GB933352A - Apparatus for fabricating metal structures - Google Patents

Abstract

933,352. Making vehicle sub-assemblies; welding by pressure. BRITISH FEDERAL WELDER & MACHINE CO. Ltd., and T. F. TRIBE. Sept. 25, 1961 [Oct. 4, 1960], No. 34006/60. Classes 83 (2) and 83 (4). [Also in Group XXX] The components of a structure, e.g. a vehicle door or floor assembly, are carried step-by-step by an endless conveyer from a loading station past at least one station at which the components are temporarily united, e.g. tackwelded, to a transfer station at which they are transferred to a reciprocating slide operating in synchronism with the conveyer to advance the components past stations at which they are permanently united, e.g. resistance welded, to an unloading-station. A floor structure, Figs. 1, 2, comprises a panel a with side flanges c and a central raised portion b having a conical locating boss h, and members d, e, f, g to be welded thereto. The conveyer consists of a number of carriages 25, Fig. 4, each having a frame 26 provided with rollers 31, 33 running on rails 34 and coupling devices in the form of a T-shaped head 32 cooperating with a socket 23 on an adjacent carriage. Adjustable abutments 52 ensure little play between coupled carriages 25. Each carriage has fixed lugs 106, 118 and adjustable lugs 121 for locating the panel a and a projection 105 co-operating with the boss h. The go and return paths of the conveyer may be side-by-side or superposed. As shown in Fig. 22, at station A1 a carriage 25 held by a latch on rails 34 on a vertically movable table 35 is raised to the level of the go-path and is coupled to the preceding carriage 25 at station A2, the latch being disconnected by a stop 49 in the fully raised position. The coupled carriages 25 are driven forward step-by-step by friction wheels 65, Fig. 15, driven by a motor 64 and lifted into engagement with surfaces 68 on the carriage 25 in station A2 by a jack 72. When the carriages 25 come to rest, jacks 76 at stations A2 and A3 engage locating pins 77 with sockets 78 on the carriages. The jacks 72, 76 and the motors 64 are controlled by a device 74 actuated by a cam 73 on each carriage 25. When a carriage reaches the transfer station A4, Fig. 17, its socket 23 is held against a stop 90 by a latch 92. The rails 34 at the station A4 rest on a second table 35 which is lowered until the carriage couples up with the carriage at the station A3 in the return-path the latch 92 being released by a stop 93 in the lowermost position of the table 35. The carriage driving and locating mechanism for the return-path is similar to that for the go-path. The components are assembled on a carriage 25 at station A1 or A2, and are temporarily clamped and manually tack welded at station A2. At station A3 a fluid pressure ram raises the work from the carriage 25 and presses it against resistance welding electrodes 127 which complete the tack welding. At station A4 the work is raised from the carriage 25 by a frame 85 reciprocated on vertical guides 87 by a crank 84. The horizontally reciprocating slide 98 having work engaging and locating arms 129 is moved under the work which is then lowered thereon by the frame 85. The slide 98 is moved forward and carries the work successively to each of the welding stations B1 . . . B3. At each welding station a table 97 carrying work supporting and locating members such as 109, 110 and 114, Fig. 20, is lifted by a fluid pressure ram 96 to press the work against resistance welding electrodes 95 and a spring-loaded clamp 112. The slide 98 is retracted and the work lowered back on to the slide 98. The work is transferred by the slide 98 when welding is completed to an unloading station B4 at which it is raised from the slide 98 and lowered on guides 135 on to a conveyer 136.