Patent GB-567586-A (GB)
Title: Power tool for rivet setting and analogous purposes
IPC: B25B27/00
Filed: 1943-07-13
Abstract: 567,586. Flanging. CHICAGO PNEUMATIC TOOL CO. July 13, 1943, No. 11358. Convention date, Sept. 14, 1942. [Class 83 (iv)] [Also in Groups VII and XXVI] A power tool, for dimpling metal sheets and for setting flanged screw sockets 23, Fig. 10, as described in Specification 555,713, comprising a casing 28, Fig. 3, containing a rotary fluid pressure motor 142 adapted to rotate a shaft 63 and a threaded bit 37 which extends through and draws the work against an anvil 36, is characterised by one driving connection between the shaft 63 and bit to rotate this and another, by relative rotation of said shaft 63 and the bit, to impart axial movement to this. Pressure air is admitted through a regulating valve 89, which is adjusted according to the power required for the work being operated on, a hand-operated inlet valve 34 and a two-way valve 51 to one or other side of a reversible air motor 142 which drives the shaft 63 through epicyclic speed-reducing gearing 69. The shaft 63 is internally threaded to engage a screwed shaft 73 in which the bit 37 is axially mounted. The shaft 73 has a collar 85 between which and the end of the shaft 63 a compressed spring 76 is arranged and this transmits rotational drive frictionally to the bit. When the bit is thus rotated clockwise in a socket 23 inserted through a sheet- or sheets 21, Fig. 10, it screws into the socket until the flange thereof presses the non-rotary anvil 36, against the action of a spring 77, into the casing 28 and the anvil presses a conical sleeve 81 against a seating 83 in the casing and thus prevents the sleeve 81, which has feathered engagement with the shaft 73, from rotating. The shaft 73 and bit 37 being thus prevented from rotating the friction drive 76, 85 slips and the still-rotating shaft 63 by its threaded engagement draws the shaft 73 and bit 37 axially inwards, thus upsetting the socket 23. The upward movement stops when the resistance. of the work is greater than can be overcome by the pressure at which the valve 89 is set and it is limited by a stop 86 adapted to engage the collar 85 and provided with some rotational freedom to prevent binding. When the valve 51 and motor are reversed the parts are returned to their original positions, an abutment 84 of the shaft 73 forcing the cone 81 out of engagement with the seating 83. The motor 142 is of the type having vanes 43, Fig. 4, moving radially in a shaft 42 which is mounted eccentrically in a cylindrical chamber 38 and this has curved spring-opened plates 49 pivoted outside so that when pressure air is admitted at 46 or 47 the corresponding plate 49 closes openings 48 and the air can only enter the chamber 38 at 44 or 45, as the case may be, the exhaust air, however, being free to pass out through the opposite openings 48. When the tool is used for dimpling, the anvil 36, Fig. 13, is provided with a convex face and a die 94 with a corresponding concave face is engaged and drawn against said anvil by the screw bit 37. When the socket 23 acts as a rivet to connect two plates, it can still receive a screw for attaching another part or merely for strength.