US3285095A - Cam means - Google Patents

Description

Nov. 15, 1966 D. c. ROCKOLA CAM MEANS Filed Dec. 11, 1964 INVENTOR DAVID C ROCKOLA 09%,6/2M5/WM ill/L275.

United States Patent 3,285,095 CAM MEANS David C. Rockola, Chicago, Ill., assignor to Rock-Ola Manufacturing Corporation, Chicago, 111., a corporation of Delaware Filed Dec. 11, 1964, Ser. No. 417,727 Claims. (Cl. 74-568) This invention relates generally to mechanical motion transmitting means and more specifically to improvements in plate cam means,

The utilization of rotatably driven plate cam means for actuating roller followers is well known in the art. Generally, such plate cam means have a fixed profile or periphery along which is suitable follower, usually a roller, moves to actuate an attendant linkage or arm in a predetermined motion pattern. For a number of years the use of simple plate cams as time actuator means for switches, wherein the switch contacts are made and brok en in response to actuation of a cam following actuator arm has gained widespread acceptance. Usually in such an arrangement the cam plate is rotatably driven by a shaft at constant rpm. and the cam profile is such as to include a pair of riser nodes, spaced at suitable arcuate distance determinative of a fixed time interval according to the rotational speed of the driven cam plate. The remainder of the cam profile provides an additional time interval; each of which intervals may be employed, as selected, for switch open or switch closed periods. Thus a convenient and simple yet operationally reliable switch timing mechanism is evolved according to practices familiar to those skilled in the art. Such time switch operation by the use of *rotatably driven cam plates is adapted to a wide variety of operations, but generally is restricted to conditions wherein fixed on and off times are encountered. It will be readily recognized that in this context the on and off periods for the switch arrangement associated with the cam follower are necessarily of a predetermined extent as established by the fixed and inflexible profile of the familiar actuating cam plates. For some time this simplified system has suffered limitation of use because of the inherent inflexible characteristics of the fixed cam profile or stated otherwise, such system defies adjustment of the switch on and off times for a given cam. To date the usual solution to this limitation is to replace the cam with another having a different profile. It is to a new and improved solution of this particular problem in the art that the present invention is directed.

In brief, the present invention contemplates a unitary plate 0am means, adapted to be driven with and by a rotatable shaft means and which is susceptible of adjustable variation of its profile in an easy and convenient manner so as to regulate the relative positioning of riser nodes thereof to correspondingly permit alteration of the responsive actuation of a follower engaging the cam profile. In general the improved cam means of this invention includes two or more plate cams, each with a fixed profile, mountable on a common hub for rotation therewith. At least one of the said cams is affixed to the hub and at least one other is rotatable about the hub and relative to the one cam affixed thereto. With this arrangement the relative positioning of adjacent cam plates commonly engagable by a single roller follower or the like, readily permits the user to regulate the arcuate spacing between riser nodes so as to correspondingly alter the operationally effective extent of the major and minor profile portions of the cam means and consequently regulate the time intervals during which the follower engages the red ice ially inward and outward profile portions of the cam :means. Thus operating time intervals for a switch or other means, associated with the follower, are adjustable according to the particular operational demands of an encountered operating sequence or circumstance. Additional means are provided in the improved cam means of this invention for frictionally interlocking the several cam plates of the combination so as to maintain their selected inter-positioning productive of a selected cam profile; said profile though adjustable being nevertheless operationally stable for a given selected positioning of parts,

The main object of this invention is to provide a new and improved cam means having an adjustable profile.

Another object of this invention is to provide a new and improved cam means comprising a plurality of adjacent cam plates, each with a fixed profile cooperatively associated in such a manner as to produce a composite cam means of adjustable profile.

Another object of this invention is to provide new and improved cam means which is particularly adapted for timing mechanism whereby the rotational driving of the cam means at a constant r.p.m. accompanied by selected adjustment of its profile permits the user to selectively alter the operating-position periods of a follower engaging the periphery of the cam means.

A still further object of this invention is to provide new and improved cam means readily usable in timing mechanism which embodies simplified means for adjusting the profile thereof while being operationally dependable.

A still additional object of this invention is to provide new and improved cam means as aforesaid which is inexpensive to manufacture and assemble and which provides the user with improved and simplified adjustibility of the actuating peripheral profile presented thereby.

Having thus described the present invention the best mode presently contemplated for carrying out its concepts and features will now be described in association with a preferred embodiment thereof, illustrated in the accompanying drawings, which taken with the hereinafter set forth description will serve to amplify and further set forth the above and further objects, features and advantages of this invention.

In the drawings:

FIG. 1 is :a rear elevational view of the improved cam means of this invention;

FIG. 2 is a front elevational view thereof;

FIG. 3 is an end elevational view thereof; and

FIG. 4 is a cross-sectional view taken substantially at line 44 of FIG. 2 and looking in the direction of the arrows thereon.

Referring now to the drawings, it will be understood from FIGS. 1 and 2, in particular, that the improved cam means of this invention, indicated generally at numeral 10 therein, comprises a plurality of cam plates, namely plates 11 and 12 in the illustrated embodiment, mounted on a common hub means 13 for rotation with the latter and a driving shaft 14 connectively associated with the hub means 13 (see FIGS. 3 and 4). The combination of this invention further includes suitable locking means 15 for fixedly coupling one of the cam plates, such as plate 11, to the hub 13' and clutch means 16 for releasably coupling the other cam plate 12 to the hub 13 and adjacent cam plate 11. Means 17 are also provided on or in association with the movable cam plate 12 for receiving suitable wrench or other engaging means (not shown) whereby the movable cam plate 12, may be rotatably moved about hub 13 and relative to the cam plate 11 affixed to said hub. Adjustable variation of the peripheral profile, for cam means 10 is visually indicated by index means comprising scale means 18 and 19, on the cam plates 11 and 12, respectively.

Turning now in greater detail to the particulars of the several elementary means comprised in the improved combination of this invention, as shown best in FIGS. 1 and 2, cam plate 11 is constructed with a substantially planar body portion 20, preferably of metal or other rigid material, such as steel and the like, which is suitably contoured to present a major semi-circular peripheral profile portion 21 and a minor semi-circular peripheral profile portion 22 interjoined at their contiguous ends by intervening riser profile portions 2323. In this regard it will be understood and appreciated that the profile portions 21 and 22 need not be semi-circular since the particular profile for the cam plate 11 as well as the form and number of riser portions 23--23 thereof may be widely varied and selected according to recognized skills and knowledge of the art according to the present invention. Essentially the profile of cam plate 11 presents a continuous peripheral edge engageable by a roller or a similar follower means 24 adapted to ride along radially inner and outer paths, as it engages the carns minor and major profile portions 22 and 21 respectively. As the roller engages either of the riser portions 2323 the same transfers to and between the major and minor profiles of the cam plate according to recognized principles.

Cam plate 11 is particularly distinguished by an enlarged central circular opening 25 adapted to fit concentrically about the hub member 13 as will be amplified in greater detail presently. The circular periphery of opening 25 is periodically interrupted by several (four as illustrated) spaced semi circular staking openings 26-26 which cooperate with the locking means 15 for rigidly afiixing and associating thecam plate 11 on and with the hub member 13, in a manner to be described more fully hereinafter. For convenience sake the one scale means 18 is associated with the cam plate 11; the same being inscribed or otherwise presented on one front face 28 of such plate contiguous to the major profile portion 21 thereof (see FIG. 2).

In the particular embodiment of the improved cam means of this invention illustrated in the drawings, cam plate 12, as shown best in FIG. 2, is formed substantially of identical shape, size and contour and peripheral profile as the above described cam plate 11. Thus, cam plate 12 comprises a substantially planar body portion 30 having a major semi-circular profile portion 31 and a minor semi-circular profile portion 32 which correspond to portions 21 and 22 respectively of the above described cam plate 11. The major and minor profile portions of cam plate 12 are likewise interconnected at their contiguous ends by intervening riser portions 33-33 whereby the roller means 24 engaging the periphery of cam plate 12 is enabled to translate between the major and minor profile portions thereof according to familiar practice. Like cam plate 11, cam plate 12 is provided with an enlarged central opening 35 which is adapted to fit concentrically about the central hub member 13.

Unlike cam plate 11, cam plate 12 is equipped with a plurality of openings 37 located radially inwardly of its periphery and which are spaced at suitable arcuate intervals, approximately 45 intervals, as illustrated, to provide a plurality of wrench or other tool engaging means 17, hereinabove referred to, whereby the cam plate 12 may be engaged and rotated about the hub 13 and relative to cam plate 11 as will appear presently. For convenience the secondary scale means 19 is disposed, as by inscribing, on the front face 38 of the cam plate 12 adjacent the minor peripheral portion 32 thereof so as to be cooperatively associated visually with the scale means 18 appearing on face 28 of the cam plate 11 all as best shown in FIG. 2 of the drawings.

The hub member 13 as herein illustrated comprises a substantially cylindrical metal member having a central axial opening 40 machined therethrough for receiving the drive shaft 14. In order to provide a convenient means for preventing rotational movement of the hub member 13 relative to and about shaft 14, one side of opening 40 is formed wiht a planar chord-a1 portion 41 which is adapted to matingly engage a flattened or cut-away area of the shaft 14 to provide an interlocking system for keeping the hub member from rotating relative to the shaft member.

As seen best from FIG. 4 of the drawings, the hub member 13 comprises an enlarged cylindrical collar portion 42 formed at one axial end 43 thereof and a cylindrical shoulder portion 44 extending coaxially outwardly of the collar portion 42; said shoulder portion 44 being of lesser diameter thanthe collar portion 42 with the circumferential surfaces of the portions 43 and 44 being concentric and interjoined by an intervening annular shoulder surface 45. The diameter of the cylindrical shoulder portion 44 is just slightly smaller than the central opening 35 of the cam plate 12 whereby the latter may be concentrically disposed about and supported on the shoulder portion 44.

Adjacent its outermost end the shoulder portion 44 is formed with a diametrically reduced cylindrical end portion 46 which is received closely within the central opening 25 of the cam plate 11 when the latter is as sembled on the hub member. In this respect it will be recognized that an annular staking shoulder 47 is formed between the concentric cylindrical surfaces of the shoulder and end portions 44 and 46 for purposes to be amplified presently.

In assembling the two cam plates 11 and 12 with and on the hub member 13, the one cam plate 12 having the wrench engaging means 17 associated therewith is disposed on and about the shoulder portion 44 nearest 'the shoulder surface 45 of the hub member, but separated therefrom by an interposed frusto-conical unitary annular spring member, comprising the previously mentioned clutch means 16 as best illustrated in FIGS. 3 and 4 of the drawings. Fixing of cam plate 11 to the hub member 13 so as to prevent relative rotation therebetween, is accomplished by means of the locking means 15 constituting upset stake portions 50 formed on the periphery of the hubs end portion 46 by axially punching such periphery opposite each staking opening 26 of the cam plate 11 according to known staking practice. By this convenient and simple expedient the material upset from the end portion 46 of the hub is coldflowed into the stake openings 26 pressing the cam plate 11 tightly against the staking shoulder 46 and fixing the same with and on the hub member 13. In such assembly of cam plates 11 and 12 on the hub means 13 there is a slight axial compression of the frusto-conical spring clutch means 16 between face 38 of cam plate 12 and the shoulder face 45 of the hub means 13.

By the combination of parts as above described, it will be appreciated and understood that the cam plate 11 is fixed to the hub means 13 while cam plate 12 is rotatable relative thereto and cam plate 11. Further, while the cam plate 12 is so relatively rotatable its rotational movement is not free and unhampered, but is frictionally regulated according to the coupling activity provided by the compressed clutch means and the interengaging or opposing faces of the two cam plates 11 and 12. In a similar fashion the engagement of the surface 38 on cam plate 12 and the larger diametered or base edge of the frusto-conical clutch means 16 provides additional frictional interference with rotation of the cam plate 12.

While the cam plate 12 is frictionally interlocked with both the cam plate 11 and a hub member 13 as above described, such frictional interlocking is of a nature to permit regulated rotation or movement of the cam plate 12 relative to the cam plate 11 and hub means 13, particularly upon the application of suitable torque to the cam plate 12 while maintaining the hub member 13 and the attached cam plate 11 stationary with shaft 14. The application of such force to rotate cam plate 12, as selected, is conveniently applied by virtue of the Wrench engaging openings 37 in cam plate 12 which permit the user to apply a torque wrench or other leverage means thereto, in a known manner. Thus it will be readily recognized and appreciated that plate 12 may be selectively moved relative to cam plate 11 so that the composite peripheral contour or profile of the cam means of this invention maybe accordingly adjusted and changed as selected.

Amplifying the foregoing, it will be understood that if the cam plate 12 is rotated: from its FIG. 2 position for example, while maintaining cam plate 11 relatively stationary with respect thereto, the major and .minor peripheral portions of the two cam plates selectively may be positioned at or between one limit position wherein their like profiles coincide and a second position wherein the major profile portion of one cam plate lies substantially coextensively opposite the minor profile portion of the other cam plate. This particular relationship and range of adjustability occurs in the presently illustrated example of the invention by virtue of the fact that the cam plates 11 and 12 are of like size and peripheral shape with the major and minor peripheral portions of each constituting substantially 180 of their respective circumferences. As previously mentioned cam plates 11 and 12 may be of either like or unlike formation so that the peripheral extent of the major and minor profile portions of each may be widely varied to accordingly provide a wide variety of peripheral shapes for cam means 10 differing materially from those attainable by the particular cam plates 11 and 12 shown. It also must be recognized that more than two cam plates may be utilized to provide an even greater range of adjustable change for the periphery of the cam means 10 of this invention.

In order to assist the operator in adjustably positioning cam plate 12 with respect to plate 11, the two cooperating scale means 18 and 19 are provided, the graduations of the scale means 18 constitute 5 arcuate 1nterval while the graduations of scale means 19 are substantially 30 apart in the particular embodiment illustrated. Such scale means, of course, may be varied, as selected, according to the particular requirements and demands of a given installation without departing from the present invention.

From the foregoing it is believed that those skllled in the art will readily recognize and appreciate the novel merits of the present invention which serve to mark the same apart from prior known cam means. Additionally apparent from the foregoing description of the present invention is the fact that the regulated interpositionlng of the two cam elements serves to eifectively change the peripheral contour of the cam means which accordingly regulates the inward and outward movement of the follower means, such as a roller follower 24 engageable with such periphery. Thus a convenient composlte cam means, having a readily adjustable and flexible contour capable of affording the user a new and simple operationally stable and dependable means having particular untility in adjusting the timing cycles of attendant mechanisms is provided by this invention; the timing being altered principally by utilization of a constant selected r.p.m. for the cam means so that change of the arcuate interspacing between successive riser portions 23 and 33 presented to the follower means will accordingly vary the time periods in which the follower means engages the effective major and minor profile portions of the composite cam means.

Having thus described the present invention it is belived that those familiar with the art will readily recognize and appreciate the features and advantages of the present invention whereby its objectives are carried out. Further while the present invention is hereinabove described in association with a particular preferred and simplified embodiment thereof illustrated of the accompanying drawing, it will nevertheless be understood that such embodiment may be subject to modification, change and substitutions of equivalents without departing from the spirit and scope of this invention. Consequently it is intended that this invention be unlimited by the foregoing description except as may appear in the following appended claims.

I claim:

1. In combination, a hub member adapted to be rotatably driven, plural cam plates adjacently mounted on said hub member for coaxial rotation therewith, each of said plates having fixed peripheral cam profile portions, means affixing one of said cam plate to said hub member, means rotatably mounting another of said cam plates on said hub member whereby the same may be rotatably moved thereabout and relative to said one cam plate, unitary clutch means operative to normally interlock said cam plate and selectively release said another cam plate upon rotation of the latter about said hub member whereby the said fixed peripheral cam profile portions of said cam plates may be selectively related and arranged to provide a plurality of selected composite profiles for said cam means, and means for coupling torque applying means to said other cam plate to effect said rotation thereof.

2. Plate cam means comprising a hub member adapted to be rotatably driven and having coaxial cylindrical shoulder and collar portions, a pair of cam plates each having a fixed peripheral profile with major and minor portions interjoined by riser portions, means fixedly connecting one of said plates to said hub member adjacent one end of said shoulder portion thereof, means rotatably mounting the other said plate onsaid shoulder portion contactingly adjacent said one plate and axially spaced from said collar portion unitary clutch means mounted on said shoulder portion in frictional engagement with said collar portion and said other plate, said clutch means serving to frictionally interlock said other plate with said hub member whereby the said plates are normally conjointly rotatable with said hub member, and wrench engaging means on said other plate for the attachment of torque applying tool means thereto whereby said other plate may be rotated relative to said one plate and said hub member in defiance of said frictional interlock, the rotation of said other plate relative to the said one plate serving to alter the relative positions of their respective profile portions to thereby present various selected composite profiles for said cam means effective to actuate follower means engaging the same.

3. The combination set forth in claim 2 wherein said clutch means comprises unitary annular spring means.

4. Improved cam means comprising a hub member adapted to be rotatably driven, a pair of cam plates adjacently mounted on said hub member for conjoint rotation therewith, each of said cam plates having a fixed peripheral profile, means fixedly attaching one of said cam plates to said hub member, means mounting the other of said cam plates on said hub member for rotation thereabout and relative to said one cam plate as selected, clutch means comprising spring means frictionally engaging said hub member and said other cam plate and serving to releasably interlock said cam plates whereby said other cam plate may be moved to and locked in selected positions relative to said one cam plate, and means for effectively releasing said clutch means to permit said movement of said other cam plate.

5. Improved cam means comprising a hub member adapted to be rotatably driven, a pair of cam plates adjacently mounted on said hub member for conjoint rotation therewith, each of said cam plates having a fixed a 7 V I 8 peripheral profile, means fixedly attaching one of said References Cited by the Examiner cam plates to said hub member, means mounting the UNITED STATES PATENTS other of said cam plates on said hub member for rotation thereabout and relative to said one cam plate as 2,096,182 10/1937 Kerr et 74 '568 selected, clutch means releasably interlocking said cam 5 FOREIGN PATENTS g? ZZffi 3 .fF i i t0 936,660 2/1948 France. an 0: in se ec e P081 1011 re a we 0 sm one cam 1,199,109 6/1959 Planet plate, and means for effectively releasing said clutch means to permit said movement of said other cam plate comprising means on said other cam plate for applying torque 10 thereto sufiicient to rotate the same about said hub mem- FRED MATTERN Primary Exammer' her in defiance of said clutch means. W. S. RATLIFF, Assistant Examiner.

182,484 4/ 1907 Germany.

Claims (1)

1. IN COMBINATION, A HUB MEMBER ADAPTED TO BE ROTATABLY DRIVEN, PLURAL CAM PLATES ADJACENTLY MOUNTED ON SAID HUB MEMBER FOR COAXIAL ROTATION THEREWITH, EACH OF SAID PLATES HAVING FIXED PERIPHERAL CAM PROFILE PORTIONS, MEANS AFFIXING ONE OF SAID CAM PLATE TO SAID HUB MEMBER, MEANS ROTATABLY MOUNTING ANOTHER OF SAID CAM PLATES ON SAID HUB MEMBER WHEREBY THE SAME MAY BE ROTATABLY MOVED THEREABOUT AND RELATIVE TO SAID ONE CAM PLATE, UNITARY CLUTCH MEANS OPERATIVE TO NORMALLY INTERLOCK SAID CAM PLATE AND SELECTIVELY RELEASE SAID ANOTHER CAM PLATE UPON ROTATION OF THE LATTER ABOUT SAID HUB MEMBER

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