Braking methods and apparatus

Claim 3

The method of claim 1 wherein said step of determining the angular disposition of said rotating device comprises the steps of: detecting the rotation of said rotating device through a reference position; and selectively producing a first or second signal a predetermined period of time thereafter in accordance with the occurrence of said condition requiring the arrest of said rotating device, whereby said first signal is produced if said condition has occurred, and said second signal is produced if said condition has not occurred.

Claim 4

The method of claim 2 wherein said step of defining an interval of time required to rotate said rotating device from said determined angular disposition to a desired angular disposition comprises the steps of: producing a third signal in response to the detected rotation of said rotating device through said reference position, said third signal terminating within a pre-established interval of time subsequent to the selective production of said first signal; and inhibiting the termination of said third signal when said second signal is selectively produced.

Claim 5

The method of claim 3 wherein said step of generating a braking signal comprises combining said first and third signals whereby a braking signal admitting of a duration equal to said pre-established interval of time is generated at said predetermined period of time subsequent to the rotation of said rotating device through said reference position.

Claim 6

The method claim 1 wherein said step of generating a braking signal comprises the steps of: detecting the occurrence of a condition requiring the arrest of said rotating device; comparing the time of occurrence of said condition with the angular disposition of said rotating device at said time of occurrence; and selectively generating a braking signal of pre-established time duration during said defined interval of time when said condition occurs prior to the rotation of said rotating device through said predetermined angular disposition.

Claim 7

The method of claim 5 wherein said step of comparing the time of occurrence of said condition with the angular disposition of said rotating device comprises the steps of: providing a first d.c. signal at a predetermined period of time following the rotation of said rotating device through a determined position, said predetermined period of time corresponding to a predetermined angular displacement of said rotating device; and inhibiting said first d.c. signal if said rotating device obtains said predetermined angular displacement prior to the occurrence of said condition.

Claim 8

The method of claim 6 wherein said step of selectively generating a braking signal comprises the steps of: pRoviding a second d.c. signal, said second d.c. signal terminating at an interval of time subsequent to the rotation of said rotating body through said determined position, said interval of time being equal to said defined interval of time; and generating a signal indicative of the coincidence of said first and second d.c. signals.

Claim 9

Apparatus for terminating the rotation of a rotating device in response to the occurrence of a condition such that said rotating device halts at a desired angular position, comprising: an energizable electric motor for driving said rotating device at a constant speed; indicating means for producing signals indicative of the angular position of said rotating device; signal generating means coupled to said indicating means and responsive to said produced signals for generating a brake signal when said rotating device admits of a predetermined angular position; and means responsive to said brake signal for de-energizing said electric motor, thereby producing hysteresis braking of said electric motor whereby the speed of said rotating device is reduced to a zero value when said rotating device obtains said desired angular position.

Claim 10

Apparatus for terminating the rotation of a rotating device in response to the occurrence of a condition such that said rotating device halts at a desired angular position, comprising: an energizable electric motor for driving said rotating device at a constant speed; indicating means for producing signals indicative of the angular position of said rotating device; signal generating means coupled to said indicating means and responsive to said produced signals for generating a brake signal when said rotating device admits of a predetermined angular position; and means responsive to said brake signal for de-energizing said electric motor, thereby producing hysteresis braking of said electric motor whereby the speed of said rotating device is reduced to a zero value when said rotating device obtains said desired angular position.

Claim 11

The apparatus of claim 8 wherein said indicating means comprises: sensing means for sensing the rotation of said rotating device through a reference position; and timing means coupled to said sensing means and activated thereby to produce signals at discrete intervals of time subsequent to the activation of said timing means, said discrete intervals of time being related to said speed of rotation of said rotating device.

Claim 12

The apparatus of claim 9 wherein said signal generating means comprises: comparing means for comparing the relative time of occurrence of said condition with the angular position of said rotating device; means coupled to said comparing means for inhibiting the signals produced by said timing means when said rotating device obtains said predetermined angular position prior to the occurrence of said condition; and combining means coupled to said timing means and responsive to said condition for generating a braking signal having a duration determined by said intervals of time.

Claim 13

The apparatus of claim 10 wherein said timing means comprises: a first timing circuit adapted to be selectively activated by said sensing means and said comparing means, and operable to provide a first signal at a first predetermined period of time subsequent to the activation thereof; and a second timing circuit adapted to be selectively activated by said sensing means and said comparing means, and operable to provide a second signal at a second predetermined period of time subsequent to the activation thereof, said second predetermined period of time exceeding said first predetermined period of time by an amount at least equal to the length of time required to reduce the speed of said rotating device to zero.

Claim 14

The apparatus of claim 11 wherein said combining means comprises coincidence detecting means coupled to said first and second timing circuits and adapted to produce a d.c. signal upon detecting the coincidence of said first signal and said condition, and to terminate said d.c. signal upon detecting the coincidence of said first and second signals, whereby said d.c. signal is effective to de-energize said electric motor to produce hysteresis braking thereof.

Claim 15

The apparatus of claim 9 wherein said timing means comprises: a first monostable multivibrator admitting of a stable output state and a quasi-stable output state, and adapted to assume its quasi-stable output state for a first predetermined period of time in response to an activating signal applied thereto; said first predetermined period of time being equal to the time required to rotate said rotating device from said reference position to said predetermined angular position; a second monostable multivibrator connected in common with said first monostable multivibrator and Admitting of a stable output state and a quasi-stable output state, said second monostable multivibrator being adapted to assume its quasi-stable output state for a second predetermined period of time in response to an activating signal applied thereto, said second predetermined period of time exceeding said first predetermined period of time by an amount at least equal to the time required to terminate the rotation of said rotating device as said rotating device rotates from said predetermined angular position to said desired angular position; and activating means coupled to said commonly connected first and second monostable multivibrators to apply activating signals thereto.

Claim 16

The apparatus of claim 13 wherein said activating means comprises: comparing means for comparing the relative time of occurrence of said condition with the angular position of said rotating device and adapted to produce a signal if said rotating device obtains said predetermined angular position prior to the occurrence of said condition; and means coupled to said comparing means and said sensing means for selectively applying an activating signal to said commonly connected first and second monostable multivibrators when said comparing means produces said signal and when said rotating device rotates through said reference position.

Claim 17

The apparatus of claim 14 wherein said comparing means comprises coincidence means coupled to said first monostable multivibrator for indicating the coincidence of the stable output state assumed by said first monostable multivibrator and a signal representative of the occurrence of said condition, whereby said coincidence means is inhibited when said condition occurs.

Claim 18

The apparatus of claim 14 wherein said signal generating means comprises switching means coupled to said first and second monostable multivibrators and activated by said condition for generating said brake signal when said first monostable multivibrator admits of its stable output state and said second monostable multivibrator admits of its quasi-stable output state.

Claim 19

A motor control system for regulating the operation of an electric motor comprising: motor drive means coupled to said electric motor for supplying said electric motor with operating energy; sensing means for sensing the rotation of said electric motor; means for producing a motor halt signal; means responsive to said sensing means for determining the relative angular disposition of said electric motor at the time of occurrence of said motor halt signal; brake signal generating means responsive to said determination for generating a brake signal when said electric motor rotates into a predetermined angular disposition; means for applying said brake signal to said motor drive means for altering the operating energy supplied to said electric motor whereby hysteresis braking of said electric motor is effected such that said electric motor is halted at a desired angular disposition; and supply termination means coupled to said motor drive means for terminating the operating energy supplied to said electric motor subsequent to the halting of said electric motor.

Claim 20

A motor control system for regulating the operation of an electric motor comprising: motor drive means coupled to said electric motor for supplying said electric motor with operating energy; sensing means for sensing the rotation of said electric motor; means for producing a motor halt signal; means responsive to said sensing means for determining the relative angular disposition of said electric motor at the time of occurrence of said motor halt signal; brake signal generating means responsive to said determination for generating a brake signal when said electric motor rotates into a predetermined angular disposition; means for applying said brake signal to said motor drive means for altering the operating energy supplied to said electric motor whereby hysteresis braking of said electric motor is effected such that said electric motor is halted at a desired angular disposition; and supply termination means coupled to said motor drive means for terminating the operating energy supplied to said electric motor subsequent to the halting of said electric motor.

Claim 21

A motor control system in accordance with claim 17 wherein said means for determining the relative angular disposition of said electric motor comprises: means for producing a signal when said electric motor rotates into said predetermined angular disposition; and coincidence means for detecting the coincidence of said produced signal and said motor halt signal, whereby said produced signal is immediately terminated upon a failure to detect coincidence.

Claim 22

A motor control system in accordance with claim 18 wherein said brake signal generating means comprises means responsive to said coincidence means for generating a d.c. signal of pre-established duration upon a detection of coincidence, said pre-established duration being at least equal to the time required to terminate the rotation of said electRic motor as said electric motor rotates from said predetermined angular disposition to said desired angular disposition.

Claim 23

A motor control system in accordance with claim 19 wherein said motor drive means comprises excitation means for supplying said electric motor with a rotating field whereby said electric motor rotates in synchronism with said rotating field; said excitation means being responsive to said d.c. signal to supply said electric motor with a stationary field.

Claim 24

In a facsimile transceiver including a rotating drum, apparatus for halting said drum at a desired angular position thereof, comprising: an electric motor supplied with operating energy for driving said drum at a constant speed; means for producing a halt signal requiring the halting of said drum; means for sensing the rotation of said drum and for determining the relative angular disposition of said drum at the time of occurrence of said halt signal; brake signal generating means responsive to said sensing means for generating a brake signal when said drum rotates into a predetermined angular disposition; and means responsive to said brake signal for altering the operating energy supplied to said electric motor, thereby producing hysteresis braking of said electric motor such that the speed of said drum is reduced to a zero value when said drum obtains said desired angular position.

Claim 25

In a facsimile transceiver including a rotating drum, apparatus for halting said drum at a desired angular position thereof, comprising: an electric motor supplied with operating energy for driving said drum at a constant speed; means for producing a halt signal requiring the halting of said drum; means for sensing the rotation of said drum and for determining the relative angular disposition of said drum at the time of occurrence of said halt signal; brake signal generating means responsive to said sensing means for generating a brake signal when said drum rotates into a predetermined angular disposition; and means responsive to said brake signal for altering the operating energy supplied to said electric motor, thereby producing hysteresis braking of said electric motor such that the speed of said drum is reduced to a zero value when said drum obtains said desired angular position.

Claim 26

The apparatus of claim 21 wherein said means for sensing comprises: means for producing a signal when said drum rotates into said predetermined angular disposition; comparing means for comparing the occurrence of said produced signal and the occurrence of said halt signal; and means coupled to said comparing means for inhibiting said produced signal when said drum obtains said predetermined angular disposition prior to the occurrence of said halt signal.

Claim 27

The apparatus of claim 22 wherein said brake signal generating means comprises means responsive to said produced signal when said halt signal is produced prior to the time said drum obtains said predetermined angular disposition for generating a d.c. signal of pre-established duration, said preestablished duration being at least equal to the time required to terminate the rotation of said drum as said drum rotates from said predetermined angular disposition to said desired angular position.

Claim 28

The apparatus of claim 23 wherein said electric motor is supplied with a rotating field by excitation means, whereby said electric motor rotates in synchronism with said rotating field, said excitation means being responsive to said d.c. signal to supply said electric motor with a stationary field.

Claim 29

The apparatus of claim 24 wherein said means for producing a signal when said drum rotates into said pre-determined angular disposition comprises timing means activated by the rotation of said drum through a reference position to produce a signal at a discrete interval of time subsequent to the activation thereof, said discrete interval of time being related to the speed of rotation of said drum.