US 3126459 A
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Description (OCR text may contain errors)
March 24, 1964 A. LEESON 3,126,459
CLOCKWORK-CONTROLLED ELECTRIC SWITCH Filed May 28, 1962 3 Sheets-Sheet 1 March 24, 1964 A. LEESON 3,126,459
CLOCKWORK-CONTROLLED ELECTRIC SWITCH Filed May 28, 1962 5 Sheets-Sheet 2 III/1111111".
FIG. 4. FIG. 6.
lnvenlor A Home y March 24, 1964 A. L. LEESON CLOCKWORK-CONTROLLED ELECTRIC SWITCH 3 Sheets-Sheet 3 Filed May 28, 1962 FIG. 9.
I nventor Attorney United States Patent 3,126,459 CLOCKWORK-CONTROLLED ELECTRIC SWITCH Arthur LeonardLeeson, Camber-icy, Surrey, England, as-
signor t0 Gillone Electric Limited, Camherley, Surrey, England Filed'May 28, 1962, Ser. No. 199,220 Claimspriority, application Great Britain June 1961 4' Claims. (Cl. 200-39) This invention, relates to clockwork-controlled electric switches, briefly referred to as time switches.
Some electric time switchescomprise spring-driven or electricalclockworks arranged to actuate electric switches of the. kind comprising a fixed contact and a spring-loaded moving contact which moves rapidly into either of two alternative rest positions in one of which it is in contact with the fixed contact.
Many electric time-switches are adapted to be secured towalls or mounting boards and thus cannot be readily moved. Other electric time switches, which may be in the form of clocks, are adapted to stand freely on shelves or the like and are provided with trailing leads for conconnection tomain sockets and to apparatus to be controlled by the switches; such switches can be readily moved and re-connected if the trailing leads are fitted with suitable plugs and sockets, but the trailing leads between the time switches and the main sockets constitute a hazard and the'time switches are easily knocked over and: damaged. It has also been proposed to provide a time switch with plug means whereby it may be plugged into. aconventional socket and with socket means adapted to receive a conventional plug.
The present invention is intended to provide an improved time switch.
According to the invention an electric time switch comprising a clockwork arranged to actuate an electric switch of the: kind referred to is characterised in that the electric switch comprises a spring-loaded pivotally-mounted catch plate capable of engaging the moving contact so as to cause the latter to move from either of its two rest positions into its other rest position, and a pawl, the arrangement being such that the catch-plate has two rest positions in one of which rest positions it may be temporarily retained by the pawl and to the other of which rest positions it returns under its spring-loading when released, by the pawl. The catch plate may conveniently be of a shape somewhat like that of a hollow rectangle with a gap through which the moving contact extends, and the pawl may be pivotally mounted inside the catch plate. Preferably the catch plate and the pawl are moved in turn by projections which move in the same direction as one another, for example these, projections may be on arms connected to a spindle driven by the clockwork. In an advantageous construction the time switch comprises a timing unit and a plug unit which can be secured together or separated from one another as required, and the plug unit comprises connection means of the plug type whereby it may be connected to a supply socket. This construction offers the advantage that it is possible to make timing units which are all of one pattern and any one of which can be fitted with a plug unit selected from a range of plug units to suit the various supply sockets commonly in use.
Such a plug unit may comprise socket means to receive a plug connected to an appliance, and/or such a plug unit may be provided with securing means for securing to the time switch one or more leads extending to one or more electric appliances of which the electricity supply is controlled by the time switch. The securing means may be of any desired construction, for example in the form of terminals to which wires are secured by means of screws or nuts or by soldering, and additionally or alternatively the lead or leads may be secured by one or more clamps or by clamping between parts of a casing of the switch. The timing mechanism may be of any desired kind and may be electrically driven or springdriven. The time switch may also incorporate a manually-operable by-pass switch by which-it is possible to close the circuit through the time switch to an appliance while the switch actuated by the timing mechanism is open, and it may also comprise one or more temperatureresponsive devices for operating one or more switch means. The connection means of the plug type may be of any desired size or construction, for example standard 13 amp, ring main or 15 amp. 3-pin or 5 amp. 3-pin arrangements. The timing unit preferably comprises a casing of moulded synthetic resin or polymer from which the timing mechanism may be easily removed; in an advantageous construction the timing unit and plug unit are secured together by means of a single screw. Further features of the invention appear from the following description and claims and the accompanying drawings in which a time switch according to the invention is illustrated partly diagrammatically and by way of example,
FIGURES 1 and 2 being respectively front and rear perspective views of the time switch with one form of plug unit,
FIGURES 3 and 4 being respectively a side elevation and planof the plug unit shown in FIGURES l and 2,
FIGURES 5 and 6 being respectively a sectional elevation and underneath view of the timing unit,
FIGURES 7, 8, and 9 being respectively a plan, side elevation, and underneath view of a modified plug unit,
FIGURE 10 being a plan of the electric switch controlled by the clockwork, and
FIGURE 11 being a view of parts which take part in the control of the switch shown in FIGURE 10.
The illustrated time switch comprises a moulded synthetic resin casing 10 accommodating a timing mechanism 19 (FIGURE 5) which can be set to actuate a switch shown in FIGURE 10 as explained below after the expiry of desired delay periods. The timing mechanism 159 comprises an electric clockwork driving a spindle 35 (FIG- URE 11), and the clockwork and the switch. are appropriately electrically connected to sockets 4, 5 and 6 (FIGURES 5 and 6) adapted to receive plug terminals 1, 2 and 3 (FIGURES 3 and 4, and FIGURES 7 and 8) respectively. FIGURES 3 and 4 show a plug unit in which the plug terminals 1, 2 and 3 are mounted on a plug unit body 11 which carries plug type connecting means in the form of pins 17 adapted to be plugged into a conventional mains or like supply socket, for example a 13 amp. BA. ring main socket (not shown). When the time switch is assembled the plug unit body 11 is fitted to the casing 10 and is secured in place by a single screw 34- (FIGURE 2) which passes through a hole 29 in the plug unit body 11 and enters a tapped hole in a boss 21 secured to a mounting plate 22 which carries the timing mechanism and switch and the sockets 4, 5 and 6.
To the plug terminals 1 and 2 in the construction shown in FIGURES 3 and 4 are connected two cores of a 3-core lead 13 extending to an appliance (not shown), for example, an electric room heater or immersion heater or electric blanket or light or radio set to be automatically switched on and/ or off after the expiry of the delay periods to which the timing mechanism is set. The
third core of the lead 18 is secured by a screw 23 to that one of the three pins 17 intended for making the earth connection, and the screw 23 carries an apertured earthing strap 23. A fuse 24 is arranged between that one of the three pins 17 which is the line pin and the plug terminal 3, and the latter is also provided with a bypass switch contact 9. By means of a pivoted alanine manual switch knob 7 a by-pass switch contact 3 secured to the plug terminal 2 can be moved into engagement with the contact 9 in order to by-pass the switch actuated by the timing mechanism.
FIGURES 7 to 9 illustrate a modified plug unit which may be fitted to the timing unit instead of the plug unit shown in FIGURES 1 to 4.
The plug unit shown in FIGURES 7 to 9 comprises a plug unit body 11 of modified form, carrying plug pins 17, terminals 1, 2, and 3, manual switch knob 7, by-pass switch contacts 8 and 9, screw 23 and apertured earthing strap 28, and provided with a hole 29 substantially as in FIGURES 3 and 4. In FIGURE 7 a connecting strap 29 takes the place of the fuse 24 shown in FIGURE 4. In FIGURES 7 to 9 a socket cover 25 is secured by screws 26 to the body 11 and is provided with apertures 27 corresponding to socket means adapted to receive the plug pins of a conventional plug (not shown) electrically connected to an appliance (not shown). The terminals 1 and 2 and screw 23 are appropriately connected by electrical leads 3th, 31, and 32 to the socket means.
FIGURE 10 illustrates the switch which is actuated by the timing mechanism. This switch comprises a support plate 36 which may conveniently be an end plate of the electric clockwork and is penetrated by the spindle 35 driven by the clockwork. The support plate 36 carries a pivot pin 37 on which is pivotally mounted a catch plate 38 loaded by a tension spring 3%. The catch plate 38 is of a shape somewhat like that of a hollow rectangle with a gap between a nose 33A and corner 3813, through which gap extends a moving contact 40 pivotally mounted upon a pivot pin 41 and loaded by a hairpin spring 42. The moving-contact 4G is connected through a flexible conductor 54 to a terminal 55 which is secured to the support plate 36 and connected by a wire (not shown) to the socket (FIG. 6). A fixed contact 45 is arranged so that it may be engaged by the moving contact 40 and is connected through a wire (not shown) to the socket 6 (FIG. 6). The hairpin spring 42 has a middle loop 43 and is pivotally mounted at one end upon a pin 44 secured in the support plate 36, the other end of the spring 42 being formed into a hook engaging in an apertured lug formed on the moving contact 4th. The spring 4-2. is stressed so that it presses against the moving contact 40 and causes the latter to snap quickly into either of its rest positions as hereinafter described. A pawl 46 is pivotally mounted upon a pivot pin 47 and loaded towards a tooth 38C on the catch plate 38 by a hairpin spring 4-8, the latter being supported upon the pivot pin 47 and anchored at one end to the pivot pin 37. The pawl 46 is not flat, being cranked so that it lies partly within the plane of the catch plate 38 and partly above the catch plate 38.
The switch illustrated in FIGURE is actuated by means of the timing mechanism comprising the clockwork driving the spindle 55 and the parts shown separated in FIGURE 11. Two radial arms 59 and 51 and a graduated timing disc 13 can be secured to the spindle 35 by means of a clamping nut 12 and a spring washer 52 by which the timing disc 13 and the radial arms 5% and 51 may be secured to the spindle in any desired relative positions of rotation about the spindle 35. A thin disc 53 is interposed between the switch and the radial arms. The arm 54) has a downward projection 56A which follows the path indicated by the dotted line C and is capable of engaging the catch plate 38, and the arm 51 has a downward projection 51A which follows a path indicated by the dotted line 0 and is capable of engaging the pawl 46. The switch is shown in its open position in FIGURE 10. When the projection StlA following the path C engages the catch plate 38 the latter is turned about its pivot pin 37 against the action of the spring 3? and the corner 35B engages the moving contact dil until the latter snaps over under the action of the spring 42 into a rest position in engagement with the fixed 4 contact 45. After further slight rotation of the catch plate 38 the pawl 46 urged by the spring 48 enters behind the tooth 380 so that the catch plate plate 33 is retained against movement under the action of the spring 39 by the pawl 46 engaging the tooth 38C when the projection 5ilA clears the catch plate 38.
The switch remains in the closed position so long as the pawl 46 engages the tooth 38C and prevents the catch plate 38 from moving under the action of the spring 39.
When the projection 51A following the path 0 engages the pawl 46 the latter is turned about its pivot pin 47 against the action of the spring 48. When the pawl 46 has thus moved suificiently it releases the tooth 38C and then the catch plate 38 turns about its pivot pin 37 under the action of the spring 39 and the nose 38A engages the moving contact 40 so that the latter snaps quickly back into the rest position shown in FIGURE 10 initially under the action of the spring 39 and finally under the ac tion of the spring 42. I
pointers 14 and 15 which indicate against the graduations on the timing disc 13 and there is a pointer or index mark 16 on the casing 10, see FIGURE 1.
Assuming that the disc 13 rotates once in 24 hours and is graduated accordingly, the operation of setting the time switch is as follows: firstly the nut 12 (which preferably has a left-hand screw-thread) is loosened sulficiently to allow the disc 13 and arms 50 and 51 to be rotated easily relatively to the spindle 35 and to each other. Then the disc 13 is turned until the time indicated thereon by the pointer or mark 16 is the actual time at which the operation is being elfected, the pointer 14 is moved until it indicates on the disc 13 the time at which the switch is required to close, and the pointer 15 is moved until it indicates on the disc 13 the time at which the switch is required to open. The nut 12 is then turned to clamp the disc 13 and arms 50 and 51 to the spindle 35.
A detachable transparent cover (as shown) may be provided to cover the disc 13 and pointers 14, 15 and 16 and the casing 10 may be provided with a window and an internal lamp to indicate whether or not the time switch is connected to a source of power.
It will be readily appreciated that the invention thus provides a compact and advantageous time switch, convenient for use for example in a dwelling.
1. A clockwork-controlled electric switch, comprising a support plate, a clockwork-rotated central spindle extending through said support plate, a first radial arm and a second radial arm both mounted on and adjustably securable to said spindle and spaced from said support plate, a fixed contact secured on said support plate, a spring-loaded catch plate pivotally mounted on said support plate and having substantially the form of a hollow rectangle with a gap, an internal tooth on said catch plate, a pawl pivotally mounted on said support plate within said catch plate and spring-loaded towards said tooth, a snap-action moving contact pivotally mounted on said support plate within said catch plate and extending through said gap, a projection on said first radial arm, and a projection on said second radial arm, the arrangement being such that during operation said catch plate is turned against its spring-loading by said projection on said first radial arm and moves said moving contact until said moving contact snaps into a rest position in engagement with said fixed contact, said pawl engages said tooth and retains said catch plate against movement, and said projection on said second radial arm turns said pawl against its spring-loading for releasing said catch plate whereupon said catch plate turns under its spring-loading and moves said moving contact until said moving contact snaps into a rest position remote from said fixed contact.
2. A switch as claimed in claim 1, comprising a clamping nut on said spindle for adjustably securing said radial arms to said spindle.
3. A switch as claimed in claim 1, comprising a gradsaid clamping nut being tightenable for securing said uated timing disc mounted on and adjustably securtiming disc and said radial arms to said spindle in any able Said p desired relative positions of rotation about said spindle.
4. A switch as claimed in claim 1, comprising a clamps said p g a graduated timing disc on said 5 References Cited in the file of this patent spind e etween sai clamping nut and said radial arms, and a spring washer around said spindle between said UNITED STATES PATENTS clamping nut and said timing disc, said clamping nut 2,832,856 GOOdhOIlSe P 29, 1958 being loosenable for allowing rotation of said timing 2,943,159 Goodhouse et al June 28, 1960 disc and said radial arms relative to said spindle, and 10 2,996,585 Lehde Aug. 15, 1961