Patent GB-785729-A (GB)
Title: Improvements in or relating to a door latching mechanism
Inventor: MARPLE ROLLO
IPC: E05B65/32
Filed: 1955-07-01
Abstract: 785,729. Door latches. HANCOCK MANUFACTURING CO. July 1, 1955, No. 19082/55. Class 44 A latching mechanism adapted for use on doors of automotive vehicles, has relatively movable bolt and keeper members, one of which is rotary member, the rotary member having a latching surface engageable with the other member when rotated in a latching direction, and means for dogging the rotary member against rotation in an unlatching direction, the means comprising a track 38 or 134a adjacent the rotary member and a roller 37 or 128 movably positioned on the track, the roller being adapted to wedgingly engage the rotary member when the roller is moved in one direction along the track, to thereby urge the rotary member in its latching direction, the lines of force passing through the lines of engagement of the roller with the rotary member and the track forming a greater angle with respect to a tangent to the track surface, at its line of contact with the roller, then the friction angle between the roller and the track forms with respect to said tangent, so as to prevent unlatching movement of the rotary member. In one construction Fig. 1, the rotary member is a multi-tooth rotor 21 which forms a part of the keeper mechanism and it is mounted on a plate 22 by means of a pin 35 in a housing 24. The pin 35 is so positioned that a tooth, of the rotor can project through a slot in the upper wall of the housing. The roller 37 is disposed in the housing 24 between the rotor and the track 38 which is formed on the lower wall of the housing 24. The roller is guided by a slot 42 formed in a plate 36 positioned in the housing, a pivot pin 43 on which the roller is mounted projecting through the slot and terminating in a head. The roller is urged to the left as shown in Fig. 1 by a spring 45 which engages the pin 43 and when the roller is in its leftwards position it will not prevent anticlockwise rotation of rotor 21 but will prevent clockwise rotation. The bolt mechanism Fig. 3 which co-operates with the keeper mechanism comprises a bolt 47 which is pivotally mounted on the base 48 of a mounting plate within a housing 28 and biased outwardly through a slot in the base of the housing by a spring 53. At the opposite end of the housing from the bolt is a safety member 54 pivotally mounted on a pin 57 and which is urged through a slot in the upper wall of the housing- by a spring 56. The safety member has an extension 58 extending in the opposite direction from its portion which extends through the slot and this extension is provided with oppositely disposed transverse lugs 59, 61. The bolt housing 28 moves between the rotor housing 24 and an abutment 25 on the mounting plate 22 so that the bolt 47 can engage one of the teeth of the rotor. As shown in Fig. 1 leftward movement of the bolthousing between the keeper housing and the abutment 25 will cause retraction of the safety member by the abutment and will cause-the lower end of the bolt to engage the upper surface of the rotor housing and subsequently to engage an upwardly extending tooth of the rotor to rotate it anticlockwise. The bolt is prevented from movemet while engaging the rotor in this leftward movement by a dog 65 which is pivotally mounted on the other side of the base 48 from the bolt and a toe 68 of which engages an extension 69 on the outer end of the bolt which projects through a slot in the base 48. The dog 65 is urged into its bolt engaging position by a spring 73 which engages an extension 72 and it is moved to release the bolt by a retracting lever 74 which is pivotally mounted on the same pin as the dog and which has a laterally extending toe 75 engageable with an arm 76 on the dog 65. The toe 75 is engageable by an arm 77 of a bell-crank 78 which is pivotally mounted on the base 48 and the opposite arm 79 of the bell-crank has a toe 81 engageable by an arm 82 of a roll-back 83 which is also pivotally mounted on the base 48; the upper end 84 of the rollback is flanged and it is moved by a member' 85 which may be an outside door operator. The bell-crank 78 is urged in a clockwise direction by a spring 86 which thus holds arm 77 of the bell-crank away from the toe 75 on the retracting lever 74. Movement of the operator 85 to the right as shown, in Fig. 3 will thus release the bolt 47. The safety member 54 is retracted simultaneously with the release of the bolt 47 by an arm 87 on the retracting lever 74 which engages the lug 61 on the extension 58 of the safety member, the lug 61 and arm 87 being so positioned that retraction of the safety member 54 by the abutment 25 during closing movement of the door is not prevented. The bolt can also be released by a remote operator such as an inside door handle through a bell-crank 88 which is pivotally mounted on a flange 49 at right anglesto -the base 48. One arm of this bell-crank extends downwardly and is connected by a link 91 to the remote operator and the other arm 92 is disposed above the outer end of an arm 93 which is part of the retracting lever 74 and which extends through slot 94 in flange 49. Upon anticlockwise rotation of bell-crank 88, arm 93 will be depressed causing clockwise rotation of the retracting lever to release the bolt. Release of the bolt by the member 85 can be prevented by a locking member 95 pivotally mounted above the bolt housing by a pin 96 and which has an arm 97 which can be disposed in abutting relationship with the upper portion of the flange on the rollback 83 to prevent an unlatching movement of the rollback. The locking member 95 is controlled by a slide 101 which is mounted for vertical movement on flange 49. An ear 104 at the upper end of the slide projects through an opening 105 on a control arm 106 of the locking member so that the vertical position of the slide controls the position of locking member. The slide is held in one or other of two positions by an overcentre spring. The position of the slide is controlled by a push rod 107 which extends upwardly to, for example, the inside garnish moulding of a vehicle and its position is also, controlled by a member 109 which is pivotally mounted on the flange 49 and which can be controlled by a key lock (not shown). The member 109 has a pair of arms 111, 112 in lost-motion engagement with a toe 113 at the lower end of the slide. The locking member 95 is automatically moved to unlocking position on closing of the door by means of the lug 59 on the safety member 54 which engages a cam surface 114 at the outer end of its arm 106. During closing movement of the door as previously stated the rotor is rotated by the bolt and this rotation forces the roller to the right against the pressure of its spring 45. When tooth 41 has passed the centre line of the roller the roller is returned to the left by its spring and it engagesthe underside of the tooth 41 and so forces the tooth which projects from the housing into engagement with the underside of the bolt. Any vibration subsequent to latching of the bolt will tend to move the bolt further leftwards and relieve pressure on the roller and the roller will be forced by its spring 45 further to the left and hence it will force the rotor further anticlockwise to take up the movement of the bolt. During the closing of the door the bolt is immediately redogged when it returns to its projected position. In the construction shown in Fig. 7 the rotary member is the bolt. It is in the form of a multi-tooth. rotor 127 and it is mounted in a housing 123 on. the base. 121 of a mounting plate. The rotor projects through a slot in the upper wall of the housing to engage a keeper having a striker surface 118 and a main keeper surface 119 behind the striker surface. The keeper also has a pivotally mounted safety member 117 which is normally urged by a spring to the position shown in Fig. 7. An abutment 124 on the base 121 engages an inclined upper surface of the keeper. The roller 128 is positioned in the housing 123 between the rotor and a curved track 134a formed by the lower wall of the housing. The roller is mounted on an arm 136 of the retracting lever 137 by means of a pin 135. The retracting lever is movably secured to the base 121 by a pin 138 which is disposed in an elongated slot in the retracting lever thus the retracting lever can both pivot on the pin 138 and move in the axial direction of the arm 136. The roller pin 135 also extends through a slot 146 in a rollback 141 which is slidably mounted behind the base 121 by means of a pin and washer 142 disposed within an elongated slot 143 in the rollback. The pin 135 is urged to the left-hand end of the slot 146 as shown in Fig. 7 by a spring 145 which engages the arm 136 of the retracting lever. The rollback is thus urged to the left so that the pin 142 is at the right-hand end of the slot 143 and the roller is urged into engagement with the rotor and will prevent its clockwise rotation but not its anticlockwise rotation. To release the rotor so that it -can move clockwise the rollback is moved to the right by an outside door operator 149 which engages a flange 148 on the rollback and such movement moves the roller from engagement with the rotor. The roller can also be moved from engagement with the: rotor by a remote .operator such as an inside door handle. The retracting lever 137 has an arm 151 which is engaged by an arm 152 of a bell-crank 153 mounted on a flange 122 at right angles to the base 121. The opposite arm of the bell-crank is connected by a link 155 to the remote operator and leftward movement of the link as shown in Fig. 8 causes the bellcrank to move the lever 137 anticlockwise to move the roller away from the rotor. Unlocking movement of the rollback is prevented by a locking lever 156 which is pivotally mounted on the flange 122 by the pin which mounts the bell-crank 153. The locking lever has a finger 157 which can be moved to obstruct movement of the The locki