US3140888A

US3140888A - Door latch mechanism

Info

Publication number: US3140888A
Authority: US
Inventors: Salvo Anthony J Di
Original assignee: Ford Motor Co
Current assignee: Ford Motor Co
Priority date: 1962-12-20
Filing date: 1962-12-20
Publication date: 1964-07-14
Anticipated expiration: 1981-07-14

Description

July 14,.v 1964. A. J. 01 SALVO 3,140,888

DOOR LATCH MECHANISM Filed Dec. 20, 1962 3 Sheets-Sheet 1 AMI/wavy J. 0/ 84 V0 INVENTOR.

BY 16% Qf leodld July 14, 1964 A. J. D] SALVO 3,140,333

DOOR LATCH MECHANISM Filed Dec. 20, 1962 3 Sheets-Sheet 2 ANTI/01V) J. 0/ J01 v0 INVENTOR.

July 14, 1964 D] s vo 3,140,888

DOOR LATCH MECHANISM Filed Dec. 20, 1962 3 Sheets-Sheet 3 I Ayn/am? .r. omnuvo United States Patent 3,140,888 DGOR LATCH MECHANISM Anthony J. Di Salvo, Garden City, Mich, assignor to Ford Motor Qompany, Dearhorn, Mich, a corporation of Deiaware Filed Dec. 20, 1962, Ser. No. 246,656 4 Claims. (Cl. 292-43) This invention relates to latch mechanisms for swinging doors, especially the doors of automobile or other vehicle bodies.

Most door latch mechanisms currently in use on motor vehicles comprise rotatable or pivotal latch device means adapted to engage a striker or keeper device mounted on a vehicle door framing structure, a detent means releasably engaged with the latch device means to hold the latter in door latched position, an actuating or release member operatively associated with the detent means for disengaging the same from the latch device means, and manually operable means on the outside and the inside of the vehicle door operative to cause such disengagement. ln almost all latch mechanisms of this general class, the manually operable means operative from the outside of the door acts on the detent means through the actuating or release member. The manually operable means operative from the inside of the door may be constructed and arranged to act directly on the detent means or through the actuating or release member. Most vehicles are provided with at least one front door which can always be opened from the inside of the passenger compartment even if the latch mechanism is conditioned so that the door cannot be opened from the outside.

Latch mechanisms may be categorized by the manner in which the manually operable means operable from the outside of the door is rendered inoperative to disengage the detent means from the latch device means, thus placing the latch mechanism in locked condition. This may be done by the use of a blocking means selectively positionable to block movement of the detent means actuating or release member. This may also be done by use of a disconnection means interposed in the train of members extending from the outer manually operable means to the detent means.

Reference may be made to C. F. Kramer U.S. Patent No. 2,987,336, issued June 6, 1961, for a latch mechanism exemplifying the type in which a blocking means is used to render the manually operable means inoperative to disengage the detent means from the latch device means.

it is an object of the present invention to provide a latch mechanism characterized by many of the features of the latch mechanism disclosed in the Kramer patent and which is further characterized by the inclusion of features of construction by which the means manually operable from the outside of the door, such as a handle, push button or the like operated means, may be operatively disconnected from the detent actuating member. More specifically, the train of parts or members operatively associating the outside operator with the detent means includes a part or member directly coupled to the detent actuating member but being shiftable thereon from a detent actuating to a detent nonactuating position, said part or member being shiftable by a lever operable from the outside or the inside of the door. A latch mechanism so constructed and arranged is said to be a free wheeling as distinguished from a blocked type. In other words, the outside operator is always responsive to manual manipulation regardless of whether or not the latch mechanism is in locked or unlocked condition, even though such manipulation of the outside operator is not effective in locked condition of the mechanism to cause disengagement of the detent means from the latch device means.

The major advantage to be derived from free wheel- 3,140,888 Patented July 14, 1964 ing latch mechanisms is that the latch mechanism parts, particularly those in the train of elements: between the outside operator and the detent means, may be made of much lighter gauge metal than the parts used in a blocking type lock. In a blocking type lock the parts must be made strong enough to withstand any force which might be exerted on the outside operator by means of a pry bar, hammer or other device which might be used to attempt a forceful entry through the door when the latter is in locked condition. It will be readily apparent that in a latch mechanism in which part of the train of elements may be disconnected, any force exerted on the outside operator by an implement of any kind is inelfective to distort or spring the latch mechanism parts to a degree sufficient to permit disengagement of the detent from the latch device means and the door to be opened. This, of course, applies to any impact the outside operator might sustain in a collision or upset of the vehicle. The use of light gauge metal results in manufacturing cost savings since less metal is used and longer metal stamping die life is obtained.

Other objects and advantages and the features of construction of the present invention will be made more apparent as this description proceeds, reference being had to the accompanying drawings, wherein:

FIG. 1 is a perspective view of the latch mechanism embodying the present invention as it would appear when mounted on a vehicle door, a fragmentary portion of the door being shown in dot and dash outline;

FIG. 2 is an elevational view of the latch mechanism as it would appear from the free edge wall of the vehicle door;

HG. 3 is an elevational view taken from the left side of HG. 2 as viewed in the drawing;

PEG. 4 is an elevational view in part similar to FIG. 3 illustrating parts of the latch mechanism in a second operative position; and

MG. 5 is a fragmentary view illustrating parts of the latch mechanism as they appear from the opposite side of FIG. 3.

In the drawing there is illustrated, by way of example, a preferred embodiment of the present latch mechanism, generally designated 10, as applied to the door of an automobile body. Adapted to be secured as by means of screws (not shown) to the inner side of the free edge wall or jamo opposing wall 11 of a vehicle door 12 is a latch mechanism support having a main plate 13 and a flange or second plate 14 which is adapted to be positioned along the inner panel of the door. The present latch mechanism has a pair of pivoted latch devices comprising jaw elements 15 (see FIG. 1) positioned at the outer face of the main plate 13. Each jaw element 15 is provided with a shaft or pivot portion 16 having a reduced bearing portion 17 extending through a suitable flanged aperture (not shown) in the main plate 13. T he inner reduced end or bearing portion 17 of each shaft 16 is provided with diametrically opposed flats 18 thereon. Fitted over the bearing portion 17 and keyed thereto by the flats 18 are a pair of

control plates

19 and 21. Each jaw element 15 is thus rigidly coupled to a

control plate

19 or 21, being concentric therewith on a shaft 16. As defined herein, each latch device means comprises a jaw element 15, a shaft 16 and a

control plate

19 or 21.

Each jaw element 15 is a substantially triangular plate member having its pivot axis located near its apex end. The side opposite the apex end is outwardly rounded and is provided in the center thereof with a semicircular recess or enlarged notch 22.

Each control plate is a gear sector having teeth 23, the teeth being intermeshed to thereby couple the

control plates

19 and 21 together for correlated movements. Both jaw elements 15 are thus controlled for counterdiara sss rectional swinging movement in unison toward and from each other into and out of door latched condition.

A spiral spring 24 is disposed concentrically with and adjacent the inner face of the control plate 19. The spring 24 is coupled at its inner end 25 to the shaft 16 carrying the control plate 19, the shaft having a slot or kerf 26 receiving the spring end. The outer or free end 27 of the spring 24 is looped over the edge of a slot 28 on the flange or second plate 14. The spring 24 is installed in a preloaded condition so that it at all times tends to rotate or urge the control plate 19, the shaft 16 and associated jaw element 15 in a counterclockwise direction, as viewed in FIG. 2. Since the control plate 21 is coupled to the control plate 19 through the gear teeth 23, rotative force exerted by the spring 24 on the plate 19 is transmitted to the plate 21 so that it is also at all times under a rotative force urging it, the shaft 16 and associated jaw element 15 in a clockwise direction as viewed in FIG. 2.

The control plate 21 is provided with two peripherally spaced abutments or ratchet teeth 29 and 31. Cooperable with the abutment or ratchet toothed edge of the control plate 21 is a detent 32 pivotally mounted on a shoulder rivet 33 secured to the main plate 13. It will be noted that the detent 32 extends in a substantially horizontal direction across the main plate 13 from its pivot, the shoulder rivet 33, toward the flange 14. The flange 14 is provided with an elongated vertically extending slot 34 (see FIG. through which an extension or arm 35 of the detent 32 projects.

Above the arm 35 the detent has an abutment portion 36 cooperable with the teeth or abutments 29 and 31 on the control plate 21. When the detent abutment 36 is in engagement with the control plate abutment 29, the jaw elements will be held in what is known as a secondary latched position. In other words, although the jaw elements 15 are not in a fully latched position, they are closed sufliciently to engage a striker or keeper pin therebetween to prevent opening movement of a vehicle door. When the abutment 36 is in engagement with the control plate abutment or tooth 31, as shown in FIG. 2, the jaw elements 15 will be in final latched position or fully gripping the striker or keeper pin (not shown).

The detent 32 is urged in a counterclockwise direction or toward the control plate 19 by a spiral spring 37. This spring is anchored at its inner end 38 to the shoulder rivet 33 and at its free or outer end 39 to a short upwardly extending extension 41 of the detent 32.

Pivotal actuation of the detent 32 in a clockwise direction, as viewed in FIG. 2, or in a direction away from the control plate 21, is accomplished through a detent actuating means carried on the flange or second plate portion 14. This detent actuating means comprises a horizontally extending detent actuating member 42 which is pivotally mounted on the outer edge of the plate portion 14 on a pivot stud 43. The actuating member 42 extends across the plate portion 14 toward the main plate 13 and has an end portion 44 overlying the extension 35 of the detent 32.

The actuating member 42 has an upwardly extending portion 45 terminating in a flange 46 turned outwardly from the plate portion 14, for a purpose to be explained.

The central portion of the actuating member 42 is provided with a slot 47 therein. The slot 47 is irregularly shaped and has at its end away from the pivot axis of the member 42 a substantially radially extending notch 48. The end 49 of the slot closest to the pivot stud 43 may be considered as elongated in a direction transversely of the notch 48 or circumferentially about the pivot axis of the member 42.

A control lever 51 is pivotally mounted on the second plate portion 14 for swinging movement about a pivot stud 52 located below the pivot stud 43 and inwardly of the outer edge of the second plate portion 14. The control lever 51 has an upwardly extending arm 53 which 4 is embossed to permit it to overlie the central portion of the actuating member 42. The lever arm 53 has a slot 54 the longitudinal axis of which extends substantially radially relative to the pivot axis of the control lever 51 as defined by the pivot stud 52.

The detent actuating member 42 and the arm 53 of the control lever 51 are operatively coupled to each other through a bushing element 55. This bushing element is preferably made of a plastic material having a low coefficient of friction when sliding on steel. The bushing element 55 has an enlarged head 56 frictionally engaged with the face of the actuating member 42 having bearing engagement with the surface of the plate portion 14. As best seen in FIG. 5, the plate portion 14 has an enlarged aperture 57 providing movement clearance for the head 56 of the bushing element, the head of the bushing element being bodily shiftable in the plane of the plate portion 14 during operation of the latch mechanism.

The bushing element 55 has a shank portion 58 complementary in size to the notch 48 in the actuating member 42. A plastic washer 59 is interposed between bearing surfaces of the actuating member 42 and the control lever arm 53. A steel washer 61 having a snap-fit over the projecting end 62 of the bushing element completes the assembly, except for one end 63 of an operating link 64 which is inserted through the center of the bushing element for a purpose to be explained.

The control lever 51 has two substantially

horizontal arms

65 and 66 extending in opposite directions from the pivot stud 52. The arm 65 extends toward the main plate portion 13 in position to underlie the extension 35 of the detent. The arm 66 is provided with two vertically spaced

apertures

67 and 68, each of which receives an end of an

operating link

69 and 71, respectively (as best seen in FIG. 1). The link 69 is adapted to extend upwardly through the garnish moulding of the vehicle door. The link 71 extends downwardly where it is connected at its lower end to one end 72 of a horizontally extending bell crank lever 73 which is pivotally mounted on a pivot stud 74 to a lower extension 75 of the main plate portion 13 of the latch mechanism. It will be noted that the link 64 which is coupled at its upper end 63 to the bushing element 55 extends in a substantially downward direction and is coupled at its lower end to the end 76 of a substantially horizontally extending lever 77 which is pivoted on a pivot stud 78 to the extension 75 of the main plate 13.

As best seen in FIG. 1, the end 79 of the lever 73 and the end 81 of the lever 77 are each operatively coupled to upwardly extending

operating links

82 and 83, respectively. The upper end of the link 82 is adapted to be coupled to a conventional key cylinder mechanism (not shown) accessible from the outside of the vehicle door. The upper end of the link 83 is adapted to be coupled to a conventional outside operator, such as a push button mechanism of the type shown in US. Patent 3,054,634.

The detent actuating member 42 is adapted to be swung in detent disengaging direction from the inside of the vehicle door through a bell crank lever 84 pivotally mounted on a pivot stud 85 on the flange or second plate portion 14 of the latch mechanism support plate. The bell crank lever 84 has an upwardly extending arm 86 which is adapted to be operatively coupled to the conventional remote control mechanism (not shown) mounted on the inner door panel. The bell crank lever 84 has a substantially downwardly extending arm 87 which abuts the flange 46 on the upwardly extending portion 45 of the detent actuating member 42.

, It will be noted that the pivot stud 43 which carries the detent actuating member 42 also carried a spiral spring 88 having its free end portion 89 looped over a lug 91 on the detent actuating member 42. As viewed in FIG. 3, the spring resiliently resists any swinging movement of the detent actuating member 42 in a counterclockwise direction and is, therefore, effective to restore the detent actuating member to its operative position as shown in FIG. 3 after the latter has been swung in a counterclockwise direction either by operation of the outside operator or through the inside remote control operated bell crank lever 84. A stop 92 is provided at the upper edge of the plate portion 14 to limit the counterclockwise swinging movement of the bell crank lever 84 as it is restored to its normal rest position after release of the inside operator.

It will also be noted that the control lever 51 is under the influence of a toggle spring 93 which extends between the control lever 51 and the plate portion 14 of the latch mechanism support. The toggle spring 93 is effective to ensure that the control lever is maintained in either the position shown in FIG. 3 or the position shown in FIG. 4, as Will be readily understood. The at rest position of the control lever is also controlled by a stop 94 lanced out of the flange or plate portion 14. As will be understood, the abutting relationship of the control lever arm 53 to the stop 94, provides a positive limitation on the over-center action of the toggle spring 93.

Referring now to FIGS. 2 and 3, the various parts of the latch mechanism are shown in the position they will occupy when the vehicle door is in a closed position and the latch mechanism is ready for actuation so that the door may be opened. To open the vehicle door from the outside, it is necessary to depress the outside operator push button (not shown) which results in a lifting movement on the link 33. When the link 83 is lifted, the lever 77 is swung in a clockwise direction as viewed in FIG. 2 causing the link 64 to be pulled downwardly. Since the bushing element 55 is in the end 48 of the slot 47 on the detent actuating member, downward movement of the link 64 results in a counterclockwise movement of the detent actuating member 42, as viewed in FIG. 3. The end 45 of the detent actuating member will abut the end 35 of the detent causing the latter to be swung downwardly in a clockwise direction as viewed in FIG. 2. The abutment 36 on the detent means 32 is thus released from engagement with the abutment 31 on the control plate 21. Under the influence of the spring 24, the latch device means will be swung in a direction to cause the jaws to open. The vehicle door may then be swung in an open direction.

The detent 32 may be released from the control plate 21 from the inside of the vehicle door by operation of the bell crank lever 84. If the bell crank lever 84 is swung in a clockwise direction as viewed in FIG. 3, the arm 87 thereon will abut the flange 46 on the detent actuating member 42 causing the latter to be swung in a counterclockwise direction. The end 45 of the detent actuating member will then engage the end 35 of the detent causing the latter to be swung in a clockwise direction as viewed in FIG. 2, or in a direction to disengage the abutment 36 from the abutment 31 on the control plate 21.

Upon the vehicle door being swung into a closed position, the parts of the latch mechanism will be restored to the relationship shown in FIGS. 2 and 3. If it now is desired to lock the vehicle door so that it cannot be opened from the outside, it is only necessary to shift the control lever 51 to the position shown in FIG. 4. This may be done from either the outside or the inside of the vehicle door. To do this from the outside of the vehicle door, it is necessary to insert a key in a key operated cylinder mechanism (not shown) and to actuate the latter so as to raise the end 79 of the lever 73 thereby swinging the latter in a clockwise direction as viewed in FIG. 2. When the lever 73 is swung in a clockwise direction, the link 71 is pulled downwardly thereby causing the control lever 51 to be swung in a clockwise direction from its FIG. 3 position to the FIG. 4 position in which the bushing element 55 is moved over to the end 49 of the slot 47 in the detent actuating means. When the bushing element 55 is in this position in the slot, any downward movement of the link 64 merely causes the bushing element to idle in the slot 47 without affecting any movement of the detent actuating member 42.

The same result may be achieved from the inside of the vehicle by pushing down on the link 69 which projects through the garnish moulding of the vehicle door. When the link 69 is pushed downwardly, the control lever 51 is swung from its FIG. 3 to its FIG. 4 position.

It should be noted that the door can always be opened from the inside. Regardless of the relationship of the bushing element 55 to the detent actuating member 42, the latter may always be actuated by the bell crank lever 84. Thus, even when the bushing element 55 is in the idling portion of the slot 47 in the detent actuating member 42, the detent actuating member 42 will always respond to swinging movement of the bell crank lever 84 in a clockwise direction as viewed in FIG. 4. Movement of the bell crank lever 84 in this direction will be transmitted through the detent actuating member 42 and its portion 45 to the detent 32, causing the latter to be disengaged from the control plate 21 and thereby permitting the jaw elements to spring to their open position.

The arm on the control lever 51 has an important function in that it prevents any movement of the control lever from its FIG. 3 position to its FIG. 4 position when the jaw elements 15 are in their unlatched position. When the jaw elements are in their unlatched position the portion of the control plate 21 to the right of the abutment 29, as viewed in FIG. 2, operates to cam the detent 32 against the urging of the spring 37. The detent arm 35 is thus displaced a substantial distance below its position shown in FIG. 2. When in this displaced position, it engages the upper edge of the arm 65 of the control lever 51. The control lever 51 is thereby blocked against swinging movement in a clockwise direction from the FIG. 3 to the FIG. 4 position and the latch mechanism cannot be placed in a locked condition until the latch mechanism parts are restored to the relationship shown in FIG. 2. The parts of the latch mechanism 16 cannot be placed in locked condition until the door is fully closed and the detent abutment 36 is in engagement with the abutment 31 on the control plate 21.

The manner in which the jaw elements 15 coact with a striker or keeper device to hold the door in latched condition is fully described in the aforementioned C. F. Kramer U.S. Patent No. 2,987,336.

It will be understood that the invention is not to be limited to the exact construction shown and described, but that various changes and modifications may be made without departing from the spirit and scope of the invention, as defined in the appended claims.

I claim:

1. A latch mechanism for a swing door comprising:

a support having two angularly related plate portions,

pivotal latch device means mounted on one of said plate portions,

detent means pivotally mounted on said one plate portion and engageable with said latch device means for holding the same in door latched position,

said detent means having a part extending toward the other of said plate portions,

a detent actuating member pivotally mounted on said other plate portion and having a part transversely overlying said part of the detent means,

a control lever pivotally mounted on said other plate portion and having a first arm overlying said detent actuating member and a second arm transversely underlying said part of the detent means,

coupling means coupling said detent actuating member and said control lever first arm together,

said coupling means including overlying slots in said detent actuating member and said control lever first arm,

and a bushing element projecting through said slots,

said control lever slot being arranged toaccommodate movement of said bushing element substantially radially of the pivot axis of said control lever,

said actuating member slot being arranged to accommodate movement of said bushing element both radially and circumferentially of the pivot axis of said actuating member,

said bushing element being shiftable by said control lever radially of the pivot axis of said actuating member into a first position thereon in which movement of said bushing element radially of said control lever pivot axis will pivotally move said actuating member in a direction to abut and swing said detent means to cause disengagement of the latter from said latch device means,

or said bushing element being shiftable by said control lever radially of the pivot axis of said actuating member into the portion of said actuating member slot accommodating movement circumferentially of the pivot axis of said actuating member without causing swinging movement of the latter in detent means abutting direction,

and outer manually operable means including a link directly coupled to said bushing element for moving the latter in said control lever slot in said substantially radial direction,

said detent means and said second arm of said actuating member in disengaged position of said detent means being in abutting relation and preventing swinging movement of said control lever to thereby prevent movement of said bushing element into the portion of the slot in said detent actuating member permitting movement circumferentially of the actuating member pivot axis.

2. A latch mechanism according to claim 1 having bell crank means pivotally mounted on said other plate portion and having a part thereof in abutting relation to said actuating member,

said bell crank means being operable to swing said actuating member into engagement with said detent means regardless of the relationship of said bushing element to said actuating member.

3. A latch mechanism according to claim 2 in which the latch device means comprises:

a pair of jaw elements pivotally mounted on one side of said one plate portion for swinging movement about spaced axes perpendicular to the plane of said plate portion,

a pair of control members mounted on the opposite side of said one plate portion,

each control member being fixedly coupled to one of said jaw elements for pivotal movement therewith,

said control members having intermeshed portions whereby said jaw elements are controlled for movement in unison toward and from each other to door latched and door unlatched position, respectively,

and at least one of said control members being provided with a detent means engageable portion,

the detent means when in engagement with said detent means engageable portion holding said jaw elements in door latched position.

4. A latch mechanism according to claim 1 in which the latch device means comprises:

a pair of control members mounted on the opposite side of the said one plate portion,

References Cited in the file of this patent UNITED STATES PATENTS 2,236,702 Andersen Apr. 1, 1941 2,782,062 Smith Feb. 19, 1957 2,987,336 Kramer June 6, 1961

Claims

1. A LATCH MECHANISM FOR A SWING DOOR COMPRISING: A SUPPORT HAVING TWO ANGULARLY RELATED PLATE PORTIONS, PIVOTAL LATCH DEVICE MEANS MOUNTED ON ONE OF SAID PLATE PORTIONS, DETENT MEANS PIVOTALLY MOUNTED ON SAID ONE PLATE PORTION AND ENGAGEABLE WITH SAID LATCH DEVICE MEANS FOR HOLDING THE SAME IN DOOR LATCHED POSITION, SAID DETENT MEANS HAVING A PART EXTENDING TOWARD THE OTHER OF SAID PLATE PORTIONS, A DETENT ACTUATING MEMBER PIVOTALLY MOUNTED ON SAID OTHER PLATE PORTION AND HAVING A PART TRANSVERSELY OVERLYING SAID PART OF THE DETENT MEANS, A CONTROL LEVER PIVOTALLY MOUNTED ON SAID OTHER PLATE PORTION AND HAVING A FIRST ARM OVERLYING SAID DETENT ACTUATING MEMBER AND A SECOND ARM TRANSVERSELY UNDERLYING SAID PART OF THE DETENT MEANS, COUPLING MEANS COUPLING SAID DETENT ACTUATING MEMBER AND SAID CONTROL LEVER FIRST ARM TOGETHER, SAID COUPLING MEANS INCLUDING OVERLYING SLOTS IN SAID DETENT ACTUATING MEMBER AND SAID CONTROL LEVER FIRST ARM, AND A BUSHING ELEMENT PROJECTING THROUGH SAID SLOTS, SAID CONTROL LEVER SLOT BEING ARRANGED TO ACCOMMODATE MOVEMENT OF SAID BUSHING ELEMENT SUBSTANTIALLY RADIALLY OF THE PIVOT AXIS OF SAID CONTROL LEVER, SAID ACTUATING MEMBER SLOT BEING ARRANGED TO ACCOMMODATE MOVEMENT OF SAID BUSHING ELEMENT BOTH RADIALLY AND CIRCUMFERENTIALLY OF THE PIVOT AXIS OF SAID ACTUATING MEMBER, SAID BUSHING ELEMENT BEING SHIFTABLE BY SAID CONTROL LEVER RADIALLY OF THE PIVOT AXIS OF SAID ACTUATING MEMBER INTO A FIRST POSITION THEREON IN WHICH MOVEMENT OF SAID BUSHING ELEMENT RADIALLY OF SAID CONTROL LEVER PIVOT AXIS WILL PIVOTALLY MOVE SAID ACTUATING MEMBER IN A DIRECTION TO ABUT AND SWING SAID DETENT MEANS TO CAUSE DISENGAGEMENT OF THE LATTER FROM SAID LATCH DEVICE MEANS, OR SAID BUSHING ELEMENT BEING SHIFTABLE BY SAID CONTROL LEVER RADIALLY OF THE PIVOT AXIS OF SAID ACTUATING MEMBER INTO THE PORTION OF SAID ACTUATING MEMBER SLOT ACCOMMODATING MOVEMENT CIRCUMFERENTIALLY OF THE PIVOT AXIS OF SAID ACTUATING MEMBER WITHOUT CAUSING SWINGING MOVEMENT OF THE LATTER IN DETENT MEANS ABUTTING DIRECTION, AND OUTER MANUALLY OPERABLE MEANS INCLUDING A LINK DIRECTLY COUPLED TO SAID BUSHING ELEMENT FOR MOVING THE LATTER IN SAID CONTROL LEVER SLOT IN SAID SUBSTANTIALLY RADIAL DIRECTION, SAID DETENT MEANS AND SAID SECOND ARM OF SAID ACTUATING MEMBER IN DISENGAGED POSITION OF SAID DETENT MEANS BEING IN ABUTTING RELATION AND PREVENTING SWINGING MOVEMENT OF SAID CONTROL LEVER TO THEREBY PREVENT MOVEMENT OF SAID BUSHING ELEMENT INTO THE PORTION OF THE SLOT IN SAID DETENT ACTUATING MEMBER PERMITTING MOVEMENT CIRCUMFERENTIALLY OF THE ACTUATING MEMBER PIVOT AXIS.