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Publication numberUS2545719 A
Publication typeGrant
Publication dateMar 20, 1951
Filing dateMar 3, 1948
Priority dateMay 17, 1946
Publication numberUS 2545719 A, US 2545719A, US-A-2545719, US2545719 A, US2545719A
InventorsReuben Wedeberg
Original AssigneeStewart Warner Corp
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Timing mechanism
US 2545719 A
Abstract  available in
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Claims  available in
Description  (OCR text may contain errors)

Mach 20, 1951 R. wam-:BERG

TIMING MECHANISM 2 Sheets-Sheet 1 Original Filed May 17 1946 March 20, 1951 R. WEDEBERG I 2,545,719

TIMING MECHANISM Original Filed May 17, 1946 2 Sheets-Sheet 2 70 7 1 55 y@ il w,

Patented Mar. 20, 1951 TIMING MECHANISM Reuben Wedeberg, Los Angeles, Calif., assignor to Stewart-Warner Corporation, Chicago, Ill., a corporation of Virginia Original application May 17, 1946, Serial No.

3, 1948, Serial No. 12,807

9 claims. 1

The present invention relates to timing mechanisms, and more particularly t an electrically operated timing mechanism which is adjustable to control the frequency and duration of energization oi control circuits for intermittently operable appliances or systems.

One object of the invention is to provide a new 'and improved electrically operated timing mechanism for automatically controlling intermittently operable devices or systems.

Another object of the invention is to provide a timing mechanism for automatically controlling the duration of operation of intermittenth7 operable devices 01 systems.

A further object of the invention is to provide a new and improved timing mechanism which is readily adjustable to vary the frequency of 0peration of intermhtently operable devices or systems.

A still further object of the invention is to provide a timing mechanism which is readily adjustable to vary the duration oi each period of intermittent operation of intermittently operable devices or systems.

It is also an object of the invention to provide a timing mechanism of generally improved construction which is simple and inexpensive to construct, assemble, and install, but which nevertheless is durable, reliable in operation, and readily adaptable to various uses.

More specifically it is an object of the invention to provide a timing mechanism having a cam assembly for controlling the frequency of operation which includes a cam disc of symmetrical profile and a masking disc therefor of irregular prov le adapted to be angularly adjusted relative to the cam disc to mask the symmetrical Drole symmetrically and thus provide for operation at regular intervals, and which timing mechanism also has a duration cam assembly that is adjustable to vary the duration of each period of operation of the controlled system or device.

Another object of the invenion is the provision of a timing mechanism which includes adjustable frequency and duration cam assemblies, each of which operates switch means arranged in series with respect to each other and the energizing circuit of the controlled mechanism or system so that the controlled circuit is energized only when the cam assemblies operate to close both switches simultaneously.

Other objects and advantages of the invention will appear from the following description taken in connection with. the drawings, in which:

Fig. l is a irc-nt elevation of the timing mechanism which is the subject of the invention;

Fig. 2 is a rear elevational view of the timing mechanism shown in Fig. l;

Fig. 3 is a face view or a frequency cam disc of the type used in the timing mechanism of the Divided and this application March present invention, with a masking disc associated therewith in assembled relation;

Fig. 4 is a face view of the masking disc;

Fig. 5 is a face view of the duration cam disc for the timing mechanism and its masking disc in assembled relation;

Fig. 6 is a face view of the masking disc .for the duration cam Fig. 7 is a sectional view taken diametrically through the frequency cam, the duration cam and their masking discs as assembled on their coaxial drive shafts; and

Fig. 8 is a schematic wiring diagram of an electrically operated system in which the timing mechanism of the present invention is adapted to be used.

The present application is a division of my copending application Serial No. 670,467, iiled May 17, 1946, and entitled Timing Mechanism. That application discloses an intermittently operating electrically controlled centralized lubricating system, operation of which is automatically controlled by a timing mechanism. The timing mechanism of the present invention is particularly adapted for controlling operation of a lubrieating system of the type disclosed in the above mentioned application, but it is to be understood that it may be readily adapted to the control of various other controlled devices and systems, both in the lubrication iield and elsewhere which are to be energized periodically for a predetermined interval of time particularly where it may be desirable to vary the frequency of energizetion or the duration of each period of energize,- tion of the controlled apparatus.

The general layout of the timing mechanism is shown in Fig. 1 wherein a base comprising a panel board lu is shown for supporting the elements of the timing mechanism. Upon the back of the panel I0 is secured an electric clock indicated at I2 in Fig. 2. The clock is driven by a synchronous motor of conventional construction which has the usual shafts I4 and I6 telescopically arranged as best seen-in Figs. l and 7.

Preferably the shaft I 4 corresponds to the hour hand shaft of a clock and for the purpose of this invention makes one revolution in twenty-four hours, while the shaft I6 corresponds to that which drives the minute hand of a clock and makes one revolution each hour. Instead of an hour hand, the shaft I4 carries a frequency cam disc I 8 which determines the intervals or frequency at which the timing mechanism effects energization of the circuits controlled by it, and instead of a minute hand the shaft I6 carries a duration cam disc 20 which determines the duration of the interval that the controlled circuits are energized. Each of these discs has peripheral notches or recesses for actuating electric switches. Associated with the frequency cam I8 3 is a masking disc I9, while the duration cam has associated with it a masking disc 2|, these masking discs being adjustable to determine which of the recesses or notches of the cams shall be operative at any given time.

The frequency cam I8; as shown, has a symmetrical profile defining twelve notches or recesses 22 spaced at equal intervals to form symmetrically arranged dwells so that a stationary follower element cooperating therewith will be actuated every two hours as the cam I8 rotates. The masking disc I9 associated therewith is formed as shown in Fig. 4 with peripheral recesses irregularly arranged so that it can be adjusted with respect to the disc I8 and mask the symmetrical recesses' 22 symmetrically to provide for operation of the system either at two hour intervals, at four hour intervals, at eight hour intervals, at twelve hour intervals, or only once in each twenty-four hours. If the controlled sys- I operation at less frequent intervals is desired, the f disc I9 may be shifted so that certain portions of its periphery will cover certain of the notches 22, leaving less than twelve of them effective for actuating the follower associated withthe disc.

As shown in Fig. 3, the disc I9 is adjusted to uncover only three of the notches 22, thus providing for operation of the devices or system controlled by the timing mechanism at eight hour intervals.

As shown in Fig. 7, the frequency cam disc I8 is rigidly secured to a hub 23 which is fixed to the hollow shaft I4 by a set screw 24. The masking disc I9 is rotatably mounted on the hub 23 but is held in face to face contact with the cam disc I8 by means of a coil spring 26 on the hub. A small boss or detent projection 29 on the face of the disc I9 is adapted to fit in any one of ve openings 28 in the disc I8,.which openings. are marked respectively with the numerals 24, l2, 2, 9v and 4, as shown in Fig. 3, to designate the intervals' at which the system will be operated when the masking disc is adjusted with its detentprojection 29v in the respective openings. To facilitate such adjustment, the masking disc I9. is provided with diametrically projecting, lugs 30 which may be grasped between the'thumb and nger when it is desired to force the disc |9 away from the disc I8 (against the. pressure of the spring 26) and thus release the projection 29 from the opening 28 in which it is engaged, so that the masking disc may be rotated to register the projection with another opening 28.

The duration cam disc 20, as shown in Fig. 5, has a series of peripheral notches or. recesses. 32 which differy in circumferential extent and are effective to limit operation of the controlled systemor device, respectively, to periods of one to five minutes. In other words, a follower device onl the switch which controls energization ofthe circuit of the controlled device orV system drops into one of the notches 3'2 and the device or system continues to operate until the follower is `cammed outv cf the notch. To determine which of the notches 32 shall be effective, the masking disc 2|, which is associated with the cam disc 29, has a plain peripheral portion 34 and a single notch 3 I, which is of the same width as the widest of the notches 32. By rotative adjustment of the disc 2|' with respect to the cam disc 2|), this notch. 3| may be registeredwith any of the several notches 32'so as to expose a selected one of them while the plain circular portion 34 of the disc 2l covers the remaining notches 32.

For a special purpose, to be later explained, the masking disc 2| has an additional notch 35 with a leading edge 35a disposed diametrically opposite the middle of the notch 3|. Opposite the notches 32 the cam disc 20 has a portion 31 of reduced diameter so as to expose or uncover the notch 35 at any of the several positions of adjustment of the masking disc with respect to the cam disc. At each of these positions of adjustment, the notch 3| is centered with respect to the notch 32 which it exposes; consequently the leading edge of the notch 35 is always disposed diametrically opposite the uncovered notch 32 so that the follower of a control device positioned to engage in the notch 35 will do so at the middle ofthe timing period represented by the active or exposed notch 32'.

The cam disc 20 has an opening 38 opposite each of the notches 32 and the masking disc 2| has a small boss` or projection 39 adapted to enter any one of the openings 38 when the disc 2| is suitably adjusted about its axis. As seen in Fig. '7, the disc 2| is xed to a hub 33 by curling over` the end of the hub, and the hub is secured to the shaft I5 by a set screw 5|. A coil spring 35 on the hub presses the cam disc 20 into face to face contact with thedisc 2|. The cam disc is rotatable on the hub and is provided with radial lugs or finger pieces 40, by means of which it'may be pulled forward out of contact with the disc 2|, sufficiently to release the detent boss 39 from the opening 38 in which it is engaged so that the disc 2| may be rotated and the boss 39 brought into registry with another of the openings 38. In Fig. 5 the openings 38 are marked, respectively, I-M, 2-M, 3-M, 4-M and 5-M to indicate that the notches will effect operation of the controlled device or system for periods of from one to five minutes, respectively, and as shown, the detent 39 is registered in the opening 38 corresponding to the three-minute period.

Since the cam discs I8 and 25 are similar in size and are secured in axially aligned closely spaced relation with the disc 28 and its' masking disc 2i located in front of the frequency cam I8, means are provided for facilitating observation of the numbers on the frequency cam disc I8 so that the adjustment for frequency can be made readily. Preferably this means comprises segmental windows III and e2 in the discs 23 and 2|. respectively, which may be registered with each other by rotating the discs with respect to each other. Thereafter they may be rotated together until the Windows are brought opposite the openings 28 in the disc I8 as shown in Fig. l, Since the openings 28 in the frequency cam I8 and the markings thereon will then be visible through the windows, the boss 29 on the masking disc I9 may be readily engaged in the desired opening v28 in ie cam disc I8 after which the discs 28 and 2| may be adjusted' relative to each other as desired.

In addition to the clock I2 and the timing cams just described, the panel I8 supports three switches 59, 52 and 54 suitably secured to the rear face of panel I EI as indicated in Fig. l. Switch 59 has a follower arm 5t which engages upon the periphery of the frequency cam I8 while the .switches 52 and 54 have followers 59 and 68, respectively, which engage the duration cam 29, the switches being so mounted that the cam is engaged at diametrically opposite points on its periphery as indicated in Fig. 1. These switches control the supply of current to the circuits which are to be controlled, and for the purpose of illustrating the operation of my improved timing mechanism a schematic circuit diagram in which these switches are incorporated is shown in Fig. 8. This circuit is designed to control automatically the operation of the centralized lubricating system disclosed in my aforementioned copending application for patent. it is to be understood that the circuit is exemplary only of one adaptation of my timing mechanism to the control of a system and that the timing mechanism may be used for controlling various other electrically controlled systems or devices.

In Fig. 8 lead wires 62 and 64 designate the source of current supply which is controlled by a manually operated master switch 56. rlhe clock and the frequency and duration cam assemblies along with the switches operated thereby are designated by the same numerals as previously used to designate these parts. At 58 a solenoid operated valve for controlling the how of air under pressure to the air motor of a lubricant compressor is indicated diagrammatically while the numbers 1B and 14 designate a pair of diagrammatically shown solenoid operated reversing valves between the lubricant compressor and the conduit system of the lubricating system.

The function of the timing mechanism and the solenoid operated valve 58 is to initiate operation of the lubricant compressor at predetermined in tervals and then to maintain such operations for a predetermined period of from one to iive minutes while the purpose ci the solenoid operated valves 1G and 14 is to reverse the flow of lubricant through the lubricating system when a circuit through the system is completed in one direction.

Whenever the master switch 6E is closed the clock motor l2 is energized from the leads 62 and 54 through conductors 18 and 8B and drives the frequency cam I3 and the duration cam 2B for as long as the switch 55 remains closed. As a result, the follower 55 on switch 55 will be brought into engagement with the exposed recesses 22 in the cam i8 with a frequency determined by the setting of the masking disc i9. When the follower drops into a recess it moves to close a contact 82 in the switch 5G. This contact is connected by a conductor 84 to a contact G5 in switch 52. Since the frequency cam can be set to become effective at intervals of two cr more hours, and the duration cam is driven by the clock motor i .2 at a speed to bring its exposed recess 32 to effective position once every hour, these cams and their masking discs can be readily adjusted so that the duration cam will become effective to close the switch 52 whenever the frequency becomes eiiective to close switch 5i] irrespective of the number of hours between closings of the latter switch.

Closing of the switch 52 completes a circuit from the contact 86 to the solenoid operated valve 68 by way of a conductor 88 and thence back to the main lead wire S2. Since the switch 56 is connected to the other main lead wire 54 by a conductor 9G, a circuit is energized which includes the main lead wire B4, conductor 9u, switch 50, contact 82, conductor 84, contact 85, switch 52, and conductor 88 leading to the solenoid operated valve 53. The other side of this valve is connected to the other lead wire 82 by a conductor 92 so that the solenoid operated valve is energized and initiates operation of the lubricant compressor which it controls.

The switch 52 is also connected by a conductor 94 to the third switch 54; and, since the follower 60 of this switch will be riding on the periphery 34 of the duration cam masking disc at the beginning of the period controlled by this cam, the movable contact of this switch will be held in a position to engage a contact in this switch. This contact 95 is connected `by a conductor 98 to one side of the solenoid operated reversing valve mechanism 1i?. The circuit for the latter is completed by conductors |04 and ll, the latter being connected to lead wire 62. Energization of the solenoid operated Valve 19, which will occur simultaneously with opening of the solenoid operated valve 53 for the compressor, causes the lubricant pumped by the compressor to flow in one direction through the conduit system to the various bearings to be lubricated. The time required for the lubricant to make a complete circuit of a conduit system can be determined and the recesses 32 in the duration cam 2i! may be so constructed that by the time this has occurred the duration cam will have been advanced by the clock sufficiently so that the follower 5S on switch 52 will be at the midpoint of the notch 32 with which it happens to be engaged. Since the edge 35a of the notch 55 in the duration cam masking disc is diametrically opposite the midpoint of the notch 3i in this disc, and the follower 58 of switch 52 is diametrically opposite the follower 553 of switch 54, the follower of this latter switch will drop into notch 35 at the time cam 2B has advanced to the point where follower 53 is at the midpoint of notch 32. By proper adjustment of the masking discs for the cams this may be made to coincide with the time that it takes lubricant to make a circuit of the conduit systems in one direction as will be understood.

Thereupon the arm of switch 54 will be shifted from Contact 9G to a contact 03 which is connected by a conductor H0 to one side of the second solenoid operated valve 14. The circuit for this solenoid back to the lead wire 62 is completed through a conductor H6 and conductor |66. Separation of the arm of switch 54 from contact 96 will deenergize solenoid 1f) and the engagement of the arm of this switch with contact |08 energizes the circuit for the solenoid 14. This effects a reversal in the position of the two valves and a resulting flow of lubricant through the conduit system in a direction opposite to that in which it had been iiowing.

The continued rotation of the duration cam disc 20 by the motor l2 will carry the notch 32 past the follower 58, and the notch 35 past the follower SD, so that the followers engage upon the periphery of their respective cams and masking discs. Tins opens the circuit to the solenoid operated valve 68 which controls operation of the compressor motor, and to the soleno-id voperated reversing valves 10 and 14 so that operation of the compressor is discontinued and no lubricant is delivered to the conduit system.

As long as master switch 66 is closed, the clock motor l2 will continue to rotate and will rotate the cam discs l and 20 so that the frequency disc I8 will eventually be turned far enough to carry the notch 22 in which the follower 56 of switch 5G happens to be engaged, past the follower, so that the latter will thus ride upon the periphery of the cam disc, thus moving the arm of switch 50 sufficiently to open the circuit through contact 82. Thereafter the lubricating system cannot again be energized until the frequency and duration cams have been rotated far enough by the clock motor to bring the followers 55 and 58 into engagement with exposed notches in their respective cams at the same time, and the frequency at which this occurs will of course depend on the setting of the masking disc for the frequency cam.

From the above description of the application of my improved timing mechanism to the control of a centralized lubricating system, it will be understood that the mechanism may be readily adapted to the control of other systems, devices or appliances which are to be operated `intermittently, particularly where it is desired to have a timing mechanism that can be adjusted to vary the time between periods of operation and also the duration of each period of operation. Almost unlimited variation in the sequence of operation of the devices controlled by the timing mechanism can be secured by the proper arrangement of the notches 22 and 32 in the frequency and duration cams I8 and 2D, and the notches in their masking discs, and then varying the setting of these discs as required.

It will also be recognized that while there is shown and described herein certain structure embodying the invention and illustrative thereof, the invention is not limited to the specific forms shown but embraces all changes and modifications in its various features and all equivalents thereof coming within the scope of the appended claims.

I claim:

1. In a timing mechanism, the combination comprising coaxially mounted front and rear cam discs, a masking disc for each oi said cam discs adapted to be disposed in contacting engagement with the rear face thereof, said cams and masking discs being rotatably adjustable with respect to each other, means for detachably Yfixing the rear cam and its masking disc against relative movement including a series of closely grouped detent apertures in said rear cam disc and a detent projection on said rear cam masking disc engageable selectively Iin said apertures by rotative adjustment of said cam and masking disc and visible through the aperture in which it is engaged, and registrable window apertures in said front cam and its masking disc adjustable by rotation of said discs to align said windows with each other and with series of apertures in the rear cam for observation therethrough, thereby to facilitate adjustment of the masking disc for said rear Cam..

2. In a timing mechanism, a cam disc having a peripheral cam outline, a masking disc therefor, a hub to which one of said discs is xed and upon which the other disc is rotatably adjustable, one disc having a series of detent apertures and the other disc having a detent projection adapted to engage selectively in said apertures, a spring on said hub to press said discs yieldingly in face to face contact to retain said projection in a selected aperture, radial arms extending from the rotatably adjustable disc beyond the peripheral outlines of both discs to facilitate manual manipulation of the disc in adjusting it.

3. In a timing mechanism, a clock, a frequency cam assembly driven by said clock including a cam disc having a prole dening symmetrically arranged cam dwells and a masking disc, said discs being' angularly adjustable relative to each other and said masking disc having an irregular prole including a series of dwells adapted at one position of adjustment of said discs to register with all the symmetrically arrangeddwells and at other positions of adjustment to register with a symmetrically arranged number of dwells in the cam disc greater than one and less than all, re-

Si leasable means for xing said discs against relative movement including a detent on one disc and a series of apertures in the other arranged to receive said detent for fixing said discs against relative movement at the aforementioned position,.a hub fixed to one of said discs, the other of said discs being rotatable on said hub, spring means on the hub for holding the discs in face-to-face contact and the releasable detent in disc fixing positions, and one or more radial arms on the disc rotatable on said hub to facilitate manual manipulation of the disc for adjusting the same.

4. In a timing mechanism, a clock, a duration cam disc driven thereby and having a series of circumferentially spaced apart peripheral recesses differing from each other in angular extent, a masking disc carried with said cam disc, said discs being rotatably adjustable with respect to each other and said masking disc having a peripheral recess at least equal in angular extent to the longest of the recesses in the duration cam whereby said masking disc may be adjusted to expose any selected one of said recesses of the duration cam, and detent means to retain the masking disc at each of such positions of the adjustment, said duration cam having an additional peripheral recess of angular extent at least equal to the total angular portion of the cam disc occupied by its said series of recesses, and the masking disc having a recess so positioned that one end of said recess is diametrically opposite the middle of any recess of the duration cam which the masking cam is adjusted to expose.

5. In a timing mechanism, a clock, a duration cam disc driven thereby and having a series of circumferentially spaced apart peripheral recesses differing from each other in angular eX- tent, a masking disc carried with said cam disc, said discs being rotatably adjustable with respect to each other and said masking disc having a peripheral recess at least equal in angular extent to the longest of the recesses in the duration cam whereby said masking disc may be adjusted to expose any selected one of said recesses of the duration cam, and detent means to retain the masking disc at each of such positions of the adjustment, said duration cam having an additional peripheral recess which has an angular extent at least equal to the total angular portion of the cam disc occupied by its said series of recesses, and the masking disc having a second recess so positioned that the one end of it is diametrically opposite the middle of its first mentioned recess.

6. A timing mechanism for controlling operation of intermittently operable devices or systems comprising a frequency controller including relatively adjustable cam and masking discs, one of which has a plurality of symmetrically arranged peripheral recesses and the other of which has peripheral recesses so arranged that at one position of relative adjustment of the discs one recess is unmasked and at other positions of adjustment a plurality of recesses are unmasked in symmetrical arrangement, a duration controller including relatively adjustable and masking discs having nonsymmetrically arranged recesses of Varying angular extent including rst and second recesses in said masking disc and a plurality of recesses of varying angular extent individually unmasked by the said rst recess in said masking disc upon selective adjustment of the latter and a single recess in said cam disc of sumcient angular extent to unmask the said second recess in said masking disc whenever the masking disc is.

at a position of adjustment at which the first recess therein unmasks one of said plurality of recesses in said cam disc, means to lock said cam and masking discs at desired positions of adjustment effective to cause said discs to rotate together, and means for driving said frequency and duration controllers at diiferent but correlated speeds.

'7. A timing mechanism for controlling operation of intermittently operable devices or systems comprising a frequency controller including relatively adjustable cam and masking discs, one of which has a plurality of symmetrically arranged peripheral recesses and the other of which has peripheral recesses so arranged that at one position of relative adjustment of the discs one recess is unmasked and at other positions of adjustment a plurality of recesses are unmasked in symmetrical arrangement, a duration controller including relatively adjustable cam and masking discs having nonsymmetrically arranged recesses of varying angular extent including rst and second recesses in said masking disc and a plurality of recesses of varying angular extent individually unmasked by the said first recess in said masking disc upon selective adjustment of the latter and a single recess in said cam disc of sufcient angular extent to unmask the second recess in said masking disc whenever the masking disc is at a position of adjustment at which the first recess therein unmasks one of said plurality of recesses in said cam disc, said second recess in the masking disc in said controller having one end which falls diametrically opposite the mid point of its rst recess, means to lock said cam and masking discs at desired positions of adjustment effective to cause said discs to rotate together, and means for driving said frequency and duration controllers at different but correlated speeds.

8. In a timing mechanism a duration controller comprising a cam disc having a series of circumferentially spaced apart peripheral recesses of varying angular extent, a masking disc having a rst peripheral recess at least equal in angular extent to the longest of the recesses in said duration cam, said cam and masking disc being selectively adjustable to positions at which the series of recesses in said cam disc are individually unmasked by the said recess in said masking disc, a recess in said cam disc independent of the series of recesses therein and of angular extent at least equal to the angle through which the masking disc must be moved to unmask the recesses on the opposite ends of said series, a second recess in said masking disc having one end dia-r metrically opposite the mid point of its first recess, said second recess coinciding with a portion of the said independent recess at all positions of selective adjustment of said discs, means to drive said cam disc and means on the confronting faces of said discs for locking said masking disc at said selective positions of adjustment effective to cause said masking disc to rotate with said cam disc including a projection on said masking disc diametrically aligned with the said end of said second recess, and apertures in said cam disc diametrically aligned with the mid point of said plurality of recesses in said cam disc adapted to receive said projection.

9. In a control system, a frequency controller including a pair of discs having peripheral recesses to dene cam dwells, said discs being relatively adjustable to bring the recesses therein into and out of coincidence for rendering the same effective, a duration controller including a pair of discs having peripheral edges containing recesses of different eifective lengths, said discs being relatively adjustable to bring the recesses therein into and out of coincidence and thereby individually to unmask the recesses of different effective lengths, and a second recess having a leading edge diametrically opposite the mid point of the first of said recesses which is unmasked, a source of electrical energy, a rst switch operated by the recesses in said frequency controller, a second switch operated by the recesses of different effective length in said duration controller, a circuit including said two switches and said energy source in series, and a third switch in said circuit in series with said first and second switches and having a pair of contacts adapted to be connected to a controlled mechanism, said third switch being operated by said second recess in the duration controller to open one of the contacts to which it is connected and close the other at the mid point in the eifective period of said first recess. y

REUBEN WEDEBERG.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,665,060 Hitchcock Apr. 23, 1928 2,278,452 Kocher Apr. 7, 1942

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US1665060 *Feb 5, 1927Apr 3, 1928Pittsburgh Plate Glass CoAutomatic control means for electromagnetic operating devices
US2278452 *Feb 26, 1937Apr 7, 1942Auto Research CorpLubrication
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US2982900 *May 22, 1956May 2, 1961Saia A GTiming device
US3030462 *Dec 11, 1958Apr 17, 1962Zenith Radio CorpSolar timing mechanism
US3678780 *Aug 26, 1970Jul 25, 1972Electrical Remote Control CoCam assembly
US3937910 *Apr 16, 1974Feb 10, 1976Jeco Kabushiki KaishaTimer having a variable operation period
US3988553 *May 9, 1974Oct 26, 1976Michael J. CozyLighting control
US4348568 *Oct 24, 1979Sep 7, 1982Eduard HermleSwitching mechanism
US4738336 *Apr 27, 1987Apr 19, 1988Honeywell, Inc.Controlled replenishing lubrication system
Classifications
U.S. Classification307/141.8, 184/7.4, 200/38.00R, 74/568.00T