US2286187A - Speed control mechanism - Google Patents

Description

J1me 1942- J. M. LUCARELLE EI'AL 2,286,187

SPEED CONTROL MECHANISM Filed Jan. 18, 1941 INVENTORS Joseph M. Lucarelle BY Charles Ec/cland Patented June 16, 1942 SPEED CONTROL MECHANISM Joseph M. Lucarelle and Charles Ecklund, Bridgeport, Cnn., assignors to Dictaphone Corporation, New York, N. Y., a corporation of New York Application January 18, 1941, Serial No. 374,998

6 Claims.

This invention relates to a speed control mechanism for commercial phonographs and more particularly to means for operating a speedregulating device from a relatively remote point.

In commercialphonographs, because it is desirable that the record speed suit the speech characteristics of the dictator and the ability of the transcriber, it has been usual to provide commercial phonographs with speed-control mechanisms, such, for example, as the governor-brake type shown in U. S. Patent 1,625,093 to Renholdt. Such speed control mechanisms have proved to be quite satisfactory. However, it is frequently desirable and advantageous, especially in machines of the transcribing type where a single machine is employed to reproduce records recorded on several different dictating machines, to facilitate the operation of speed adjustment by having the speed control knob in a readily accessible position so that the speed of reproduction may easily be made to accord with the speed at which the record was made. In the past this has been accomplished by carrying a rigid shaft from the speed-regulating device to a control knob on the exterior of the machine, as shown, for example, in the above-mentioned patent. Such an arrangement has the disadvantage that it limits the number of positions available for the control knob. Further, with such an arrangement, motor vibrations are transmitted to the control knob, and the efficiency of the customary resilient motor suspension is affected by the contact, even through damping material, of the control shaft with the phonograph frame.

7 It is an object of this invention to provide a speed control mechanism avoiding these difficulties in which a speed-regulating device may be adjusted accurately and without hysteresis or backlash by means of a control lever remotely positioned with respect to the speed-regulating device and connected thereto by a simple and relatively light flexible connection. Other objects will be in part obvious and in part pointed out hereinafter.

The invention, accordingly, consists in the features of construction, combination of elements, and arrangements of parts which will be exemplified in the structure to be hereinafter described and the scope of the application of which will be indicated in the following claims.

In the accompanying drawing, in which is shown one of the various possible embodiments of the invention;

Figure 1 is a side elevation of a speed control mechanism made in accordance with the present invention, showing a portion of the base plate and motor of a phonograph;

Figure 2 is a front elevation of the parts shown in Figure 1;

Figure 3 is a rear elevation of the control unit forming a portion of the mechanism shown in Figure 1, taken on line 3-'3 of Fi u e 1;

Figure 4 is an enlarged cross-section of this control unit, taken on line 4-4 of Figure 3; and

Figure 5 is a bottom plan view of the speedregulating device forming a portion of the mechanism shown in Figure 1, taken on line'5-5 in Figure 1.

As shown in the accompanying drawing, the motor Hi is mounted upon and forms part of a motor frame I2 which is preferably suspended by spring mountings 14 from the base plate 16 of the phonograph. This spring suspension of the motor frame 12 allows it to have movement relative to the base plate 16, so that the vibrations of the motor and parts connected thereto will not be transmitted to the base plate l6 nor to the sound recording and reproducing mechanism attached thereto.

For controlling the speed of the motor, the motor shaft I8 is provided with a speed-regulating governor which, in the embodiment of the invention herein disclosed, comprises a plurality of weights 20 mounted on bow-springs 22 connected at one end to a sliding collar 24 carrying a brake disc 26, as can best be seen by referring to Figure 2,. When the shaft is rotated, the weights 20 are thrown outwardly by centrifugal force, and this causes the springs 22 to bow and draw the brake disc 26 outwardly from the motor, the other ends of the bow springs 22 being anchored to the shaft I8 by a collar, not shown. The extent of traveling movement of the brake disc 26 to the right, as seen in Figure 2, is controlled by the centrifugal force developed in the weights 2|) and therefore the speed of shaft .I8, assuming that the brake disc 26 is free to move.

By opposing the traveling movement of the brake disc 26, the speed of shaft l8 of the motor can be varied since the pressure of the brake disc against the means opposing its movement produces sufficient friction to retard the rotation of the brake disc. The amount of traveling movement allowed to the brake disc 26, therefore, determines the speed at which the motor may operate, according to a predetermined plan.

For the purpose of opposing the traveling movement of the brake disc 26, there is usually provided a braking mechanism, which, in the form herein shown, comprises a pair of friction pads 28, whose position relative the brake disc 26 may be suitably controlled. In the embodiment shown, referring to Figures 1 and 5, the pads 28 are carried by a yoke 30 having a pivotal connection 32 to a rotatable speed-regulating lever 34. This speed-regulating lever 34 is preferably fulcrumed on a stud 36 on a supporting plate 38 which is secured directly to the motor frame I2 by means of bolts 48 which are also used to secure the spring mountings [4 to the motor frame, the plate 38 being perforated at 42 toallow the bolts 40 to pass therethrough. r

This speed-regulating lever 34 may, of course, be operated in any suitable way. In the past, for example, it has been usual to operate this lever by means of a cam secured to one end of a rotatable shaft passing through an aperture in the base plate 18 of the phonograph and adapted to be rotated by a control knob mounted on its other end, in the manner shown in the above-mentioned patent. Such an arrangement is disadvantageous because it greatly limits the number of places on the phonograph in which the control knob may be positioned. In addition, the vibrations of the motor are transmitted along such a control shaft to the control knob, thus making it more difiicult for an operator to make a proper speed adjustment, and also making it necessary to surround the shaft where it passes through the aperture in the base plate with vibration-damping material to suitably journal the shaft and prevent such vibrations from being transmitted to the base plate. Further, contact between the control shaft and the base plate tends to influence and impair the efficiency of the vibration-damping effect of the spring mountings M of the motor II].

In accordance with the present invention, these disadvantages are eliminated by the provision of a Bowden-wire element between the speed-regulating lever 34 of the speed-governor mechanism mounted on the supporting plate 38 attached to the motor I0, and a suitable speed control knob 44 attached to a control unit, generally indicated at 46, which may be positioned at any convenient place on the phonograph.

The control unit 46 comprises a bracket 48 shaped substantially as shown in Figures 1 through 4, which is adapted to be secured in any desired position on the phonograph frame by any suitable means such as screws 58 passing through bent tabs 52forming part of the bracket. A rotatable control shaft 54 is suitably journaled on the bracket 48 as shown in Figure 4, and the control knob 44 is attached to one end of this shaft, as by means of a set screw 56. A spiral-shaped cam 58 is secured to the other end of shaft 54 by means of a lock nut 68. The control shaft 54 is held in .any position to which it is adjusted by the friction between the facing surfaces of cam 58 and bracket 48 produced by the force of a spring 55 compressed between the bracket 48 and a flange 51 secured to the control shaft 54, as shown in Figure 4. A lever 62 is pivotally attached to the bracket 48 by means of a stud 64, as shown in Figure 3. This lever 62 is provided with a projecting portion 66 which acts as a cam-follower riding on the surface of cam 58. This projection 66 also serves, in conjunction with a projection 68 on the cam 58, as a stop to limit the range of rotation of control knob 44, shaft 54, and cam 58 to slightly less than one revolution.

A Bowden-wireelement 18, having the usual outer member, sheath 69, and inner member, operating wire H, connects the control unit 46 with the speed-governing mechanism on the motor [0. One end 12 of the sheath 69 of the Bowden-wire element 18 is threaded into and thus adjustably anchored to a tab 14 on the bracket 48 of control unit 46, as shown in Figures 2 and 3, and its other end 16 is similarly anchored to a tab 18 projecting from the supporting plate 38 of the speed-governing mechanism on motor In. Lock nuts and 82 are adjustably threaded onto the ends 12 and 16 of the sheath -69 to permit them to be locked in any desired position with respect to the tabs 14 and 18, respectively. The end 84 of the inside member or operating wire ll of the Bowden-wire element 18, which projects beyond the end 12 of the sheath 69 is provided with an expanded terminal member 86, positioned in a slot in the free end 63 of the control lever 62 of the control unit 46, as is best shown in Figures 2 and 3. The other end 88 of the inner wire H of the Bowden-rwire element 18, which projects beyond the end 16 of the sheath 69, is provided with an expanded terminal member 90, positioned in a slot in the end 92 of the speed-regulating lever 34, on the opposite side of the fulcrum 36 from the friction pads 28, as is best shown in Figures 2 and .5. A coiled spring 94 connects the supporting plate 38 to the end 92 of the speed-regulating lever 34 to bias this lever in a counterclockwise direction, referring to Figure 5, to tend to hold the friction pads 28 away from the brake disc 26. This spring 94 likewise maintains a direct pull on the inner wire ll of the Bowdenwire element 18, thus biasing lever 62 of the control unit 46 in a counterclockwise direction, referring to Figure 3, so as always to press the cam-follower projection 66 against the surface of cam 58. The frictional effect between these surfaces due to the pull of spring 14 and the friction between the facing surfaces of cam 58 and bracket 48 tend to hold the speed control lever 62 in its adjusted position at all times.

In operation, when the control knob 44 is turned to rotate shaft 54 in a counterclockwise direction, referring to Figure 3, the cam-following projection 66 rides up toward the high point of cam 58, thus rotating lever 62 in a clockwise direction, and thereby exerting a direct pull on the inner wire H of the Bowden-wire element 10. This pull on the inner wire H of the Bowden-wire element rotates the speed-regulating lever 34 in a clockwise direction, referring to Figure 5, against the tension of spring 94, and forces the friction pads 28 against the brake disc 26 of the speed-governor on the motor [0, thereby adjusting its speed in the manner above-described, from any suitable remote point on the phonograph and without transmitting vibration from the motor to any other part of the machine.

Another advantage of a speed control mechanism embodying the present invention is that the limits of the speed control range can be simply and easily changed by threading the ends 12 and I4 of the sheath 69 of the Bowden-wire element 18 in and out of the tabs 14 and 18, respectively, so as to vary the length of this sheath between these tabs. As the length of the sheath between these tabs is increased, this effectively shortens the inner wire I I which forces the yoke 38 and the friction pads 28 closer to the brake anism effective at a slower speed than that at which it would be effective if the length of the sheath 69 between the tabs 14 and 18 was decreased.

It will be seen that there is provided by this invention a construction of an essentially practical nature in which the several objects of this invention are attained.

As many possible embodiments may be made of the above invention without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawing is to be interpreted as illustrative only and not in a limiting sense.

We claim:

1. A speed-controlling device for phonographs comprising, in combination, phonograph driving means, a supporting plate secured to said driving means, a speed-regulating member movably attached to said plate and operatively connected to said driving means, resilient means biasing said member toward a predetermined position relative to said plate, a control unit bracket adapted to be remotely positioned relative to said driving means, a speed control lever movably attached to said bracket, a Bowden-wire element extending between said plate and said bracket, the sheath of said Bowden-wire being anchored at one end to said plate and at the other end to said bracket, one end of the movable inner wire of said Bowden-wire' element being secured to said speed control lever and the other end being secured to said speed-regulating member to pull against the force of said resilient means when said speed control lever is moved in one direction, means for holding said latter lever in any desired position against the action of said resilient means thereby to position said speed-regulating member in any desired position, and means associated with one end of the sheath of said Bowden-wire element for adjusting its position with respect to its anchorage to vary the limits of the range of control of said speed control mechanism.

2. A speed-controlling device for phonographs, comprising, in combination, a phonograph motor, a brake-type governor for said motor, a supporting plate secured to said motor, a speedregulating member rotatably attached to said plate for adjusting said governor, a single spring for rotating said member to bias it toward a predetermined position relative to said plate, a control unit bracket remotely positioned on said phonograph relative to said motor, a lever pivotally attached to said bracket, a cam rotatably mounted on said bracket for moving said lever to any desired position against the pull of said spring, a control knob for positioning said lever, and a Bowden-wire element extending between said plate and said bracket, the sheath of said Bowden-wire being anchored at one end to said plate and at the other end to said bracket, one end of the movable inner wire of said Bowdenwire element being secured to said lever and the other end being secured to said speed-regulating member so as to pull against said spring when said lever is rotated in one direction by said control knob whereby said motor may be adjusted to any desired speed by operation of said control knob.

3. In a speed control mechanism for phonographs, the combination of, a movable speedregulating member positioned in proximity to the driving means of a phonograph and adapted to coact therewith, a manually operable control member remotely positioned relative to said speed-regulating member, a Bowden-wire element extending between and connected to said speed-regulating member and said control member so that movement of said control member in one direction pulls directly on said BoWden-wire element to produce a corresponding movement of said speed-regulating member in one direction, biasing means for urging said speed-regulating member in the opposite direction, and means associated with said control member for holding it in any desired position in opposition to the pull, of said biasing means transmitted through said Bowden-wire element whereby the speed of said driving means may be adjusted through said speed-regulating member by movement of said manual control member.

4. A speed-controlling device for phonographs, comprising, in combination, phonograph driving means, a supporting frame secured to said driving means, a speed-regulating member movably attached to said frame and operatively connected to said driving means, resilient means biasing said member toward a predetermined position relative to said frame, a control unit bracket adapted to be remotely positioned relative to said driving means, a speed control lever movably attached to said bracket, a Bowden-wire extending between said frame and said bracket, one element of said Bowden-wire being anchored at one end to said frame and at the other end to said bracket, one end of the other element of said Bowden-wire being secured to said speed control lever and the other end being secured to said speed-regulating member to pull against the force of said resilient means when said speed control lever is moved in one direction, means for holding said latter lever in any desired position against the action of said resilient means thereby to position said speed-regulating member in any desired position, and means associated with one end of one element of said Bowden-wire for adjusting its position with respect to its anchorage to vary the limits of the range of control of said speed control mechanism.

5. A speed-controlling device for phonographs, comprising, in combination, phonograph driving means, a supporting frame secured to said driving means, a speed-regulating member movably attached to said frame and operatively connected to said driving means, a control unit bracket adapted to be remotely positioned relative to said driving means, a speed control member movably attached to said bracket, a Bowdenwire extending between said frame and said bracket. one element of said Bowden-wire being anchored at one end to said frame and at the other end to said bracket, one end of the other element of said Bowden-wire being secured to said speed control member and the other end being secured to said speed-regulating member to position it as desired, and means associated with one end of one element of said Bowdenwire for adjusting its position with respect to its anchorage to vary the limits of the range of control of said speed control mechanism.

6. A speed-controlling device for phonographs, comprising, in combination, phonograph driving means, a supporting plate secured to said driving means, a speed-regulating lever rotatably attached to said plate and operatively connected to said driving means, a control unit bracket remotely positioned relatively to said driving means, a speed control lever rotatably attached to said bracket, a Bowden-wire cable extending between said plate and said bracket, the sheath with said speed control lever for moving it' in one direction to pull on said inner element of said Bowden-wire cable to move said speed-regulating lever away from said; predetermined position, and means: for holding said control lever in its adjusted position against the pull of said spring whereby said speed-regulating lever may be rotated to any desired position by rotation of said. remotely positioned control lever.

JOSEPH M. LUCARELLE. CHARLES ECKLUND.

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