US2643552A - Control cam and apparatus for positioning the same - Google Patents

Description

F. H. OWENS June 30, 1953 CONTROL CAM AND APPARATUS FOR POSITIONING THE SAME Filed July 23, 1947 FIG. 2

INVENTOR. A FREEMAN H. OWENS C Patented June 30, 1953 UNITED CONTROL CAM AND APPARATUS FOR POSITIONING THE SAME Freeman H. Owens, New York, N. Y.

Application July 23, 1947, Serial No. 762,949

2 Claims.

The present invention relates to a control cam and to apparatus for positioning the sameiin response to the difference between two stimuli.

It is often necessary, in connection with various types of apparatus, that a control cam or other control mechanism be positioned or actuated in accordance with the incidence of two separate factors and more specifically in accordance with the difierence between said two factors. For example, in coin-operated amusement devices, such as record players, the two factors involved are the number and denomination of coins inserted into the apparatus and the number of records played in response thereto. Thus, if each record reproduction costs five cents, themechanism controlling the operation of the record player must be responsive to the number of five cent units deposited in the machine and to the number of records reproduced in response thereto, so that the same number of records will be reproduced as are paid for and so that a number of five cent pieces or their equivalents may be inserted into the machine at one time and without waiting for the reproduction of each record. In other words,;the mechanism controlling the operation of such a record player must have a memory. It must remember the number of five cent units deposited in it and it must remember the number of records played in response thereto to the end that,'once these two quantities have become equal, functioning of the record player will terminate.

In the past, various arrangements have been devised to accomplish this result, the most common of-which is to employ a ratchet wheel which is actuated according tothe number of money units deposited in the machine, the ratchet wheel rotating a shaft against the tension of a coiled spring. As each record is played, the ratchet wheel is released to move back one step, urged in that direction by the spring. This type of mechanism. has proved itself subject to the extremelyv serious defect that it is not positive in operation, nor is it dependable after a period of use. Since the tension of the spring is greatest when a large number of money units have been deposited in the machine, such an apparatus has a tendency, when a large number of coins are involved, to rotate in the reverse direction so rapidlyand with such force as to move more than one step at a time. This results in the reproductionof a fewer number of records than have been paid for, a fact keenly resented by the users of suchmachines. Moreover, after the spring has been flexed and unfiexed for a number oftimes,

its resiliency tends to decrease, and it consequently happens that when it is substantially unwound, it has insufiicient force to rotate the ratchet wheel and consequently even though that wheel be released forrotation, the rotation will not take place. This results in the reproduction of more records than have been paid for, a fact keenly resented by the owners and operators of such apparatus.

In order to reduce the incidence of these defects, many expedients have been resorted to, all of them characterized by the fact that they require relatively complicated apparatus which is expensive, relatively diificult to maintain and relatively bulky.

It is the prime object of the present invention to devise an apparatus which will eliminate the above set forth defects and disadvantages of prior art apparatus.

It is another object of the present invention to devise a control cam structurewhich is easily and inexpensively fabricated, light of weight, and which takes up but a minimal space in the complete apparatus.

It is yet another object of the present invention to devise a mechanism for rotating a control cam which is positive in operation, which has no parts subject to deterioration upon use, which is simple and compact in construction, and which is assembled of parts all of which are easily susceptible of mass production.

The present invention is here illustrated in a form specifically applicable for use in coin controlled amusement apparatus such as record record reproducers, but it will be apparent that its scope of usefullness and its inventive merit is not confined to such an application, but is rather susceptible of wide use wherever it is desired to control an apparatus in accordance with the difference between two separate stimuli.

To the accomplishment of the foregoing objects and such other objects as may hereinafter appear, the present invention relates to a control cam and to apparatus for operating the same as defined in the appended claims and as set forth in this specification, taken together with the accompanying drawings, in which:

Fig. 1 is an idealized perspective view showing the general arrangement of the parts of the mechanism for controlling the cam;

Fig. 2 is a side view of a particular cam embodiment illustrating its manner of functioning;

and

Fig. 3 is a View showing the cam of Fig. 2 in which the thickness of the cam is materially exaggerated for purposes of clarity.

The apparatus of the present invention comprises, in broad outline, a control cam generally designated A fastened to and rotated by a shaft generally designated B. A cam follower C is in contact with and follows the cam surface on the cam A and positions appropriate control mechanism generally designated D in accordance with said cam surface. Means generally designated E and F respectively are provided to posi tively rotate the shaft B and consequently the cam A in a step by step manner, the means E being effective to rotate them in one direction and the means F being effective to rotate them in the opposite direction. apparent that the position of the cam A and consequently the portion of the cam surface thereon in contact with the cam follower C is determined by the cumulative action of both of the means E and F and, more specifically, is determined by the difference between the amounts which the means E and F have caused the shaft B to rotate.

As here illustrated, the shaft B is retained in a bearing 2 which pierces a wall 4 of a casing 6 which may, for example, be the casing of an automatic coin controlled record reproducer. Mounted fast on the shaft B are a pair of ratchet wheels 8 and I each having ratchet teeth [2 I disposed in opposite directions. Pawls l4 and I 6 are positioned so as to normally be out of engagement with the teeth 12 of the ratchet wheels 8 and [0, respectively, but movable into engagement therewith so as to rotate each of the ratchet wheels 8 and [0 a given distance, preferably the distance represented by a single tooth l2. Each of the pawls .is pivotally mounted, by means of pin l8, onmounting arms and 22 respectively, each of these arms in turn being fastened to and preferably integral with collars 24 and 26 freely rotatable on the shaft B. Operating arms 28 and 30 project from the collars 24 and 26 and are in turn pivotally connected, by means of pin 32, to connector arms 34 and 36 respectively, these connector arms in turn constituting armatures for the solenoids 3.8 and 40. Springs 42 and 4.4 spring load the pawls l4 and I 6 and stops .46 are provided on the mounting arms 20 and 22 to limit the pivotal motion of the pawls I4 and I6 in response to the tension of springs 42 and 44. Sleeves 4] and 49 are provided for spacing purposes.

Each of the solenoids 38 and 40 are made responsive in any conventional manner to the stimuli which are to control the operation of the apparatus. Thus, solenoid 38 may be responsive to the number of records reproduced and solenoid 40 may be responsive to the number of money units deposited in the apparatus. The means by which this may be accomplished are many and varied, are well known in theart, and form no part of the present invention. "Insofar as the present structure is disclosed, it is necessary only that for each money unit deposited in the apparatus, the solenoid 40 be given separate and distinct energizing impulses. Eachone of these impulses will cause the armature 36-to be drawn within the solenoid 40, thus raising the operating arm 30 so as to cause the pawl Hi to engage with a, tooth I 2 of the ratchet wheel- I 0 so as to rotate that wheel one step, preferably the amount of separation between adjacent teeth l2, in a counter-clockwise direction as viewed from the end 48 of the shaft B. This will rotate It will therefore be the shaft B a similar amount and, since the pawl I4 is disengaged from the ratchet wheel 8, this rotation is permitted. The cam A is consequently similarly rotated.

Let us assume that five nickels are deposited in the apparatus and that each nickel calls for the reproduction of a single record. The five nickels will energize the solenoid 40 five separate times and consequently the ratchet wheel lo, the shaft B, and the cam A will be rotated five steps in a counter-clockwise direction.

After each record is played, the solenoid 38 may be energized by any appropriate means and each energization thereof will result in the rotation of the ratchet Wheel 8 and consequently of the shaft B and the cam A in a clockwise direction for a single step. If the steps of rotation brought about by energization of the solenoid 3B are equal in magnitude to the rotational steps brought about by energization of the solenoid 40, then the solenoid 38 will have to be energized five times in order to bring the shaft B and the cam A .back to the position initially occupied prior to the energization of the solenoid 40. In order to accomplish this, five records must be played, thus corresponding to the five nickels deposited in the apparatus.

It will, of course, be apparent that if the size of the rotational steps caused by energization of either one of the solenoids differs from that caused by energization of the other, a different relationship will ensue. For example, should the tooth spacing on the ratchet wheel 8 be double that of the tooth spacing on the ratchet wheel 10, then each energization of solenoid 38 will cancel out two energizations of the solenoid 40. Such an arrangement would be appropriate if the solenoid 40 were to be energized upon the insertion of five cent units into the apparatus but if each record to be reproduced were to cost ten cents. The flexibility of operation of the mechanism described will be apparent from the above example which is set forth by way of exemplification only.

It will be noted that rotation of the shaft 13 in either direction takes place only when the shaft is positively urged in rotation by means of a stimulus applied either to-the solenoid 38 or to the solenoid 40. The pawls l4 and I6 are at all times disengaged from the ratchets except when they are employed to rotate the ratchets. Hence, there is nothing to wear out, and the life of the apparatus is extremely great.

In order to prevent overrunning of the shaft B when it is urged in rotation in either direction, the bearing 2 may frictionally engage the shaft B to a degree sufficient toprevent said overrunning, but, of course, not to such a degree as to prevent rotation of the shaft B when urged by engagement of a pawl and ratchet.

In Fig. 1 the various elements of the mechanism'as thus far described are spaced considerably one from the other. This has been done solely for the purpose of clarity of illustration and it will be appreciated that said apparatus may be so organized that all of the elements thereof willbe placed adjacent one another so that the entire control mechanism will take up but a few cubic inches of space and in particular so that the length of the shaft B need only be on the order of one inch.

As illustrated in Fig. 1, the cam A comprises adisc or drum 50 fixed to the shaft B and rotatable therewith and bearing on its. periphery the spiral cam track 52 which is here illustrated .as

being so shaped as to have several consecutive turns of equal height, a-depression 54at one end thereof, and astop 55 at the other end thereof. Switch bracket 58 is pivotally mounted on pin -56 attached to the wall 4 and the cam follower'C is rotatably mounted on pin fiz'projectingfrom one end of the bracket 58. The'follower C is not only rotatable on the pin 62-;bu'tis also slidable ierealong, in a direction of the arrowsv 64.. Depending from the bracket 58 is arm 56 to which any suitable control mechanism may be attached, here illustrated as the mercury switches 68. Any suitable means, such as a weight 18 or a spring active on the end of the bracket 58 opposite from the cam follower C, may be'provided to bias the bracket 58 so that the follower C engages and follows the cam track 52, or the switches '68 may be mounted in unbalanced position so as themselves to provide the biasing'force.

When the cam A has been rotated so that the cam follower C makes contact with the depression 54 in the cam track 52, the bracket 58 will tilt in the direction of the arrow 12 so as to open the circuits through the mercury switches 68 and deenergize the record reproducing mechanism so that no records will be played. As soon, however, as the cam A has been rotated to the position of Fig. 1, the cam follower C will be forced out in order to conform to the raised section of the cam track 52 and the bracket 58 will therefore be pivoted so as to close the cihcuits through the mercury switches 68 which cause reproduction of the records. If a number of money units have been inserted into the apparatus, the solenoid it will have been energized a number of times and consequently the shaft B and the cam A will have been rotated more than one step. As each record is played, the solenoid 38 will be energized and will turn the shaft B and the cam A in the opposite direction one step, but until the number of steps of reverse rotation equal the number of steps of initial rotation, the cam follower C will at all times be on a raised portion of the cam and consequently reproduction of records will continue. As soon as the number of steps of reverse rotation equal the number of steps of initial rotation, the cam follower C will fall into the depression 54, the record reproducing apparatus will be deenergized and reproduction of the records will cease.

With the solid drum of Fig. 1, it will be apparent that a very large number of money units may be handled by the apparatus. Let us assume that the ratchet wheel it contains 18 teeth. The cam A may be rotated almost three full revolutions before the cam follower C will come up against the stop 55. Since it will take 18 energizations of the solenoid 40 to rotate the cam A once, it is apparent that the cam A can accommodate up to approximately 50 money units without overtaxing its capacity. Of course, more turns could be placed upon the cam A or more teeth could be formed on the ratchet wheel Ii] to increase the capacity thereof. The cam follower C is slidable along the pin 62 in order to follow the spiral of the cam track 52.

The difliculty of devising a cam structure according to the teachings of the prior art, and particularly one embodying a tensionable spring, which would have the capacity of the cam of the present disclosure is obvious. In addition, it will be understood that although the spacing between the adjacent turns of the cam track 52 and the width of those turns is made rather large in Fig. 1, this is done only for clarity of illustration and the cam A may be, and preferablyis, longitudinally compressed so as to take up much less space than is illustrated. Accordingly, by means of the present invention, a cam and associated control mechanism has been produced which, in a far smaller space than has been possible heretofore, has a far greater capacity than has been possible heretofore, and is at the same time positively actuated. I

In Figs. 2 and 3, an alternative cam construction is illustrated which'permits of simplification of the basic structure without sacrificing any of its advantages. The cam A as illustrated in Fig. 3 comprises a strip 14 of metal which is curled or curved into'helical form. This strip may be of plastic or of metal and may be round or, as here illustrated, of flat shape. The exposed periphery of the strip or, in the case illustrated, the exposed edge 16 of the flat strip 74 is shaped to define the desired 'cam surface. In Fig. 3, the strip 14 is indented to define the depression 54' and one of its ends is bent up to define the stop 55. The end near the depression 54 may be provided with a pair of bolt holes 18 adapted to receive bolts in a disc 82 which is attached to the shaft B by means of set screw 84, and which carries a supporting drum 83 loosely received within the coiled strip 14 to provide sufiicient rigidity thereto.

When using a cam of this type, it is not necessary that the cam follower C be slidable along the pin 82. As may best be seen from an examination of Fig. 2, the cam follower C is positioned slightly outboard of the disc 82 and the inherent resilience of the strip 715 permits the cam A to adapt itself to the position of the cam follower 0 rather than forcing the cam follower C to adapt itself to the position of the cam track 52 as was necessary in Fig. 1. However, the cam follower C could be mounted as in Fig. 1 so as to have some degree of lateral play without de- Eracting from the advantages of this construc- The cam of Figs. 2 and 3 is simpler and cheaper to manufacture than the cam of Fig. l, and with its use the mounting of the cam follower C is also simplified. Thus, not only is a less expensive structure involved, but the structure takes up a somewhat smaller amount of space in view of the fact that a separation between only two of the adjacent turns of the cam track need be provided for, whereas in the construction of Fig. 1 each of the convolutions must be separated one from the other.

The contro1 mechanism and actuating mechanism construction herein disclosed present, as the previous discussion has pointed out, many advantages over the prior art. Insofar as the cam itself is concerned, a simple structure is provided which has an exceedingly high capacity, yet which takes up a minimum amount of space. Insofar as the operating mechanism is concerned, it is positively operated in both directions so that it is accurate at all times. It is composed of a plurality of simple and easily fabricated parts which are in turn easily assemblable into an exceedingly small space and it eliminates the employment of any units such as springs the life and dependability of which are small and inconstant. By suitable design of the ratchet wheels 8 and It, any desired relationship between the two stimuli relied upon to control the apparatus may be achieved without in any way increasing the complexity, cost, or volume of the apparatus. In this flexibility of operation alone, it

represents a considerable advance over-devicesin common use.

While only a limited number of embodiments of the present invention have been here illustrated and described, the principles of operation thereof will be apparent and it will be clear that many variations may be made in specific design Without departing from the spirit of the invention as defined in the appended claims.

I claim:

1. In combination, a rotatable helical cam comprising a'resilient strip curled into helical form, the helical periphery of said strip being shaped to define a cam surface, one portion of said cam being fixed in position relative to motion in :the direction of the axis of rotation thereof andanother portion of said cam being movable in the direction of the axis of rotation thereof, a cam follower engageable with said cam surface and non-movablein a direction parallel to the axis of rotation of said cam, and means for'rotating said cam.

2. In combination, a helical cam comprising a resilient strip curled into helical form, the helical periphery of said strip being shaped to define a cam surface, a rotatable supporting drum around which said cam is curled and to which one portion of said strip is secured, the unsecured portions of said strip being slidable over said drum in the direction of the axis of said drum, a cam follower engageable with said cam surface and non-movable in a direction parallel to the axis of said drum, and means for rotating said drum.

FREEMAN -H. OWENS.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date Holmes Dec. 19, 1893 Cheyne Apr. 18, 1899 Paul May 10, 1910 Reisbach Jan. 26, 1915 Geiger May 30, 1916 Simon Feb, 1, 1921 Allis Nov. 21, 1922 Newcomb Feb. 20, 1923 Hugershoff Aug. 19, 1930 'Halvorson May 3, 1932 Bellah Dec. 25, 1934 Seiden et a1 Aug. 13, 1935 Twyman Aug. 20, 1935 'Hoban -1. Apr. 6, 1937 Berton June 6, 1939 Von Zimmerman Sept. 19,1939 Jacob Apr. 9, 1940 Osborne Apr. 8, 1941 .Harkness Oct. 2, 1945 Myers Aug. 20, 1946 Bryant Oct. 30, 1951 FOREIGN PATENTS Country Date Germany Apr. 22, 1931

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