US3320373A - Positive timing device with infinite setting - Google Patents

Description

May1$, o. CJKROLOPF POSITIVE TIMING DEVICE WITH INFINITE SETTING Filed Aug. 4, 1964 5 Sheets-i$heet l mummmf" .mmmmmmmjimmmm m I NVEN TOR.

May 16, 1967 o. c. KROLOFP 3,320,373

POSITIVE TIMING DEVICE WITH INFINITE SETTING 5 Sheets-Sheet 2 Filed Aug. 4, 1964 r i1 r LT V m T r L M 6 m Q. Q 7 W R \w 17 Milli j 3: W U/LKVMZ/ bu c h I \N MN MN T May 16, 1% 5. 3. KRQLQPP 3,32@,373

' POSITIVE TIMING DEVICE WITH INFINITE SETTING United States Patent 3,320,373 POSITIVE TIMING DEVICE WITH INFINITE SETTING Otto Charles Krolopp, Villa Park, Ill., assignor to Blaw- Knox Company, Pittsburgh, Pa., a corporation of Delaware Filed Aug. 4, 1964, Ser. No. 387,382 11 Claims. (Cl. 200-38) This invention relates to a continuous repeat cycle timing device, and particularly to such a device capaable of continuously delivering timed electrical impulses at a uniform rate, said rate being, for commercial purposes, infinitely adjustable within the limits of the device and having a repeat timing accuracy between the individual impulses and cumulative totals of of 1% or better.

Accordingly, a primary object of the invention is the provision of a small, compact, continuous repeat cycle timing device having exceptional accuracy.

Another object is the provision of such a timing device having two accurately locatable electrical switches and an actuator which is driven at a uniform rate of speed in one direction until it engages one of said switches, and then at a uniform rate of speed in the opposite direction until it contacts the opposite of said switches.

Another object is to provide, in a continuous repeat cycle timing device, an actuator whose movement is circular whereby a maximum range of movement can be provided in a minimum physical space.

Yet another object is to provide a continuous repeat cycle timer having an actuator whose path of travel can be shortened or lengthened, and thereby timing intervals correspondingly shortened or lengthened, during operation as well as when the components are at rest.

Another object is to provide a continuous repeat cycle timing device which is very flexible and has general application to a wide number of uses, and is particularly well-adapted for use with an automatic weigh feeder of the type illustrated generally in Patents Nos. 2,869,743, 2,869,715, and 2,869,714.

Another object is to provide a method for controlling the operation of a timed, intermittently operable mechanism.

Other objects and advantages of the invention will become apparent upon a reading of the following description of the invention.

The invention is illustrated more or less diagrammatically in accompanying drawings wherein:

FIGURE 1 is a top plan view with the timer cover removed of the timer device of this invention;

FIGURE 2 is a side view of the mechanism illustrated in FIGURE 1;

FIGURE 3 is a view taken substantially along the line 33 of FIGURE 1;

FIGURE 4 is a detailed view of the actuator arm and associated structure; and

FIGURE S-is a schematic wiring diagram.

Like reference numerals will be used to refer to like parts throughout the following description of the drawing.

The timer assembly is indicated generally at 10 in FIGURES 1 and 2 and a motor assembly at 11, the motor assembly including a synchronous reversing motor 12. The timer assembly controls the direction of rotation of the output shaft 13 of motor 12. The motor may for example by a 60 cycle single phase synchronous reversing motor Whose output shaft 13 may for example rotate at 75 revolutions per minute. The motor is bolted or otherwise suitably secured to the rear plate 14 of the timer housing. Left and right timer housing side walls are indicated at 15 and 16, respectively, and a front plate at 17.

A timer cover, not shown for purposes of clarity, may extend over the top and down along the outer surface of the right side wall 16.

Motor shaft 13 is received within and rigidly connected to a motor coupling 20 which carries a worm 21 at its free end. Worm 21 drives a timer worm gear 22 which is non-rotatably fastened to worm gear shaft 23. The left end of the worm gear shaft may be journaled in a flange bearing, not shown, carried by left side wall 15. The right end of the worm gear shaft may be journaled in a flanged bearing 24 carried by an upwardly extending projection 25 of right side wall 16.

The worm gear shaft also carries an actuator arm 27 which includes a collar portion 28, shown best in FIGURES 1 and 4, and an outwardly extending lever portion 29. The actuator arm is non-rotatably fixed to the shaft so that worm gear 22 and actuator arm 29 rotate together, and in the same direction, upon revolution of warm 21.

The actuator arm traverses an arcuate, in this instance circular, path whose extremities or end points are defined by a pair of timing switches 30, 31. These switches may both be arranged to be movable with respect to one another and to the timer housing or either one may be constructed for movement relative to the balance of the machine and the remaining switch to remain stationary with the machine. In this instance switch 30 is stationary, its position being fixed by a stationary switch mounting bracket 32 to which it is secured, and which in turn is secured to the rear plate 14 of the timer housing.

In this instance the movable timing switch 31 is mounted for movement toward and away from stationary switch 30 along an arcuate path which is, at all times, the same radial distance from the axis of worm gear shaft 23. The switch 31 is secured to an adjustable switch bracket 34 which in turn is integral with a worm gear 35. Worm gear 35 is concentrically mounted with respect to shaft 23 and is spaced from worm gear 22 and actuator arm 27 by a bearing sleeve 36 and a spacer 37, shown best in FIGURE 4. There is no connection between the worm gear 35 and shaft 23 so the gear is free to rotate with respect to the shaft, and it may do so when the shaft is stationary or in motion.

It will thus be seen that the length of the circular are between switches 30 and 31 may be shortened or lengthened by moving adjustable switch 31 towards and away, respectively, from stationary switch 30. With actuator arm 27 moving at a constant speed it is thus apparent that the time interval between consecutive switch actuations is directly dependent upon the lineal distance be tween the two switches as measured along the arc of movement of the actuator arm at the appropriate radial distance from shaft 23. When switch 30 is actuated motor 12 will cause output shaft 13 to rotate in one direction and actuator 27 to move towards switch 31. Upon actuation of switch 31 the motor will be reversed and shaft 13 will be rotated in the opposite direction, thereby returning actuator arm 27 toward switch 30. Preferably the motor 12 is of the synchronous, steeping type, which is instantly reversible. A motor which is reversible within about /2 cycle of frequency is considered to be instantly reversible, and such motors are available from many sources.

The control mechanism for accurately positioning movable switch 31, and therefor the time increment between consecutive switch actuations, is indicated generally at 40.

The control mechanism includes a control or knob shaft 4.1 which is supported at its outer end in the front plate 17, and, at its inner end, in a flanged bearing received in a lug 42 projecting inwardly from left side wall 15, all as seen best in FIGURES l and 2. A knurled knob is indicated at 43 and an engagement spring at 44.

A spur gear 45, is carried by the control shaft near its innermost end.

Another larger spur gear .is indicated at 46. Spur gear 46 is carried by a shaft 47, see FIGURE 3, whose outermost end is supported in a lug secured to the inside face of front plate 17 and whose innermost end is supported in an aligned aperture in lug 42. Engagement spring 44 normally forces knob shaft 44 outwardly to the FIGURE 1 position, and thereby spur gear 45 out of contact with spur gear 46. When the control knob is pushed inwardly the spur gears are brought into engagement.

Shaft 47 also carries a Worm 48 which meshes with a worm gear 49 carried by shaft 50. The ends of shaft 50 are supported in suitable bearings carried by the left and right side walls as best seen in FIGURE 3.

Shaft 51) also carries a worm 53 near its end adjacent right side wall 16. Worm 53 meshes with worm gear 54 carried by shaft 55 which is journaled in the front and rear plates 17 and 14 respectively of the timer housing.

Shaft 55 carries a worm worm gear 35.

It will thus be seen that by moving control shaft 41 inwardly, and thereby spur gear 45 into engagement with spur gear 46, the position of movable actuating switch 31 may be varied either toward or away from stationary switch 30 depending upon the direction of rotation imparted to control knob 43. Since the gear ratio from spur gear 45 to worm gear 35 is continuously stepped down, it will be at once apparent that a large number of revolutions of control shaft 41 must be made to cause worm gear 35 to make one revolution,and accordingly control shaft 41 and spur gear 45 when moved into engagement with spur gear 46, provides a very fine adjustment for movable switch 31.

Means for making a rapid coarse adjustment of position of movable switch 31 with respect to stationary switch 30 is indicated generally at 60.

The coarse adjustment assembly includes a small, high speed motor 61 which may be bolted or otherwise suitably secured to the left side plate 15 as best shown in FIGURES 1 and 3. For example, a small A.C.-D.C. HP. motor of 5000 r.p.m. rating presently marketed under the trade name Deyton as Model No. 2MO33 may be employed. The motor output shaft 62 drives a small pulley 63 which is vertically aligned with a large pulley 64 located therebelow. Driven pulley 64 is rotatable with a shaft 65 whose outer end is journaled in a flanged bearing in front plate 17 as best shown in FIGURE 2, and whose inner end is supported in lug 42. An ring 66 drives pulley 64 from driving pulley 63. A spur gear 67 is carried by shaft 65 on the opposite side of lug 42 from driven pulley 64. Spur gear 67 is always in contact with spur gear 46 as best shown in FIGURE 2. Pulley shaft 65 also carries a miter gear 68 which functions as a driving gear whenever the motor 61 is actuated. 'Miter gear 68 meshes with a similar driven miter gear 69 supported on the end of a shaft 76 which extends outwardly from a counter 71. Since the gear ratio between the miter gears is 1 to 1, rotation of spur gear 67 one revolution will induce a similar rotation of one revolution of counter shaft 70. Shaft 70 may be connected in any suitable manner to a conventional counter having a dial which may be read through an aperture in front plate 17.

Since spring 44 maintains spur gear 45 out of contact with spur gear 46 actuation of motor 61 will have no 56 which in turn meshes with effect on spur gear 45 and its carrying shaft 41. The

counter shaft 70 will however always be rotated irrespective of whether rotation is imparted to shaft 41 or shaft 65 since the linking gear 46 is always rotated.

The use and operation of the invention are as follows: The gear ratios are so arranged that an exceedingly large number of revolutions of control shaft 47 must be made to cause one revolution of Worm gear 35 and consequently one revolution of movable switch 31. Purely by way of example the following values are given as illustrative of the magnitude of adjustment possible.

The ratio between worm gear 35 and worm 56 may be on the order of to 1; between worm gear 54 and worm 53 about 20 to 1; between worm gear 49 and worm 48 about 20 to l; and between spur gear 46 and spur gear 45 about 3 to 2. It is thus obvious that several rotations of control shaft 41 will result in only a very minute adjustment in location of movable switch assembly 31, and accordingly a very precise and accurately variable time interval between consecutive switch actuations is provided.

Under some circumstances it may be desired to make a rapid, coarse adjustment of the distance between movable switch 31 and stationary switch 30. If the timer assembly is used in connection with one of the weighing and feed devices illustrated and described in the afore mentioned patents, it may for example be desirable to change the setting between the termination and commencement of weighing operations on different sized batches of materials. In this event coarse adjustment motor 61 is run in the appropriate direction by any suitable switch means not shown. Rotation of motor shaft 62. will drive shaft 65 at a rate of speed proportional to the diameters of pulleys 63 and 64. Since the motor may have a nominal rating of about 5000 rpm, spur gear 67 will be driven at several thousand r.p.m. with the result that the position of worm gear 35 and movable switch 31 will be varied much more rapidly than can be done by hand twisting of control knob 43. When motor 61 is actuated, spring 44 maintains spur gear 45 out of contact with spur gear 46 so the control knob is not alfected.

It should be noted that counter 71 will indicate the extent of adjustment whether movement control of switch 31 is accomplished by motor 61 or knob 43. This follows from the fact that large spur gear 67 is always in contact with smaller spur gear 47 so that counter shaft 70 is always actuated.

The reversible synchronous motor 12 may have a 75 rpm. rating from a volt 60 cycle power supply. The ratio between worm gear 22 and worm 21 may be on the order of about 75 to 1 so that only one revolution of shaft 23 occurs for every 75 revolutions of motor shaft 13.

A typical wiring diagram is illustrated in FIGURE 5. Once the positions between actuating switches 30 and 31 have been set by means of the adjustment mechanism just described, the operation of the timer'assembly will be substantially as follows:

Closure of main switch MS 1 will energize the synchronous motor 12 through lines 80, 81, 82 and 83.

The motor will drive in a forward direction through terminal 84 and contact 86 until the switch 30 is actuated. It should be noted that contact 86 is controlled by relay coil 85.

Upon closure of movable switch 31, a circuit is completed through the reversing relay coil 85. Closure of this circuit moves contacts 86 and 87 into the normally open position associated with terminals 88 and 89.

Closure of contact 86 onto terminal 88 reverses current to the synchronous motor, thereby causing the motor to drive in the opposite, or reverse direction.

During this portion of the cycle contact 87, which is now in contact with terminal 89, holds relay coil 85 energized, thus sustaining drive of the motor in the reverse direction.

The motor runs in the reverse direction until timing switch 30 is actuated,

Timing switch 30 opens the holding circuit 'to relay coil 85, allowing contact 86 to return to its normally closed position in contact with terminal 84.

The return of contact 86 into its normally closed position causes the motor to reverse its direction of rotation.

The above cycle is repeated indefinitely until the master switch MS 1 is opened, thus terminating current to the reversing motor 12.

It should be noted that the timing switches 30, 31, are double pole, single throw switches. One set of poles are used to maintain continuous cycling as above described. The second set of poles are used to provide a continuously cycling timed impulse or interlock, or an alternating time impulse or interlock as desired.

Although a preferred embodiment of the invention has been illustrated and described it will at once be apparent to those skilled in the art that various modifications may be made within the spirit of the invention. Accordingly it is the intention that the scope of the invention be limited, not by the scope of the foregoing exemplary description, but solely by the scope of the hereinafter appended claims when interpreted in light of the pertinent prior art,

I claim:

1. Apparatus for generating timed signals which may be imparted to a cyclical mechanism such as a reversing motor, comprising first and second switches located in spaced relation to one another, each of said switches, when actuated, generating a signal,

means supporting said first and second switches and carrying an actuator arcuately movable at a substantially constant rate of speed over substantially the entire distance between the spaced switches, and

means for varying the distance between the spaced switches, and thereby the time interval derived from movement of the actuator between the switches, said distance varying means including a switch supporting member carrying the first switch which is movable relative to the sec ond switch, and gear mean-s carried by the supporting means for moving the switch supporting member, and the first switch carried thereby, independently of movement of the actuator.

2. The apparatus of claim 1 further characterized in that the gear means includes a powered coarse adjustment means and a manual fine adjustment means for moving the switches relative to one another.

3. The apparatus of claim 2 further characterized by and including a reading indicator associated with the gear means and operable to indicate adjustment by both the coarse adjustment means and the fine adjustment means.

4. The apparatus of claim 2 further characterized in that powered coarse adjustment means includes a motor powered gear train and further including means for disconnecting one adjustment means when the other operates.

5. The apparatus of claim 2 further characterized in that the manual fine adjustment means includes manually actuated gear train means and further including means for disconnecting the manual adjustment mean-s during operation of the coarse adjustment means 6. The apparatus of claim 4 further characterized in that the means for disconnecting one adjustment means when the other operates includes a shaft carrying a gear which is slidable into and out of meshing engagement with a gear train common to both the coarse adjustment means and manual adjustment means, and

yieldable means for norm-ally holding the gear out of engagement with the gear train.

7. The apparatus of claim 2 further characterized in that the switch supporting member is rotatable about the axis which carries the actuator.

8. The apparatus of claim 7 further characterized in that the switch supporting member and actuator are coaxial and co-exten-sive, one rotating about the other.

9. The apparatus of claim 8 further characterized in that the switch supporting member rotates about the actuator.

10. In combination,

a reversible motor and a reversing circuit therefor,

a pair of switches disposed in spaced relationship to one another operatively associated with the reversing circuit,

each switch, when actuated, causing a reversal of the direction of rotation of the reversible motor,

a switch actuating member operatively driven by the reversible motor,

means for moving the switch actuating member along a substantially circular arc of travel between the pair of switches and into actuating relationship with first one and then the other switch,

means for varying the arcuate distance between the switches including a powered coarse adjustment means and a manual fine adjustment means, and means for disconnecting one adjustment means when the other operates.

11. The combination of claim 10 further including structure for operating the arcuate distance varying means during movement of the actuator.

References Cited by the Examiner UNITED STATES PATENTS 2,556,095 6/1951 Loewenstein 20038 BERNARD A. GILHEANY, Primary Examiner. G, MAIER, H. E. SPRINGBORN, Assistant Examiners,

Claims (1)

1. APPARATUS FOR GENERATING TIMED SIGNALS WHICH MAY BE IMPARTED TO A CYLCICAL MECHANISM SUCH AS A REVERSING MOTOR, COMPRISING FIRST AND SECOND SWITCHES LOCATED IN SPACED RELATION TO ONE ANOTHER, EACH OF SAID SWITCHES, WHEN ACTUATED, GENERATING A SIGNAL, MEANS SUPPORTING SAID FIRST AND SECOND SWITCHES AND CARRYING AN ACTUATOR ARCUATELY MOVABLE AT A SUBSTANTIALLY CONSTANT RATE OF SPEED OVER SUBSTANTIALLY THE ENTIRE DISTANCE BETWEEN THE SPACED SWITCHES, AND MEANS FOR VARYING THE DISTANCE BETWEEN THE SPACED SWITCHES, AND THEREBY THE TIME INTERVAL DERIVED FROM MOVEMENT OF THE ACTUATOR BETWEEN THE SWITCHES, SAID DISTANCE VARYING MEANS INCLUDING A SWITCH SUPPORTING MEMBER CARRYING THE FIRST SWITCH WHICH IS MOVABLE RELATIVE TO THE SECOND SWITCH, AND GEAR MEANS CARRIED BY THE SUPPORTING MEANS FOR MOVING THE SWITCH SUPPORTING MEMBER, AND THE FIRST SWITCH CARRIED THEREBY, INDEPENDENTLY OF MOVEMENT OF THE ACTUATOR.

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