Patent GB-1275315-A (GB)
Title: A device for obtaining equal or different delivery changes in two variable-delivery pumps
IPC: B62D11/18
Filed: 1969-08-14
Abstract: 1275315 Hydrostatic transmission control; link work SARL COLMAS 14 Aug 1969 [28 Aug 1968] 40734/69 Headings F2D and F2K Two hydrostatic transmissions driving the tracks of a vehicle are controlled by a single lever H pivotable about perpendicular axes B-C, E-F to respectively effect identical and equal and opposite displacement changes in the transmission pumps. In Fig. 1 the lever H is pivoted about a horizontal axis E-F to a lower lever A which is pivoted about a horizontal axis B-C perpendicular to the axis E-F. Arms I, L of the lever H are connected through linkages including bell cranks 3, 4 pivoted on the lower lever A to the pump displacement control levers 18, 22. Movement of the lever H longitudinally of the vehicle pivots both levers A, H about the axis B-C to effect identical displacement changes in both pumps whereas movement of the lever H transverse to the vehicle pivots the lever H about the axis E-F to effect equal and opposite changes in the displacement of the two pumps. In Fig. 2 (not shown) the lever (H) is pivoted about a vertical axis E-F to a lower lever (A) which is pivoted about a horizontal axis (B-C). Arms (I, L) of the lever (H) are connected directly by links (15, 16) to the pump displacement control levers (18, 23). Movement of the lever (H) longitudinally of the vehicle pivots both levers (A, H) about the axis (B-C) to effect identical displacement changes in both pumps whereas movement of the lever (H) transversely to the vehicle pivots the lever (H) about the axis (E-F) to effect equal and opposite changes in the pump displacements. In Fig. 3 the lever H is pivoted about s horizontal axis E-F to a lower lever A which is pivoted about a horizontal axis B-C perpendicular to the axis E-F. The lower lever A is connected by a link 34 to a parallel lever 32 having a pivot 34 carrying a rocker 39 which is connected to the pump displacement control levers by links 35. The lower end of the lever H is formed as a tooth sector J engaging a rack 36 connected by a Bowden cable 37 to a rack 38 engaging a tooth sector on the rocker 39. Movement of the lever H longitudinally of the vehicle pivots both levers A, H about the axis B-C. The movement of the levers A, H is transmitted through the link 34 to the lever 32 and rocker 39 to effect identical changes in the displacement of both pumps. Movement of the lever H transversely to the vehicle pivots the lever H about the axis E-F to cause axial movement of the rack 36 which is transmitted through the Bowden cable 37 to the rack 38. Axial movement of the rack 38 turns the rocker 39 on its pivot 34 to effect equal and opposite changes in the pump displacement. The Bowden cable 37 may be replaced by a fluid column. In Fig. 4 (not shown) the lever (H) is pivoted about a horizontal axis (E-F) to a lower lever (A) which pivots about a perpendicular axis (B-C). The lower end of the lever (H) engages a fork in a rocker (44) pivoted on the lower lever (A). Movement of the lever (H) longitudinally of the vehicle pivots both levers and the rocker about the axis (B-C) to effect identical changes in the displacement of both pumps whereas movement of the lever (H) transverse to the vehicle pivots the rocker (44) relative to the lower lever (A) to cause equal and opposite changes in the pump displacements. The connection between the end of the lever (H) and rocker (44) may be replaced by toothed sectors. In Fig. 5 (not shown) the lever (H) is mounted on a slide (D<SP>1</SP>) fast with a lower lever (A) which pivots about an axis (BC) and carries a rocker (M) on a pivot (L<SP>1</SP>). The lever (H) carries a rack (S) meshing a tooth sector (N) on the rocker (M). Movement of the lever (H) longitudinally of the vehicle pivots both levers and the rocker (M) as a unit about the axis (B-C) to effect identical displacement changes in both pumps whilst movement of the lever (H) transversely rotates the rocker (M) to effect equal and opposite pump displacement changes. In Fig. 6 (not shown) the lever (A<SP>1</SP>) is pivoted about an axis (B-C) to a lower lever (D<SP>11</SP>) which is pivoted about a perpendicular axis (F-G) and carries a rocker (L<SP>11</SP>) on a pivot (H<SP>1</SP>). The lever (A<SP>1</SP>) passes through a slot in the rocker (L<SP>11</SP>). Movement of the lever (A<SP>1</SP>) longitudinally of the vehicle moves both levers and the rocker (L<SP>11</SP>) as a unit about the axis (F-G) to effect identical displacement changes in both pumps whereas movement of the lever (A<SP>1</SP>) transversely of the vehicle rotates the rocker (L<SP>11</SP>) about its pivot to effect equal and opposite pump displacement changes.