Patent GB-734969-A (GB)
Title: Improvements in adjustable seats
Inventor: ROBERTSON STANLEY CROXFORD
IPC: B60N2/54
Filed: 1953-04-11
Abstract: 734,969. Adjustable seats. HALLAM, SLEIGH & CHESTON, Ltd. Feb. 22, 1954 [April 11, 1953], No. 9912/53. Class 52 (2). A seat, e.g. a vehicle seat, is provided with an adjustable seat bottom and a back slidably adjustable in a forward and rearward direction relative to the seat bottom, both adjustments being effected by a common operating means. As shown in Fig. 2, parallel inclined links 3, 4 are hinged at 11 to angle-sectioned base members 1, fixed to a support, and to horizontal side tubular members 6 of a back-supporting frame 5 sliding in channelled side members 2a of a main seat frame. Cross-tubes 8 and 9 connect the integral upstanding parts 7 of the frame 5, an upholstered angularly adjustable back support 10 being pivoted, e.g. by clips, on tube 8. Crossing tie-bars 13, 14 connect together the links 3 and 4 on opposite sides, respectively. A bar 15 joins the centres of links 3 and 4. Support of the main seat frame is by links 16, 19 jointed at 17, 20 to the links 4, 3 respectively and at 18, 21 respectively to member 2a this latter link 19 extending beyond pivot 21 in a short forwardly extending curved arm 22. A central screw shaft 23, with a cranked handle 26, swivably connected at its front end to front bar 2b of the main seat frame, engages a nut in a central tube 24 carried by a cross-tube 25 on the transverse bar 9. A U-shaped auxiliary frame 27 having flanged sides is jointed at 18 at their ends to the extremities of the member 2a. The cross-bar of this frame, carrying a seat cushion 29 lies above the front bar 2b of the main seat frame whilst the sides rest on the arms 22. When the handle 26 is used to screw the shaft 23 into the tube 24, the back support is drawn forward with members 6 sliding in members 2a of the main seat frame. The front ends of links 3 and 4 move forward and downward to lower frame 2. Rotation of the handle 26 in the opposite direction raises the frame 2. However, as link 3 is lowered, the extension 22 is raised to counteract the lowering in part as far as the front of the cushion 29 is concerned, whilst the rear end of cushion 29 is lowered with the main frame. The front edge of the cushion remains more or less a constant distance from the steering wheel. Extension 22 may be of any suitable shape. The position of frame 27 may be reversed, i.e. the frame being jointed at its front end to the bar 2b and supported at its rear on members similar to 22. The seat cushion may be supported directly on main frame 2 omitting frame 27 and extensions 22. In a further embodiment (Fig. 9 and 11), shoes 33 on opposite ends of a bar 34 slide in front and rear channelled members 31 and 32 in a base frame 30, movement being due to a screw turned by a handle 38 engaging in an internal thread in a bar 36 fixed at right angles to a sleeve 37 surrounding bar 34. A bar 47 diagonally connects the horizontal tubular sides 45 of a back support which slide in guide channels 46 in the sides of the base frame 30. This bar 42 passes through a sleeve 42 fixed or pivoted to the sleeve 37 so that movement of the bar 34 causes the sides 45 to move forward or backward as the case may be. A hinged top frame 49 for a seat cushion 50 is pivoted by trunnions 48 to the guide channel 46. The front rounded ends of a pair of arms 53, pivoted at 51 to brackets 52, fixed to the base frame 30, mount on ramps 54 welded to the front corners of the horizontal part of the back frame. A cross-bar 55 connects the arms 53 and their outer ends engage beneath the top frame 49 to lift it when the back 43 is moved rearwardly and leave it horizontal when it is moved fully forward. In a third modification, Fig. 13, the two outer horizontal tubular members 58 and 60 of a back support of L-shape slide in side channels 61 of a rectangular base frame, being braced together by a cross-bar 62. A third horizontal member 59 of the back support has an internal thread engaged by a screw-shaft 63 rotated by a handle 56. A top frame 67 supporting a seat cushion is pivoted at 68 to the base frame. The inclined ends of members 58 and 60 on being moved forward by the screw 63, engage under and lift the top frame 67 at the front. Rearward movement of the members 58, 60 lowers the top frame front. In modifications of the previous constructions, the front edge of the seat may be raised or lowered by the rearward movement of the seat back, or the seat hinged at either the front or the back or varied in height uniformly with the position of the back. Any suitable means may be used to give simultaneous movement to the seat bottom and the back and the operating part being at the front or the side of the seat. The back may be moved mechanically without moving the seat bottom. The back of the seat may be connected to the seat underframe or to a relatively fixed part by links to cause inclination of the seat track by the forward and rearward movement of the back. According to the Provisional Specification, the back may be slidably mounted and adjustable by a separate control or by manual control only.