Patent GB-522282-A (GB)
Title: Improvements in portable equipment for use with cinematographic and like projectors
IPC: G03B29/00
Filed: 1938-12-05
Abstract: 522,282. Kinematograph projectors. SOC. DES TELEPHONES ERICSSON. Dec. 5, 1938, No. 35434. Convention date, Nov. 18. [Class 97(i)] [Also in Groups XIII and XL] Apparatus for transforming the current supplied t( a mercury vapour lamp replacing the usual lamp in a kinematograph projector and for supplying cooling water to the lamp, is con tained in two separate portable cases one of which houses the lamp during transport; permanent water connections are provided for the lamp, and permit the ready removal of the lamp from its case for insertion in operative condition in the projector. Fig. 1 shows one case 1 containing a transformer 2 connectible by plug sockets 5, 6, respectively, to 110 or 220 volt supply mains, and supplying current, through flexible leads 7, 8, respectively, at 110 volts to the projector motor and to a pump motor. The case 1 also contains a transformer : supplying the lamp current and to which current at 22( volts is supplied from the transformer 2. Switches 9, 10, a plug socket 11 for the lamp cable, a pilot light 12, and a volt meter are mounted on the top plate of the case 1. A pump 20, Fig. 3, supplying water through a flexible pipe 25 to the lamp and the pump motor 16, are housed in a case 14; water returns from the lamp through a flexible pipe 35, enters a chamber 44 containing a pivoted vane controlling a mercury switch in the primary circuit of the transformer 3, passes to a chamber 50 provided to retain such lamp fragments as may be carried to it from a broken lamp, and thence passes to a radiator 22, cooled by a fan 23, and to the pump. The lamp is housed in a compartment 15 during transport, and a socket 17 receives a plug 18 on the flex 8 when the apparatus is assembled. Fig. 10 shows the electrical connections ; the flex 8 contains three leads, one lead 58, connected to the hand switch 9, being common to the circuits of the motor 16 and of the switch 53 controlled by the vane in the chamber 44, and another lead 56 serving to connect the switch 53 with the hand switch 10 in the primary lamp circuit. The arrangement of the switches ensures that closure of the lamp switch 10 cannot be effective unless the motor pump switch 9 has been closed, and the water is circulating in sufficient volume to tilt the vane in the chamber 44 against spring action, thus closing the switch 53. The lamp cable is connected to a plug 51 having four pins to engage the socket 11, two of the pins 60 being short and connected together to complete the primary circuit of the transformer 3, and two of them, 62, being longer and connecting the transformer and lamp. The lamp 29 is housed in a cooling box 27, being held by a collar 31, Fig. 4, and nut 30 in a cell 28 through which water flows between permanent connections 26, 34 for the pipes 25, 35 respectively. The cell has a lateral glassclosed chamber through which the light is emitted, and this chamber is provided with an escape channel 42 for air bubbles. The terminals 64, 65 are permanently connected to the lamp cable, and a terminal 66 is provided by which the box 27 may be earthed when it is placed in the lamp house of the projector. Flanges on the box 27 are received by the usual reflector guides in the lamp house, and the reflector and an ordinary incandescent lamp may be used alternatively to the lamp 29 &c.