face, whereby to further block return movement of said bolt and define the fully latched position of said movable members;

' (E) release means on said one member operative to move said detents out of the trace of said faces, whereby to release said bolt for return movement to its rest position and thereby allow said movable member to be opened; and

(F) a locking member (I) mounted for movement between a rest position and a locking position in which it blocks operation of said release means and (2) following a path between its said positions which is blocked by said second detent with the latter in its said normal position, whereby an operator attempting and failing to move said locking member to its locking position will be thereby apprised that saidmovable member is in its partially rather than its fully latched position;

8. A mechanism for latching a movable member to a fixed member comprising (A) a bolt on one of said members presenting first and second faces each having a substantial extent in a direction transverse to the path of movement of said bolt;

(B) first and second detents normally positioned adjacent said path;

(D) means operative 1) in response to the aforesaid movement of said first face past said first detent to move the latter from its normal position to a working position within the trace of said first face, whereby to block return movement of said bolt and define a partially latched position of said movable member, and

(2) in response to the aforesaid movement of said second face past said second detent, to move the latter from its normal position to a working position with the trace of said second face whereby to further block return movement of said bolt and define the fully latched position of said movable member;

(E) release means on said one member operative to move said detents out of the trace of said faces whereby to release said bolt for return movement and thereby allow said movable member to be opened (1) said release means including a release member moved in response to the aforesaid operation of said release means'along a given path;

(F) a locking member (I) mounted for movement between (a) a rest position and (b) a locking position in which it lies in said given path, whereby to block operation of said release means, and

(2) following a path between its said positions which is blocked by a portion of said second detent with that detent in its said normal position, whereby an operator attempting and failing to move said locking member to its locking position will be thereby apprised that said movable member is in its partially rather than its fully latched position.

9. Amechanism for latching a swinging member to a fixed member comprising (A) a rotor on said swinging member presenting first and second faces each having a substantial radial extent;

(B) first and second detents pivotally mounted adjacent the periphery of said rotor;

(C) coacting means on said swinging and fixed members operative in response to closing of said swinging member on said fixed member to rotate said rotor from a rest position through an angular distance sufficient to move said first and second faces circumferentially past said first and second detents, respectively,

(D) means operative (1) in response to the aforesaid movement of said first face past said first detent to pivot the latter from its normal position to a working position within the trace of said first face, whereby to block return movement of said bolts and define a partially latched position of said swinging member, and

(2) in response to the aforesaid movement of said second face past said second detent, to pivot the latter from its normal position to a working position within the trace of said second face whereby to further block return movement of said bolt and define the fully latched position of said swinging member;

(E) release means on said swinging member operative to engage said detents with the latter in their aforesaid working positions and pivot them back to their aforesaid normal positions, whereby to release said bolt for return movement and thereby allow said swinging member to be opened,

(1) said release means including a release lever pivoted along a given arcuate path in response to the aforesaid operation of said release means; and

(F) a locking member (1) mounted for pivotal movement between (a) a rest position and (b) a locking position in which it lies in said given arcuate path, whereby to block operation of said release means, and

(2) following an arcuate path between its ,said positions which is blocked by a portion of said second detent with that detent in its said normal position, whereby an operator attempting and failing to move said locking member to its locking position will be thereby apprised that said swinging member is in its partially rather than its fully latched position.

10. A mechanism for latching a swinging member to a fixed member comprising (2) a second follower surface followed in said given direction of rotation by a second radially inwardly extending surface;

(B) first and second pivotally mounted detents,

(1) each of said detents including a follower arm and said second detent further including a blocker arm (C) spring means normally urging the follower arm of said first detent radially inwardly against said first follower surface at a location thereon relatively near said first radially inwardly extending surface;

(D) spring means normally urging the follower arm of said second detent radially inwardly against said second follower surface at a location thereon relatively distant from said second radially inwardly extending surface;

(E) coacting means on said swinging and fixed members operative in response to closing of said swinging member on said fixed member to rotate said rotor in said given direction, whereby the follower arms of said first and second detents slidably follow said first and second follower surfaces, respectively, and first the follower arm on said first detent and thereafter the follower arm on said second detent move under the urging of said spring means radially inwardly into the trace of the related inwardly extending surface as the latter is moved there past;

(F) release means on said swinging member operative to pivot said follower arms back out of the trace of said radially inwardly extending surfaces, whereby to release said rotor for return rotary movement and thereby allow said swinging member to be opened (1) said release means including a release lever (G) a locking lever (1) mounted on said swinging member for pivotal movement between (a) a rest position and (b) a locking position in which it lies in said given arcuate path, where-by to block operation of said release means, and

(2) following an arcuate path between its said positions which is blocked by the blocker arm of said second detent with that detent in its said normal position, whereby an operator attempting and failing to move said locking member to its locking poistion will be thereby apprised that said swinging member is in its partially rather than its fully latched position.

References Cited UNITED STATES PATENTS 30 MARVIN A. CHAMPION, Primary Examiner.

RICHARD E. MOORE, Examiner. I

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No 3 ,334 ,935 August 8 1967 James W. Eddy It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below Column 2 line 71 after "throw-" insert out arm 30 defining therebetween a slot or throat 32 column 3 line 1 strike out "out arm 30 defining therebetween a slot or throat 32 column 4 line 62 for "has" read as Signed and sealed this 19th day of November 1968 (SEAL) Attest:

EDWARD J. BRENNER Edward M. Fletcher, J r.

Commissioner of Patents Attesting Officer

Claims

1. A MECHANISM FOR LATCHING A MOVABLE MEMBER TO A FIXED MEMBER COMPRISING (A) A BOLT ASSEMBLY ON ONE OF SAID MEMBERS DEFINING A SAFETY TOOTH AND A FULLY LATCHED TOOTH; (B) COACTING MEANS ON SAID FIXED AND MOVABLE MEMBERS OPERATIVE IN RESPONSE TO CLOSING OF SAID MOVABLE MEMBER ON SAID FIXED MEMBER TO MOVE SAID BOLT TO A POSITION BLOCKING RETURN MOVEMENT OF SAID MOVABLE MEMBER; (C) DETENT MEANS ON SAID ONE MEMBER OPERATIVE IN RESPONSE TO THE AFORESAID MOVEMENT OF SAID BOLT TO MOVE (1) FIRST INTO A POSITION OF ENGAGEMENT WITH SAID SAFETY TOOTH AND THEREAFTER, WITH CONTINUED MOVEMENT OF SAID BOLT, (2) INTO A POSITION OF ENGAGEMENT WITH SAID FULLY LATCHED TOOTH, WHEREBY TO BLOCK RETURN MOVEMENT OF SAID BOLT; (D) RELEASE MEANS ON SAID ONE MEMBER OPERATIVE TO MOVE SAID DETENT MEANS OUT OF ENGAGEMENT WITH SAID TEETH, WHEREBY TO ALLOW RETURN MOVEMENT OF SAID BOLT AND THEREBY ALLOW SAID MOVABLE MEMBER TO BE OPENED; (E) LOCK MEANS ON SAID ONE MEMBER OPERATIVE TO RENDER SAID RELEASE MEANS INOPERATIVE, WHEREBY TO PREVENT RELEASE OF SAID DETENT MEANS; AND