US2089846A

US2089846A - Mechanical positive driving system

Info

Publication number: US2089846A
Application number: US118191A
Authority: US
Inventors: William G H Finch
Original assignee: Individual
Current assignee: Individual
Priority date: 1936-02-26
Filing date: 1936-12-30
Publication date: 1937-08-10
Anticipated expiration: 1954-08-10
Also published as: US2133811A; US2145717A; US2069061A; US2071227A; US2048604A; US2098802A

Description

Aug. 10, 1937. w. G. H. FINCH MECHANICAL POSITIVE DRIVING SYSTEM Original Filed Feb. 26, 1936 4 Sheets-Sheet 1 Snnentor WILLIAM 6H. F'INCH (Ittomeg Aug. 10, 1937. w. s. H. FlNCH v MECHANICAL POSITIVE DRIVING SYSTEM Aug. 10, 1937. w. H. FINCH MECHANICAL POSITIVE DRIVING SYSTEM Original Filed Feb. 26, 1936 4 Sheets-Sheet 3 Fig25.

3nventor WILLIAM GH. FINCH 'Jttorneu Aug. 10, 1937. w. G. H. FINCH' MECHANICAL POSITIVE DRIVING SYSTEM Original Filed Feb. 26, 1936 4 Sheets-Sheet 4 WILLIAM GHHNCH (Ittomeg Patented Aug. 10, 1937 UNITED STATES PATENT OFFICE Original applications February 26, 1936, Serial No. 65,869, and April 6, 1936, Serial No. 72,991. Divided and this application December 30, 1936,

Serial No. 118,191

6 Claims.

This invention relates to novel apparatus for substantially instantaneously connecting and disconnecting a driven member from a driving member, together with novel means for compensating for inertial displacements due to the connections and disconnections.

This application is a division of the parent application Serial No. 65,869, filed February 26, 1936, which matured into Patent No. 2,047,863, entitled Telecommunications system, and is a division of my copending application, Serial No. 72,991, filed April 6, 1936 and entitled Telepicture synchronizing system.

In the transmission of pictures to remote points, it is essential that the receiver picture drum be in phase synchronism with the transmitter drum. Many attempts have been made to attain such phase synchronization. It is extremely desirable to provide a positive driving connection between the motor and the revolving drum to avoid any deleterious eiiects due to frictional coupling. In my Reissue Patent No. 19,575, I have disclosed a system for connecting and disconnecting the positive driving connection between the driving motor and the drum in re sponse to synchronizing signals to maintain phase synchronization.

In my present invention, I utilize an overrunning or positive clutch for maintaining the drum in phase synchronism. To overcome the eiiects of rotational inertia present in a large telepicture system having a large revolving drum, I provide a flexible mechanical coupling between the positive clutch and the receiving drum. This coupling is designed to permit a momentary phase displacement of the drum due to accelerating or decelerating inertial forces acting on the drum during the substantially instantaneous connection and disconnection thereof from the driv rig motor. .The flexible coupling is further designed to promptly automatically compensate for these momentary phase displacements.

This compensation is accomplished by mechanical means of a positive nature, to bring the driven member or drum back to the position it had at the instant of connection or disconnection. The flexible connection can accordingly be considered as a member in a mechanical positive driving connection between the motor and the drum since no rubber, fluid or other relatively elastic connection is used. Elastic connections are undesirable for picture work since any tendency to set will distort the picture reproduction.

It is accordingly an object of my present invention to provide a novel driving system employing an over-running or positive clutch connection to the driven member.

Another object of my invention is to provide a mechanical flexible coupling in the positive drive for a rotatable member, which automatically compensates for any momentary phase displacement due to acceleration or deceleration forces.

A further object of my invention is to provide a novel combination of a positive clutch engaging and disengaging means for a revolving member and a positive driving connection to permit substantially instantaneous connection and disconnection of the member.

Other objects of my invention together with the'foregoing will become apparent in the following description in connection with the drawings, in which:

Figure 1 is a plan view of a preferred embodiment of the telepicture receiver.

Figure 2 is an enlarged cross-sectional view through the receiver drum and drive of Figure 1.

Figure 3 is a cross-sectional view taken through Figure 2 showing a partially enlarged plan view of the drive mechanism and clutch trip levers.

Figure 4 is a. perspective disassembled view of the clutch mechanism.

Figure 5 is a cross-sectional view illustrating a fragmentary detail of the internal clutch roller assembly.

Figures 6, 7 and 8 are cross-sectional views taken respectively along 6-6, 'l--'I and 88 of Figure 2 showing details of the synchronizing clutch control mechanism.

Figure 9 is'a modification of the synchronizing clutch control mechanism corresponding to Figure 7.

Figure 10 is a cross-sectional view along ll0 of Fig. 9.

Referring to Figure 1, the telepicture receiver is mounted on a cast iron base I I if it is designed for non-portable use. Synchronous motor I2 drives the receiver drum l3 through the overrunning clutch H and suitable gearing contained in housing I 5. Synchronous motor I! is connected by leads l6 to electrical supply lines I! for electrical energization thereof. Reduction gearing l8 connects worm or feed screw I to spindle end 20 rotating with drum l3. If drum l3 rotates 100 revolutions per minute and 100 scanning lines per inch are used, the pitch oi. worm'lfl and its rate of revolution will be designed to advance receiver carriage 2| at the rate of one inch per minute so that the scanning of the film 22 mounted on drum l3 will progress in a continuous helical path. The light beam 23 emanating from focusing system 24 in this example is designed to be .01 of an inch in width to prevent translation overlapping. Carriage 2| houses the receiver electro-optical system and rides on V-tracks 25 and 25 with V-

rollers

21 and 23.

The record sheet 22 is clamped upon drum |3 by clamping members 30. A scale is marked upon the drum in the under-lap portion to indicate the length of the record sheet being used. The plurality of roller sections 3| are shown out of position and are used to aid in smoothly mounting record sheet 22 on drum |3 in a manner described in the parent application already referred to. Drum i3 is rotatably supported by pointed spindle 32 supported in tail stock 33.

Figure 2 is the cross-sectional view of Figure 1 through the axis of drum l3, illustrating in detail the mechanism for driving and mounting drum i3. The shaft 34 driven by the motor |2 through the flexible coupling 35 rotates worm 35 which drives worm gear 31. The hub 33 of worm gear 31 is connected to the clutch driver 43 by projections 4| of the hub 35 into corresponding grooves in the clutch driver 45. The worm gear 31 and the clutch driver 40 are free to rotate upon the spindle 42. The housing l5 encloses the worm and pinion drive and contains bearing 43 which supports one end of the spindle 42. The opposite-end 44 of spindle 42 is conical and coacts with the metallic insert 45 pinned to end plate 45 of drum |3 by pin 41, and supports drum l3. Metallic insert 41 attached to opposite end plate 48 coacts with the conical end 43 of thespindle 32 supported in tail stock 33. Hollow shaft 50 rigidly connects the metallic inserts 45 and 41. Drum i3 is accordingly rotatably supported by the conical ends 44 and49. I

Figure 4 is a perspective illustration of the overrunning clutch l4 disassembled to more clearly explain its operation. The clutch cam plate 5| is rotatably mounted within the clutch driver 45 upon spindle 42 (shown in dotted). There are four openings 52 on the surface of the cam plate which contain metal cylindrical rollers 53. The clutch stop plate 54 is fitted adjacent to the cam plate 5| and contains four pins 55 which coact with the cylindrical rollers 53.

Figure 6 is a sectional view through the overrunning clutch l4 taken along 5-5 of Figure 2 illustrating the character of the recesses 52 in the cam plate 5|. The principle of the overrunning clutch is well known in the art. The rollers 53 are wedged between the inner surface 55 of the clutchdriver 43 and the inclined surfaces 51 of the recesses 52. Plungers 58 set in cam plate 5| are forced against each roller 53 by springs 53 set within the cam plate 5|. The wedging action of the rollers 53 between surface 55 and inclined surfaces 51 serves as a positive connection between the clutch driver 40 and the cam plate or clutch driven member 5|.

Figure 5 is a cross-sectional enlarged detailedview illustrating the arrangement of a roller 53 and its stop plate pin 55 within a recess 52 of the cam plate 5| in engaged position where the plunger 53 is pressed against the roller 53 by spring 53 set in the cam plate 5|.

Referring to Figures 2 and 4, the hub 50 of cam plate 5| has a V notch 5| atone end thereof which coacts with a V projection 52 on the coupling. member 53. Coupling member 53 has keyway's'54 that slidably engage corresponding keys 55 set in the spindle 42. It is to be understood that the coupling member 53 is slidable axially on the spindle 42 and that this coupling member 53 provides the driving connection for the spindle 42 since no relative angular'movement therebetween is possible.

Accordingly, when the overrunning clutch I4 is engaged the motor drive I2 is transmitted by the worm and pinion 35-31, the engaged clutch i4 and the coupling member 53 to the spindle 42. The face plate driver 55 is rigidly mounted on the spindle 42 by pin 51. A projection or key 58, on the face 59 of the face plate driver 55, sets into a corresponding groove in the end plate 48 of the receiver drum I3. A positive driving connection is accordingly had between the motor l2 and the receiver drum l3 when the positive or overrunning clutch I4 is engaged.

A set of pins 10 project from the opposite end II of the face plate driver 55 to press the coupling member 53 into engagement with the V notches 5| of the cam plate 5|. Springs 12 press the pins 10 against the face 13 of the coupling member 53. A positive driving connection of coupling member 53 with cam plate hub 50 is had for all practical purposes in the operation of the system, since the pins I3 maintain the engagement of V projection 52 and V grooves 5| during the driving cycle of the drum.

An important feature of my present invention resides in the automatic connection and disconnection of the positive or overrunning clutch M to maintain the revolving receiver drum l3 in phase synchronism with the transmitter drum (not shown). In my Re. Patent No. 19,575, is described one method for connecting and disconnecting the positive drive from between the source of motive power and the revolving drum.

My present invention embodies the principle of the overrunning clutch in an instantaneous synchronization' mechanism. Synchronization according to Re. Patent No. 19,575 depends upon the actuation of a pawl engaging a ratchet wheel in the positive driving connection. The limits of phasing positions are accordingly within the pitch or width of one tooth of the ratchet wheel.

By employing an overrunning clutch, the positive drive is had during the rotation of the drum l3 and accurate phase synchronization is feasible at any point in the circumferential movement of the drum. The stop plate 54 contains the pins 55 which coact with the wedging rollers 53. When the cam plate 5| is driven by the clutch driver 45 during the wedging action ofthe rollers 53, the stop plate 54 is also driven and revolves with the cam plate 5|. However, I provide a notch I4 on the periphery of the stop plate 54 biased by spring 11 toward the stop plate 54.

Figure 7 illustrates the engagement of lever.

projection 15 with the corresponding notch 14 in the stop plate 54. In this position the stop plate is prevented from further rotating counterclockwise, as indicated by the arrow. The pins 55 accordingly abut the rollers 53 within the overrunning clutch .l4 and force the rollers 53 against the piungers 58 to disengage the clutch l4, as will be understood by those skilled in the art. The rollers 53 are moved along the inclined surfaces 51 releasing the wedging action of the rollers 53 from between the cam plate 5| and the inner clutch driver surface 55. The motor l2 continues to rotate the clutch driver 40 but the driving of the drum I8 therefrom is instantaneously discontinued.

A pawl 88 is mechanically biased toward the stop plate 84 by spring 8i. Pawl 88 projects into a notch 82 on the periphery of stop plate 88 at the instant the projection I8 of the trigger lever I6 engages the notch I8 in the stop plate 88 The pawl 80 accordingly prevents rebound o? the stop plate when its notch is arrested, thus insuring a positive disengagement oi the overrunning clutch I4.

Figures 3, 7 and 8 illustrate one modification for actuating the clutch I8 in response to synchronizing signals. For rapid engagement of the overrunning clutch II in response to synchronizing signals,'i'alling weight 88 is caused to impact theend 88 of the trigger lever I8, removing the projection I5 from the notch I8 in the stop plate 84 and permitting the plungers 88 to wedge the rollers 53 between the cam plate II and the clutch driver 88. The movement of weight 88 is guided by post 85 through a hole inthe center of the weight 88.

Figure 7 illustrates the weight in its upper position. A projection 88 on the armature 81 of the synchronizing magnet 88 holds the weight 83 in its upper position in readiness for release. When a synchronizing impulse is impressed upon magnet 88 through its leads 8888 in a manner well known in the art and described in detail in the parent application, the armature is attracted toward the magnet 88 against the spring 8| permitting the weight 83 to drop and impact the end 88 of trigger lever I6 to drivingly engage the clutch I 8 as illustrated in Figure 8.

The weight 83 is replaced to its upp r position by means of the lever 82. A pin 88 projects from the surface of the stop plate 88 and once per revolution of the stop plate, the pin 88 presses the end 83 of lever 82 downward so that the opposite end 85 automatically raises the weight 88 to its upper position shown in dotted in Figure 8. Spring 8I moves the armature 81 away from the magnet 88 permitting the projection 88 to engage the bottom corner of the weight 83 to hold it in its upper position in readiness for its cyclical release. Figure 3 is a sectional view through Figure 2 showing the driving connections from the motor coupling 88 and is a plan view of the synchronizing levers I6 and 82, weight 83 and magnet 88.

The receiver drum I3 is maintained in phase synchronism by means of cyclically transmitted synchronizing signals during the underlap period of the transmitter drum (not shown). The receiver synchronizing cam I88 is mounted at the end 28 01 the spindle 82 outside the housing I8 clearly illustrated in Figure 2. The subtended angle oi! the cam nib I8I may be made equal to the corresponding subtended angle of the underlap portion of the receiver drum I8 so that the receiver synchronizing switch I82 will be maintained open during this interval to cause synchronizing magnet 88 to be connected in .the circuit of the receiver amplifier output as .described in the parent application.

As there described, the amplifier is a class B amplifier and the tubes are biased to cut oil", so that when no signal is impressed in the input circuit, zero plate current will flow and the synchronizing magnet 88 connected therein will not be energized until the synchronizing impulse is impressed. In my preferred embodiment. the synchronizing impulse is or a magnitude greater than the largest telepicture signal so that the synchronizing magnet will respond only to the synchronizing signals.

ably made of aluminum to reduce its rotational inertia, The coupling member 88 coacting with v the driven, cam plate ii of the overrimning clutch I8 acts as a shock absorber to resist the inertial resistance of the drum I8 during its starting from rest to synchronous speed, or of any inertial forces it may present during the synchronizing action.

When there is a tendency for the cam plate 8| to advance in phase with respect to the coupling member 88, the coupling member will'slide axially along the spindle 82 away from the clutch cam II and against the pressure of the pins I8 mechanically biased by springs I2. The V notches 8| 0! the cam hub 88, coacting with the V projections 82 of the coupling member '88, eiiects a positive driving action between the two when they are in engagement. A relative motion between the cam plate II and member .88 causes its V projection to slide away from the V notches 8I proportional to the iorces tending to resist their in-phase movement. Such forces occur momentarily, and the coupling member 88 is again forced into normal engagement with thevnotchesflbythepinsll.

Any momentary relative movement between the clutch driven member 8I and the member 88' is automatically compensated by the return of the V projections 82 into normal engagement with the V notches N. A spring I88 connects an elet pin I88 secured in the coupling memher 8 and another eyelet pin: I8.|' secin'edin the hub 88 of the cam plate 8|, as illustrated in Figures 7 and 8. Spring I88 facilitates the automatic return engagement oi. the V projection" 82 lithe Vnotches 8I ot'the corresponding memor splined to the spindle 82 and the face plate driver 88 is rigidly keyed to the spindle 82, the

,. receiver drum I8 is driven positively from the coupling member 88. ,The source of motive- Since, the coupling member a is mam, keyed connection. The relation of the hub 88 and coupling member 88as already described is a flexible positive connection since it permits momentary changes in phase, but-automatically returns to the normal phase relation. .The synchronizing apparatus operating on the clutch stop plate 88 disconnects the positive driving connection between thesource oi motive power I2 and the receiving drum I8 at the positive or overrunning clutch I8 it the receiver drum I8 is not in phase synchronism with the transmitter driun (not shown).

Itistobeunderstoodthatthereceiverdrum I8rotatesinandinphasewiththe corresponding transmitter drum. and that the carriage 2I simultaneously advances the impinging signal light beam 28 axially along the him 22 mounted on the drum I8 to record the picture being transmitted, The intensity of the light beam 23 sharply focused upon the film 22 varies in accordance with the shading of the picture being transmitted as is evident to those skilled in the art.

A modification of the synchronizing magnetclutch trigger arrangement is illustrated in Figure 9 corresponding to Fig. 7. The synchronizing magnet H corresponding to magnet 88 is mounted on a bracket III below the surface H2 of the base II. The poles H3 of the synchronizing magnet IIll project through the surface H2 to coact with the armature plate II4 attached to the end H5 of the trigger lever I6.

Figure is a cross-sectional view through the magnet III] illustrating how the armature plate I I4 is arranged above the two poles I I3--I I3 of the electromagnet III) and how the trigger end H5 is positioned between the poles II3-I I3. The trigger I6 is accordingly directly actuated by the synchronizing magnet H0 without the use of a falling weight 83 as in the hereinabove described modification. While the clutch I4 and stop-plate 54 are rotating, the lever I6 will be held in the dotted position of Fig. 9 so that the armature plate H4 will be close to the poles I I3 of the magnet I Ill. The peripheral surface of the stop-plate 54 will abut the trigger projection I5 and press the lever I6 .toward the poles H3 against the action of the biasing spring 11. The armature plate I I4 will accordingly be close to the poles H3 of the magnet H0 during the major portion of the revolution of the stop-plate 54, but will tend to be moved away under the'action of spring 'II when the notch I4 comes in engaging position with the projection I5 of the trigger I6.

If the drum I3 is in phase synchronism, the synchronizing impulses will arrive at the synchronizing magnet III through leads II6-IiI'I in time to hold the trigger 16 away from engagement with the stop-plate notch I4 and permit the drum I3 to continue in phase synchronism. It is to be understood that if the drum I3 is out of phase synchronism, the notch I4 will engage the trigger projection I5 to disengage the positive or overrunning clutch I4. When the synchronizing signal is received by the magnet I III, the stopplate 54 is released and the clutch reengages to rotate the drum in proper phase synchronism.

I claim:

1. The combination with a driving means and a driven shaft, of a positive clutch for connecting and disconnecting said driving means and shaft comprising a driving member connected to said I driving means and a driven member; an element for coupling said driven member to said driven shaft, slidably keyed to the driven shaft, and having a contact engagement with said driven clutch member symmetrical about said driven shaft for balancing the forces of coupling, and means for maintaining said element in continuous engagement with said driven clutch member including structure coaxial with and secured to the driven shaft, having pins spring biased against said coupling element, for permitting a momentary relative angular displacement between said driving means and shaft.

2. The combination with a driving means and a driven shaft, of a positive clutch for connecting and disconnecting said driving means and shaft comprising a driving member connected to said driving means and a driven, member; an element for coupling said driven member to said driven shaft, slidably keyed to the driven shaft, and having a contact engagement with said driven clutch member symmetricaLabout said driven shaft for balancing the forces of coupling, said engagement comprising V-projections from said element cooperative with V-notches in said driven member arranged on opposite sides of the driven shaft and means for maintaining said element in continuous engagement with said driven clutch member including structure coaxial with and secured to the driven shaft, having pins spring biased against said coupling element, for permitting a momentary relative angular displacement between said driving means and shaft.

3. The combination with a driving means and a driven shaft connected to rotate a drum, of a positive clutch for connecting and disconnecting said driving means and shaft comprising a driving member connected to said driving means and a driven member; an element for coupling said driven member to said driven shaft, slidably keyed to the driven shaft, and having a contact engagement with said driven clutch member symmetrical about said driven shaft for balancing the forces of coupling, said engagement comprising V-projections cooperative with V-notches arranged on opposite sides of the driven shaft and means for maintaining said element in continuous engagement with said driven clutch member for permitting a momentary relative angular displacement between said driving means and shaft; means for arresting the rotation of said driven clutch member at a predetermined angular position whereby said drum will be returned to said predetermined angular position after the momentary angular displacement resulting from inertial forces thereof.

4. The combination with a driving means and a driven shaft connected to rotate a drum, of a positive clutch for connecting and disconnecting said driving means and shaft comprising a driving member connected to said driving means and a driven member; an element for coupling said driven member to said driven shaft having a contact engagement with said driven clutch member symmetrical about said driven shaft for balancing the forces of coupling and permitting a momentary relative angular displacement between said driving means and shaft; and means for arresting the rotation of and preventing rebound of said driven clutch member at a predetermined angular position whereby said drum will be returned to said predetermined angular position after the momentary angular displacement resulting from inertial forces thereof.

5. The combination with a driving means and a driven shaft connected to rotate a drum, of a positive clutch for connecting and disconnecting said driving means and shaft comprising a driving member connected to said driving means and a driven member; an element for coupling said driven member to said driven shaft, slidably keyed to the driven shaft, and having a contact engagement with said driven clutch member symmetrical about said driven shaft for balancing the forces of coupling;-means for maintaining said element in continuous engagement with said driven clutch member including structure coaxial with and secured to the driven shaft, having pins spring biased against said coupling element, for permitting a momentary relative angular displacement between said driving means and shaft; and means for arresting the rotation of and preventing rebound of said driven clutch member .at a predetermined angular position whereby said 6. The combination with a driving means and a driven shaft connected to rotate a drum, of a positive clutch for connecting and disconnecting said driving means and shaft comprising a driv- 5 ing member connected to said driving means and a driven member; an element for coupling said driven member to said driven shaft, slidably keyed to the driven shaft, and having acontact engagement with said driven clutch member symmetri- 10 cal about said driven shaft for balancing the forces of coupling, said engagement comprising V-projections from said element cooperative with V-notches in said driven member arranged on opposite sides of the driven shaft; means for 15 maintaining said element in continuous engagement with said driven clutch member including structure coaxial with and secured to the driven shaft, having pins spring biased against said coupling element, for permitting a momentary relative angular displacement between said means; and means for arresting the rotation of and preventing rebound of said driven clutch member at a predetermined angular position whereby said drum will be returned to said predetermined angular position after the momentary angular displacement resulting from inertial forces thereof, comprising a stop plate coacting with said driven clutch member having a notch in its periphery and a pawl spring biased against the periphery of said stop plate for engaging said notch.

WILLIAM G. H. FINCH.