Patent GB-216328-A (GB)
Title: Improvements in means for controlling the vacuum in osmo regulated gas-filled x-ray tubes
IPC: H01J35/20
Filed: 1923-05-17
Abstract: 216,328. Schall, W. E. May 17, 1923. Relays.-The supply of gas to a burner is determined by the movements of a coil suspended in the field of a permanent magnet through which coil the current in the hightension circuit passes. In the apparatus shown diagrammatically in Fig. 6, the coil a controls the gas supply valve t through a relay comprising electromagnets p, q adapted to be energized by a source of current connected to a positive terminal A and negative terminals B, C. A movable contact h<5> connected to the conductor 1 is mounted between contacts n, n<1> and is urged by a spring against the contact n until the high-tension current exceeds a determined value, whereupon it is urged by the coil a against a contact n<1>. In the first case current passes from the terminal A by conductor 1, contact n, conductor 2, through the winding of the electromagnet p and conductor 3 to the terminal B. The electromagnet p attracts an armature r<1> to which is attached a cushion valve t thus allowing the passage of gas. The electromagnet p also draws an armature r away from a contact r<0> breaking the circuit of the electromagnet p the armature s of which is then urged by a spring against a contact s<1>. When the contact h<5> leaves the contact n, the circuit of the electromagnet p remains completed through conductor 6, contact s<1> armature s and conductor 4 until the contact h<5> engages the contact n<1>, whereupon the circuit of the electromagnet p is completed to the terminal C. The armature s is thereupon attracted, breaking the circuit through the electromagnet p and allowing closure of the valve t. The armature r is urged by its spring against the contact r<0> completing the circuit through the electromagnet q until the contact n is again engaged by the contact h<5>. The coil a is mounted in a cylindrical recess in a block g, Fig. 1, joining the pole-pieces of a horse-shoe magnet b and surrounds a fixed core secured to the base of the block. The coil a is provided with arbors mounted in fittings on the block g and is controlled by a hair-spring e<1> secured at its periphery to the block and a hairspring e<2> secured at its periphery to the edge of a, disc e<4> adjustable by a knob e<8> provided with a pointer. The contact h<5 >is mounted at the end of a counter-weighted needle h pivotally mounted on an axis in alignment with that of the coil a. The contacts n, n<1>, of which only n<1> is shown, are mounted on pillars o' between which is mounted a mica plate o<2>. The needle h is actuated by the forked end l of a bent arm k secured to the coil a and provided with an insulating sector h<4>. Gas enters the valve chamber t<1>by a pipe u and leaves by a pipe u<1> the end of which forms the seating for the valve t<2>. The valve chamber t<1> may also be connected to the burner by a tube having a manually-operated tap. One end of the coil a is connected to the earthed end of the generator. According to the Provisional Specification, the electromagnet q may have a second armature arranged to give the contacts n, n<1> a knock when it is attracted.