Automatic tape threading mechanism

Claim 2

In a video tape-recorder having a supply reel, takeup reel, means for driving said supply reel and a lead tape attached to one end of a reel of recording tape wound on said supply reel, a device for detecting an acidental stoppage of the lead tape and for de-energizing the drive means, comprising: a. a light source; b. a light sensitive element arranged in opposed relation to said light source for generating a train of pulses; c. a circuit for integrating said pulses to produce a first signal; d. means for detecting the feed of said lead tape from said supply reel and producing a second signal; and e. switching means selectively operated in a predetermined sequence in response to said first and second signals whereby said drive means is de-energized when said accidental stoppage of said lead tape is detected.

Claim 3

In a video tape-recorder having a supply reel, a take-up reel, means for driving said supply reel and a lead tape attached to one end of a reel of recording tape wound on said supply reel, a device for detecting an accidental stoppage of the lead tape and for de-energizing the drive means, comprising: a. a drum having an annular slot thereon in contact with one edge of said lead tape and rotatable about the center thereof; b. a disc having a spindle at the central portion thereof and a transparent portion therein, said spindle being connected to the center of said drum; c. a light source facing the surface of said disc; d. a light sensitive element arranged in opposed relation to said light source for generating a train of pulses; e. a circuit for integrating said pulses to produce a first signal; f. means for detecting the feed of said lead tape from said supply reel and producing a second signal; and g. switching means selectively operated in a predetermined sequence in response to said first and second signals whereby said drive means is de-energized when said accidental stoppage of said lead tape is detected.

Claim 4

In a video tape-recorder having a supply reel, a take-up reel, means for driving said supply reel and a lead tape attached to one end of a reel of recording tape wound on said supply reel, a device for detecting an accidental stoppage of the lead tape and for de-energizing the drive means, comprising: a. a drum having an annular slot thereon in contact with one edge of said lead tape and rotatable about the center thereof; b. a disc having a spindle at the central portion thereof and a transparent portion therein, said spindle being connected to the center of said drum; c. a light source facing the surface of said disc; d. a light sensitive element arranged in opposed relation to said light source for generating a train of pulses; e. a circuit for integrating said pulses to produce a first signal; f. means for detecting the feed of said lead tape from said supply reel and producing a second signal; and g. switching means selectively operated in a predetermined sequence in response to said first and second signals whereby said drive means is de-energized when said accidental stoppage of said lead tape is detected.

Claim 5

In a video tape-recorder having a supply reel, a take-up reel, means for driving said supply reel and a lead tape attached to one end of a reel of recording tape wound on said supply reel, a device for detecting an accidental stoppage of the lead tape and for de-energizing the drive means, comprising: a. a drum having an annular slot thereon in contact with one edge of said lead tape and rotatable about the center thereof; b. a disc having a spindle at the central portion thereof and a pair of metal strips on opposite surfaces thereof, said spindle being connected to the center of said drum; and c. a pair of brushes in opposed relation to each other and in contact with said metal strips for generating a train of pulses; d. a circuit for integrating said pulses to produce a first signal; e. means for detecting the feed of said lead tape from said supply reel to produce a second signal; and f. switching means selectively operated in a predetermined sequence in response to said first and second signals whereby said drive means is de-energized when said accidental stoppage of said lead tape is detected.

Claim 6

In a video tape-recorder having a supply reel, a take-up reel, means for driving said supply reel and a lead tape attached to one end of a reel of recording tape wound on said supply reel, a device for detecting an accidental stoppage of the lead tape and for de-energizing the drive means, comprising: a. a drum having an annular slot thereon in contact with one edge of said lead tape and rotatable about the center thereof; b. a disc having a spindle at the central portion thereof and a pair of metal strips on opposite surfaces thereof, said spindle being connected to the center of said drum; and c. a pair of brushes in opposed relation to each other and in contact with said metal strips for generating a train of pulses; d. a circuit for integrating said pulses to produce a first signal; e. means for detecting the feed of said lead tape from said supply reel to produce a second signal; and f. switching means selectively operated in a predetermined sequence in response to said first and second signals whereby said drive means is de-energized when said accidental stoppage of said lead tape is detected.

Claim 7

In a video tape-recorder having a supply reel, a take-up reel, means for driving said supply reel and a lead tape attached to one end of a reel of recording tape wound on said supply reel, a device for detecting an accidental stoppage of the lead tape and for de-energizing the drive means, comprising: a. means for detecting movement and stoppage of said lead tape and producing a first signal; b. a spindle; c. an arm pivoted at the intermediate thereof on said spindle and having at one end an arcuate portion, said arcuate portion transversing the passage of said lead tape; d. a pair of make contacts adjacent the other end of said arm to provide a second signal; and e. switching means selectively operated in a predetermined sequence in response to said first and second signals whereby said drive means is de-energized when said accidental stoppage of said lead tape is detected.

Claim 8

In a video tape-recorder having a supply reel, a take-up reel, means for driving said supply reel and a lead tape attached to one end of a reel of recording tape wound on said supply reel, a device for detecting an accidental stoppage of the lead tape and for de-energizing the drive means, comprising: a. means for detecting movement and stoppage of said lead tape and producing a first signal; b. a spindle; c. an arm pivoted at the intermediate thereof on said spindle and having at one end an arcuate portion, said arcuate portion transversing the passage of said lead tape; d. a pair of make contacts adjacent the other end of said arm to provide a second signal; and e. switching means selectively operated in a predetermined sequence in response to said first and second signals whereby said drive means is de-energized when said accidental stoppage of said lead tape is detected.