Patent GB-363739-A (GB)
Title: Stand heads for camera tripods and like stands
IPC: F16M11/12
Filed: 1930-10-06
Abstract: 363,739. Stands. SPENCE, J. L., 175, Varick Street, New York, U.S.A. Oct. 6, 1930, No. 29873. Convention date, May 22. [Class 52 (v).] A stand head for a motion picture camera consists of a tilting table carried by a turntable and resilient means interposed between the tilting table and turntable to prevent the sudden descent of the camera due to its own weight. In the construction shown the head comprises a base bowl 1, a levelling table 10 rockably supported therein, a turntable 23 rotatable on the table 10 and carrying a tilting table 30. The tilting table and turntable are moved either by hand or by crank handles, the movements being steadied by trains of gearing and flywheels. Levelling table. The base bowl 1 and the levelling table 10 are connected by a tie bar 15, Fig. 4, with a spherical end 16 engaging a seat formed in a central tubular extension 13 of the table, the bar passing through a central hole in the bottom of the bowl to receive a lock nut 20 by which the base and table can be clamped together. Turntable. The turntable is domed-shaped and rotates on the rim 10<1> of the levelling table. The tables are interconnected by the upper end 150 of the extension 13 being rotatably secured in a socket at the top of the turntable. The tables may be locked together by a brake block carried by the turntable and moved by a handle 158, Fig. 1, to engage the levelling table. Tilting table. The tilting table 30 is rotatable on a shaft 29 carried by standards 28 on the turntable and has opposed depending sectors, one 31, Fig. 1, having peripheral teeth 33 and the other 32, Fig. 2, an arcuate slot covered by a plate 35. A fixed pin 36 engages the slot centrally of its length, springs 37 being arranged in the slot one on each side of the pin to yieldingly maintain the tilting table in its normal horizontal position. The table may be locked in position by a pin 142 engaging one of a series of holes 141 in an arcuate plate 140, Fig. 3, secured to the sector 31. Operation of tilting table and turntable. The tilting table and turntable are normally moved by a handle 38 secured to the tilting table, the movements being controlled by gearing and flywheels arranged within the levelling table and turntable. Tilting table control. The teeth 33 of the sector 31 engage a pinion 55 secured to a shaft 48, Fig. 1, carrying a gear wheel in mesh with a train of multiplying gearing including a frictionally-driven flywheel which may be put out of service by rotating a cam shaft 124, Fig. 3, mounted in bearings within the turntable, so that the cam thereon, acting through a lever, moves a spring-pulled swinging frame on which the flywheel is mounted. ' Turntable control. A rack 21, Fig. 2, on the rim of the levelling table engages a pinion 75 secured to a shaft 74 rotatable with the turntable and carrying a gear wheel in mesh with a train of multiplying gearing including a pair of frictional driven flywheels. Either or both of the flywheels can be put out of action by rotating a hollow cam shaft 128, Fig. 3, revoluble on the cam shaft 124, having a pair of cams which, through levers, move spring pulled swinging frames on which the flywheels are mounted. Alternative operation of tilting table. The tilting table may be operated by rotating, with a crank handle, a longitudinally movable shaft 103, Fig. 1, mounted in bearings within the turntable and provided with a pair of pinions either of which can be geared with the tilting table control gearing, one pinion producing slow motion and the other rapid motion of the table. Alternative operation of turntable. The turntable may be operated by rotating, with a crank handle, a longitudinally movable shaft 113, Fig. 3, mounted in bearings within the turntable and provided with a pinion which can be geared with the turntable control gearing. Gearing. To eliminate backlash the master gears of the turntable and tilting table control gearings are each formed in two parts 46, 47, Figs. 9 and 10, one of which 46 is keyed, at 49, to the shaft 48 and carries a pin 50 projecting into an orifice 51 which merges into a radial slot 52 in the other part 47, a spring-pressed plunger cam 53 mounted in the slot engaging the pin 50 to yieldingly force the teeth of the parts 46, 47 slightly out of alignment. Other wheels may be in two parts which are relatively displaced by tension springs.