US2638979A - Control device - Google Patents

Description

J. L. HARRIS CONTROL DEVICE Filed Aug. 2, 1948 uvymvron Patented May 19, 1953 UNITED STATES PATENT 2,638,979 OFF ICE CONTROL DEVICE John L. Harris, Whitefish Bay, Wis. Application August 2, 1948, Serial No. 42.119

This invention relates to automatic control apparatus and is more particularly concerned with timers of the manual reset type. The primary ob ject of the invention is to provide a timing mechanism which is simple and rugged in construction and which is easy to operatc'by the user.

A further object of the invention is to provide a timer in which the switch mechanism is operated at the end of the resetting stroke so as to eliminate the variable of the time of manual re setting.

A further object of the invention is to provide an interval timer mechanism which is adapted to be set for varying time periods or to accurately repeat predetermined periods for which the mechanism is set. 7

Another object of the invention is to provide an interval timer mechanism in which a-si-ngle switch or control device may be operated by the timing mechanism or may be operated independently of the timing mechanism.

Other objects will appear from the following detailed description and the appended claims.

For a full disclosure of the invention reference is made to the following detailed description and the accompanying drawings in which:

Fig. 1 is a front view of the timer mechanism;

Fig. 2 is a side view, partly in section, of the timer shown in Fig. 1;

Fig. 3 is a view of the switching mechanism when the pointer is in the Oii position;

Fig. 4 shows the switching mechanism when the pointer is in the on position;

Fig. 5 is a similar'view with the switching mechanism in the Lock-On position;

Fig. 6 illustrates the operation of the pointer to the On position-by resetting movement of the dial;

Fig. '7 is a wiring diagram.

' Referring particularly to Figures -1 and 2, reference character I indicates generally a-housing which may be of two-piece construction, including a front housing member 2 and a rear housing member 3. Located in the upper portion of the housing member I is a synchronous motor and gear train mechanism 4 which is of well known construction. This motor and gear train mechanism is supported on posts 5 which are secured to the front housing member 2. The synchronous motor includes a drive shaft 16 which extends through the housing member 2 and sup-ports a hub 7. The hub l'is secured to the shaft by a suitable set screw and is formed with a shank portion 8 and a head portion 111. This hub carries a dial. H and a reset member 12 which is located behind the dial. The dial and reset member are pressed against the head portion in of the hub by means of a sprlng'mem'ber l3 which isv formed with sharp surfaces adapted to bite into the shank portion 8 of the hub. This spring member provides a friction drive between the hub and the-dial and reset members. The reset member .12 carriesxa reset pin 1!. In the embodiment of the invention shown this pin consists of the shank portion :of a 'it'humb screw having a head 9 Glaims. (Cl. 161-1) IS. The head 15 as seen in Figure 1 overlaps the dial 1 i so that part of the thumb screw serves to clamp the dial and reset member together.

The dial-l I is provided with a pin 'I'B which extends inwardly for operating a pointer l 7 which is carried on a shaft I 8 extending through the front of the housing member'z. The rearen'do'f the shaft l8 receives a screw H! which is tightly threaded into the shaft andwhich passes loosely through a switch mounting plate 20 of insulating material. Thus the shaft 18 is journalled'in'the housing member 2 and the switch mounting plate 20; member 2 by meanso'f suitable screws 21, spacers- 22 and nuts 23. 1

As shown more clearly in Figures 3, 4 and 5 the shaft I8 carries a cam 24fwhich is arranged to operate a control device taking the form of a snap switch mechanism 25. This snap switch mechanism forms no part of the invention and is illustrated as including a base 26 which is supported on the mounting plate 20 bymean's'of suitable screws and nuts. An insulating member .21 is mounted between the snap switch mechanismand mounting plate 20 and as shown in Figure 2- the movable contact blade to assume the position in which the contacts are open. As-the cam is rotated to urge the cam follower member 2-8 to the left, it carries the 6 spring 29 over center causing the movable contact blad'e to snap to the position shown in Figure 4, for engaging the contacts.

The cam 24 :isalso arranged to operate a switch 33 in the circuitof the synchronous motor. This switch is .shown as consisting of a bracket 34 which is mounted on the panel ZU-and which car ries a switch-blade 35. This switch blade is of generally U shape and is adapted "at its free end to engage a pin 36 which serves as a stationary contact. Lit-will be noted that the parts areprm portioned so .thatwhen the pointer I7 is in either the position shown in Figure 3 or the position shown in Figure 4, this switch remains closed."-

When the pointer is moved to the position shown in Figure 5 the switch blade 35 disengages the fixed contact-or pin 38 for breaking the circuit to the timer motor. a l

Referring to Figure 7 this figure-shows the manner in which the control is wired. The cord 4) is provided with a plug, H for attachment in a standard electric :outlet. One side of this cord is connected to the timing motor 4 and-to one side of the receptacle 42 which is mounted in the side' of the housing. The other leg-o'f the cord m is attach'edto the switch 25, the other side-"o'fthis The plate 20 is supported on the housing motor must pass in series through the switches 25 and 33.

It should be noted that the pointer 11 is provided with a cam surface 44. For repeat operation of the control the operator loosens the thumb screw [5 and sets the reset member on the dial for the timing desired and retightens the thumb screw. The operator then rotates the reset member l2 in a clockwise direction as far as it will go and releases the reset member immediately. Asthe reset member approaches the end of its stroke the stud l4 engages the cam surface 44 of ;the, pointer l1 and by a caming action causes the pointer H to rotate clockwise to the position shown in Figure 6. In this position the stud [4 has reached the bottom of the cam surface which prevents further rotation of the reset member. During the reset movement of the reset member the dial rotates therewith and'thus carries the pin IS on the dial a certain angular distance away from the pointer I'l. Therefore the action of the reset member provides a predetermined angular relationship between the dial pin I6 and pointer I] for each adjustment of the reset member 12 with respect to the dial.

At the end of the resetting stroke the pointer ll assumes the On position as shown in Figure fi which causes the switch parts to assume the position shown in Figure 4. It will be noted in Figure 4 that a lobe '45 on the cam has caused the switch 25 to closeand that a lobe 46 on the camstill holds the switch 33 closed. The outlet receptacle for the timer is therefore energized for operating the appliance controlled by the timer. Also, the timing motor 4 is placed into operation at the end of the resetting stroke. The timing motor now operates in a counterclockwise direction causing the pin [6 on the dial to approach'the operating portion 4'! of the pointer. It will-be apparent that a counterclockwise rotationof the pin l6 after engagement with the pointer I! will cause rotation of the pointer from the On position to the Off position. The parts are arranged so that as the zero position on the-dial passes the center of the shaft Hi, the snap switch 25 opens for breaking the circuit to the appliance and to the timing motor. Thus the timer remains stationary until it is again operated manually. It will be apparent that this construction serves to provide for repeat operations in which the control may be set for a certain. timing and provide this timing for any number of operations.

The control may also be operated independently of the reset member I2 when the operator desires a different timing for each operation. In this case the dial is merely rotated so that the timing on the dial is indicated by the dot in the center of the screw 48 which fastens the pointer to the shaft 18. After the dial is set in this manner the pointer I1 is operated from Off to fOn. It will be apparent that the timing motor will be energized and operate the, pointer back to its Off position at the end of the set time.

In certain cases it is'desired to turn on the controlled appliance and to have the appliance stay on until manually turned off. When such operation is desired the-user rotates th pointer to the position marked Lock-On. The parts then assume the position shown in Figure 5 in which a. lobe 50" on the cam causes the switch 25 to reclose, thereby energizing; the appliance. At

this time the cam'lobe 45 is'disengaged from the switch blade 35, therefore permitting this switch blade to disengage the stationary contact 36 for breaking the timer motor circuit. The timer, therefore, is not in operation and the appliance will stay on indefinitely. While it is not'absolutely essential, it is preferable to design the cam and switch blade 35 so that the motor switch 33 opens before the switch 25 recloses in the Lock-On position. This prevents any possibility of the pointer 11 being left in an intermediate position in which the motor runs in the Lock-On position.

It should be noted that the pointer I1 is formed with a projection 5| which serves as a stop for the pin [6 on the dial even when the pointer is in the Lock-On position. This feature maintains the proper relationship between pin- [6 and stud M with respect to the'pointer so that the control is always in operating condition. It will be apparent that if the projection 51 were not present, it would be possible to move'the dial so that the pin l6 gets on the wrong side of the pointer. If the pointer 11 were then returned from the Lock-On to the Off position the control would not be operative until the parts are rearranged in proper relationship. The design of the pointer I l avoids the possibility of such an occurrence.

From the foregoing description it will be apparent that the present invention provides a simple and positive timing mechanism which is easy to understand and use on the part of the operator. It will also be apparent that the invention provides for repeat operations at the same setting by the use of the reset member [2. Also independently set operations may be obtained by first setting the dial to the timing desired and then operating the pointer from Oil to On. It will further be apparent that theinvention provides a simple arrangement for turning on the controlled appliance independently of the timing mechanism. It will also be noted that the mechanism is completely foolproof in that the parts cannot be moved out of proper operating relationship.

While a single embodiment of the invention has been shown it is obvious that many variationsin structure and application may be made without departing from the scope of the invention. It is, therefore,,desired to be limited only by the scope of the appended claims.

What-is claimed is:

1. In a timer mechanism, the combination of, timer motor means, a switch, means including an operator for said switch constructed and arranged to move the switch from a first position to a second position and then back to its first position as the operator moves in a single direction, actuating means operated by the timer motor means for actuating said operator in a direction to move the switch from its first position to its second position,- means for setting: the actuating means for a predetermined period of time, and means operated by the setting means at the end of its setting stroke for actuating said operator in a direction to move the switch from its second position to its first position.-

2. In a timer mechanism, the combination of an electric timer motor, load switching means for a controlled appliance, said switching means having a first position and a second position, said switching means also being arranged to control the timer motor, to de-energize .the same when the switching means isingthe second position,

means includin an oscillating operator for the switching means constructed and arranged to move the same from its first position to its second position and back to its first position as the operator moves in a single direction, means for limiting the travel of said operator to provide two end positions therefor, and actuating means adapted to be driven by the timer motor for moving the operator from one end position to midposition for moving the switching means from its first position to its second position.

3. In a timer mechanism, the combination of an electric timer motor, load switching means for a controlled appliance, said switching means having a first position and a second position, said switching means also being arranged to control the timer motor, to de-energize the same when the switchin means is in the second position, means including an oscillating operator for the switching means constructed and arranged to move the same from its first position to its second position and back to its first position as the operator moves in a single direction, means limiting the travel of said operator to provide two and positions therefor, setting means for setting the actuating means for a predetermined period of time, and means operated by the setting means for actuating said operator from midposition to one end position as the setting means approaches the end of its setting stroke, and means operated by the timer motor for returning said operator to an intermediate position at the end of the timed period.

4. In a timer mechanism, the combination of an electric timer motor, load switching means for a controlled appliance, said switchin means having a closed position and an open position, said switching means also being arranged to control the timer motor, to energize the same when the switching means is in the closed position, means including an operator for the switching means constructed and arranged to move the same from its closed position to its open position and back to its closed position as the operator moves in a single direction, from a first position through an intermediate position to another position, and means operated by movement of the operator from said intermediate position back to its first position for de-energizing said timer motor, even though said switching means is closed.

5. In a timer mechanism, the combination of, a first shaft, timer motor means for rotating said first shaft in one direction, a second shaft, an operating member carried by said second shaft, switching means controlled by rotation of said second shaft, means including a pair of spaced abutments carried by said first shaft, said operating member having a portion extending between said abutments so that one abutment rotates the operating member in one direction and the other abutment rotates the operating member in the opposite direction, means for retaining the operating member in the position to which it is last moved, manual means for moving said abutments, and slip friction drive means interposed between the timer motor means and the abutment means for permitting motion of the abutment means by the manual means.

6. In a timer mechanism, the combination of, an electric timer motor, a load switch, a cam shaft arranged to be rotated in one direction by the timer motor and to be rotated manually in the opposite direction, cam means on the shaft for controlling said load switch, said cam means bein constructed and arranged to provide an intermediate position of the shaft in which the load switch is open, while closing said load switch upon movement of the shaft in either direction from said intermediate position, a second switch, circuit connections including said load switch and said second switch in series for controlling said timer motor, and means operated by said shaft on movement from said intermediate position in said one direction for opening said second switch, whereby the load switch is closed without operation of the timer motor.

7. In a timer mechanism, the combination of, an electric timer motor, a shaft arranged to be rotated in one direction by the timer motor and to be rotated manually in either direction, a load switch, a motor switch, means operated by said shaft for operating both of said switches, said last mentioned means being constructed and arranged to provide an intermediate position of the shaft in which the load switch is open and the timer motor de-energized, to close the load switch and open the motor switch when the shaft is moved in said one direction from said intermediate position, and to close both of said switches when the shaft is moved in the opposite direction from said intermediate position.

8. In a timer mechanism, the combination of, a first shaft, an electric timer motor for rotating said first shaft in one direction, a switch shaft, a load switch and a timer motor switch operated by rotation of said switch shaft, an operating member carried by said switch shaft, means including a pair of spaced abutments carried by said first shaft, said operating member having a portion extending between said abutments so that one abutment rotates the operating member in one direction and the other abutment rotates the operating member in the opposite direction, means for retaining the operating member in the position to which it is last moved, manual means for moving said abutments, and slip friction drive means interposed between the timer motor means and the abutment means for permitting motion of the abutment means by the manual means.

9. In a timer mechanism, the combination of, a first shaft, timer motor means for rotating said first shaft in one direction, a switch shaft, an operating member carried by said switch shaft, switching means controlled by rotation of said second shaft, means including a pair of spaced abutments carried by said first shaft, one of said abutments being spaced from the first shaft a distance to cause it to come into line with said first shaft to provide a stop therefor, said operating member being provided with a cam surface adapted for engagement with said one abutment for causing rotation of said switch shaft in one direction as said one abutment approaches the same, the other of said abutments being arranged to engage said operating member for rotation of the switch shaft in the opposite direction.

JOHN L. HARRIS.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,050,614 Kerr Aug. 11, 1936 2,053,143 Frederick Sept. 1, 1936 2,106,042 Stark Jan. 18, 1938 2,230,191 Knight Jan. 28, 1941 2,254,795 Daniels Sept. 2, 1941 2,459,876 Gibson Jan. 25, 1949 2,500,476 Von Stoeser Mar. 14, 1950

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