Power transmission device between a plural number of rotors of cineprojectors

Claim 2

A power transmission device for a motionpicture projector, and the like comprising in combination: a take-up reel spindle (6) which is rotatable to take part in film winding; a supply reel spindle (4) which is rotatable to take part in film feeding; driving means for operating said projector, said driving means having a driving shaft (9) which is rotated by the driving force of said driving means; a first pulley (9) which is coupled directly to said driving shaft and rotates integrally therewith; a second pulley which constantly rotates integrally with said take-up reel spindle; a third pulley (3) which constantly rotates integrally with said supply reel spindle; an endless band-form body (8) stretched between said first, second, and third pulleys in a manner to be friction-engaged with said respective pulleys, said endless baNd-form body receiving the driving force of said driving means through said first pulley when said driving means is driven, and transmitting said driving force to said second and third pulleys; and a band-form body adjusting means having a relation to respond to the directions and magnitude of the driving force of said endless band-form body caused by said first pulley, said adjusting means eliminating slack produced in the band-form body adjacent said first pulley which is driven by said driving shaft.

Claim 3

A device as set forth in claim 1, wherein the band-form body adjusting means is rotated and displaced in cooperation with the first pulley.

Claim 4

A device as set forth in claim 1, wherein the band-form body adjusting means is provided with a rotatable roller which hits and contacts the above-mentioned endless band-form body.

Claim 5

A device as set forth in claim 3, wherein the roller established on the band-form body adjusting means is mounted at the approximately symmetrical position to the above-mentioned first pulley.

Claim 6

A device as set forth in claim 1, wherein the band-form body adjusting means is arranged on the first pulley and rotated and displaced in cooperation with the rotation of said first pulley.

Claim 7

A power transmission device for a motion picture projector comprising: reversible driving means having a driving shaft (9) which is rotated by the driving force of said driving means; a take-up reel spindle (6) which is rotatable to take part in film winding; a supply reel spindle (4) which is rotatable to take part in film feeding; a first pulley (9) which constantly rotates integrally with said driving shaft; a second pulley (5) which constantly rotates integrally with said take-up reel spindle; a third pulley (3) which constantly rotates integrally with said supply reel spindle; an endless band-form body (8) stretched between said first, second and third pulleys in a manner to be friction-engaged with said respective pulleys, said endless band-form body receiving the driving force of said driving means through said first pulley, when said driving means is driven, and transmitting said driving force to said second and third pulleys; and tension adjusting means for said band-form body, said adjusting means eliminating slack produced in the band-form body adjacent said first pulley which is driven by said driving shaft, said adjusting means being connected to said driving shaft through slip clutch means (23) and having a tension member (23,30,33, 68) which is rotatable about the rotational axis of said first pulley and includes pressure contact means (26,28,31,34,70), said tension member, when said driving shaft rotates, receiving a rotational force through said slip clutch means to rotate in the same direction as said driving shaft to adjust the tension of said band-form body.

Claim 8

A power transmission device for a motion picture projector comprising: reversible driving means having a driving shaft (9) which is rotated by the driving force of said driving means; a take-up reel spindle (6) which is rotatable to take part in film winding; a supply reel spindle (4) which is rotatable to take part in film feeding; a first pulley (9) which constantly rotates integrally with said driving shaft; a second pulley (5) which constantly rotates integrally with said take-up reel spindle; a third pulley (3) which constantly rotates integrally with said supply reel spindle; an endless band-form body (8) stretched between said first, second and third pulleys in a manner to be friction-engaged with said respective pulleys, said endless band-form body receiving the driving force of said driving means through said first pulley, when said driving means is driven, and transmitting said driving force to said second and third pulleys; and tension adjusting means for said band-form body, said adjusting means eliminating slack produced in the band-form body adjacent said first pulley which is driven by said driving shaft, said adjusting means being connected to said driving shaft through slip clutch means (23) and having a tension member (23,30,33, 68) which is rotatable about the rotational axis of said first pulley and includes pressure contact means (26,28,31,34,70), said tension member, when said driving shaft rotates, receiving a rotational force through said slip clutch means to rotate in the same direction as said driving shaft to adjust the tension of said band-form body.

Claim 9

The improvement according to claim 6, wherein said slip clutch means comprises a friction element.

Claim 10

The improvement according to claim 7, wherein said friction element comprises a spring.

Claim 11

The improvement according to claim 7, wherein said friction element comprises a spring and a felt.

Claim 12

The device according to claim 6, wherein said tension member comprises an elongated plate which is rotatably supported by said first pulley at an intermediate portion of the plate, said plate having at its opposite ends said pressure contact means.

Claim 13

The improvement according to claim 10, wherein said pressure contact means comprises a rotatable roller.

Claim 14

A power transmission device for a motion picture projector comprising: reversible driving means having a driving shaft which rotates by the driving force of said means; a take-up reel spindle which is rotatable to take part in film winding; a supply reel spindle which is rotatable to take part in film feeding; a first pulley which constantly rotates integrally with said driving shaft; a second pulley which constantly rotates integrally wIth said take-up reel spindle; a third pulley which constantly rotates integrally with said supply reel spindle; an endless band-form body stretched between said first, second, and third pulleys in a manner to be friction-engaged with said respective pulleys, said endless band-form body receiving the driving force of said driving means through said first pulley, when said driving means is driven, and transmitting said driving force to said second and third pulleys; and tension adjusting means for inwardly urging said band-form body in order to eliminate slack which is produced adjacent said first pulley driven by said driving shaft, when said band-form body runs around the pulleys, said adjusting means having an elongated tension member which is rotatably mounted at one end thereof to said first pulley through slip clutch means and includes at the other end of the tension member pressure contact means, said tension member being rotated through the slip clutch means in the same direction as said first pulley to urge said band-form body.

Claim 15

A power transmission device for a motion picture projector comprising: reversible driving means having a driving shaft which rotates by the driving force of said means; a take-up reel spindle which is rotatable to take part in film winding; a supply reel spindle which is rotatable to take part in film feeding; a first pulley which constantly rotates integrally with said driving shaft; a second pulley which constantly rotates integrally wIth said take-up reel spindle; a third pulley which constantly rotates integrally with said supply reel spindle; an endless band-form body stretched between said first, second, and third pulleys in a manner to be friction-engaged with said respective pulleys, said endless band-form body receiving the driving force of said driving means through said first pulley, when said driving means is driven, and transmitting said driving force to said second and third pulleys; and tension adjusting means for inwardly urging said band-form body in order to eliminate slack which is produced adjacent said first pulley driven by said driving shaft, when said band-form body runs around the pulleys, said adjusting means having an elongated tension member which is rotatably mounted at one end thereof to said first pulley through slip clutch means and includes at the other end of the tension member pressure contact means, said tension member being rotated through the slip clutch means in the same direction as said first pulley to urge said band-form body.

Claim 16

The improvement according to claim 12, wherein said slip clutch means comprises a friction element.

Claim 17

The improvement according to claim 13, wherein said friction element comprises a spring.

Claim 18

The improvement according to claim 13, wherein said friction element comprises a spring and a felt.

Claim 19

The improvement according to claim 12, wherein said pressure contact means comprises a rotatable roller.