to compress the cover plates inward on the split balls, compressing the balls on to the supports and firmly securing the supports at any desired point. A pin inserted in each 5 split ball insures that the split in the ball will be normal to the pressure of the cover plate.
In the drawings Fig. 1 is a side elevation of a preferred embodiment of the invention.
10 Fig. 2 is a top view of the lamphouse bracket showing the clamp of the invention in greater detail.
Fig. 3 is a side elevation of the invention adapted to a typical motion picture pro
Fig. 4 and Fig. 5 are diagrammatic elevations of the invention showing the angular relations involved in a-change in the angle of projection.
20 Referring to the drawings, a member 1 having a cup-shaped surface is formed in or attached to the base 2 of the projector. This member 1 may conveniently be designed to serve also as a clamp for the legs 3 of the
25 base 2. Suitable bolts 4 secure the clamp to the base 2 and may be slackened to permit the legs 3 to be adjusted. A projection 5 is formed in the member 1 and serves as a support for one end of the member 6. The mem
30 ber 6 is retained in place by the projection 5 and the screw 7. The upper end of the member 6 forms a cup-shaped surface which is aligned with the cup-shaped surface of the member 1. Secured to the lower end of the
35 supports 8, are ball-shaped members 9 supported and retained by the opposed cupshaped surfaces formed in members 4 and 6. By means of the screw 7 the member 6 may l>e pressed as tightly as desired on the ball 9.
40 The ball 9 is pierced centrally by a hole slightly larger than the supports 8 and radially divided by the slot 10 and is pinned to the end of the support 8 so that the slot 10 is normal to the direction of the pressure
45 exerted by the member 6. The pressure exerted by the member 6 compresses the ball 9 partially closing the slot 10. The natural elasticity of the material of the ball 9 holds the ball firmly yet resiliency in the cup
60 shaped members 4 and 6.
Cup-shaped surfaces 11, 11. are formed in
the ends of the lamphouse bracket 12 which
• forms the rear element of the support for the
lamphousfi 13. Projections 14,14 are formed
55 on the ends of the bracket 12, and serve as supports for one end of clamping members 15,15. A cup-shaped surface is formed near the other end of clamp members 15, 15 aligned with the cup-shaped surfaces formed
60 on the ends of the bracket 12. Seated in the opposed cup-shaped surfaces of the bracket 12 and the members 15, 15 are suitable ballshaped members 16. 16. The ball-shaped members 16, l(i are pierced centrally by a hole
85 slightly larger than the supports 8, 8 and are
radially divided by the slot 17. Pins 18 secured in the bracket 12 retain the ball-shaped members 16, 16 so that the slots 17, 17 are always normal to the direction of the pressure exerted by the clamping members 15.15. TO A rod 19 is loosely mounted in a suitable hole longitudinally formed in the bracket 12. One end of the rod 19 is formed into a head 20 bearing on one of the members 15. The other end of the rod 19 is suitably threaded T5 to receive a handle 21 which may be screwed on the rod 19 until the handle 21 bears on the other member 15. By further screwing the' handle 21 on the rod 19, both of the mem- -i. bers 15,15 will be drawn inward compressing 80 the ball-shaped members 16, 16 on the sup- l ports 8, 8 and securely clamping the bracket 12 to the supports 8, 8. By unscrewing the handle 21, the pressure of the members 15,15 on the members 16, 16 is relieved and the 85 natural resilience of the members 16, 16 will cause them to spring away from the supports 8, 8 and allow the bracket 12 to be moved along the supports 8, 8. As only a small movement of the handle 21 is necessary to 80 release the clamp, the bracket 12 may be readily released for adjustment along the supports 8, 8 and readily clamped in the new position.
The motion picture projector illustrated in 88 Fig. % includes a film reel 22, from which the film is drawn by suitable mechanism 23 through which the picture is projected by means of light supplied by a lamp in the lamphouse 13. If the projector is adapted 100 also for the reproduction of soxind from a sound record on the film, the film is drawn through suitable mechanism 24 by which the sound record may be reproduced. The film is then reeled upon a suitable take-up reel 106 mounted in housing 25.
Due to the large differences in the size and shape of the theatres and in the location of the projection room in the theatre, a motion picture projector must be designed so that 110 the line of projection may be elevated above or depressed below the horizontal. In order to avoid an undesirable kink in the film, the horizontal axis of the projector is generally located near the front, as indicated by the. 115> dotted circle 26. The lamphouse 13 is" slid- f ably mounted on two rods 29, 29 supported by a bracket suitably pivoted about the horizontal axis 26, and secured to the bracket 12. The bracket 12 is adjustably elevated and 120 supported by the threaded rod 27 and hand wheel 28. By operating the hand wheel 28 the angle of projection may be readily changed as required, for example in changing from front of stage to rear of stage 1M screening.
A motion picture projector of the type described is composed of the following structural elements: (1) a base which is normally horizontally located; (2) a vertical por- ISO