Switch actuating arrangement for use in motion picture projectors or the like

Claim 2

In an apparatus for transporting elongated flexible webs, particularly in a motion picture projector, a combination comprising storing means arranged to store a supply of elongated web of finite length having a trailing end connected to said storing means; guide means defining for the web an elongated path; transporting means operable at least in a direction to advance the web lengthwise from said storing means along said path and to progressively change the tension of the web after the supply of web in said storing means is depleted to a predetermined extent; a scanning device adjacent to said path and being movable by the web from a normal position to a first displaced position and from said first displaced position to a plurality of second displaced positions as said change of tension respectively reaches a lower value and a plurality of higher values; an electric switch actuatable to terminate the operation of said transporting means in said direction; and actuating means for said switch, said actuating means being movable by said scanning device from a starting position to a first additional position in which said actuating means actuates said switch and said scanning device assumes said first displaced position, and beyond said first additional position to a plurality of second additional positions in each of which said actuating means continues to actuate said switch and in each of which said scanning device assumes a different one of said second displaced positions, said actuating means being arranged to offer to said scanning device a substantially constant resistance to movement of said actuating means beyond said first additional position to any of said second additional positions.

Claim 3

A combination as defined in claim 1, wherein at least a portion of said scanning device consists of elastomeric material and said scanning device tends to assume and remain in said normal position thereof.

Claim 4

A combination as defined in claim 1, further comprising resetting means operable to return said actuating means to said starting position.

Claim 5

A combination as defined in claim 3, further comprising selector means actuatable to change the direction of Operation of said transporting means and to thereby operate said resetting means.

Claim 6

A combination as defined in claim 1, wherein at least a portion of said scanning device consists of elastomeric material and said scanning device is movable with respect to said actuating means from said displaced positions to said normal position thereof.

Claim 7

A combination as defined in claim 5, further comprising friction generating means arranged to oppose the movement of said actuating means from said starting position thereof so that said actuating means changes its position in a direction away from said starting position only in response to a corresponding change in the position of said scanning device in a direction away from said normal position.

Claim 8

A combination as defined in claim 6, further comprising resetting means operable to return said actuating means to said starting position.

Claim 9

A combination as defined in claim 7, wherein said resetting means is arranged to change the direction of operation of said transporting means in response to actuation thereof for returning said actuating means to said starting position.

Claim 10

A combination as defined in claim 1, wherein said actuating means includes a lever which is pivotable from said starting position to said first additional position and beyond said first additional position to said second additional positions.

Claim 11

A combination as defined in claim 9, wherein said lever comprises a first arm which receives motion from said scanning means and a second arm which actuates said switch, said second arm having a cam surface which engages said switch in said first additional position of said actuating means and a second surface inclined with respect to said cam surface and engaging said switch in said second additional positions of said actuating means.

Claim 12

A combination as defined in claim 10, further comprising a lamp electrically connected with said switch, said lamp being arranged to assume a first condition prior and a different second condition subsequent to actuation of said switch by said actuating means.

Claim 13

A combination as defined in claim 1, further comprising resetting means operable to return said actuating means to said starting position, said switch comprising an element which is frictionally engaged by said actuating means in said additional positions of said actuating means whereby said element exerts upon said actuating means a locking action to hold said actuating means against movement except by way of said scanning device or by way of said resetting means.

Claim 14

A combination as defined in claim 12, wherein said actuating means includes a cam surface and said element is a spring-biased follower which engages said cam surface at least in said first additional position of said actuating means.

Claim 15

A combination as defined in claim 1, wherein said transporting means is further operable in a second direction counter to said first mentioned direction, and further comprising resetting means for returning said actuating means to said starting position in response to operation of said transporting means in said second direction.

Claim 16

A combination as defined in claim 1, wherein said switch comprises an element which is movable by said actuating means along a straight second path between an extended position and a depressed position, said actuating means having a first surface which makes with said second path an oblique angle and engages and depresses said element during movement of said actuating means from said starting position to said first additional position, and a second surface which is normal to said second path and engages said element to maintain the latter in said depressed position in said second additional positions of said actuating means.

Claim 17

A combination as defined in claim 1, wherein said guide means includes means for providing the web in said path with a loop having a concave side, said scanning device being adjacent to said concave side of said loop anD the length of said loop decreasing in response to operation of said transporting means after the supply of web in said storing means is depleted to said predetermined extend whereby the loop moves said scanning device from said normal position.

Claim 18

In an apparatus for transporting elongated flexible webs, particularly in a motion picture projector, a combination comprising storing means arranged to store a supply of elongated web of finite length having a trailing end connected to said storing means; guide means defining for the web an elongated path; transporting means operable in a first direction to advance the web lengthwise from said storing means along said path and to progressively change the tension of the web after the supply of web in said storing means is depleted to a predetermined extent, and in a second direction counter to said first direction; a scanning device adjacent to said path and being movable by the web from a normal position to a first displaced position and from said first displaced position to a plurality of second displaced positions as said change of tension respectively reaches a lower value and a plurality of higher values; an electric switch actuatable to terminate the operation of said transporting means in said first direction; actuating means for said switch, said actuating means being movable by said scanning device from a starting position to a first additional position in which said switch is actuated and said scanning device assumes said first displaced position, and beyond said first additional position to a plurality of second additional positions in each of which said switch remains actuated and in each of which said scanning device assumes a different one of said second displaced position, said actuating means being arranged to offer a substantially constant resistance to movement beyond said first additional position to any of said second additional positions; and resetting means for returning said actuating means to said starting position in response to operation of said transporting means in said second direction, said resetting means comprising a rotary member which is respectively driven in a first and a second direction in response to operation of said transporting means in said first and second directions, a motion transmitting member rotatably mounted on said rotary member, friction clutch means interposed between said rotary member and said motion transmitting member for moving the latter against said actuating means so as to return said actuating means to said starting position in response to rotation of said rotary member in said second direction and for moving said motion transmitting member away from said actuating means in response to rotation of said rotary member in said first direction to thereby allow said actuating means to leave said starting position under the action of said scanning device.

Claim 19

In an apparatus for transporting elongated flexible webs, particularly in a motion picture projector, a combination comprising storing means arranged to store a supply of elongated web of finite length having a trailing end connected to said storing means; guide means defining for the web an elongated path; transporting means operable in a first direction to advance the web lengthwise from said storing means along said path and to progressively change the tension of the web after the supply of web in said storing means is depleted to a predetermined extent, and in a second direction counter to said first direction; a scanning device adjacent to said path and being movable by the web from a normal position to a first displaced position and from said first displaced position to a plurality of second displaced positions as said change of tension respectively reaches a lower value and a plurality of higher values; an electric switch actuatable to terminate the operation of said transporting means in said first direction; actuating means for said switch, said actuating means being movable by said scanning device from a starting position to a first additional position in which said switch is actuated and said scanning device assumes said first displaced position, and beyond said first additional position to a plurality of second additional positions in each of which said switch remains actuated and in each of which said scanning device assumes a different one of said second displaced position, said actuating means being arranged to offer a substantially constant resistance to movement beyond said first additional position to any of said second additional positions; and resetting means for returning said actuating means to said starting position in response to operation of said transporting means in said second direction, said resetting means comprising a rotary member which is respectively driven in a first and a second direction in response to operation of said transporting means in said first and second directions, a motion transmitting member rotatably mounted on said rotary member, friction clutch means interposed between said rotary member and said motion transmitting member for moving the latter against said actuating means so as to return said actuating means to said starting position in response to rotation of said rotary member in said second direction and for moving said motion transmitting member away from said actuating means in response to rotation of said rotary member in said first direction to thereby allow said actuating means to leave said starting position under the action of said scanning device.

Claim 20

A combination as defined in claim 17, further comprising stop means for limiting the extent of movement of said motion transmitting member away from said actuating means.

Claim 21

A combination as defined in claim 18, wherein said friction clutch means comprises a sleeve mounted on and rotatable with said rotary member, said motion transmitting member including an elastic clip frictionally engaging said sleeve and having a portion which is respectively movable into engagement with said actuating means and with said stop means in response to rotation of said rotary member in said second and first directions.

Claim 22

A combination as defined in claim 19, wherein said portion of said clip is arranged to reduce friction between said sleeve and said clip when said portion engages said stop means and said rotary member continues to rotate in said first direction.