833,567. Machines for handling coke-oven doors. GILLOTT, J. M. March 7, 1958 [March 14, 1957], No. 8402/57. Class 55 (1). A machine for handling a coke-oven door comprises a carriage movable towards and away from a coke-oven door frame, an extractor on the carriage which is aligned with the door frame, a contact member on the extractor to make contact with the door or an adjacent part of the coke-oven structure, e.g. a buckstay, in the approach movement of the carriage, a valve operable by the contact member upon making contact with the door or the coke-oven structure, a support member movably mounted in the extractor and which is positioned by the approach movement to lift the door, an hydraulic cylinder connected to the support member and supplied with pressure fluid under control of the valve, to enable the support member to lift and maintain a door that is to be removed from the door frame and to lower a door that is being replaced on the door frame during a withdrawing movement of the extractor. As shown in Fig. 8, a coke-oven door 2 is applied to a door frame and is held by locking bars 15 engaging in hooks 14 carried by the sides of the door frame. The extractor 1 of the door-handling machine is pivotally mounted in an extractor head 3 carried by a leg 4 supported by a carriage 5, Fig. 1, and pivotable about a vertical axis. The extractor 1 has two vertical members 24 rigidly connected by transverse members and a support member 26 to lift the door is movable between the vertical members 24 against the action of a spring 27. The rear end of the support member 26 is pivoted at 29 to a link 30 on a transverse pivot 31. The support member carries a cross-bow 33 with a roller 34 at each end to make contact during the approach movement with adjustable pads 35 on buckstays 36. Outside the vertical members 24 levers 37 pivoted at 38 and carrying at their forward ends a wide roller 39 to bear on the underside of the support member 26 close to its lifting end 32. A pair of hydraulic cylinders 40 are supplied with pressure fluid through a valve 41 and serve to depress the rear ends of the levers 37, the valve 41 being operated by a pair of levers 42 connected by a link 43 to the levers 37 and having at their rear ends a roller 44 which follows as the approach movement continues a cam surface with three sections 45, 46 and 47 formed on an extension of the link 30, the support member 26 being raised into contact with a lifting pad 23 to lift and maintain the door when the roller 44 is in the cam section 47. Simultaneously with the first contact of the rollers 34 with the pads 35, rollers 51 carried by pairs of parallel levers 52 make contact with plates 21 on the door and move upwardly so that pads 55 on the ends of the levers 52 release the locking bars 15. The levers 52 are pivoted at 53 on the vertical members 24 and to hydraulic cylinders 54. One of the upper levers 52 has an arm 56 which in the position shown lies under a cross-member 57 of a latch 58. During the approach movement the arm 56 clears the cross-member 57, allowing the latch 58 to engage with a plate 22. A lower latch 58 is connected by a rod 59 and falls into engagement with a plate 22 simultaneously with the upper latch. The extractor may now be withdrawn carrying the door locked in position. When the door is replaced the extractor is advanced towards the door frame until the sealing strips on the door make contact with the door frame when the levers 52 are moved to compress slightly the hydraulic cylinder 54 and relieve the pressure between the latches 58 and the plates 22. At this time an electric thruster 60 is operated by manual control to rock a bell-crank lever 61 pivoted at 62 on a projection of the top latch 58 to move the end 63 from a retaining notch 64 which has ensured that the latches 58 have been secured in engagement with the plates 22. The lever 61 is then caused to strike a downward projection 58A of the upper latch 58 and lift both latches from the plates 22. The extractor is now withdrawn and the locking bars 15 are lowered into the hooks 14 and the weight of the door transferred from the support member 26 by the reverse action of the cam sections 47, 46 and 45 on the valve 41 and the resulting reverse operation of the cylinders 40. The hydraulic pressure necessary for operation of the cylinders 40 and 54 is supplied by a double-acting hydraulic cylinder 65, Fig. 1, which utilizes parts of the total advancing and withdrawing movements of the carriage 5. A hydraulic cylinder may replace the electric thruster 60 in operating the bell-crank lever 61. Specification 703,659 is referred to.