US 3908354 A
Abstract available in
Claims available in
Description (OCR text may contain errors)
United States Patent Tomasello ELECTRIC TIMEPKECE DRIVE inventor: Frank Tomasello, Bayonne, NJ.
Assignee: Engler instrument Company,
division of Sangamo Electric Company, Springfield, Ill.
Filed: Sept. 20, 1974 Appl. No.: 507,726
US Cl. 58/23 D; 58/23 A; 58/145 R int. Cl. G04C 3/00; G04B 5/20 Field of Search 58/23 R, 23 A, 23 D, 39.5, 58/145 R References Cited UNITED STATES PATENTS Hart et ai 58/145 R Little 58/23 A [451 Sept. 30, 1975 Primary Examiner-Edith Simmons Jackmon Attorney, Agent, or Firm-Harry B. Rook  ABSTRACT An electric drive includes a solenoid operable on low power and an electronic control circuit for use wherever accurate timing is required, for example, in driving an elapsed time hour meter, the electronic circuit including a voltage regulator, and a relaxation oscillator, receives the power input at any voltage between predetermined minimum and maximum voltages, for example, from l0l30 volts, and controls the output to the voltage and frequency required for operating the solenoid. with which is associated an armature or flapper that actuates a pawl and ratchet device which is drivingly connected to the meter.
7 Claims, 7 Drawing Figures US. Patent Sept. 30,1975 Sheet 1 of 2 US. Patent Sept. 30,1975 Sheet 2 of2 3,908,354
I 10 TO 130v. ac.
\ INPUT ELECTRIC TIMEPIECE DRIVE I BACKGROUND OF THE- INVENTION This invention relates in general to an electric drive for timing mechanism and particularly to a' drive mechanism for an elapsed time hour meter, operable on low voltage direct current such as a battery. i)
The invention contemplates the use of a 'simple and relatively inexpensive electrical solenoid as the driving motor and an electronic control circuit therefor, as distinguished from some prior art devices that include complicated spring operated mechanical balance wheel escapement movements and other prior art devices that include synchronous motors andrrieans to ensure rotation thereof in only one direction.
SUMMARY OF THE INVENTION A primary object of the inventionis to provide a novel and improved simple and relatively inexpensive electronic time-piece drive including asolenoid and an electronic control circuit, for example, a drivefor a chart or an elapsed time hour meter, designed to operate on any'direct current voltage over a wide'range, for example, between predetermined minimum and maximum voltages such as ten to one hundr'edthirty volts, respectively, over a temperature'range of the order of minus 55 to plus 70C. I
It is important that the same drive be operable over such wide ranges so that same drive can be used in any of many different installations which maybe adapted to supply only a specific voltage within 'a particular range of voltages. I
It is contemplated that the invention be especially adapted to an elapsed time hour meter'which has a drum type register capable of recording 10,000 hours and is also equipped with a running indicator.
In general, the inventionincludes-(Dan electronic control circuit; (2) a solenoid having associated therewith a pivoted armature or flapper; (3) a rocker pawl actuated by said flapper and which drives a ratchet on a shaft of, for example, a timepiece de'viceto be driven, for example, said drum type register, or a chart.
The electronic circuit can be 'divided'into three sections, (a) a voltage regulator which accepts as an-input voltage any voltage between wide predetermined limits, such as to 130 volts and controls its output to a constant voltage; (b) a temperature compensated relaxation oscillator which controls its own frequency and whose output is a sawtooth pulse'adjusted to a specific frequency and which is of sufficient power to 0p erate the solenoid and drive the counter, and (c) the solenoid electrically connected to the output of the oscillator and to the power input and an armature associated therewith. I
The solenoid consists of a straight wound coil, 21 core and a coil housing. The armature-or flapper is designed to engage into a slot in a rocker and the rocker drives a ratchet on, for example, the first "wheel of the drum type register which also serves as a motion indicator. Flapper motion is directly related to the generated timing pulse, and the timing pulse is directly controlled by the electronic circuit. Y
BRIEF DEsc IPTION or TIIE DR AW NGS For a more complete understanding of the invention, reference should be had to the following description in conjunction with the accompanying drawings in which:
FIG. 1 is a front elevational view of an elapsed time hour meter having an electric drive mechanism embodying the invention, with the major portions of the dial plate and the casing cover broken away;
FIG. 2 is a longitudinal vertical sectional view on the plane of line 2-2 of FIG. 1;
FIG. 3 is a horizontal sectional view on the plane of line 33 of FIG. 1;
FIG. 4 is a longitudinal vertical sectional view on the plane of line 44 of FIG. 1;
FIG. 5 is a perspective view of the ratchet and first wheel of the hour meter;
FIG. 6 is a perspective view of the pawl or rocker, and
FIG. 7 is a diagrammatic or schematic view of the electronic circuit including the solenoid, illustrating one embodiment of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS As hereinbefore indicated the invention contemplates a timepiece drive wherein the electricallypowered driving unit comprises a solenoid and means associated therewith, particularly an armature and a driving connection between the armature and the timepiece, and in accordance with the invention an electronic circuit controls the operation of the driving unit.
As shown in FIG. 7, the control circuit includes three sections, namely Section 1, a voltage regulator, Section II, a relaxation oscillator, Section III and said solenoid which is energized by the pulse generated by said relaxation oscillator.
The voltage regulation stage, Section I, includes at least one high voltage power transistor Q, which acts as variable series resistance and whose collector is connected to one of the two input terminals .1 and H and whose emitter is connected to one of the two output terminals of the voltage regulator. A voltage reference element ZI) for example a zenerdiode is connected between the negative input terminal H and resistors R and R of which R acts as a voltage limiting resistance and R is connected in series with the baseof transistor Q,. A diode D is connected in series with the power input terminal .I to protect the circuit against accidental polarity reversal. The input voltage may be any voltage within a range between predetermined minimum and maximum limits of the order of 1 to 15, respectively, particularly, from 10 to volts, so that the circuit is usable for the majority of battery powered devices. The output of Section I is a constant voltage and is held constant independent of the input voltage. The output of this Section I is used to power the other sections of the circuit.
Section II comprises one complementary unijunction transistor Q with its base at B connected to the negative output terminal of the voltage regulator and its base at B connected to one side or terminal of the solenoid coil L, and the emitter terminal E connected to resistor R.,. A trimmer R is connected in series with resistor R and a capacitor C and is used to adjust the timing cycle. This oscillator controls its own frequency and its output is a sawtooth pulse adjusted to a specific fre- I quency for powering the solenoid. The momentary pulse is energized through a charge stored in the capacitor.
Section III comprises the coil of solenoid L which is electrically connected to the output of said oscillator.
The solenoid coil is straight wound coil of about 110 ohms which operates at low power and at low temperature, for example within a range of the order of from minus 55 to plus 70C. Specifically, the terminals of the coil are connected to the base B, terminal of the unijunction transistor and one side of the power source, that is the positive output terminal of the voltage regulator, respectively.
In this circuit the component values, preferably are:
R, 10K 2 Watt hms R, 470 W R, 33K A" R, 15K W R, 4.7K A" C, 220MF l volts Q, Low power.
High voltage transistor- Gain amplification 25 times minimum 0-, Silicon Complementary unijunction transistor ZD Zener Diode 9.1 volt, etc.
Rectifier 420 RMS Coil l l0 Ohms It will be understood that the particular component values mentioned are primarily for the purpose of illustrating the principles of the invention and that the specific values may be varied depending upon the input voltage range at the voltage regulator and the output power and frequency of the relaxation oscillator in section I] desired for the driving solenoid.
As hereinbefore stated, the invention is designed for use in various types of apparatus such as elapsed time totalizing meters, chart recorder drives, clocks and the like wherever operation on direct current over a wide voltage range and at low power, with low heat generation, is desired. For example, the invention is here shown in an elapsed time hour meter having a drum type register N.
Referring to FIGS. 1 to 6, inclusive, the circuit components are assembled on a small printed circuit board generally designated E, which is secured in and supported by a mounting frame F which is preferably formed of molded plastic insulating material and includes spaced apart side portions F, and F having coaxial complemental segmentally cylindrical surfaces separably engaging an interior cylindrical surface 22 of a housing G which has a cylindrical side wall 23 and an end wall 24, all preferably molded of plastic insulating material. The circuit board is shown seated in longitudinal grooves 25 in said side portions F, and F of the mounting frame.
The drum type register N includes the usual number of odometer wheels 4 rotatable on a shaft 5, and transfer pinions 6 mounted on a shaft 7 for transmitting motion from one wheel to the next adjacent wheel in the known manner. Both shafts are mounted in and between the side portions of the mounting frame with their axes in parallel spaced relation.
For driving the wheels 4, the invention provides the solenoid coil L which is suitable for the circuit voltage and is wound on a core 8 which is rigidly secured in an auxiliary frame or bracket 0 and has associated therewith the armature or flapper 10 which is fulcrummed on the frame and actuates a rocker pawl 11 that is coactive with a ratchet 12 rotatably mounted on the shaft 5 and formed to drivingly coact with the first transfer pinion 6a to rotate the first odometer wheel 4a.
One end of the core of the solenoid winding 8a is riveted on the main portion 13 of the auxiliary frame or bracket 0 with an insulation disk 14 between the coil and the frame, and at the other end of the core are riveted an insulating disk 15 and an insulating support 16 for the terminal wires 17, 18 of the coil which are connected by the respective pins 19, 20 to the printed circuit on the board E as indicated at 19a and 20a. The main portion of the auxiliary frame has upstanding hanger arms 13a which are secured by screws 13b to extensions F, of the side portions of the main support frame F.
The armature lever or flapper is formed of flat sheet metal with two alined arms 26 at one side of the core each bifurcated and straddling one of the hanger arms 13a to fulcrum or pivotally mount the armature on the auxiliary frame. A tension spring 27 is connected between a lug 28 on the armature and a lug 29 on the main portion of the auxiliary frame to normally bias the armature lever away from the juxtaposed end of the core. At the side of fulcrum of the armature lever opposite the lug 28, the lever has a long arm 30 normally projecting into a slot 31 in the hub 32 of the rocker pawl 11 which is oscillatable on the shaft 5 and has two teeth 33, 34 at opposite sides of the ratchet hub differently shaped to coact with the teeth 35 of the ratchet so that upon oscillation of the pawl one pawl tooth moves the ratchet one step in one direction to move the odometer wheel 4a in the desired or right direction while the other tooth prevents rotation in the opposite or wrong direction. As shown, the ratchet disk has a notch 12a with which the teeth of the transfer pinion 6a coact in the same known manner in which the transfer pinions coact with the number wheels in hour meters or odometers.
As above indicated, the flapper or armature is actuated in one direction toward the solenoid core by momentary pulses from stored capacitor charges generated by the oscillator so energization of the solenoid is controlled by the electronic circuit. As shown, for example in FIG. 7, the circuit board has four terminals, two, namely H and J for connection to the power input and two, namely 21 and 22 for connection to the solenoid coil.
The terminals H and J are in the printed circuit and coact with terminals S and T which are mounted in the housing G. The terminals S and T are identical in construction, each one being formed of heavy sheet metal with two angularly related arms and 41. The terminals are rigidly secured in the end wall of the housing with one arm 40 exposed outside the housing for connection to the power line, and the other arm extending into the housing. These arms 41 have two resilient fingers 42 spaced apart to snugly frictionally receive the edge portion of the circuit board between them with at least one finger contacting the corresponding printed circuit terminal H or J as the board in the mounting frame F is slid into the housing through the open end thereof.
1. An electric timepiece drive comprising a solenoid drivingly connected to the timepiece and an electronic control circuit therefor, including components which may be for convenience, divided into a plurality of sections or stages, namely first, a voltage regulator having two input terminals to receive the power input from a source at any voltage within a range between predetermined minimum and maximum voltage limits of the order of l to and two output terminals and whose output is substantially constant voltage independent of the power input voltage, said voltage regulator including at least one transistor which acts as a variable series resistance; second, a relaxation oscillator to receive the output of said voltage regulator which includes a complementary unijunction transistor and whose output is a sawtooth wave pulse at a predetermined frequency;
and third, a solenoid electrically connected to the output of said oscillator and to said power source and means associated therewith, which transduces the electrical pulse output of said oscillator into the mechanical form of pulsating motion the rate of which is controlled by the output of said oscillator and which drives said timepiece.
2. A timepiece drive as defined in claim 1, wherein A. said first section, a voltage regulation stage and the source of power for all other stages, includes 1. said one transistor Q whose collector is connected to one of the two power input terminals and whose emitter is connected to one of the two output terminals of the voltage regulation stage,
2. a voltage reference element ZD connected between the negative input terminal and resistors R and R of which R acts as a voltage limiting resistance with R connected in series with the base of transistor Q 3. a diode D in series with the power input terminal to protect against accidental polarity reversal;
B. said second section, a relaxation oscillator stage,
1. said complementary unijunction transistor Q with base B terminal connected to the negative output terminal of the voltage regulator, base B terminal connected to one side of solenoid coil and the emitter terminal connected to resistor R, and capacitor C; and trimmer R which is in series with C and R and is used to adjust the timing cycle;
C. said third section comprises said solenoid L electrically connected to the output of said oscillator and said power source, and an armature associated therewith and drivingly connected to the timepiece.
3. An electric timepiec drive according to claim 1 wherein the voltage regulator is constructed to operate with supply input voltage within a range of 10 to 130 volts.
4. An electric timepiece drive according to claim 2 whose component values are such as to enable operation of the timepiece drive over a voltage range of 10 to 130 volts.
5. An electric timepiece drive according to claim 2 whose component values are such as to enable operation of the timepiece drive over a voltage range of 10 to 130 volts and whose solenoid comprises a straight wound coil of the order of ohms on a magnetic core.
6. An electric timepiece drive according to claim 2 whose component values are such as to enable operation of the timepiece drive over a voltage range of 10 to volts and whose solenoid comprises a coil having a resistance of the order of 100 ohms on a magnetic core.
7. An electric timepiece drive as defined in claim 1 wherein said timepiece includes a main frame, a wheel to be driven mounted on a shaft journaled in said frame, said solenoid comprises a coil having a core mounted on said frame, and said means associated with the solenoid comprises an armature lever fulcrummed on said frame normally biased away from said core and to be momentarily actuated in one direction toward the core upon energization of the solenoid by a pulse from said oscillator, a ratchet disk having teeth and rotatable on said shaft and having means to coact with means on said wheel for rotating the wheel step-by-step, a pawl oscillatably mounted on said frame and having two teeth so shaped and disposed at opposite sides of the ratchet teeth that upon oscillation of the pawl by said armature lever one pawl tooth moves the ratchet disk one step in one direction to rotate said wheel while the other tooth prevents rotation in the opposite direction.