US2748858A - Clock controlled switching device - Google Patents

Description

June 5, 1956 c. s. ASKEW CLOCK CONTROLLED SWITCHING DEVICE 2 Sheets-Sheet Filed Aug. 16, 1951 Crawford 5. Askew IN VEN TOR.

Jun 5, 1956 c. s. ASKEW CLOCK CONTROLLED SWITCHING DEVICE Filed Aug. 16, 1951 2 Sheets-Sheet 2 Fig.3. 39

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4 Crawford 5. Askew INVENTOR.

States This invention relates to switches operated by time setting devices by means of an electric circuit containing current consuming appliances which may be closed at a preset time so as to start operation of the appliance and thereafter may remain closed until opened again at a preset time, the closing and opening of the circuit being initiated by an electrically or mechanically driven clock. Time controlled switches of this type have, during recent years, been manufactured as separate units not specially adapted to any single consumption apparatus. This entails however certain disadvantages. Some of the consumption apparatus, such as electric motors, sadirons and other appliances which are frequently controlled by such switches draw heavy currents in the starting or cold phase which may produce arcs and which may easily damage the contacts. Also the interruption of relatively heavy current drawn by an appliance operating at the normally used line voltage is likely to cause arcing at the controlling contacts unless special precautions are taken and the distance through which the contacts move upon interruption is large and the speed with which they move is high. The introduction of snap switches or similar switches producing such a contact movement during interruption into devices of this type is however a major complication of devices operating with clocks, as clocks cannot usually furnish the necessary energy for a power consuming operation.

It is a main object of the invention to so arrange and connect the contacts of the time setting device that are formation between them is effectively suppressed or is minimized, this result being obtained without the addition of any auxiliary device or appliance.

A further object of the invention consists in providing a contact device having contacts of very small size which permits to obtain the highest accuracy while at the same time effectively minimizing and suppressing arcing.

According to the invention the contact devices moved by the clock are always in series with the relay winding operating the contact switches and if this relay is of relatively high ohmic and inductive resistance, the development of arcs upon separation of the contacts is effectively suppressed or minimized, while nevertheless the full line voltage can be applied to the electric appliance controlled by the contact device.

Further, according to the invention, the contact surfaces of the control contacts move in the same plane which they never leave and which either contains a conducting or an insulating surface cooperating with a contact of very small surface projecting into this plane.

Further, according to the invention, it is possible on account of the effective suppression of arcs, to reduce the contact surface of at least one of the contacs to such an extent that a high accuracy of timing is obtainable which exceeds the accuracy obtainable with other types of contacts.

Further features of the invention and further objects will be explained in detail in the following specification.

The invention will be best understood by describing it 2,748,858 Patented June 5, 1956 ice with reference to the accompanying drawings showing one embodiment of the invention. It is however to be understood that the embodiment illustrated in the drawings has been shown by way of example only in order to explain the principle of the invention and the best mode of applying said principle. The principle of the invention may be carried into effect in several ways, as will be clear to the expert, and a departure from the example shown in the drawing is therefore not necessarily a departure from the principle of the invention.

Figure l is an isometric view of the clock operated time setting and switching device.

Figure 2 is a plan view of the mechanism with the casing removed.

Figure 3 is an elevational front view of the mechanism.

Figure 4 is an elevational sectional view of one of the time setting devices, the section being taken along line 4-4 of Figure 5.

Figure 4a is an elevational sectional view of the other time setting device;

Figure 5 is an elevational side view of the time setting devices shown in Figure 4.

Figure 6 is an elevational view of the essential parts of the arrangement and also diagrammatically shows the electrical connections.

Essentially the combined time setting and switching device according to the invention comprises an electric clock, two pairs of circuit control contacts, and a relay switch with a relay winding and with switch contacts controlling the load circuit containing the appliance.

The energization and de-energization of the relay switch is controlled by the aforesaid two pairs of circuit control contacts. Each pair of contacts comprises a clock driven contact and a manually adjustable contact, and each contact of each pair moves in a circle with its contact surface always remaining in the same plane. By adjusting and presetting the position of one of the contacts of each pair by hand by means of a setting device, the other clock driven contact will reach or leave preset contact at a definite time and thereby either make or break the circuit controlled by the said circuit control contacts.

One of the two contact pairs closes the circuit of the relay switch at the time at which the clock driven contact sweeps past the preset contact. Thereby the relay switch is energized with the relay winding which is of high resistance, in series with the contacts. The operation of the relay switch then switches in the appliance to be controlled on the load circuit and also shifts the connections in such a manner that now the second pair of contacts is in series with the relay winding thereby holding the relay winding energized even after the first named pair of contacts has separated. The relay switch remains energized until at a predetermined time, again fixed by the presetting of one of the said contacts, the two contacts of the second pair separate and the relay switch circuit is interrupted, the relay switch then falling back. It will be noted that the relay switch winding is always in series with the contacts of the combined time setting and switching device when making or breaking of these contacts occurs. When the relay switch is de-energized the load circuit is cut off from the source of electric power.

Referring now to the embodiment of the invention which is represented in the drawing it will be seen that Figure 1 illustrates the general arrangement and outward appearance of the electric clock operated time setting and switching device. The device comprises a casing it} mounted on a suitable base 11, said casing housing the clock motor 20 (shown in Figure 2) and also housing the two time setting devices 21, 22 and the contacts associated with the same. The base of the clock preferably houses the relay switch with its relay coil 24, the cus tomary manual switch 25, signal lights 23, 26 and other units to be described.

On the front of the clock casing a clock dial 12 is arranged over which an hour hand, minute hand and second hand 14, 15, 16 respectively, may move. From the two sides of the casing 19 two lateral wing plates 17, 18 project which form the indicator dials for the two time setting devices 21, 22. The setting devices are provided with a time setting lever 19, 29 respectively, each lever being provided with a handle 28 and a pointer 27, the latter being in front of the wing plate and moving over a graduated scale 30 on the said arcuate wing plate. The graduations in front of the wing plate 17, 18 indicate hours, half hours, quarter hours and minutes, the graduations, of course, being selected in accordance with the degree of accuracy which is obtainable and desired. The levers 19, 29 are pivoted at a point inside the casing 10 and may be moved around said pivot point in order to set the device in a manner described below.

The base 11 of the casing 10 is provided with two windows 31, 32 behind which indicator lights 23, 26 are arranged indicating the condition of the appliance to be controlled. A manual switch 25" controls the connection of the time setting device and of the load circuit with the supply lines. Through a further opening in the base the supply cable 33 ending in a plug 34 to be inserted into any outlet connected with the power lines may pass. Finally a socket 35 is provided into which the plug (not shown) of the cable leading to the appliance to be controlled is inserted.

The clock mechanism driving the pointer is conventional and comprises the usual single phase synchronous motor 20 (Figure 2) driving the main clock shaft 36. Within the casing a framework 37 is arranged for carrying the time setting mechanism which framework consists of two spaced parallel frame plates 38, 39 and of the front bail 46, the two frame plates being held by spacer bolts 4-1 while the strip-like substantially U-shaped bail member 49 is held on the front frame plate 39 by means of rivets or bolts.

The clock shaft 36 driving the hour hand passes through suitable bores in the three frame members and is hollow and encloses the shafts for the minute and second hands which are driven by means of gear trains from the clock shaft 36 (not shown) in the conventional manner, said gear trains having the required ratio for the transmission of movement between the said shafts.

The hour hand shaft 36 may have a rearward extension 42 provided with a knob in order to be able to adjust the clock.

The shaft 36 carries and drives the main gear wheel 44 which may be provided with a sleeve fixed on the shaft 36 by means of a set screw. This main gear wheel meshes with two spur gear wheels 45, 46 which are freely rotatable on pins 47, 48 respectively, held in the frame members 39 in a manner described below.

The gear wheel 45 drives the contact device controlling the making or closing of the relay switch circuit. This gear wheel is mounted on a substantially cylindrical fiber body or disk 49 upon the front portion of which a metal collar 50 is mounted. This metal collar has a substantially cylindrical peripheral portion surrounding the fiber body and from the said collar a contact tooth 51 projects radially and inwardly (Figure 6). It will be seen that the metal collar 50 and the contact tooth 51 which are both mounted on the fiber body move with the gear wheel 45 and therefore both are driven by the clock shaft 36. During such movement the contact tooth 51 therefore always occupies a position which corresponds to the position of the pointers on the dial and to the hour indicated by said position.

The pins 47, 48 are hollow and may be provided with internal screw threads for about half their length. They may be held on the frame member by means of screws 55 which engage the internal screw threads of the pins.

One half of the hollow pins 47 serves as a bearing for a shaft 56 which may also be journaled in a bore of the bail member 4t). This shaft 56 carries a further fiber disk 59 surrounded by a metal collar 54. The fiber disk 59 may be pressed on or may otherwise be fixedly mounted in order to rotate with the shaft 56.

The fiber disk 59 carries a contact pin 65] which may fit into and may be held by a small metal tube 62 which pierces the fiber disk 59 and which is held by it. This tube may be joined to the metal collar 58 by means of an elastic wire connection 63.

On that portion of the shaft 56 which projects beyond the bail member 40 towards the front a pinion 65 is mounted which is secured to the shaft 56 for rotation. Between the bail member 40 and the fiber disk 59 a spring 64 is inserted pressing the fiber disk 59 and the shaft towards the fiber disk 49.

The two fiber bodies or disks &9, 59 are therefore held in such a manner that the pin 6t? is always applied against the end surface of the fiber disk 49 and may come into contact with the contact tooth 51 of the metal collar 50 projecting inwardly on the surface of said disk during the rotation of the fiber bodies or disks.

The pinion 65 meshes with the toothed segment 66 carried by the pivoted lever 19 of the time setting device 21. The pivot of lever 19 is formed by the pivot pin 68 which is held in the frame members 39 and 4d. The pivot pin is provided with a retainer disk 69 between which and the bail member 40 a spring 70 is inserted. Said spring maintains the lever and the toothed segment in its correct axial position.

The lever 19, as already described above, is provided with a handle 28 and with the pointer 27 which moves over the graduations 30 on the front side of the wing plate 17. The graduation of the wing plate, as will be clear, is made along the arc of a circle the center of which is formed by the axis of the pivot pin 68.

In order to supply current to the contact device a contact rod 72 may be provided (Figure 6) which carries a retainer disk or piston 73 inserted into a cylindrical housing made of fiber or of any other insulating material. A spring 74 inside said housing is applied against the retainer disk or piston 73 pressing the contact rod 72 against the collar 50. A simplified form of this contact device is shown at 76 which represents a fiber housing having a bore 77 into which a brass spring 78 is inserted pressed on one side against a fixed contact member 79 and on the other side pressing against the movable contact rod 80 which is pressed against the metal collar.

The contact elements of the second time setting device 22 which disconnects at a predetermined time is very similar to or identical with those described; merely the contact making disk 88 connected with the spur gear wheel 46 differs in its construction from its counterpart in the device 21. The elements of the device 22 which are of a construction identical with that of their counterparts in the device 21 have been designated by the same reference letters which were used when describing the device 21 followed by the index a. These elements need therefore not to be described.

The above mentioned contact disk of the device 22 comprises a body of fiber material 25 the front end of which is covered by a cup-shaped metal collar 90. This cup-shaped member has a cylindrical peripheral outer portion to which an inwardly projecting annular skirt portion 91 covering a part of the front end of the fiber disk 95 is joined. The said annular skirt portion 91 is provided with a cut or indentation 92.

The second contact member comprises a fiber disk or body 86 which is encircled by a cylindrical metal collar 83 which carries a pin 88 projecting from the end of the fiber body towards the fiber body 95. The pin is inserted into the tube 62a carried by the fiber body and is connected with the cylindrical metal collar 83 by means of an elastic wire connection 63a. The contact rod 82 which is applied against the peripheral portion of the cup-shaped metal collar is in electrical connection with the metal collar 90 by mean: of pin 38 applied against the skirt portion 91 which contact is maintained practically all the time except when the cut portion or indentation 92 moves past the pin 85;.

The relay switch 24, the signal lights, and the manual switch 25 will best be described in connection with the operation as their structure is conventional. However, it may be mentioned that the winding of the relay switch 24 has a predetermined relatively high ohmic and inductive resistance which as will be seen is in the circuit controlled by the contact device when the appliance is cut out or switched in. This permits a very small size of the contact surfaces as arcing is prevented or very substantially reduced on account of the high resistance in said circuit during the switching operation.

The surface may be as small as .003 inch. When using such a small size of the contact the danger of arc formation is in itself reduced or eliminated.

During operation which will be explained with reference to Figure 6, the operator, if he wants to operate an electrical appliance at a predetermined time, first throws switch 25, then seizes handle 28 and turns arm 19 until the pointer 27 is moved to the proper graduation mark, indicating the desired hour. The setting of arm 19 by means of handle 28 moves the two segments 66, pinion as and shaft 56 thereby turning the fiber body 59 and the pin 6d. Setting the pin for a definite position, say the one shown in Figure 6. The clock is assumed to be in operation and the clock motor 2% therefore moves the shaft 35 carrying the pointers of the .clock and also moves the spur wheel 4d and thereby the spur gear wheel 45 and the fiber body or disk 49 with its collar 51 and with its contact tooth 51 all the members rotating around the axis of pin 47.

During rotation of the clock the fiber disk 49 is in contact with the end or contact surface of pin 69 all the time. When rotation has progressed to the point in which the projecting tooth 51 is in front of pin 64) and makes contact with it the circuit is closed running from terminal 98 over conductor 1%, relay winding 24 (which has the selected resistance value) over closed switch 25, conductor 102, contact rod '72, collar 59, contact tooth 51, pin 69, collar 54, contact rod 81, conductor 103, junction point 1&5, conductor 1'94, terminal 96. The relay now attracts the armatures 166 and 108 closing contacts 109, 116 thus connecting the appliance outlet 35 directly with the source of electric power at 96, 98. This circuit connection remains unchanged as long as the relay is energized. The relay once energized, closes a holding circuit running from 98 over 101, 24, 111, S2, 83, 88, 91, 90, iii), 112, 1%, 110, 1415, 1%, 96. When the appliance socket is connected with the power line, signal light 23 indicates that full line voltage has been applied.

When the operator desires to cut out the appliance at a preset hour he adjusts lever 29 moving it to the point indicated on the graduation scale corresponding to this hour. This moves segment 66a, pinion 65a and fiber disk 83, placing pin 88 to a definite point which is reached by the indentation 92 at the time which has been indicated by the graduation mark on the wing plate 18. When the hour corresponding to the setting of the pointer and lever 29 has been reached the holding circuit or relay is interrupted, as this circuit includes pin 88 which now rests on the fiber disk 95 as long as the indentation 92 moves past pin 88. The relay is de-energized and cannot be energized again after the passage of the indentation 92 when pin 33 comes again into contact with the metal surface of the cup-shaped collar 90, as contacts 109, iii) are now open.

The red light 26 is preferably a gas filled glow tube and is in series with the relay winding 24 when the switch 25 is thrown and its resistance must be so selected that it is itself energized when in series with the relay 24, but that it cuts down the voltage for the relay 24 to such an extent that the relay does not operate with the lamp 26 in series with it. Otherwise expressed the red light must operate on the voltage drop across its termi= nals when the relay coil is in series with it, while the high ohmic relay operates substantially only on the full voltage available, but not on a voltage which has been reduced by the gas filled tube 26.

Upon throwing of the switch 25 therefore the red light 25 Will be energized and will light up while the relay coil 24 is not energized because it is in series with the lamp .26. The red light then indicates that the apparatus is ready for operation.

When the pin 60 of the appliance controlling device 21 reaches the tooth 51, the connection 104, 193, 81, 60, 51, 5th, 162, 25, 24, 101 short circuits the red light 26 which goes out while the relay 24 is energized. As long as the relay 24 remains energized the red light is inoperative, the relay being energized over its holding circuit which does not contain the red light 26. However, as soon as the appliance is cut in, the yellow indicator light 23 is energized, as has been described above.

The relay holding circuit, as described above, now includes the annular skirt 91 of collar 90, the pins 38 and 82 and the conductors 103 and 112. When the cut 92 of the skirt portion 91 faces the pin 83 this holding circuit is interrupted the relay 2d falls back and is now in series with the red light 26. The red light is now energized and indicates that the device has been cut out again.

It will be seen that the contact device operated by the electric clock may operate with a normal line voltage of to v. without applying the full voltage to the control contacts as the relay winding with its high resistance is always in series with the contacts when the contacts are opened or closed. This reduces arc formation so materially that the control contacts may be provided with very small contact faces thus increasing the accuracy of the device.

As the relay winding with its high resistance is in the circuit it is also possible to keep the starting current of an appliance from passing the contacts, thus reducing wear and preventing efiectively damage which may be done by a current surge.

It will be obvious that many changes may be made in the unessential details without in any way departing from the essence of the invention as defined by the annexed claims.

Having described the invention, what is claimed as new is:

1. In a combined time setting and switching device for making and breaking a load circuit at definite preset times, a first rotatable contact device for producing a short timed contact, a further rotatable contact device for maintaining a connection for a definite period of time and for interrupting a closed circuit at a predetermined instant, both contact devices consisting of two cooperating, contiguous rotatable disks of insulating material, each provided with a contact having a contact surface arranged in the plane of rotation of the said disks on the side facing the other disk, said contact surfaces being arranged at such distances from the axis of rotation that the contact surfaces of the two disks come into contact with each other during rotation of the disks, a clock mechanism rotating one of the said insulating disks of each contact device with uniform angular velocity, means for manuaily rotating the other insulating disk of each contact device to move its contact to a predetermined point for each desired operation, a relay switch with a relay winding or" predetermined resistance and with relay switch contacts, controlling said load circuit, an energizing circuit for said relay switch, controlled by the first rotatable contact device, and a holding 7 circuit for said relay switch controlled by the relay switch contacts and by the further rotatable contact device.

2. A combined time setting and switching device for making and breaking connections in a load circuit at definite preset times, comprising a clock mechanism operating a shaft rotated at uniform angular speed, circuit controlling contact devices, each including a first rotatable insulating body, rotated by the said clock operated shaft, and a contact carried by said insulating body, having a contact surface arranged in the plane of rotation, each of said contact devices moreover including a further rotatable insulating body, and a contact carried by said last named insulating body, said contact having a contact surface in a plane of rotation coincident with that of the first named contact, means for manually adjusting the position of said last named contact, a relay switch with a relay winding of predetermined resistance, relay switch contacts controlling said load circuit, an energizing circuit for said relay switch, and a holding circuit for the same, the latter controlled by the relay switch contacts and closed upon closure of the load circuit, a first one of said circuit controlling contact devices having a contact on the said first rotatable body moved by the clock operated shaft, being normally out of contact with, but moved towards the manually adjustable contact carried by the further insulating body for producing an operative contact at a predetermined time, a second one of said circuit controlling contact devices having a contact on said first rotatable body, normally in contact with a manually adjustable contact, but moved out of contact after a predetermined angular rotation, the energizing circuit of the relay switch being controlled by the first one of the circuit controlled devices, and the holding circuit of the relay switch being controlled by the second one of the said circuit controlling contact devices, the clock mechanism thus, after the setting of the manually adjustable contact devices to desired positions, energizing the relay switch when the movable contact of the first contact comes into operative contact with the manually adjustable contact of this device, said relay switch thereafter remaining energized after its first energization by means of its holding circuit, until the latter is opened by the second contact device, de-energizing the relay switch and opening the load circuit.

3. In a time setting and switching device for making and breaking a load circuit at definite preset times, a first rotatable contact device for producing a short timed con tact, a further rotatable contact device for maintaining a connection for a definite period of time and for interrupting said connection at a predetermined instant, each of said contact devices including a body of insulating material having an end face located in a plane of rotation, and a second body of insulating material with an end face facing the first named insulating body, a clock mechanism driving a shaft, gear means on said shaft meshing with gear means mounted on the insulating bodies of each of said controlled devices, an insulating body of the first rotatable contact device being provided with a projecting contact finger, having its contact face arranged in the end face of the insulating body located in the plane of X'Qtc: tion of the said body, the second insulating body of the said first contact device carrying a contact having its contact surface arranged in the same plane of rotation in which the contact finger moves, at a distance from the axis which is substantially equal to the radial distance of the contact finger from said axis of rotation, means for adjusting manually the position of the last named contact, a relay switch with a relay winding of predetermined resistance controlling the load circuit, an energizing circuit for the relay switch controlled by the first rotatable contact device, said circuit including the relay winding of the relay switch, a holding circuit for said relay switch also including the relay winding of the relay switch, controlled by the further rotatable contact device, the relay winding by its resistance thus limiting the current intensity of the circuits controlled by the contact devices, the clock mecha- &

nism, after the setting of the manually adjustable contact of the contact devices, thus energizing the relay switch when the movable contact of the first contact device comes into operative engagement with the manually adjustable contact of this device, the relay switch thereafter remaining energized over its holding circuit until the latter is opened, by the further contact device de-energizing the relay switch and opening the load circuit.

4. A time setting and switching device for making and breaking a load circuit at definite preset times as claimed in claim 1, wherein the insulating body of the further rotatable contact device maintaining a connection for a definite period and interrupting said connection at a predetermined instant is provided with a conducting sheet covering its end face, said sheet being provided with an indentation, and being in contact with the contact surface of a contact provided on the second insulating body facing it.

5. A time setting and switching device as claimed in claim 2, wherein each of the insulating bodies is provided with a peripheral metal collar, a conducting connection between each contact having a contact surface parallel to the plane of rotation and the said metal collar and a stationary contact rod sliding on said metal collar during rotation of the insulating body for producing a connection between the contacts and the outer circuits.

6. A time setting and switching device as claimed in claim 1, wherein the means for adjusting manually the position of the contact carried by the second insulating body of each circuit controlling device comprises a hand operated pivoted lever, rotatable around a fulcrum, and provided with a pointer, a graduation scale cooperating with said pointer to indicate the adjustment, a connection between said pivoted lever and the insulating body to be rotated, said connection including a toothed segment fixed to the lever and a gear wheel, a shaft connecting said gear wheel with the said insulating body and means for pressing said insulating body against the insulating body facing it.

7. In a time setting and switching device for making and breaking a load circuit at definite preset times, a source of current, a relay switch with a relay winding of predetermined resistance provided with switch contacts, controlling said load circuit, a holding circuit for the relay winding controlled by the said relay switch contacts and closed when the load current is closed, a rotatable contact device producing a short timed contact, a further contact device normally maintaining a connection but interrupting the connection at a predetermined instant, both contact devices consisting of two cooperating contiguous rotatable disks of insulating material, each provided with a contact carried on its end face, the contact surfaces of the said contacts being arranged in the plane of rotation of the said disks, and at such distance from the axis of rotation that the contact surfaces of the contiguous disks come into contact with each other during rotation, a clock mechanism, means operated by said clock mechanism rotating one of said insulating disks of each contact device, means for manually rotating and adjusting the other one of said insulating disks so as to move its contact surface to a predetermined point, a circuit controlled by the contact device for producing a short timed contact, connecting the source of current with the relay winding to initiate the relay switch operation, said relay switch contacts, when first operated, shifting the connection of the relay winding so as to include the holding circuit and the contact device for maintaining a connection for a definite period of time in series, said holding circuit being interrupted and the load circuit being cut out by the said further contact device normally maintaining the connection, when the relative movement of the contact of this device produces an interruption of the connection.

8. In a time setting and switching device for making and breaking a load circuit at definite predetermined times, comprising a casing, an electric clock. with a dial and pointers moving over said dial, wing plates projecting from said casing on both sides of the dial of the electric clock, said wing plates being provided with graduations, a clock operated shaft rotated at uniform angular speed, two circuit controlling means, each including a first rotatable insulating body driven by the clock operated shaft and a contact carried by said body, having a contact surface arranged in a plane of rotation, and moreover including a further rotatable insulating body, and a contact carried by the said last named insulating body, said contact havin a contact surface in a plane of rotation coincident with that of the first named contact, a manual adjustment lever for adjusting the position of the contact on said further rotatable insulating body, said lever being provided with a pointer moving over the graduation scale of one of wing plates, a toothed segment carried by said manual adjusting lever, a gear wheel meshing with said segment, connected with and rotating the said further rotatable insulating body and circuits connected with and controlled by the said contact devices, said circuits including a. relay winding, an energizing circuit for said relay winding, controlled by one of said circuit controlling means, relay contacts operated by said relay Winding, the load circuit being closed by said relay contacts upon energization of the relay winding, a holding circuit for the relay winding likewise closed by said relay contacts upon energization, the holding circuit being controlled by the second one of said circuit controlling means, the clock mechanism, after the setting of the manually adjustable contacts of the contact devices to desired positions, energiz. ing the relay switch when the movable contact of one of said contact devices comes into operative contact with the manually adjustable contact of this device, said relay switch thereafter remaining energized by means of its holding circuit, until the latter is opened by the second one of the contact devices, de-energizing the relay switch and opening the load circuit.

9. A combined time setting and switching device for making and breaking load circuits at definite predetermined times, comprising a clock mechanism, a first and a second contact device for making and breaking a circuit respectively, the first contact device including a manually adjustable contact moved into a fixed position for each desired operation and a movable contact adapted to be moved into operative engagement with the contact moved to a fixed position, the second contact device including a manually adjustable contact and a movable contact in operative contact relation with the manually adjustable contact, said movable contact being adapted to be moved out of contact with the manually adjustable contact during its movement, means for manually adjusting the contacts to be set for each desired operation in each of the contact devices, means for driving the movable contacts of the contact devices by the clock mechanism, a relay switch with a relay coil and relay switch contacts, an energizing and a holding circuit for the relay coil of said relay switch, said holding circuit being controlled by the relay switch contacts, and the energizing circuit being controlled by the first contact device, said holding circuit being additionally controlled by the second contact device, said relay switch contacts further controlling the load circuit which is closed by the energization of the relay switch and opened upon de-energization of the relay switch, the said clock mechanism after the setting of the manually adjustable contacts of the contact devices to fixed desired position operating the first contact device to energize the relay switch by moving the movable contact of the first contact device into operative contact with the manually adjustable contact, the holding circuit being closed by the energization of said relay switch and remaining closed, until again opened by the second contact device, moving its movable contact out of operative engagement with the manually adjustable contact.

10. A combined time setting and switching device for making and breaking an appliance carrying load circuit at definite predetermined times, comprising a clock mechanism, a first and a second contact device for making and breaking a circuit respectively, each contact device including two coaxial rotatably mounted insulating contact carriers witn parallel sides facing each other, each of said parallel sides carrying one contact member brought into and out of contact with the contact member on the opposite carrier side during rotational movement, means for manually adjusting the angular position of one of said contact carriers carrying a contact member, means for driving the other contact carrier and its contact member by the clock mechanism, a circuit connected with each of said contact devices, a relay switch provided with a relay winding of predetermined resistance and with switch contacts operated upon energization of the winding of the relay, said relay Winding being included in the circuit controlled by the first contact device, a holding circuit for maintaining the relay switch closed after its energizetion, said holding circuit being controlled by the relay switch contacts and by the second contact device breaking the circuit controlled by it, the load circuit in its turn being controlled by the contacts of said relay switch and being closed when the relay switch is energized and opened upon de-energization of the relay switch, the clock mechanism, after the setting of the manually adjustable contact devices to fixed desired positions, thus energizing the relay switch when the movable contact of the first contact device comes into operative engagement with the manually adjustable contact of this device, the energization of said relay switch also closing the holding circuit which continues to energize the relay switch until the holding circuit is opened by the second contact device de-energizing the relay switch and opening the load circuit.

References Cited in the file of this patent UNITED STATES PATENTS

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