Patent GB-190802480-A (GB)
Title: Improvements in Electrically Driven Elevating Gear for Ordnance.
Filed: 1908-02-04
Granted: 1908-09-24
Abstract: 2480. Krupp Akt.-Ges., F. May 16,1907, [date applied for under Section 91 of Patents &c. Act, 1907]. Mountings.-Relates to electric elevating-gear, and consists in employing a hunting switch having a special contact-piece which automatically causes a resistance to be included in the armature circuit of the operating-electromotor so that this motor slows down as the gun reaches either the firing position or the loading position. Fig. 1 shows a side elevation of the apparatus and a diagrammatic view of the complete wiring arrangements. The gun A slides in a cradle B, which is supported by its trunnions b<1> on the gun carriage C. A pointer D attached to an arm d' is carried loosely on the trunnions b<1>, and can be moved through gearing e<1> by a hand-wheel E over a graduated arc c<1>, along which also moves a pointer b<2> attached to the cradle B. Attached to the trunnion b<1> is a beam b<3>, which can be moved to elevate the gun A by a spur-wheel F driven by a motor G and carries insulated contact bars b<4>, b<5>. Pivotally mounted on the end of the arm d' is a three-cornered insulated contact-piece d<2>, which bears against the stem of a spring-controlled contact-piece d<4> beneath which are situated contact-pieces d<5>, d<6>. A double electro-magnetic relay is provided, which consists of coils K, M and armatures N, P, the armatures having cross-bars which carry ,insulated contacts n<1>, n<2>, n<3> and p<1>, p<2>, p<3>, respectively. A motor G has its armature connected to the contacts n<2>, p, and a source of current S+, S- is provided to which the field coils g<1> of the motor are directly connected, and which sends a current in the direction for elevating the gun through the armature G when the coil M is excited and the armature P moves to the right, and sends a current in the direction for depressing the gun when the coil K is excited and the armature N moves to the left. Another relay is provided consisting of coils Q and armature R, the armature having a cross-bar r<1> adapted to join contacts r<2>, r<3> when the coil Q is excited. When the pointer D is moved downwards through a small angle, the piece d<2> makes contact with the bar b<5>, a circuit through the coil M is completed, and the armature P is attracted, which causes another circuit through the armature of the motor G and the resistance U to be completed. The arm b<3> then turns until the piece d<2> slips into the gap between the bars b<4>, b<5>, whereupon the armature P is released and the motor G stops. The gun can then be fired by closing the switch T, for the pieces n<3>, p<3> are then in contact, and a circuit through the firing-device J is complete. When a large angle of elevation is required to be given to the gun, the contact-piece d<2> moves farther on the bar b<5>, and rotating on its pivot forces the piece d<4> to make contact with the pieces d<5>, d<6>, whereupon the coil Q is excited, the armature R is attracted, and the resistance U is thereby short-circuited, causing the speed of the motor to increase. This increase of speed continues until the piece d<2> again comes into the gap between the bars b<4>, b<5>, whereupon the contact d' is first released and the motor slows down ; then the contact d' assumes its position of rest and the motor stops.