US3444764A - Counter drive apparatus - Google Patents

Description

,May 20, 1969 R. GREENWOOD 35444764 COUNTER DRIVE APPARATUS Filed March 20, 1967 Lral. h3 vrea?.

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United States Patent O 3,444,764 COUNTER DRIVE APPARATUS Roger Greenwood, North Hollywood, Calif., assignor to International Telephone and Telegraph Corporatlon, a corporation of Delaware Filed Mar. 20, 1967, Ser. No. 624,373 Int. Cl. F16h 25/16 U.S. Cl. 74-822 6 Claims ABSTRACT F THE DISCLOSURE A number wheel of a mechanical counter has a plurality of equally spaced projections arranged about the wheel axis. A cam in its rest position hold-s a rst member against a projection securing the wheel against rotation. Actuation of the cam releases the wheel for rotation and advances the wheel by sequentially driving a second member and the first member against the projections. Reciprocating small-angle and 360 degree rotation actuation are alternatives.

The present invention pertains generally to counter drive apparatus, and, more particularly, to such apparatus for providing the driving force for a mechanical counter Wheel.

Background of the invention A well-known type of mechanical counter ha's a number of wheels or discs, one for each digit of the count, with numerical indicia arranged on the circumferences. A lever arm is frequently used to advance the lowest order wheel thereby accomplishing the basic counting function. When the lowest order wheel has been driven through its total capacity (0 9 in a decimal counter) linkage is automatically actuated to advance the next higher order counter wheel, and so on.

It is customary in present known mechanical counters to produce a units count in the low order wheel by a ratchet and pawl or escapement type mechanism. More particularly, a notched wheel (either the counter wheel itself or means drivingly associated with the counter wheel) is rotated through the required angular amount by a pawl which is received within a notch. After moving the wheel forward, the pawl is allowed to drag across the top of the notched wheel to a position of readiness for further operation. Innumerable structural variations of this principle have been used, all of which rely, in one way or another, on the stated principles of operation.

Although mechanical counters based on ratchet and escapement drive have been found to be generally satisfactory, they possess certain inherent disadvantages. First of all, drive by a pawl engaged in a notch results by its very nature, in an impact loading of the counter wheel which, of course, has a deteriorative effect on operating life. Also, sliding of the drive pawl on the teeth or notched wheel circumference as it returns to the ready condition between adjacent counts has an adverse effect upon both speed of operation and life of the counter.

It is, therefore, a primary object and feature of the present invention to pro-Vide counter drive apparatus that applies the requisite actuation force in a smooth and continuous manner without impact.

Another object is the provision of mechanical counter Wheel drive apparatus suitable for high speed operation as a consequence of mass inertia and displacement of moving parts being held at the optimal minimum.

A further object is the provision of indexing apparatus as in the above objects relying upon cam action rather than ratchet or escapement devices.

Yet another object is the provision of counter wheel drive apparatus which is quickly and simply convertible ice from stroke to rotation, or rotation to stroke, actuation.

Another object is the provision of a counter drive mechanism that can be initiated by a rotative motion in either direction to produce an add count.

A still further object and aspect is the provision of counter drive apparatus as in the above objects which is straight-forward in design, relatively simple and inexpensive to manufacture Iand amenable to the application of high volume, machine production techniques.

Summary of the invention The above objects and features of this invention are achieved by counter drive apparatus in which a disc-like counter wheel includes a plurality of members extending from a major circular surface. First movable arm means are disposed in the rest position to engage certain of the members preventing rotation of the wheel. Second movable arm means in the rest condition are disposed out of contact with the members. When adding a count to the counter, a drive cam disengages the rst arm means and moves the second arm means into contact with a member rotating the wheel a certain angular extent. The cam then returns the second arm means to the rest condition and drives the iirst arm means against a member to complete the indexing movement and once again detent the wheel. A further aspect is that the cam can be so constructed as to produce wheel advancement on small-angle rotation of the cam or, in a modified form, on 360 degree rotation of the cam.

Other objects and advantages of the invention will be clear to those skilled in the art to which it pertains on reference to the following description when taken in the light of the accompanying drawing.

Brie]c description of the drawing FIGURE l depicts a mechanical counter wheel and drive apparatus of the invention shown in the rest position.

FIGURE 2 is an elevational, sectional view of FIGURE l.

FIGURE 3 is identical to FIGURE 1 except that it shows the relation of the various parts during operation.

FIGURE 4 illustrates a modied form of the invention that is actuated by a full 360 degree rotation of the drive cam.

FIGURE 5 shows an electromagnetic form of actuation for the apparatus of FIGURE 1.

Description of the preferred embodiment With reference now particularly to FIGURES 1 and 2, member having numerical indicia 11 arranged on the a member Wheel 10 is seen to comprise a disc-like body member having numerical indicia 11 arranged on the circumferential periphery in an equally spaced manner. Although it is readily appreciated that indicia of various kinds can be used, it will be assumed for the present description that the wheel is a decimal counter wheel bearing the indicia 0-9.

On the same major circular area of the wheel 10 there are arranged ten (l0) advancement members 12. These members, of generally cylindrical, rod-like construction, are suitably secured to the wheel in an equally spaced arrangement along a circular path. As shown -best in FIG- URE 2, the rod-like members project normally from the wheel surface, and all to the same extent.

A shaft 13 is axially xed to the wheel 10 for common rotation therewith. A hub portion 14 of the shaft 13 extends outwardly a limited extent from the major surface of the Wheel containing the members 12 for receiving a drive shaft 15 thereon in such manner that the latter may be freely rotated without transferring such motion to the hub and wheel 10.

A drive cam 16 is mounted to the Vdrive shaft 15. As shown in FIGURE 1, the cam has an upper portion 17 that rises a relatively large amount upon counterclockwise rotation, and a curved lower portion 18 that rises a lesser amount for the same rotation.

A first arm 19 is mounted at one end for swinging motion about a pivot 20 that is secured to the inside wall surface of a counter wall or casing 21. The first arm, in the rest position depicted in FIGURE l, is firmly secured against the inwardly directed surface of one of the members 12, identified as 22, by the curved lower portion 18 of the cam 16. This latter condition serves to lock or detent the wheel against rotative motion of any kind at this time. A coil spring 23 is received about the pivot 20 and resiliently urges the detent arm 19 toward the cam causing it to follow the cam. As seen best in FIGURE 2, the first arm has a member engaging portion 24, whereas the remainder of the arm is Vcut away to permit it to pass over the outer ends of the advancement members during camming.

A second arm 25 is similarly mounted at an end thereof for swinging movement about a second pivot 26 secured to the counter wall 21. The pivot carries a coil spring 27 that resiliently and continuously urges the arm against the cam 16 so that the arm will follow the cam throughout its rotation. It will be noted that the pivot 26 is located at a point diametrically opposite that of pivot 20 thereby disposing the two arms somewhat parallel of one another in the rest position and extending in opposite directions.

The second arm further includes a member engaging portion 28, with the remainder of the arm being cut away back to the pivot 26 to permit the arm to pass freely over the extremities of the other members during swinging movement.

Operation of the apparatus shown in FIGURE 1 is initiated by rotating the drive shaft counterclockwise a limited extent, which causes the portion 18 of the cam to move upwardly permitting the spring-loaded first arm 19 to also move upwardly and release the wheel 10 for rotation. At the same time, the upper portion 17 of the Cam drives the second arm 25 upwardly which, in turn, drives against a member 12 to rotate the counter wheel counterclockwise. The cam is so constructed that at the limit of the counterclockwise actuation rotation, the driven advancement member is at the position shown in FIGURE 3 which is the same as 12' shown in dashed-line in FIG- URE 1. At this time, the counter wheel is advanced substantially midway to the next adjacent position.

The cam is now returned to the position of rest, as in FIGURE 1, by clockwise rotation of the shaft 15. Since the drop of cam portion 17 vis relatively sudden, the second arm 25 can swing back to the rest position without engaging any of the adjacent advancement members, the closest one of which occupies a position as shown in dashed line at 12". At the same time, first arm 19 is affirmatively cammed downwardly to engage the member 12" and effect still further counterclockwise rotation of the wheel 10 until it is brought to rest and detented as in the FIGURE 1 position (although, of course, displaying the next indicia from that shown in FIGURE 2). The counter wheel is now fully advanced to a new position.

FIGURE 4 shows an alternate form of the invention amenable to a prime moving drive motion that is a 360- degree rotation. The counter wheel, first and second arms, and pivots are identical to those in the FIGURE 1 embodiment, and, accordingly, the same numerals are used for those parts. The fundamental change is in the construction of the drive .cam 249, making it adaptable to advancing the wheel and returning to the rest position in one full rotation. The upper and lower parts of the cam, 30 and 31 respectively, are of the same general circular curvature and separated by relatively straight or slightly curved side portions. The cam is so mounted on the drive Shaft 1 5 that the cam surface 31 extends farther out than does the surface 30. In operation, rotation of the shaft 15 counterclockwise (as seen in FIGURE 4) moves the camming surface 31 upwardly which permits the second arm to similarly move upwardly away from detenting position through action of the spring 20. Next, as the camming surface 31 engages the second arm 25 it moves it against an adjacent member 12, driving the wheel counterclockwise until the surface 31 reaches the maximum upward position. Continuing rotation in the same direction, the surface 31 finally returns to the position of FIGURE 4 with the rst arm locked against a new member 12 and the second arm removed from contact with the advancement member it had just been driving. An important aspect of this modified form of the invention is that the actuating drive rotation can be either clockwise or counterclockwise, and equally satisfactory results are obtained.

In many instances the fundamental actuation force is provided manually or by physical engagement of a lever arm connected to the shaft 15 with a moving object to be .counted thereby achieving direct drive of the counter wheel. However, in the greater number of applications it is more convenient to command addition of a count to the counter by an electric signal. FIGURE 5 illustrates one form of apparatus for achieving this result using electromagnetic means with the counting apparatus of FIG- URE 1. An electromagnet 32 including a magnetizable core 33 and a coil 34 arranged about the core is connected to a source of electric power (not shown) through a suitable switching means. An armature 35 of magnetically attractable material is resiliently held in a spaced condition to the core 33 by a spring 36. Drive link 37 interconnects the armature and an extenson lever 38 secured to the cam 16. On application of electric power to the coil 34 the armature is attracted toward the core which applies a downward force -on the lever 38 via the link 37 to rotate the cam 16 and advance the counter wheel part way in the manner already described. Deenergization of the electromagnet allows the spring 36 to return the armature upwardly completing the forward motion of the wheel and returning the cam (and counter) to the rest condition.

By appropriate modification of the means transferring motion from the armature to the cam, the version shown in FIGURE 4 can be made to operate from an electromagnet in that on attraction of the armature the upper portion 30 of the cam 29 is moved to the lowermost position, and, upon deenergization of the electromagnet, spring drive moves the portion 30 back to its rest position.

While the principles of the above invention have been described in connection with specific embodments thereof, it is to be clearly understood that this description is made by way of example and not as a limitation of the scope of the invention.

What is claimed is:

1. Counter wheel drive apparatus, comprising:

a support base;

a shaft mounted on the support base, the counter wheel 'being rotatably received thereon;

a plurality of spaced members secured to the same major surface of the counter wheel;

a first arm pivotally mounted to the support base for swinging movement over the major surface of the counter carrying the members, said arm having portions that are brought into driving contact with at least one member during swinging movement of said arm in a first direction to rotate the counter wheel;

a second arm pivotally mounted to the support base for swinging movement over the counter surface carrying the members, said second arm having portions that engage at least one member and rotate the wheel during swinging movement; and

a cam mounted for cyclic rotative motion having surfaces that drive against the first and second arms in such direction to turn the wheel a prescribed angular extent each cycle, said cam during a first part of the cycle simultaneously driving the rst arm portions against a member and releasing the second arm portions from engagement with a member; and during a further part of the cycle driving the second arm portions against a member to complete advancement of the counter wheel while simultaneously releasing the first arm portions from engagement with a member, said members being arranged in an equally spaced manner along a circular path about the shaft as a center; the first and second arms being pivotally mounted from a respective end at points on the base disposed at opposite sides of the counter wheel with the arm drive portions lying within the circular path of the members.

2. Counter wheel drive apparatus as in claim 1 in which spring means are provided interacting between the base and first and second arms resiliently urging the arms against the cam throughout its motion.

3. Counter wheel drive apparatus as in claim 1, in which the cam is rotatably mounted upon the shaft and has a surface that in the rest position holds the second arm against a member serving as a detent against counter wheel rotation.

4. Counter wheel drive apparatus as in claim 1, in which there are further provided electromagnetic means including a movable armature and means linking the armature and cam, such that energization of the electromagnetic means causes the cam to rotate the counter wheel.

5. Counter wheel apparatus as in claim 2, in which means are provided for rotating the cam in a first direction through a limited angular extent to drive the first arm against a member during the first part of the cycle, and for then driving the cam in the opposite direction to drive the second arm against a member to complete the cycle.

6. Counter wheel apparatus as in claim 2, in which the cam is constructed with symmetrically arranged camming surfaces, and a cam drive means provides a 360 degree rotation of the shaft for each operating cycle.

References Cited UNITED STATES PATENTS 2,588,977 3/1952 Gartner et al 74-822 XR 2,923,165 2/1960 Patzer 74-126 3,048,949 8/ 1962 Johnson 74--126 XR FOREIGN PATENTS 523,648 4/ 1931 Germany.

HALL C. COE, Primary Examiner.

U.S. Cl. X.R.

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