Patent GB-712661-A (GB)
Title: Improvements relating to means for adjusting vehicle suspension springs to suit variable vehicle loading
IPC: B60G17/02
Filed: 1952-04-23
Abstract: 712,661. Control of motors; actuation of switches. DAIMLER-BENZ AKT.-GES. April 23, 1952 [April 23, 1951], No. 10268/52. Addition to 686,219, [Group XXXII]. Classes 38(3) and 38(5) [Also in Group XXXII] In means for adjusting vehicle suspension springs according to the parent Specification, comprising a motor operative in one direction or the other according to whether spring resistance is to be increased or decreased and control means including a cut out operated by stop means movable with a driven part for arresting motor operation: when a limit has been reached in either direction, the cutout and the stop means are adapted also for preparing a circuit for a reverse operation' of the motor when the limit in either direction has been reached. In the arrangement according to Fig. 1 in which torsion rod springs 10, 11 are adjustable through respective arms 12 and 13 by threaded push rods 14, 15 slidable in correspondingly threaded . and rotatable sleeve extensions of a driving wheel 19 and in which the wheel is driven through gearing by an electric motor 31, the direction of rotation of the motor is controlled by a manually or automatically operated lever 32 to operate a solenoid switch 23 or 24 in the motor circuit, through either of a pair of contacts 33 or 34 in circuit with the solenoids of the switches. An arm of the lever 32 extends into the path of and between abutment devices 30, 31 carried by a rod fixedly connected to the push-rod 15. The circuit for each switch solenoid is completed through a change-over switch in which a switch arm 38 is operated with a snap-action towards a contact 35 or 36, the arm being operated by a pin or projection on a wheel 40 driven from the gearing and engaging an arm 39 loaded by a tension spring 41. In operation, movement of the lever 32 to the left from the position shown, to increase spring resistance, closes switch 23 and the push rods 14, 15 are moved outwardly towards their limit until the abutment device 31 returns the lever 32 to the position shown. Simultaneously therewith one of the pins on wheel 40 drives the arm 39 to a position in which arm 38 is snapped over to contact 36 thereby preparing a circuit for the solenoid of switch 24 which is completed by movement of lever 32 to the right when decrease of spring resistance is required, the lever 32 being restored to the position shown by abutment device 30 when inward limit of the push rods 14, 15 is reached. According to Figs. 2 and 4 the changeover switch comprises a lever 39 pivoted on a shaft 61 and having a wedge-shaped part 43 which co-operates with a pin 44 on a slotted spring loaded slide 46 and abutment arms 47, 48 which cooperate with abutments 49, 50 on a gear wheel 40 driven from the electric motor. The arrangement is such that rotation of the wheel 40 in either direction causes one or the other of the abutments 49, 50 to engage the part 43 which displaces the slide 46 to effect rocking action of the lever 39. The slide is guided on the shaft 61 and on the shaft 52 of the gearwheel. Another slide 59 disposed behind a plate 62 providing a bearing for the shaft 61, carries a pin 60 which engages a lever 38 on a shaft 51 mounted on a housing 57. A switch lever 58 mounted on the shaft 51 is rockable by means of a tongue 53 on the lever 39 which engages with one or the other of projections 54, 55 on the lever 38. In operation, the switch lever 58 is engaged with one or other of contacts 35, 36 as soon as the wedge-shaped part of lever 38 slides over pin 60 against a tension spring 63 on the slide 59. The contact remains until the tongue 53 engages the other projection 54 or 55 to move the wedge tip of the lever 38 over the pin 60 to close the switch to the other of the contacts 35 or 36. The levers 38, 39 are stamped-from sheet metal while the parts 47, 48, 53, 54 and 55 are formed by stamping or bending.