US3254294A

US3254294A - Electrical supply system indicator

Info

Publication number: US3254294A
Application number: US250432A
Authority: US
Inventors: Bergsma Rudolph
Original assignee: King Seeley Thermos Co
Current assignee: King Seeley Thermos Co
Priority date: 1963-01-09
Filing date: 1963-01-09
Publication date: 1966-05-31
Anticipated expiration: 1983-05-31

Description

May 31, 1966 R. BERGSMA ELECTRICAL SUPPLY SYSTEM INDICATOR 2 Sheets-Sheet 1 Filed Jan. 9, 1963 INVENTOR.

Alli/- 7 May 31, 1966 R. BERGSMA ELECTRICAL SUPPLY SYSTEM INDICATOR 2 Sheets-Sheet 2 Filed Jan. 9, 1963 INVENTOR. )7z/a o/ Z' 28757774 United States Patent 3,254,294 ELECTRICAL SUPPLY SYSTEM INDICATOR Rudolph Bergsma, Ann Arbor, Mich., assignor to King- Seeley Thermos C0., Ann Arbor, Mich., a corporation of Michigan Filed Jan. 9, 1963, Ser. No. 250,432 9 Claims. (Cl. 322-99) This invention relates to signaling systems, and more particularly to signaling systems for indicating the existence or attainment of a preselected condition in an electrical circuit.

Primary objects of this invention are to indicate the eX- istence or attainment of a critical or dangerous condition in an electrical circuit by alarm means controlled by a pair of contacts that are operatively associated with first condition responsive means which tend to close the contacts when a first predetermined condition exists in the circuit and second condition responsive means operatively associated with the contacts to compensate for said contact closing tendency of said first condition responsive means until a second predetermined condition occurs in the circuit; and to indicate such a critical or dangerous condition by means including such a pair of contacts which are controlled by such first and second condition responsive means which are further characterized by the ability to maintain said contacts closed for a predetermined period when the electrical circuit is first energized in order to show that the signaling system is in proper working order.

The nature of the invention and its objects and features will become more apparent from a consideration of the following detailed description of the invention when read with reference to the accompanying drawings, in which:

FIGURE 1 is a diagrammatic view of an electrical circuit including one embodiment 'of the signaling system of the present invention;

FIGURE 2 is a top plan view of a combined signal relay and voltage regulator device constructed in accordance with certain of the principles of the present invention;

FIGURE 3 is a view in vertical section taken substantially along the line 33 of FIGURE 2 looking in the direction of the arrows;

FIGURE 4 is a view in vertical section taken substantially along the line 44 of FIGURE 2 looking in the direction of the arrows;

FIGURE 5 is a bottom plan view of the device illustrated in FIGURE 2.

Referring now to the drawings, and electrical circuit is illustrated in FIGURE 1 which includes a signal relay 12 and a voltage regulator 14 for controlling a voltage supply system for an automobile or the like of the type having a voltage generating device .16, a battery 18, and a switch 20 which may, for example, be the ignition switch of an automobile. The voltage regulator 14, in accordance with conventional automative practice, serves to maintain the voltage of the battery 18 between limits which are acceptable for many vehicle requirements and includes terminals T T and T for electrically connecting it in circuit with the battery 18 and voltage generating device 16. The voltage regulator 14 is representatively illustrated in the structural views as a regulator of the type having three stages of operation produced by electrothermally responsive means as more fully disclosed in the copending United States application No. 218,412, filed August 21, 1962, of Ernest L. Klavitter, for Voltage Regulator. It will be understood from the following discussion that the signaling system of the present invention is equally suited for use with other regulators which are responsive to conditions in an electrical circuit.

3,254,294 Patented May 31, 1966 ICC The voltage generating device 16 more particularly includes an armature 22 and a field coil 24 which are electrically connected to the terminals T and T of the voltage regulator 14, respectively. The battery 18 is connected by a conductor 25 and the switch 20 to the ter minal T Both the generating device 16 and battery have a load 26 connected thereacross such as the lights, instruments or other electrical circuits of an automobile or the like. The battery Y18 and the voltage generating device 16 are thereby interconnected in a conventional fashion so that either source of potential may supply the requirements of the load 26. The sources of potential, in elfect, float on the same. lines so that the battery 18 will be charged by the voltage generating device 16 so long as the voltage output therefrom is greater than the voltage across the battery terminals. Conventional cutout switch means (not shown) may be included in the circuit in a conventional manner to prevent discharge of the battery 18 through the armature 22 of the device 16 when the switch 20 is closed and an engine or the like driving the device 16 is not running.

The signal relay 12 includes a pair of contacts 28, 30, which control a lamp 32 or other suitable signaling device which may be disposed on the dashboard or any other convenient place in a vehicle within the vision or other perception of the vehicle operator. to indicate when a predetermined critical or dangerous condition is present in the electrical system 10. The lamp 32, more specifically, is electrically connectedto the relay 12 by means of a terminal T The signal relay .12, more particularly, includes a U- shaped polymetallic element 36 having a first leg portion 38 anchored at one end thereof by suitable fixed support means representatively illustrated, by the grounding symbol 40 which does not connote electrical grounding and a second leg portion 42 which has one end thereof connected to the opposite end of the first leg portion 38 by means of a crosspiece 44 which includes an upright flange portion 46 which is provided to increase the stiffness of the crosspiece 44 to the point where it will not deflect to any significant degree in response to the mechanical or thermal forces to which the unit is subjected. The freely movable end of the second leg portion 42 carries the contact 2-8 which is mechanically and electrically integral therewith relative to the contact 30 which is mechanically and electrically connected to a movable arm portion 48 of electrically conductive material which is controlled by the voltage regulator 14 in a manner which will be discussed in greater detail subsequently.

The leg portions 38, 42 of the polymetallic element 36 are located substantially in a common plane when they are at the same temperature. The relay 12, however, includes means for differentially heating such leg portions to cause the freely movable end of the second leg portion 42 to deflect out of such a common plane.

Differential heating of the leg portions 40, 42 is accomplished, more particularly, by heating means in the form of a heater winding :50 representatively disposed in heat transfer relationship with the second leg portion 42 and, more particularly, coiled around that leg portion. One end of the heater winding 50 is electrically connected to the conductor 25 and the other end thereof is connected to ground. .As a result, when the ignition switch 20 is closed, the heater winding 50 is connected across the battery 18 and the voltage generating device :16 so that current flows therethrough when the device 16 is operative. The resultant heating of the second leg portion 42 causes the freely movable, contact-carrying end thereof to deflectin a direction to separate the pair of contacts28, 30.

It will'be appreciated that the provision of a U-shaped polymetallic element 36 of the nature shown will permit compensation of ambient temperature variations since the effect upon the position of the freely movable end of the second leg portion 42 of heating of the first leg portion 38 is the opposite of that produced by equal heating of the second leg portion 42.

As will be discussed in greater detail when the structural views are described, the voltage regulator 14 includes means for electrically connecting the arm portion 48 thereof to the conductor 25. Thus, when the contacts 28, 30 are closed, current passes through a circuit comprising battery 18, switch 20, conductor 25, the voltage regulator 14, the closed contacts 28, 30, the body of the polymetallic element 36, lamp 32, and suitable conductor means to ground to light the lamp 32 and thereby indicate a critical condition in the system.

In the structural views, illustrating a preferred construction of a signal relay and voltage regulator device adapted to be associated with a voltage supply system such as that illustrated in FIGURE 1, the device is mounted on a base 52 of suitable electrical insulating material and includes a first electrical contact 54 secured to a strip 56 of electrically conductive material which is in spaced parallelism and generally transverse to a recessed surface 58 on one face of the base 52 adjacent one end thereof. One end of the strip 56 is mechanically secured to the base 52 by means of a rivet 60 which also electrically connects the contact 54 and the strip 56 to the terminal T, which connects the device to the battery 18 as discussed above.

The opposite end of the conductive strip 56 is adjustably movable with respect to the base 52 by means of a threaded screw 64 in threaded engagement with the base 52 which has one end thereof directed through the base into engagement with a resilient bumper element 66 of suitable electrical insulating material which is secured to the opposite end of the strip 56.

A second contact 68 is carried on a strip of conductive material 70 which is in spaced parallelism with the strip 56 and supported on the recessed surface 58 of the base 52 by means of a rivet 72 which is directed through the base 52 to electrically connect the strip 70 to the terminal T which is adapted to be connected to ground.

In the preferred construction, a movable contact 76 is located intermediate the

contacts

54, 68 on the freely movable end of an elongated cantilevered spring arm 78 which has the opposite end thereof anchored to the base 52 by suitable fastening means such as a transverse bar 79 which is held against the spring arm 78 by a rivet 80 or the like. The spring arm 78 is also electrically connected to the terminal T of the device by means of a suitable electrically conductive element which is representatively illustrated as a rivet 82 which secures the terminal T on one face of the base 52. A pair of laterally spaced elongated spring arms 88, 90 extend longitudinally from the anchored end of the spring arm 78 and on either side thereof to a point adjacent'the freely movable end of the spring arm 78 where they are interconnected by means of a transverse arm 92 and joined to a base portion 98 of a connector element 100. The elongated spring arms 88, 90 and the spring arm 78 are all spring-biased toward the connector element 100 which acts to space the spring arm 78 a predetermined distance from the spring arms 88, 90.

Furthermore, the cantilevered spring arm 78 is operatively connected to and controlled by an electrothermal actuator which is representatively illustrated as a wire 86 which has appropriate electrothermal characteristics including a finite resistance and a high coeflicient of thermal expansion. More specifically, in the preferred embodiment, the wire 86 is representatively illustrated as comprising a single'long wire which is wound to define a plurality of reaches, representatively four in number, which extend substantially parallel to the recessed surface 58 of the base 52. One end of the wire 86 connects to 7 one end of an anchor post 104 having the opposite end thereof secured to the base 52. The wire extends therefrom longitudinally of the base 52 to the connector element where it is wound around an outwardly directed ear portion 106 thereof from whence it returns to the opposite end of the base 52 where it is wound around the outer circumferential surface of a nut 108 which is rotatably and eccentrically mounted on one end of a post 110 which has its opposite end directed through base 52 where it is secured to a terminal 112 by means of a snap ring 114.

The wire 86 is directed from the adjusting nut 108 lon gitudinally of the base 52 to the connector element 100 where it is wound around a second outwardly directed ear portion 116 thereof which is spaced laterally of the first ear portion 106. The wire then returns to the opposite end of the base 52 where it connects to one end of an anchor post 118 which has the opposite end secured to the base 52.

In the preferred embodiment, the wire 86 is electrically connected to the terminal T by means of an insulated conductor 120 which has one end thereof electrically connected to the rivet 60 and the opposite end thereof electrically connected to the terminal 112. An elongated strip of conductive material 122 is located on the opposite face of the base 52 and has one end thereof electrically connected to the rivet 72 and the opposite end thereof electrically connected to the pair of spaced anchor posts 104, 118 by means of a transverse arm portion 124.

Hence, when the regulator 14 is connected in a system such as the voltage supply system illustrated in FIGURE 1, current will pass through terminal T conductor 120, adjusting nut 108, wire 86,

conductive strips

124, 122, rivet 72, and thence to the grounding'terminal T The wire 86 will accordingly elongate between the anchor points defined by the connector element 100 and the anchor posts 118, 104 to allow the cantilevered spring arm 78 to move the contact 76 with respect to the first and second

fixed contacts

54, 68.

In the preferred embodiment, a voltage divider 126 including

resistor elements

128, 130 is mounted on the face of the base 52 opposite the face having the recessed surface 58. More specifically, the first resistor element 128 has one end thereof electrically connected to the terminal T and the opposite end thereof connected to the terminal T at the rivet 82. Intermediate the terminals T T the resistor element 128 is wound on an elongated strip of insulating material 132 which is directed substantially longitudinally of the base 52 with the opposite ends thereof connected to the rivet 60 and the rivet 84, respectively.

The resistor 130 of the voltage divider 126 has the opposite ends thereof electrically connected'between the terminal T and the terminal T and is wound intermediately thereof on an elongated strip of insulating material 134 which has the opposite ends thereof connected to the rivet 72 and the rivet 82, respectively. Such an arrangement enables ambient air to circulate completely around each of the resistor elements of the voltage divider 126 so that heat generated thereby will be dissipated by the surrounding air to prevent an undesirable temperature increase in the regulator 14.

When the preferred construction is included in an electrical system of the type illustrated in FIGURE 1, and the voltage applied across the wire 86 is less than a first predetermined voltage, wire 86 will not be heated sufficiently to permit separation of the

contacts

54, 76. Under this condition the field coil 24 is energized to the maximum extent via a load or output circuit including battery 18, switch 20, conductor 25, terminal T closed

contacts

54, 76, spring arm 78, terminal T and coil 24 to ground. It will be observed that under this condition the resistor element 128 is rendered ineffective by the

contacts

54, 76 and the resistor element 130 shunts the coil 24. Accordingly, the generator 16 will then develop its maximum output voltage (for its then driven speed).

When the voltage output of the generator 16 is between the first predetermined voltage and a second predetermined voltage the

contacts

54, 76 begin to pulse in a cyclic fashion. When the voltage applied across the wire 86 exceeds the first predetermined voltage level, the Wire 86 Will elongate between the anchored ends thereof until the spring arm 78' causes the movable contact 76 to separate from the contact 54. This renders the resistor 128 effective and thereby reduces the voltage across coil 24 so that the voltage output of device 16 falls. This reduces the voltage applied across wire 86 causing it to contract and close the

contacts

54, 76.

In cases in which the voltage output of the device 16 reaches a. value above the second predetermined Voltage (but less than a third predetermined voltage) which characterizes a combination of operating conditions which are most frequently present in a given electrical system of this type, the wire 86 will elongate between the anchored ends thereof and hold the movable contact 76 between the

contacts

54, 68.

When the voltage output of the device 16 attains or exceeds the third predetermined voltage, the wire 86 will elongate still further to cause the movable contact 76 to engage the contact 68 in a cyclic fashion to short out the voltage producing device to prevent overcharging of the battery 18.

Each of the aforesaid stages of regulator operation are more specifically discussed in the above mentioned copending application of Otto et al. for Voltage Regulator, the disclosure of which is hereby incorporated by reference as fully as if that disclosure had been explicitly disclosed herein.

In the preferred construction, the signal relay 12 is operatively associated with the voltage regulator 14 as follows. The polymetallic element 36 of the signal relay 12 has the first leg portion 38 thereof anchored on the base 52 by means of suitable fastening means such as a rivet 136 and has the freely movable end of 'the second leg portion 42 located adjacent the crossarm 92 which interconnects the spring arms 88, 90. The rivet 136 also electrically connects the element 36 to the terminal T; which is secured by the rivet 136 on the opposite face of the base 52. p

The transverse arm 92 (which corresponds to the movable arm portion 48 in FIGURE 1) has the contact 30e1ectrically and mechanically integral therewith. The heater winding 50 of the signal relay 12 one end thereof connected to a terminal 138 and the opposite end thereof connected to a terminal 140. The terminals 138, 140 are adapted to be electrically connected across the voltage producing device'16 so that a component of the cur- I rent output of the device Will pass therethrough causing the temperature of the second leg portion 42 to increase and thereby deflect the leg in a direction to separate the contact 28 from the contact 30.

The signal relay and voltage regulator device, in accordance with certain of the principles of the present invention has time delay characteristics which enable a signaling device such as the lamp 32 to be tested. Such testing occurs in the illustrated arrangement when the ignition switch is initially closed. At this point the voltage generating device 16 is ineffective and the wire 86 is accordingly deenergized and contracted between the anchored ends thereof causing the

contacts

54,76 to be in engagement. The contracted wire 86 will also have moved the elongated spring arms 88, 90 in a direction to cause the contact 30 on the transverse arm 92 to engage the contact 28 on the polymetallic element 36. Accordingly, current will pass from the battery 18 through the terminal T rivet 60, conductor strip 56,

closed contacts

68, 76, spring arm 78, spring arms 88, 90, closed contacts 28, 30 and thence through polymetallic element 34, terminal T and lamp 32 to ground. The lamp 32 will thereby light.

During normal operation of the voltage supply system, the voltage generating device 16 will produce a voltage across the wire 86 which will cause it to elongate sufficiently to allow the spring arms 88, 90 to separate the operative contacts 28, 30 of the'signal relay 12. Such separation will be delayed a preselected time period following closure of the switch 20 (the testing period) and Will thereafter cause deenergization of the lamp 32. Under normal conditions the lamp 32 will not relight following the lamp testing period.

Under abnormal operating conditions the voltage imposed across the wire 86 is sometimes reduced to a point which will cause the Wire to contract between the anchored ends thereof sufiiciently to cause the spring arms 88, 90 to be deflected in a direction which will tend to move the contacts 28, 30 into engagement. Such an abnormal condition might, for example, occur in the illustrated system when an extremely large load is imposed across the voltage generating device 16 during periods in which the device 16 is driven at relatively low speeds. During such operation the contacts 28, 30 of the signal relay 12 would close to energize the lamp 32 to give a false indication of a dangerous or critical condition (such as failure of the generating device 16) except for the presence of the polymetallic element 36 and heater winding 50.

The heater winding 50 on the second leg portion 42 of the polymetallic element 36 will prevent a false indication of such a dangerous or critical condition since it will carry a component of the current output of the voltage generating device 16 during such abnormal load conditions. Accordingly, the second leg portion 42 will be heated to deflect in a direction to maintain the operative contacts 28, 30 of the signal relay 12 open so long as the voltage generating device 16 continues to function.

FIGURES 3 and 4 show the components of the signal relay 12 and the voltage regulator 14 in the positions assumed under such abnormal operating conditions and hence the second leg portion 42 of the signal relay 12 is deflected in a direction to separate the contact 28 from the contact 30, and the

contacts

76 and 54 of the voltage regulator are held in engagement by the wire 86 acting through the connector element and the spring arm 78.

When there is a critical condition present in the voltage supply system, for example, when there is no output from the voltage generating device 16 because of failure thereof, there will no longer be a current component passing through the heater winding 50 and hence the second leg portion 42 of the signal relay 12 will cool and deflect in a direction to cause the contact 28 mounted thereon to engage the contact 30 of the voltage regulator 14 and thereby complete a circuit from the battery 18 through ignition switch 20, conductor 25, voltage regulator 14, closed contacts 28, 30, the body of the polymetallic element 36, lamp 32, and suitable conductor means to ground causing the lamp 32 to light and thereby indicate that the critical condition is present in the system.

The improved signal relay and voltage regulator device, accordingly, will initially indicate whether the signaling system is operative when the ignition switch in a voltage supply system of an automobile or the like is initially closed and will thereafter function to maintain a signaling device such as the lamp 32 in a deenergized stateduring both normal and abnormal load conditions and will only be energized when a dangerous or critical condition corresponding to failure of the voltage output device occurs in the electrical system.

While it will be apparent that the embodiment of the invention herein disclosed is well calculated to fulfill the objects of the invention, it will be appreciated that the invention is susceptible to modification, variation and change without departing from the proper scope or fair meaning of the subjoined claims.

What is claimed is:

1. A signaling system for indicating a condition in a voltage supply system of the type including a voltage generating device and a voltage regulating means for controlling the voltage generating device, comprising a movable contact arm controlled by the voltage regulating means, signaling means, and signal relay means controlling said signaling means and including a pair of electrical contacts, one of said electrical contacts being controlled by the movable contact arm of the voltage regulating means, said signal relay means further including means responsive to the fluctuations of the voltage supply system for controlling the other one of said electrical contacts.

2. The combination of claim 1 in which a switch controls the actuation of the voltage supply system and in which said signal relay is eflective upon actuation of the switch to operate said signaling means for an interval demonstrating the operability of said signaling means and for terminating the operation of said signaling means after said interval.

3. A signaling system for indicating a condition in a voltage supply system of the type including a voltage generating device and a voltage regulating means for controlling the voltage generating device, comprising a movable contact arm controlled by the voltage regulating means, signaling means, and signal relay means controlling said signaling means and including a pair of electrical contacts, one of said electrical contacts being cont-rolled by the movable contact arm of the voltage regulating means, said signal relay means further including electrothermally responsive means responsive to the fluctuations of the voltage supply system for controlling the other one of said electrical contacts.

4. The combination of claim 3 in which said thermally responsive means moves said other contact away from said one contact in response to an increase of the system voltage. v

5. The combination of claim 3 in which the movable contact arm moves in a direction to tend to close said contacts in response to a reduction in the system voltage and in which said thermally responsive means compensates for the contact closing tendency of the movable contact arm until a critical condition is present in the voltage supply system.

6. The combination of claim 5 in which the movable contact arm moves said one contact to a preselected position when the voltage of the voltage supply system falls to a preselected value below a normal value, and in which said thermally responsive means holds said other contact substantially spaced from said one contact when the voltage of the voltage supply system is normal and slowly moves said other contact towards said one contact when the voltage of the voltage supply system falls to said preselected value.

7. A signaling system for indicating a condition in a voltage supply system of the type including a voltage generating device and a voltage regulating means for controlling the voltage generating device, comprising a movable contact arm controlled by the voltage regulating means, signaling means, and signal relay means controlling said signaling means and including a pair of electrical contacts, one of said electrical contacts being controlled by the movable contact arm of the voltage regulating means, said signal relay means further including an electro-thermally responsive means responsive to the fluctuations of the voltage supply system for controlling the other one of said electrical contacts, said thermally responsive means including a polymetallic element having a freely movable end portion controlling the other one of said contacts and heating means therefor electrically connected to the voltage generating device for heating said polymetallic element in accordance with the output from the voltage generating device.

' 8. The combination of claim 7 in which aswitch controls the actuation of the voltage supply system and in which said signal relay is effective upon actuation of the switch to operate said signaling means for an interval demonstrating the operability of said signaling means and for terminating the operation of said signaling means after said interval.

9. The combination of claim 7 in which the movable contact arm moves said one contact to a preselected position when the voltage of the voltage supply system falls to a preselected value below the normal value, in which said heating means heats said polymetallic element when References Cited by the Examiner UNITED STATES PATENTS 2,064,460 12/1936 Carr et a1 340-220 2,511,631 6/1950 Gordon 340220 2,833,889 5/1958 Boddy 200-122 3,022,456 2/1962 Larson et a1 320-48 X NEIL C. READ, Primary Examiner.

R. M. ANGUS, Assistant Examiner.

Claims

1. A SIGNALING SYSTEM FOR INDICATING A CONDITION IN A VOLTAGE SUPPLY SYSTEM OF THE TYPE INCLUDING A VOLTAGE GENERATING DEVICE AND A VOLTAGE REGULATING MEANS FOR CONTROLLING THE VOLTAGE GENERATING DEVICE, COMPRISING A MOVABLE CONTACT ARM CONTROLLED BY THE VOLTAGE REGULATING MEANS, SIGNALING MEANS, AND SIGNAL RELAY MEANS CONTROLLING SAID SIGNALING MEANS AND INCLUDING A PAIR OF ELECTRICAL