678,454. Escalators. WAYGOOD-OTIS, Ltd. Jan. 6, 1950. [May 4, 1949] No. 396/50. Class 78 (i). [Also in Groups'X and XXV] In an escalator having steps connected at opposite sides to endless driving chains, the steps are supported by wheels disposed between side links of the chains and running on tracks in juxtaposition to the chains, and additional wheels of the same diameter as the step-supporting wheels are also disposed between side links of the chains intermediate the step-supporting wheels and also run on the said tracks. Driving gear. The escalator steps 32 are driven by a pair of chains 34 passed around driving sprockets 33 and idler sprockets 37. Driving sprockets 33 are mounted on a shaft 35 by means of hubs 140, Fig. 3, each of which also carries an outer sprocket 233. This transmits a drive via a chain 234 to a sprocket 231 bolted to the hub of a newel wheel 225 for driving the hand rail 47 at that side. On one side a gear wheel 145 is bolted to the driving sprocket 33 and a direct gear train is established by this gear, a gear 147, a small gear 146 on a shaft 157, and a worm wheel 156 on a shaft 157 engaging a worm 155 on the shaft 158 of the driving motor 36. Associated with shaft 157 7 is a motion detector switch MD. Fig. 23, and an overspeed switch OS is provided on the motor. The escalator brake is an electromagnetic type 161 on the motor shaft 158 and is operated by a brake release coil BR. Energizing this coil opens a contact BR1. The idling chain sprockets 32 are mounted in a carriage 40 running on rails 41 and pressed to the left in Fig. 1 by a spring 42 to tension the chains. A fulcrummed lever 44 is pivotally connected with the carriage 40 so that in the event of a chain breaking the resulting movement of the carriage operates a broken chain switch BC to stop the motor. The control switches are duplicated at top and bottom of the escalator and consist of a starting switch SS, Fig. 3, operated by a key, and a stop button SB mounted on one of the balustrades 260 supporting the hand rail gear. A three phase supply L1, L2, L3, Fig. 23, supplies current for a motor DMR and also through a transformer TRF and threephase rectifier RF supplies direct current for the control circuit. On operating either switch SS, current flows through the various contacts of an up or down circuit depending on which way the key of switch SS is turned. For the up circuit current passes through the coil of a relay U, contact D4 of an open-circuited down relay D, stop button switches SB, broken chain switches BC and overspeed switch OS. Contacts C1, U2, U3, U5, and. U6 then close while U5 completes a circuit through a relay H which closes contacts H1 and H2. Current can now pass via U6 and H2 and BR1 to operate brake release BR so that the brake is released as current flows through U1 and U2 to the motor DMR. On actuation of BR, BR1 opens inserting a resistance R5 to reduce the current in BR to a maintenance value, whilst as soon as the motor rotates the motion detector closes switch MD suppling a maintenance current via resistance R1 through relay U, so that SS can be switched off, the key being withdrawn. On pressing one of the stop buttons all the U contacts immediately drop out and remain out when the stop button is realeased on account of R1. Relay H however has a time delay, owing to the condenser CO maintaining a current controlled by resistance R2, R3, while R4 still allows sufficient maintenance current to BR. This allows slowing down of the escalator before the brake is applied. The operation of the down control circuit is similar except that the relay H is not used, since on stopping, the brakes are applied immediately owing to the weight of passengers exerting a driving force which would prevent the escalator from slowing down quickly enough on its own. Combplate lamps. Small lamps CL, Fig. 3, are also included in the circuit, and operated by H1 during upward movement, or D3 during downward movement. These lamps illuminate the combplates 73 at either end of the escalator. Travelling platforms and associated parts. The combplates, Fig. 4, have removable separate teeth 72 formed on sections 68 bolted to the combplates. The teeth mesh with grooves 71 on the platforms. A transverse groove 74 at front and rear of each platform is painted to mark the edges of the steps. The supporting frame 64 of each platform is pivoted at its front to stub shafts 54 on the chains 34 at every third joint. Every joint is provided with a rubber tyred roller 55 running on a track 90. A rubber tyred roller 82 at each side of the rear part of frame 64 runs on a track 100 and a projection 104 of T-shape engages the underside of a parallel rail 102 to prevent rollers 82 rising on the curves of track 100. On the incline of the operating run tracks 90 and 100 merge into one. While passing around the driving sprockets rollers 82 are received between two guides and both rollers 82 and 55 are guided between two guides on the return run. The platforms can be disconnected from the stub shaft 64 on the chains by releasing a spring loaded locking pin 77. The chains 34 consist of narrow outer links 51, linking the joint spindles 53, and wider inner links 50 linking bushes on pins 53. The roller 55 is mounted on a ball bearing on each bush, chains are guided on to the end sprockets from the end portion 116 of track 90 by two supporting rollers 114, 115, having rubber tyres of stepped form to accommodate the different widths of outer and inner links. An additional roller 360 mounted on a spring pressed bracket 361 Fig. 24, may be added beyond roller 115. The spacing between these rollers is the chain pitch. Handrail mechanism. The handrail 47 on each balustrade, is reinforced with canvas and by a steel strip. The hand rail is made in endless form, with the ends of the steel strip lapping. It is pressed around the newel wheel 225, a corresponding idler newel 243 and with a reverse bend around a tensioning pulley 246 mounted on a sliding carriage 247 for screw adjustment. A guide 245, Fig. 18, extends along the operative run of the handrail. Guide portions 303, 304 of similar shape are positioned at either side of the tensioning pulley 246. The guide 245 is made as an extension and is supported by an extension 269 the two being secured together by bolts 273, and to a plate 265 running along the top of the balustrade by bolts 272. The end portion of the extension 269 continues beyond the end of the guide 245 but is widened to leave a gap for the newel wheel rim to emerge after which it narrows again forming split extrusions which cover the space between the balustrade panelling and the newel wheel rim, which is rubber-covered. The handrail enters a hole 300 in the balustrade, Fig. 3, to commence the return run. In a modified form of balustrade the return run of the handrail is turned through 90 degrees, the purpose of which is given below. Structural details. Brackets 341a welded to the plate 265 forming the top of the balustrade, Fig. 18, are bolted to an edge moulding 341 abutting a plate 344 having clips 345. These clips can be sunk in an adjoining plaster wall 343. Moulding 260 is then fixed in section by bolts 338 over plate 265. The extrusions 269 include a depending flange 266 under which sections of board 317 forming the sides of the balustrades can be inserted, the sections being connected by vertical T-shape members, not shown. Adjustable bolts 322 on plates depending from plate 265 nip the boards 317 tightly, the lower ends of the boards being clamped at 327, Fig. 3, to a vertical plate 306 secured to the main frame. The hole 300 for the handrail 47 is protected by a rubber yoke 298 and fixing plate 296, and is vertically below the newel wheel shaft. In a modified balustrade the boards 317 are replaced by panels of translucent tempered glass 370, joined by accordian shaped flexible plastic mouldings 388, Fig. 26, behind which is placed a reflecting plate in which are secured a number of cathode tubes for lighting effect. This necessitates the return run of the handrail being turned through 90 degrees as previously mentioned. The driving motor chamber is covered by a door 180 hinged at 182 and locked by a locking bolt [see Group XXV].