US1968398A - Timing mechanism - Google Patents

Description

July 31, 1934. L, c, IRWIN 1,968,398

TIMING MECHANISM Filed Sept. 28, 1931 2 Sheets-Sheet 1 WITNESS INVENTOR 1\ T Lfll VAE/VCE C IRWl/V A TTORNE VS L. C. IRWIN TIMING MECHANISM July 31,1934.

Filed Sept. 28, 1951 2 Sheets-Sheet 2 INVENTOR A NM N m W 5 Wm A L WITNESS 05%?? Patented July 31, 1934" PATENT OFFICE TUBING MECHANISM Lawrence C. Irwin, Brooklyn, N. Y., assignor to Charles J. Tagliabue Mfg. 00., BrooklynrN. Y.,

a corporation of New York Application September 28, 1931, Serial No. 565,534

Claims.

The present invention relates to timing mechanism for use in controlling the duration of an operation or treatment in a time controlled apparatus wherein articles or materials are sub jected for various lengths of time to a heating, pressure or other medium.

The various forms of time controlled mechanism now on the market are usually made adjustable so that the time for any particular operation may be varied in order to take account of the different sizes or compositions of the articles or materials to be treated, or of the diiferent degrees of heat, pressure, etc. to which they are to be subjected. With such end in view, the timing mechanism is generally so constructed that. in one of its extreme positions. of adjustment it will permit the material being subjected to treatment to be operated upon for the maximum length of time permissible, while for shorter periods of treatment the timing'mechanism is suitably adjusted to interrupt the treatment at the end of a shorter time interval. As, however, the timing mechanism, which is usually a cam, is of such size and its rate of rotation is so selected that it will make a complete revolution, or nearly a complete revolution, in the maximum time period for which an article is'to be subjected to treatment, the cam will be in an intermediate position at the end of a treatment of. shorter duration. Before another article or batch of material can then be treated under the control of this mechanism, the latter must first be set to zero, either manually or with the aid of more or less complicated automatic mechanism. Such-known timing mechanism thus has the disadvantage that it requires the attention of an operative to re-set it to zero position, or else must be provided with rather complicated mechanism to perform such resetting automatically. It is the object of the present invention to provide a timing mechanism of simple character which, no matter what the duration of the time.

interval which it is to supervise, will always be at its initial or zero position at the end of the selected time interval, so that the attention of an operative is rendered unnecessary and no time is consumed in returning such mechanism to the initial or zero position. To this end I have devised a timing mechanism which includes a movable element, such as a rotatable cam, which is so constructed that at the end of a fraction, say substantially half, of the time interval during which the article is to be subjected to treatment, 'such movable element is reversed, so that during the remainder or second half of such time interval the mechanism returns to its initial position, and at the end of the interval is back at the starting position and is ready to be employed for the next control operation without further manipulation.

A preferred embodiment of the invention is illustrated by way of example on the accompanying drawings, in which Fig. 1 is a diagrammatic view in front elevation of my improved timing mechanism;

Fig. 2 is an end view of the same;

Fig. 3 is a plan view;

- Fig. 4 is a view in elevation of the control lever;

Fig. .5 is a detail;

Fig. 6 illustrates a suitable form of reversing 7o snap switch operated by the control lever;

Fig. 7 is a plan view of the lever l shown in 4; and

Fig. 8 is a schematic wiring diagram.

The timing mechanism illustratedis operated 7 by means of a reversible motor, such as a Warren motor 1, which is mounted upon-four pillars 2, of which only one is shown (see Fig. 3) and is secured to the base plate 3 by means of screws 4.

A driven shaft 5 is suitably geared to the motor 5, thecam 7 is of slightly greater diameter than the cam 6.

A control lever 10 is arranged to cooperate with the cams 6 and 7 and is pivoted at 11 about a vertical axis upon a lever 12 arranged above the same so that the lever 10 can move horizontally with respect to lever 12., The latter is pivoted at 13 upon a bracket 14 fixed to the housing of the instrument so as to move in a vertical plane. A spring 15 arranged above the pivot 13 urges the lever 12 constantly into engagement with the lever 10; while a spring 16a (Fig. 3) anchored at 16b to the lever 12 and at 160 to lever 10 urges the latter against a stop 16 projecting downward- 1y from the lever 12 so as to limit the lateral movement of lever 10. The lever 10 cooperates with a reversing switch mechanism indicated generally at 17 (see Figs. 3, 4, 6 and 7) and is adapted in difierent angular positions thereof ina horizontal plane to move such switch into one or the other of its endpositions in which it closes con- 1 ocf tacts 13, 18 or 19, 19 (Figs. 3 and 3). The reversing switch may be of any suitable construction, preferably of the snap type in which the contact opening and contact closing movements of the switch are extremely rapid in order to avoid arcing. The snap switch illustrated is of the type disclosed and claimed in the copending application of Frank J. Bast, Serial No. 548,520, filed July 3, 1931, now Patent No. 1,905,788, dated April 25, 1933, and consists essentially of a. base plate 20 upon which are mounted two resilient supports 21 against which the opposite ends of plates 22 and 23 bear, the ends of such plates being provided with knife edges to reduce friction and wear. The plates 22 and 23 meet along a knife edge joint indicated at 24., the plate 22 being provided with an arm 25 which engages in a slot in the support 21 for limiting the upward and downward movement of the plates. It will be understood that the normal distance between the resilient supports 21 is less than the total length of the plates 22 and 23 between their opposite knife edge ends, so that as such plates are moved toward their central or neutral position, the resilient supports 21 are flexed outwardly to such a degree that when the plates reach their neutral position, or even before such neutral position is reached, they quickly snap to a reverse position with the aid of the energy stored in the flexed supports 21. The plate 22 is considerably shorter than the plate 23, so that it accomplishes a greater angular displacement than the latter; to this shorter plate there is attached a flexible arm 26 carrying a jumper 27 which in one position of the switch bridges the contacts 18 and in the other the contacts 19. As explained in the above-mentioned application, the parts are so constructed and arranged that when one or the other pair of contacts is bridged, the spring arm 26 is flexed, as indicated by its curvature in Fig. 6, so that it does not follow the initial movements of the plate 22 toward the neutral position but is quickly pulled away from the'contacts 18 towards the contacts 19, or vice versa, as the switch mechanism snaps past the neutral plane into the reverse position.

The lever 10 is provided at one end with a rider 28 which engages the cam surfaces 7 and 6 'in' alternation as described hereinbelowj The opposite end of the lever is bent laterally as indicated at 29 and terminates in a bifurcated portion into the furcations of which are threaded adjustable screws 31. The furcations 30 straddle the larger plate 23 of the snap switch 17 and upon horizontal oscillation of the lever '10, one or the other of the screws 31 engages such plate and moves the same toward the neutral plane, whereupon the plates snap into their reverse positions. When the lever 10 is against the stop 16, the

spring arm 26 of the snap switch 17 is in a position in which the contacts 18 are bridged by the jumper 2'7.

The cams 6 and 7 are provided with registering notches 32; when the rider 28 is engaged in such notches, the cams are in their, initial or zero position. When the lever 10 is held against the stop 16 by the spring 16a, the cam engaging end of the rider 28 is in the plane of the cam 7 so that upon rotation of such cam the rider mounts the inclined wall of the notch in such cam and upon continued rotation of the sam 7, rides upon the outer circumference of the latter. When this occurs, the lever 12, whose lefthand end (Fig. 1) rests upon the lever 10 so that it follows the vertical movements of the latter,

is oscillated in a clockwise direction, whereupon its other end, which is of elongated form perpendicularly to the plane of Fig. l and is pro-- vided with a plurality of adjustable screws 33, only one of which is illustrated, moves away from weighted flap valves 34 which control the discharge openings of nozzles 35 of pilot valves 36. The latter are fed with air in known manner and by the operation of the valves 34 control the pneumatic pressure in a number of air operated diaphragm valves or other servo-motors (not shown) which control the feed of various media,

ing device, and the opening and closing of a hydraulic valve.

It will be clear from the drawings that so long as the lever 12 is maintained in such a position that the flap valves 34 are released by the lower end of such lever, the servo-motors controlled by the pilot valves .36 will remain in the same condition. In accordance with the present in-v vention the cam trip arm 9 is so positioned that at the end of substantially half the time interval during which the flap valves 34; are to remain in their closed position, the rider 28 rests upon the circumference of cam 7; at the end of such half internal,- however, the rider is shifted by the arm 9 forwardly, as viewed in Fig. 1, and leftwardly as viewed in Fig. 2, until it falls upon the cam 6. When this occurs, the lever 10 is oscillated counterclockwise as viewed in Fig. 3, so that'screws 31 move to the right (Fig. 6) and cause the snap switch to move quickly to its reverse position in which the contacts 19 are bridged, whereupon the circuit to the coil 1a of the Warren motor 1 is closed and eflects reversal of the movement of .the cams 6 and 7. The rider is prevented from returning to its original position (wherein the lever 10 rests against the stop- 16 of lever 12) by the portion of the cam 7 projecting above the periphery of cam 6.- 'The cams now rotate in a clockwise direction and contin'ueto do so until the rider 28 falls into the notch 32. To time the opening of the nozzles 35 in order, for example, to effect discharge of air-from tires in a. vulcanizer, the cam 6 may be provided with a portion 6a of reduced diameter with which cooperates a cam segment 6b whose radius is equal to the larger radius of cam 6.- This segment is clamped to to the shaft 5 by the nut 8 and may be adjusted to vary the distance between itself and the notch 32. When the rider falls from the segment 6b upon the cam 6,- the nozzle of the pilot valve controlling the supply of air to the tires is opened to efiect discharge of such air. When the rider falls into the notch 32, the left-hand ends of levers 10 and 12 (Fig.- 1) fall, whereupon the remaining nozzles 35 are opened. At the same ,time the rider 28 is shifted into the plane of the cam 'Z by the spring 16a and the mechanism is then in its initial or zero position in which it is ready to begin immediately the; next control operation without the intermediation of an operative or of a re-setting mechanism.

The trip .9 is beveled, as shown at 9a in Fig. 2, and engages a roller 28a on the rider to shift the latter from cam 7 to cam 6. The trip may be provided with a pointer 9b and the cam 6 may be suitably graduated in minutes to facilitate adjustment of the trip.

The timing mechanism is started by closing a spring-tensioned push button 37 (Fig. 8) which thereupon closes a circuit from the positive line, through the push button contacts, contacts 18, coil lb to the negative line. The push button is held in closed position until an extension 28b on the rider 28 has risen sufllciently to close contacts 39 which operate to maintain the circuit through the coil 1b. When the rider again falls into the notch 32 at the end of a control operation, the contacts 39 are opened and the flow of current through the coil 1a thereupon ceases. It will be understood that the push button 37 is released as soon as the contacts 39-close and opens under the action of its spring. The contacts 39 are so arranged that they are closed by extension 28b very shortly after the cams begin to move. The

stopping of the motor can also be accomplishedby means of a contact upon the tire press or other apparatus with which the timing mechanism is associated. m

It will be clear that with my improved device,

. wherein the timing cam moves in one direction for approximately half the period during which a given condition is to be set up in a controlled apparatus, higher speeds may be employed which afford the advantage of longer distances along the periphery of the cam per unit of time. It will be understood that where the longest control period for which the timing mechanism is to be employed is, say, 30 minutes, the cam may be rotated at such speed that it makes a nearly complete revolution in 15 minutes.

Variations may be resorted to within the scope of the appended claims without departing from the spirit of the invention. For example, it is not necessary for the rider to return to the plane of cam 7 at the end of a cycle. Thus the bottom of the notch 32 of the cam 6 can be made lower than the notch of the cam '7 so that when the rider drops into the notch of cam 6, it remains in the plane of the latter, while the operating motor is stopped, as described above, by the opening of the contacts 39. To start the motor running, the rider 28 can then be merely lifted onto the bottom of the notch 32 of the cam 7, whereupon switch 17 is reversed and the contacts 39 are closed and thereby close the motor circuit. In such construction the push button 37 can be spensed with. It is therefore to be understood that where in the claims I speak of the return of the timing mechanism to its initial position, I mean the initial angular position with respect to the trip arm 9, and not any specific position of the rider axially of the shaft 5, since such rider may come to rest in the notch of either cam 6 or cam 7..

I claim:

1. The combination with a timed element adapted to be maintained in a selected condition of adjustment for a predetermined interval of time, of a timing mechanism comprising two axially aligned rotatable cams having peripheral surfaces of equal radius at the zero or starting point but of unequc radius for substantially the remainder of such surfaces, a reversible electric motor for rotating said cams, a lever cooperating with said cam-surfaces and arranged to engage first the cam of larger radius, a second lever pivoted to move in a plane parallel to the planes of the cams and operatively associated with said controlled element to establish said selected condition of adjustment, said first lever pivoted to said second lever to move transversely to the planes of the cams, said second lever resting on said first lever so as to follow the movements of the latter in a plane parallel to the planes of the cams, a trip associated with said cams and adjustable to a position corresponding to approximately half of said time interval, said trip operative to shift said first lever laterally onto the smaller cam, a reversing switch for said motor associated with said first lever to be operated thereby upon the shifting thereof to reverse said motor, whereby at the end of said interval said timing mechanism is at its initial position, means for stopping the motor when the initial position is reached, and means for returning the first lever into the plane of the larger cam.

2. The combination with a timed element adapted to be maintained in a selected condition of adjustment for a predetermined interval of time, of timing mechanism comprising a timing member, mechanism associated with said timing member and cooperating with said timed element to establish said selected adjustment of said element, means for causing the timing member to advance in one direction and for then causing the direction of movement of said member to be reversed at the expiration of a predetermined degree of movement of said member, and for causing return of said member and said associated mechanism to their initial positions, and means for stopping the motion of the timing member upon the return of said member to its initial position.

3. The combination with a timed element adapted to be maintained in a selected condition of adjustment for a predetermined interval of time, of timing mechanism comprising a timing member, means for moving said member in opposite directions at a substantially uniform rate of speed, mechanism associated with said timing member to establish a selected adjustment of said element, means for causing said first-mentioned means to advance said timing member in one direction, mechanism operative to cause reversal of said first-mentioned means at the expiration of approximately one-half of the said predetermined time interval to effect return of said member and said associated mechanism to their initial positions, and means for eflecting stopping of the timing member upon the return-of said member to its initial position. v

4. The combination with a timed element adapted to be maintained in a selected condition of adjustment for a predetermined interval of time, of a timing mechanism comprising a cam mechanism, means for rotating said mechanism at substantially uniform speed, means controlled by the cam mechanism and cooperating with said controlled element to establish said selected condition of adjustment, mechanism including a switch for reversing said rotating means at the expiration of approximately half of the predetermined time interval to effect return of said cam mechanism to its initial position, and means for stopping the motion of said cam mechanism upon the return of the latter to its initial position.

5. The combination with a timed element adapted to be maintained in a selected condition of adjustment for a predetermined interval of time, of a timing mechanism comprising a cam mechanism, means for rotating said cam mechanism at substantially uniform speed, a lever device controlled by said cam mechanism and cooperating with said timed element to establish said selected condition of adjustment of such-element, mechanism cooperable with said lever device for reversing the rotation of said cam mechanism at the expiration of approximately one-half of the said predetermined time interval, whereby'atthe end of said interval said cam mechanism is atits initial position; said last mentioned. mechanism including an adjustable member for determining the duration of-the said time interval arranged to be engagedby said lever device, and means for stopping said cam mechanism upon the return of the latter to its initial position.

6. The combination with a timed element adapted to be maintained in a selected condition 16 of adjustment for a predetermined interval of time, of a timing mechanism comprising a cam mechanism, means for rotating said cam mechanism at substantially uniform speed, a lever device controlled by said cam mechanism and cooperat- 20 ing with said timed element to establish said selected condition of adjustment of such element. mechanism cooperable with said lever mechanism for reversing the rotation of said cam mechanism at the expiration of approximately one-half of '25, the said predetermined time interval, whereby at the end of said interval said cam mechanism is at its initial position, said last mentioned mechanism including an adjustable member arranged to-shift said lever mechanism, and said reversing mechanism including a switch operated by said lever mechanism upon the shifting of such lever device, andmeans for stopping said cam mechanism upon the return thereof to its initial position.

7. The combination with a timed element adapted to be maintained in a selected condition of adjustment for a predetermined interval of time, of a timing mechanism comprising a cam mechanism having two cam surfaces of different 40: radii, means for rotating said cam mechanism at substantially uniform speed, a lever device controlled by said cam mechanism and cooperating with said timed element to establish said selected condition of adjustment of such element, and mechanism for reversing the rotation of said cam mechanism at the expiration of. approximately one-half the selected prdetermined time interval, whereby at the end'of said interval said cam mechanism is at its initial position, said reversing 501 mechanism comprising, an adjustable trip arm arranged to be engaged by said lever mechanism to shift the latter from one cam surface to the other, and a switch member operated by said lever mechanism upon said'shifting to reverse the direction of said rotating means, and means for stopping saidcam mfiianism upon the return thereof to its initialposition. v

8. The combination asset forth in claim 7, wherein said lever device comprises a lever enm; gaging said cam mechanism and cooperating with said switch member, a second leverassociated with the timed element to effect actuation thereof, said second lever arranged to be controlled by the outline of said cam mechanism, and said first lever pivoted to said second,,lever so as to be shifted by said trip arm axially of the cam mechanism independently of the second lever.

9. The combination with a timed element adapted to be maintained ina selected condition of adjustment for a predetermined interval of time, of timing mechanism comprising a rotatable cam, a reversible electric motor for rotating said cam at substantially uniform speed, a lever;

arranged to be actuated by said cam and cooperating with said timed element to establish said condition of adjustment, means operative at the expiration of approximately onehalf of said time interval to effect reversal of the cam motor, whereby at the end of said time interval said timing mechanism isat its initial position, and means for stopping said motor upon return of said cam'to its initial position.

10-.The combination as set forth in claim.9, wherein said reversing means comprises a trip associated with said cam, mechanism and adjustable to a position corresponding to approximately one-half of saidinterval, a member carried by said lever' and 'engageable with said trip to'be moved relatively to said lever, and .a switclrdevice operatively associated with said member to be actuated thereby to effect reversal of said motor.

11. The combination with a timed element adapted to be maintained in a selected condi-e tion of adjustment for a predetermined interval of time, of a timing-mechanism comprising two axially aligned rotatable cams having peripheral surfaces of equal radius at the zero orstarting point but of unequal radius for substantiallythe remainder. of such surfaces, an electric motor 109 for rotating said cams, means associated with said cams and cooperating with said controlled ele-' ment to establish saidcondition of adjustment,

a member cooperating with said cam surfaces and arranged to-engage first the cam of larger radius; a trip associated with said. cams'and adjustable to a position corresponding to approximately half of said time interval, said trip operative tov shift said member laterally onto the smaller cam,;a switch associated with said member and opera. 119 time upon'the shifting-of said 'memberto effect reversal of said cam, whereby at the end of said interval .said; timing mechanism is at its initial position, andmeans for stopping said motor when said initial position is reached.

12. The combination as set forth in claim 11, wherein the first mentioned means includes 'a member arranged to follow the radial cam-can'- trolled movements of the first mentioned member. 13. The combination as set forth in claim' 11, .29 wherein the smaller cam is provided with a portion adjoining the zero point thereof of a radius intermediate the larger. and: smaller radii of;such cam, said combination including an intermediate cam segment of a radius equal to the larger radius 136 of the, smaller cam and adjustable to vary the effective length of said intermediate portion of' thesmaller cam,- whereby the first mentioned member, may be caused to return to its initial position in predetermined step-wise fashion.

14, The combination with a timed element adapted to be maintained in a selected condhtion of adjustment for a predeterminedinterval of time, of 'a timing mechanism comprising means movable first in one direction and-then in the opposite direction and arranged to maintain said condition of adjustment during such vmovement, and mechanism operating at the end of a portion of the predetermined time interval to causere versal of themovement of said means fromthe, 140 one to the opposite direction and including a driving device effective on said movable means and operating at such speed during said reverse movement that the movable means is returned to its initial position upon the expiration of said time interval.

15. The combination with a timed element adapted to be maintained in a selected condition of adjustment for a predetermined interval of time, of a timing mechanism comprising a cam 5 tion of said predetermined time interval to effect the return of said cam mechanism to its initial position during the remainder of said time interval, and means for stopp n the motion of said cam mechanism upon the return of the latter to its initial position.

LAWRENCE C. IRWIN.

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