US2521693A - Timing mechanism - Google Patents

Description

Sept. 12,1950 R. L. CQULTRIP TIMING MECHANISM Filed May 9, 1947 Sheets$heet 1 INVENTOR.

Sept. 12, 1950 R. L. COU LTRIP TIMING MECHANISM Filed May 9, 1947 Patented Sept. 12, 1950 TIMING MECHANISM Raymond L. Coultrip, Milwaukee, Wis., assignor to Perfex Corporation, Milwaukee, Wis., a corporation of Wisconsin Application May 9, 1947, Serial No. 746,941

10 Claims. 1

This invention relates generally to a control device capable of producing timed operating periods, and more particularly to a device for effecting periodic operation of any desired means, for example, a'fuel feeding means such as an automatic coal stoker. The primary object of this invention being to provide a compact, easily adjustable timing mechanism for controlling such a means.

A further object of this invention is to provide a timing mechanism wherein both the frequency and duration of the timed operating periods may be easily and accurately adjusted.

A further object of this invention i to provide a timing mechanism which can be manually operated to produce an operating or nonoperating period of a fuel feeding or other means independently of the timed sequence of such periods.

A further object of this invention is to provide a timing mechanism having a face panel upon which all timing adjustments can be made, the face panel and all adjustment parts protruding therefrom being electrically dead, thus eliminating the possibility of electrical shock to the person adjusting the timing mechanism.

Still another object of the present invention is to provide a commercially satisfactory timercam actuated switching mechanism which is inherently effective to accomplish one or more of the aforementioned objects and which can be readily manufactured at a favorably competitive cost.

Numerous other objects and advantages of this invention will become apparent from the following detailed description and drawing, wherein,

Fig. 1 represents a front view of a mechanism embodying the invention, with a portion cut away to permit positioning of additional views;

Fig. 2 is a sectional view of the mechanism shown in Fig. 1 and taken generally along the lineII-II of Fig. 1, with portions cut-away to permit positioning of additional views;

Fig. 3 is a sectional view of the mechanism shown in Fig. 1 taken generally along the line 111-411 of Fig. 1;

Fig. 4 is a view taken generally along the line IVIV of Fig. 3;

Fig. 5 is a view similar to Fig. 1 with portions of the face plate and cam broken away to show alternate positions of the control switches;

Fig. 6 is a sectional view taken generally along the line VIVI of Fig. 5 showing the construction and operation of one of the control switches;

Fig. 7 is a sectional view taken generally along the line VII-VII of Fig. 4 showing the construction and operation of another of the control switches;

Fig. 8 is an enlarged detailed view of aportion of the cam and switch shown in Fig. 7;

Fig. 9 is an exploded view of the timing mechanism;

Fig. 10 is a front view of the cam shown in Fig. 9;

Fig. 11 is a front view of the ratchet wheel shown in Fig. 9;

Fig. 12 is a sectional view of the cam taken generally along line XII-XII of Fig. 10 with the ing and adjusting electrical circuit controlling switch mechanisms.

Referring now to Figs. 1, 2, 3, and 9, a, face plate III has secured thereto by rivets II a U- shaped bracket I2 which in turn carries spacers l3 and bolts l4 mounting conventional driving means comprising a small synchronous motor and enclosed gearing mechanism [5. This driving means is not described in detail since it forms no part of the present invention. A cupshaped member l6 has a D-shaped hole in its closed end into which the out-put shaft l8 of the motor I5 extends, a portion of the shaft l8 being D-shaped in cross section. A connecting member I9 has a hole in one of its ends which receives the shaft l8 and extends into the cupshaped member IS. The member I9 and member I6 are securely fastened together and prevented from rotating relative to each other by the splined portions 20 and 2| of the connecting member l9 and cup-shaped member l6 respectively, as may be seen in Fig. 9. The intermediate portion of member I9 is surrounded by a bushing 22 which extends through a hole 24 in the face plate l0 and is provided with a shoulder 23 (see Fig. 9) which is rigidly fastened to plate ID in any suitable manner. One end of the bushing 22 abuts the outwardly flanged base of the cup-shaped member IS. A switch supporting bracket 26 has a hole therein through which the bushing 22 extends, the bracket 26 being free to rotate upon the shoulder 25 of bushing 22. A circular cam member 21, having arcuate, circumferentially spaced, indented portions or cam portions "and 29 therein is supported on the member IS in a manner permitting rotation of cam member 21 independently of and relative to member i9.

Ratchet means comprising wheel 3| having pe-' of member i9. The knob 34 has ribbed portions 35 which extend into openings 31 (see Fig. 10) in the cam 21.

Referring now to Figs. 4, 6, 7, and 9, a control switch 39 is mounted on the bracket 25 by means of rivets 40. The switch 39 includes a body portion 4| formed of suitable electrical insulating material and mounting a reciprocable follower part or pin 42 which extends therethrough and is also made of suitable electrical insulating material. One end of pin 42 abuts the cam member 21-and its other end abuts a resilient contact carrying strip 43 which is secured to switch body 4| by a rivet 44 and carries a contact 45, the latter coacting with a fixed contact 45, also mounted on switch body 4| by means of bracket 48 and rivet 49. Resilient member 43 and bracket 48 are provided with tabs 50 and 5|, respectively, providing suitable points for electrical connection to the switch. The pin 42 extends through a supporting collar 52, which is part of the switch body 4|, and the collar 52 and pin 42 are adapted to extend through an arcuate slot 53 in the face plate ||I (see Fig. 9). Bracket 25 is provided with an integral L-shaped depending tab 54 having a portion which extends through an arcuate slot 55 in the face plate l0.

A control switch 51 (Fig. 7) is secured to a supporting arm 58 by rivets 59, the arm 58 being pivotally mounted on the rear side of the face plate ID by means of the pivot pin 50. This switch is similar to the switch 39, having a body rivet 55. A fixed contact 55, carried by a bracket 51 secured to the switch body 5| by rivet 58, coacts with the contact 18 carried by the resilient member 54. Member 54 and bracket 51 are provided with extending tabs 1| and 12, respectively, providing suitable electric connecting points. The free end of arm 58 is oilset from the body thereof and extends through a slot 13in the face plate I. An L-shaped resilient piece 15 is fastened to the end of arm 58. The other end bears securely against the inner edge of the slot 13. A small tension spring 15 (Fig. 4) which is fastened to arm 58 and to an ear 11 struck from base plate In, tends to bias arm 28 to its lower position in slot 13.

In operation, motor driven shaft |8 rotate at a suitable speed, for eicample, one revolution per hour and through its driving connection with parts It and |9 and ratchet wheel 3|, cam member 21 is also rotated at the same speed and in the same direction. With the arm 58 at the bottom of the slot 13, which is the "one half hour position designated by the lower marking on the face of base plate in (Fig. 1). The broken line position is shown in Fig. 5. Pin 52 will be positioned opposite that portion of cam member 21 placing the pin in the path of both the wide cam portion 28 and the narrower cam portion 29. Thus as cam member 21 rotates clockwise (see Fig. 1) the drop-off oi cam slot 28 will move to a point opposite the end of pin 52. When this occurs, resilient member 54 will move the pin 52 and close contacts 55 and 18 (see Fig.7)

With the bracket 25 positioned with its extending portion 54 disposed opposite the numeral 1" on scale 8| indented in face plate III, the switch actuating pin 42 is disposed substantially diametrically opposite the switch actuating pin- 52 across the cam member 21, and a, movement of bracket 25 to a position with its portion 54 tacts 45 and 45) is still held closed by pin 42..

If both of these switches are connected in series in a control circuit for a fuel feeding means (Fig. 13), a timer controlled on period for the fuel feeding means occurs only when both are closed. As the cam member 21 continues to rotate, the drop-off of cam slot 29 is moved opposite the end of pin 42. whereupon resilient member 43 moves pin 42 onto the cam portion 29 and opens contacts 45 and 45 (switch 39) thereby ending the on" period of the fuel feeding means. Continued rotation of cam member 21 causes the switches 39 and 51 to reset, the switch 51 slowly opening and the switch 39 slowly closing, as the sloped portion, of cam portions 28 and 29 move into contact with pins 52 and 42. Since the pin 42 is not diametrically opposite pin 52 across the cam member 21, the pin 52 will be moved, opening the switch 51 before the pin 42 is moved to close the switch 39, thus avoiding a momentary on period during the reset operation.

Scale 5| is marked to represent the duration of the on period in minutes. Thus with the tab 54 set at its solid line position and with the arm 58 set in the one half hour position, broken line position, (both shown in Fig. 5), an on period of the fuel feeding means will occur every half hour, since pin 52 is positioned to be successively engaged by both cam portions 28 and 29. The duration of the on" period will be approximately two minutes as indicated on scale 8|. If the tab 54 is moved to its broken line positionand arm 58 moved to solid line position (Fig. 5) the switch 39 will be moved clockwise about the axis of rotation of cam 21, and switch 51 will be moved radially away from the center of cam member 21. As a mult, pin 42 will then be displaced to a greater distance from a point diametrically opposite pin 52 across the cam member 21, and the pin 52 will be displaced radially a greater distance from the center of cam member 21. Pin 42 will continue to be engaged by both cam portions, but pin 62 will now be out of the path of cam portion 29, as may be seen in Fig. 8. Thus pin 92 will be engaged by portion 29 only, and an on period will be initiated only once in every revolution of cam member 21, or once every hour. The duration of the "on period will be increased to six minutes, as indicated on scale 3!, because of the relatively greater distance cam portion 29 must travel before engaging pin 42.

In this connection it should be particularly noted (see Figs. 4, 6, and 7) that when a timing mechanism such as is hereinbefore described is incorporated in a control circuit as indicated in Fig. 13, the movement of cam follower (pin 82) into an indented cam portion abruptly closes the circuit including switches 39 and 51 and that the subsequent movement of cam. follower (pin 42) into the indented cam portion diametrically opposite that engaged by follower 92 results in an abrupt opening of switch ,39 and of such circuit. And it should now be apparent that following an abrupt opening of switch 39 with arm 58 positioned to effect a one half hour timing interval, a continued rotation of cam member 21 operates through cam portions 28, 29 and through followers 42 and 62 to first gradually open switch 51, to then gradually close switch 39, and to thereafter abruptly close switch 51 as above described. When arm 58 is positioned to effect a one hour timing interval, only follower 42 engages both cam portions 28 and 29 during each revolution of member 21. And as a result, switch 39 gradually closes, abruptly opens and again gradually closes during the interval between the gradual opening and abrupt closing of switch 51. Stated differently, the closing and opening of a load circuit including the timer actuated switches 39 and 51 is always effected with a positive snap action, thereby eliminating the arcing or frying contact action inherently present when load carrying contacts are opened or closed by a slow-moving simple cam structure. This much of the timercam actuated switching mechanism, as well asthe means for adjusting the position of switch 39, affords in general the same functions and advantages as that disclosed and claimed in J. A. Deubels co-pending application, Serial No. 746,107, filed May 5, 1947, but differs therefrom as to the novel and improved nature of the apparatus employed.

During initial starting or later adjustment of the fuel feeding means, it may be desirable to manually initiate or terminate an "on period. This may be readily jdone by manually turning knob 34 clockwise, which, through the ribs thereon and holes 31 in the cam 21, rotates cam 21 clockwise thereby actuating switches 51 and 39. The projections 32 on ratchet wheel 3| are so formed that the cam 21 may overrun the ratchet wheel 3i in clockwise direction, allowing the cam 21 to be manually rotated independently of the ratchet wheel 3|. The manual rotation of knob 34 is thus not transmitted to the gear mechanism, which is therefore not subject to the weakening and wearing effect of forcing the gears to rotate at a speed faster that that at which they are rotatedby the motor. Knob 34 has finger grips 85 cut in the end thereof, which permit it to be easily rotated in clockwise direction, but difficult to rotataig counter-clockwise direction. This arrangemeiFt is desirable since rotation of knob 34 countergclockwise would also rotate ratchet wheel 3| and force the gear mechanism.

Since such timing mechanism as presently described is often located in the basements of dwellings which may frequently be damp and wet, the possibility of uncomfortable or even danserous electrical shock to the persons adjusting the timing mechanism should be guarded against. This is done in the presently described device by utilizing a construction wherein no portion of face plate It, arm 58, knob 34, cam 21, or bracket 29 forms a part of the electrical circuit of the switches. An electrically dead front is thus provided; that is, if the face plate In is grounded, the face plate and all the parts projecting therefrom remain at ground potential during actuation of the switches.

It will also be noted that the component parts of the presently described device, including the cam member 21, and the switches 39 and 51, may be easily removed and replaced should this prove necessary. And it should now be apparent that in accordance with this invention only a few parts of simple design are required to construct an apparatus affording all of the advantages hereinbefore mentioned and that such an apparatus is obviously extremely durable and trouble free and can be readily manufactured with a minimum of time, effort, and skill,

In addition it should be apparent that certain of the features of construction and certain of the combinations of parts herein described are applicable to timing switches other than the fuel feeding device timing switch above mentioned, and that apparatus embodying the invention may vary considerably from that herein shown and described for the purposes of illustration. It should therefore be understood that it is not intended to limit the invention to the exact construction and/or combinations of elements shown and described herein, as various modifications within the scope of the appended claims may occur to persons skilled in the art.

\Vhat is claimed is:

1. In a timing mechanism, a rotatably mounted cam member having circumferentlally spaced cam portions of differing widths engageable with follower parts disposed at different radial distances from the axis of rotation of said member, control switches mounted for actuation by said cam member and including separate cam follower parts engaged therewith, one of said follower parts being relatively adjustable radially of the axis of rotation of said member and another being angularly adjustable about said axis, and a driving means for rotating said member.

' j 2. In a timing mechanism, a rotatably mounted disc-like cam member having circumferentially spaced arcuate-shaped cam portions of materially different radial widths, control switches mounted for actuation by said cam member and including circumferentially spaced cam follower parts engaged therewith, said follower parts being relatively adjustable both radially of the axis of rotation of said member and angularly about said axis, and a driving means for rotating said member.

3. A timing mechanism comprising a face plate, a disc-like cam member rotatably mounted on said plate in closely opposed relation to one side thereof and presenting circumferentially spaced cam portions, said face plate having spaced openings therethrough adapted to expose said cam portions, switches adjustably mounted on the other side of said face plate and adjacent said openings for relative angular movement about the axis of rotation of said member, said switches including cam followerparts projecting through said openings and en- 8881118 said cam member for actuation thereby, means protruding from said one side of said face plate for manually angularly adjusting the position of one of said switches, and a driving means carried by said face plate in adjacent relation to said other side thereof and having an operative driving connection with said cam member.

4. A timing mechanism comprising a face plate, a disc-like cam member rotatably mounted on said plate in closely opposed relation to one side thereof and presenting circumferentially spaced cam portions engageable with follower parts disposed at different radial distances from the axis of rotation of said member, said face plate having spaced openings therethrough adapted to expose said cam portions, switches adjustably mounted on the other side of said face plate and adjacent said openings for relative movement radially of and angularly about said axis, said switches including cam follower parts projecting through said openings and ens tion, said switches including cam follower parts Projecting thro eh said openings in said face plate and engaging said cam member for actuagaging said cam member for actuation thereby,

means protruding from said one side of said face plate for manually independently adjusting the radially and angularly movable ones of said switches, and a driving means carried by said face plate in adjacent relation to said other side thereof and having an operative driving connection with said cam member.

5. A timing mechanism comprising a generally plane face plate, a disc-like cam member rotatably mounted on said plate in closely opposed relation to one side thereof and presenting circumferentially spaced cam portions, said face plate having spaced openings therethrough adapted to expose said cam portions, a firstswitch pivotally mounted on the other side of said face plate for movement radially of the axis of rotation of said cam member, a bracket and a second switch mounted thereon, said bracket being pivotally mounted on said other side of said face plate and pivotally movable about said axis of rotation, said switches including cam follower parts projecting through said openings in said face plate and engaging said cam member for actuation thereby, means protruding from said one side of said face plate for manually moving said first switch radially of said axis of rotation and for manually moving said bracket and said second switch about said axis of rotation, a driving means carried by said face plate in adjacent relation to said other side thereof comprising a ratchet wheel mounted adjacent said cam member and rotated by said driving means, said ratchet wheel having projections thereon engageable with corresponding openings in said cam member for transmitting rotation of said driving means thereto, and means for manually rotating'said cam member independently of said driving means.

6. A timing mechanism comprising a face plate, a disc-like cam member rotatably mounted on 'said plate in closely opposed relation to one side thereof and presenting circumferentially spaced cam portions, said face plate having spaced openings therethrough adapted to expose said cam portions, 9. first switch pivotally mounted on the other side of said face plate for movement radially of the axis of rotation of said cam member, a bracket and a second switch mounted thereon, said bracket being pivotally mounted on said other side of said face plate and pivotally movable about said axis of rotation thereby, means protruding from said one side of said face plate for manualiy'moving said first switch radially of said axis of rotation and for manually moving said bracket and said sec-' ond switch about said axis of rotation, and a driving means carried by said face plate in adjacent relation to said other side thereof and having an operative driving connection with said cam member.

7. A timing mechanism comprising a generally plane face plate, a disc-like cam member rotatably mounted on said plate in closely opposed relation to one side thereof and presenting circumferentially spaced cam portions, said face plate having spaced openings therethrough adapted to expose said cam portions, 8. first switch pivotally mounted on the other side of said face 'platefor movement radially of the-axis of rotation of said cam member, a second switch mounted on said other side of saidface plate for movement circumferentially aboutsaid axis of rotation, said switches including cam follower parts projecting through saidopenings insaid face plate and engaging said cam member for actuation thereby, means protruding from said one side of said face plate for manually moving said first switch radially of said axisof rotation and for manually moving said second switch circumferentially about said axis of rotation, and a driving means carried by said face plate in adjacent relation to said other side thereof and having an operative driving connection with said cam member.

8. A timing mechanism comprising a generally plane face plate, a disc-like 'cam member rotatably mounted on said plate in closely opposed relation to one side thereof and presenting circumferentially spaced cam portions, said face plate having spaced openings: therethrough adapted to expose said cam portions, 9. first switch pivotally mounted on the other side of said face plate for movement radially of the axis of, rotation of said cam member, a second switch mounted on said other side of said face plate for movement circumferentially about said axis of rotation, said switches including cam follower parts projecting through said openings in said face plate and eng ing said cam member for actuation thereby, means for manually moving said first switch radially of said axis of rotation and for manually moving said second switch circumferentially about said axis of rotation, and

a driving means having an operative driving connection with said cam member.

9. A timing mechanism comprising a face plate, a disc-like cam member rotatably mounted on said plate and presenting circumferentially spaced cam portions, a first switch pivotally mounted on said face plate for movement radially of the axis of rotation of said cam member, a bracket and a secondswitch mounted thereon, said bracket being pivotally mounted-on said face plate and pivotally movable about said axis of rotation, said switches including cam follower parts engaging said cam member for actuation thereby, means for manually moving said first switch radially of said axis of rotation and for manually moving said bracket and said second switch about said axis of rotation, a driving means including a ratchet wheel mounted adjacent saidcam member and rotated by said driving means, said cam member having a series a disc-like cam member mounted for rotation 10 by said driving means and presenting circumi'erentially spaced cam portions having diflering radial dimensions, a first switch pivotally mounted for adjustment radially of the axis of rotation of said cam member, a second switch movably mounted for adjustment circumferentiaily about said axis of rotation, said switches including cam follower parts engaging said cam member for actuation thereby, means for manui0 ally displacing said first switch radially of said axis of rotation and for manually displacing said second switch circumi'erentiaily about said axis of rotation.

RAYMOND L. COULTRIP.

aEEEnEscEs crTEn The following references are of record in the fiieof this patent:

UNITED STATES PATENTS Number Name Date 1,886,492 Shoemaker et al. July 5, 1932 2,202,077 Arthur May 28, 1940 2,203,236 Randolph June 4, 1940 2,238,097 Blain Apr. 15, 1941 2,302,626 Gallagher Nov. 17, 1942 2,326,002 Baak Aug. 3, 1943 2,364,519 Coiiman Dec. 5, 1 944

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