Patent GB-408464-A (GB)
Title: Track wrench
IPC: E01B29/28
Filed: 1933-05-27
Abstract: 408,464. Power wrenches. NORDBERG MANUFACTURING CO., Milwaukee, Wis consin, U.S.A. May 27, 1933, No. 15384. Convention date. March 20. [Class 83 (iii).] Bolts and nuts, screwing up and unscrewing.-A power wrench particularly for tightening up or removing nuts in railway track maintenance comprises a base movable along the track and a carriage movable transversely on the base and carrying an adjustable wrench socket operated by a driving motor. The fishplates A<3> joining the track rails A<1> have bolts A<6>, the nuts of which may be screwed on or off by the wrench. The base frame B consists of tubular members, braced transversely and fitted with bearing pins for rollers B<5> which are of double conical form and have a single flange B<6>. A cross tube B<10> encloses an adjustable tube B" provided at its outer end with a flanged roller which runs on the opposite track rail from the rollers B<5>. An arcuate member B<17> serves as a guideway for the upper carriage C which is pivoted at C<6> to the base frame. The upper carriage, Fig. 11, has a pair of rollers C' engaging the guide B" and a roller C' running on one of the cross members B<2>. The upper carriage has half bearings which co-operate with one or more cap members to accommodate the parallel shafts of the driving gearing. The frame and carriage may be locked together by locking ears engaging between faces C<9> on the carriage. A suitable driving motor may be secured to bosses C<19> of the upper carrage. Arcuate hoop-like members C<22> are secured to the upper carriage at C<21>, the hoops being connected by braces C<23>, two of which are extended to form handles C<2><4>. The drive shaft D of the motor, Fig. 3, carries a bevel gear driving in opposite directions loose gears D<4>, D<5> on a cross shaft D<6>. The gears D<4>, D<5> are internally toothed and engage toothed clutch plates D<9> which may be selectively engaged with members D<11> keyed to the shaft D<6> by means of pressure plates D<12> operated by yokes F<2>, F<3>. These yokes are operated by a shaft F, the arrangement being such that when one pressure plate is moved forward the other is withdrawn. In a neutral position both clutches are disengaged and the shaft D<6> is not rotated. Shaft D<6> is connected by gears D<19> to a gear E loose on a parallel shaft E<1> and fitted with an adjustable overload device. The gear E is provided with ribs E<3> having bearings for a pair of arms E', Fig. 5, which at their outer ends are urged against a spacing washer E<20> preferably of resilient material by springs E<12>. The arms carry rollers E<13> engaging cam-like projections on a member G<5> keyed to the shaft E<1>. Normallv the rollers engage the cam projections to transfer the drive to the shaft E<1>, but when a predetermined load is exceeded, the arms E<7> separate against the spring pressure and the rollers ride over the cams. The safety coupling is effective in either direction of rotation. The shaft E<1> carries loose gears H<1>, H which are selectively locked to the shaft by a splined olutch member H<3> to impart a two speed drive to a parallel shaft I which is connected by a triple sprocket and chain gear to a shaft K<1> mounted at the end of a pair of wrench arms I' pivoted on roller bearings on the shaft I. The shaft K<1> has squared ends engaging in socket members K<6> which have nut engaging sockets K<7>. The arms I' have abutment screws I<21> engaging surfaces on the upper carriage to align the sockets with the track nuts and to prevent lifting of either of the rollers B<4>. A spring L normally tends to raise the wrench arms. A pair of rods L<6> carry bearings for the sleeves of control arms L<12>, L<13>, the former being connected by linkage L<15>, L<21>, L<18>, to the shaft F to determine the direction of operation. The arm L<13> is connected by lever mechanism L<14>, L<25> to the clutch member H<3> controlling the two speed gearing, this mechanism being normally loaded to maintain the high speed in engagement. In use the hoops C<22> serve as rollers for removing the machine from the track and also to protect the mechanism during this movement. While the machine is being moved the base frame and upper carriage are locked together, but for using the wrench the upper carriage is tilted about its pivot by the operator, the movement being limited by stops B<25>. A removable or fixed counterweight may be placed on the shaft B <11> to prevent tilting movement transverse to the track.