US2681394A

US2681394A - Flasher device

Info

Publication number: US2681394A
Application number: US265658A
Authority: US
Inventors: Jesse R Hollins
Original assignee: Individual
Current assignee: Individual
Priority date: 1952-01-09
Filing date: 1952-01-09
Publication date: 1954-06-15
Anticipated expiration: 1971-06-15

Description

J. R. HOLLINS FLASHER DEVICE June 15, 1954 Filed Jan. 9, 1952 FIG.7

Vila/I72 F. I 6 INVENTOR rjfsse J? f/oi/z'ns BY a & ORNEY FIGS Patented June 15, 1954 UNITED STAT TENT OFFICE 8 Claims. l

This invention relates to periodic circuit interrupters, commonly known as flashers, as used in signalling circuits to flash signal lamps. More particularly, the invention relates to an improved flasher having a novel self-cleaning contact arrangement.

Flashers of the type used in automotive vehicle signalling arrangements are generally of the thermal type, including a high resistance or hot wire of Nichromc or the like initially in the the signal circuit. When the circuit control switch is closed, the resistance wire is included in the lamp circuit. Its resistance is sufficiently high to prevent suflicient current flow to the signal lamps to illuminate the latter.

The current flowing through the high resistance wire causes the latter to become hot and expand. This expansion allows a pair of contacts, in shunt relation to the hot Wire to close, allowing sufiicient current flow to illuminate the signal lamps. However, the shunted resistance wire cools and contracts to break the shunt circuit so that all current must again flow through the resistance wire. This operation is cyclically repeated, effecting flashing of the signal lamps.

The usual vehicle source of electrical energy is D. C'., including a battery and a D. C. generator. Thus, the current flow through the flasher is D. 0. As is known to those skilled in the art,

unidirectional current flow across a pair of make and break contacts, which are when they are separated, under load, causes a mound to form on one contact and pitting of the other contact. This is due to the unidirectional current flow across the are formed by the breaking contacts, and has resulted in inefficiency and short life of flashers. At the least, frequent dressing and replacement of the contacts is necessary, representing a maintenance expense.

The present invention is directed to a novel contact arrangement for flashers, in which arcing of the contacts is substantially reduced. Even more important, one of the contacts is arranged to wipe over the other contact during separation, thereby effecting automatically a cleaning or dressing of the contacts each cycle of flasher operation. Consequently, the efiiciency of the flasher remains substantially unimpaired, the contact life is Very substantially lengthened, and the necessity of dressing of the contacts is reduced to a negligible amount.

A further feature of the invention is the provision of a relay armature carrying the wiping contact, and which is spring biased to the contact open position. This armature is so mounted as to follow the movement of a contact carried by a resistance Wire controlled spring arm, as the latter is moved by contraction of the resistancewire, for a predetermined travel. The two contacts then disengage, deenergizing the relay, and the spring snaps the armature back making a quick contact break and thus reducing arcing of the contacts. As the relay armature follows the spring arm, the two contacts wipe over each other to clean or dress the contacts.

For an understanding of the invention principles, reference is made to the following description or" a typical embodiment thereof as illustrated in the accompanying drawing. In the drawing:

Fig. l is a part elevational and part sectional view of the invention flasher in the inoperative or open position, and schematically illustrating a source of power and a signal circuit connected to the flasher;

Fig. 2 is a view similar to Fig. l of a modified arrangement for effecting alternating flashing of signal lamps.

Fig. 3 is a left end elevation view, on the line 33 of Fig. 1, of the flasher of Fig. 1;

Fig. 4 is a right end elevation view, on the line t--4 of Fig. l, of the flasher of Fig. l; and

Figs. 5, 6 and 7 are sectional views taken on the correspondingly numbered lines of Fig. '1, illustrating the conventional pivoting mounting of the relay armature on the relay frame.

Referring to Fig. l, the invention flasher I0 is illustrated in connected circuit relation with a grounded battery ii, a grounded pilot lamp i2, and a control switch it for selectively energizing grounded signal lamps i3, i3.

Flasher it includes a dielectric base It on which is fixedly mounted a metal frame I! including an electrically conductive core It of a relay 2%) fixedly mounted on frame ll. One upstanding arm 2! of frame ii carries an outwardly facing contact 22. Adjacent this arm is a flat spring 23 secured to base it and carrying a contact 25 at its free end, spring 23 normally tending to engage contact 25 with contact 22. A. high resistance wire 31!, of Nichrome or the like, is anchored at one end to the outer end of spring 23, and at the other end, to a terminal 24 on base Iii. Normally, wire 39 holds spring 23 away from frame arm 2!.

Contact 25 is of such length and so mounted that it projects at least slightly beyond contact 22, extending sufficiently inwardly to have adequate surface engagement with contact 22. A conductor 2% connects frame arm 2! to terminal 24. Contact 25, when engaged with contact 22, is arranged to be engaged by a contact 21 on the outer end of arm 3! of relay armature 32. Due to the projection of contact 25 outwardly beyond contact 22, contact 21 does not engage contact 22.

Armature 32 is mounted through arm 28 of frame ii, this arm forming a fulcrum for the armature and having a reentrant outer end 29 acting as a limit stop for the armature. The pivotal mounting of armature 32 on arm 28 of frame ii is conventional, as best seen in Figs. 1, 5, 6 and 7. The armature is spring biased to the contact disengaging position by a relatively strong tension spring 38 connected between the armature and the end 33 of frame ll. Secured to armature 32 is a spring 31 carrying a contact 3 1. This latter is engageable with a contact 36, on a fixed arm 39 secured to base IE5, when

contacts

25 and 27 are engaged.

Battery H is connected by conductor ll to core it and frame IT. A conductor 42 connects one end of relay coil 35 to spring 23. A conductor :33 connects the other end of coil 35 to terminal M connected by conductor 46 to switch it. El to pilot lamp l2.

Flasher iii operates in the following manner: When switch i is closed current flows from battery ll through conductor 6i, core it, frame i'l,

arm 2 I, conductor 26, terminal 2 3, resistance wire 3i spring 23, conductor e2, coil 35, conductor 43, terminal conductor lG, control switch i5, and the signal lamps i3, i3 to ground. Due to the high resistance of wire 38, the current fiow is insuffici nt either to operate relay 2% or to effect sensible illumination of the signal lamps.

As wire 30 becomes hot, due to current flow, it expands, allowing spring 23 to engage contact 25 with contact 22. This shunts wire 30, allowing current to flow from battery I I through conductor ll, core 28, frame ll, arms 2i, and through contacts i2, 255, spring 23, and conductor ll. to coil The current flow is now sufilcient to operate relay ill and to illuminate the signal lamps.

As a result of full energization of relay coil 35, armature 32 is now pulled toward the upper end of core it, swinging counter-clockwise to engage its contact 2i with contact 25, and to engage its contact M, on spring 3?, with contact 36. Engagement of contacts 25 and 2? establishes the following circuit in parallel with the circuit including arm 2i, contact 22 and contact 25: battery ii, conductor ii, core l8, frame ill, armature 32, arm 3 l, contact 2'! and contact 25. Thus, there are now two parallel energizing circuits for relay coil til. Engagement of contacts 3c and 35 energize pilot lamp i2 over the following circuit: battery ii, conductor il, frame ll, armature 32, spring 3'3, contacts 35 and 3%, arm 39, conductor A3, and pilot lamp 152.

Due to the shunting of high resistance wire 39, the latter cools and contracts. As wire 39 contracts, it draws the upper end of spring 23 to the left, or counterclockwise, disengaging contact 25 from contact 22. As these contacts are in one of two parallel energizing circuits for coil 35, there is substantially no current load on

contacts

22 and 25 as they separate, as the full current for relay coil 35 will be carried through the circuit including contacts 25 and ill, this circuit maintaining coil 35 fully energized. As there is substantially no load on

contacts

22, 25 as they separate, there will be substantially no arcing between these contacts.

Terminal l! and conductor 18 connect arm As contact 255 is moved to the left or counterclockwise by contraction of wire 39, armature 32 continues to swing counter-clockwise due to the full energization of relay coil 35 resulting in the pull of core i8 on armature 32 being maintained. Contact 2? thus remains engaged with contact but, due to the relative motions of spring 23 and armature contacts 25 and 2'! have relative movement while remaining in surface-tosurface engagement. Thus, these contacts wipe over each other resulting in a cleaning or dressing of the contact surfaces.

The limit of counter-clockwise movement of armature 32 is determined by engagement of the armature with the upper end of core It. At the limit of movement of armature 32, with spring 23 still being pulled to the left by contraction of wire 39, contacts 25 and 2'2 are separated. This breaks the shunting circuit around high resistance wire 3i! and which has been main taining full energization of relay coil 35. The current through coil 35 is thus substantially instantaneously reduced to a value insufficient to effect full energization of the coil so that spring 38 snaps armature 32 counter-clockwise. This quick breaking action by the

contacts

25 and 21 substantially eliminates any arcing across these contacts. At the same time, contacts 3 and 36 are snapped apart due to the snapping of armature 32 clockwise by spring This breaks the pilot lamp energizing circuit, with the quick break substantially eliminating arcing of

contacts

34 and 36. The current flow, due to inclusion of high resistance wire 3%! in the energizing circuit for the relay and for lamps l3, 3, is insufficient to effectively energize these lamps.

Should a signal lamp be defective, the current flow through coil in series with the signal lamps, will be insufficient to fully energize the coil so that armature 32 will not be drawn toward the upper end of core it. As wire 38 expands and contracts, spring 23 will flex back and forth alternately engaging and disengaging

contacts

22 and 25. However, as relay armature 32 is not operated,

contacts

34 and 35 will not be engaged so that pilot lamp i2 will not be lit. Thus, the operator is apprised of a defective signal lamp condition by the failure of the pilot lamp to light. The relatively low current iiow across

contacts

22 and 25, due to one of the signal lamps being defective, will not be sufficient to cause pitting or damaging of these contacts.

Fig. 2 illustrates an alternative arrangement, whereby sets of signal lamps may be flashed in alternation. The same reference characters have been used to designate the same elements.

In this arrangement, control switch 15 is replaced by a control switch 15' between battery 1 l and the relay. An insulating block 5! on the inner side of arm 39 supports a conductive metal arm 52 extending toward armature 32 and carrying a contact 53 which is engaged by a back contact Ed on the outer side of spring 3! when armature 32 is at the limit of its clockwise movement under the influence of spring 33. Arm 52 is connected by a conductor 56 to grounded signal lamps 5's, El.

When switch 55' is closed, current flows from battery ii through switch 15, core it, frame ll, armature 32, spring contacts as and E3, arm 52, conductor and lamps Thus, these latter lamps are initially energized. When armature is swung counter-clockwise as a result of full energization of relay coil 35, as previously described, contacts 53 and 5A are separated, thus breaking the energizing circuits of lamps 51, 51'. At the same time, engagement of contact with contact 22 will have completed the shunt circuit around resistance wire 30, effecting full energization of coil and lamps l3, 13. This circuit is supplemented by a second shunt circuit when armature contact 2? engages contact 25, as has been previously described. Engagement of contacts and at, when armature 32 is swung counter-clockwise, lights pilot lamp t2. When high resistance wire 30 contracts, resulting in eventual snapping of armature 32 clockwise under the influence of spring 38, lamps l3, :3 and pilot lamp ii! are extinguished, and lamps 51, 5'1" are relit when contact 54 re-engages contact 53. Thus, lamps 5T, 51 are flashed in alternation with lamps I3, I3", pilot lamp I2 being flashed in synchronism with lamps 63, IS".

The foregoing construction thus provides a durable flasher having low contact maintenance. Additionally, the pilot lamp circuit is independent of the relay coil circuit, and so arranged as to indicate when a signal lamp is defective.

While a specific embodiment of the invention has been shown and described in detail to illustrate the application of the invention principles, it will be understood that the invention may be otherwise embodied without departing from such principles.

What is claimed is:

l. A flasher comprising, in combination, a supporting base a fixed contact, a movable contact supported on said base, a high resistance wire connected to said base and to said movable contact and arranged, when shunted, to disengage said movable contact from said fixed contact, means biasing said movable contact to engage said fixed contact to complete a first shunt circuit for said resistance wire, a relay including a metal frame supporting said fixed contact, a metal core connected to said frame, an operating coil on said core connected in circuit with said movable contact and said resistance wire, and a movable metal armature pivoted on said frame included in a second shunt circuit for said resistance wire, said relay coil being included in both shunt circuits, said armature carrying a third contact engageable with said movable contact when said coil is energized through said first shunt circuit closed by engagement of said movable contact with said contact, said armature swinging toward said movable contact as the latter is retracted by contraction of said high resistance wire so that said movable contact and said third contact wipe over each other, and said movable contact disengaging said third contact to break said second shunt circuit, in the full retracted position of said movable contact, to deenergize said relay coil, and spring means connected to said frame and armature and operable to bias said armature away fom said movable contact when said relay coil is deenergized.

2. A flasher comprising, in combination, a supporting base a fixed contact, a movable contact supported on said base, a high resistance wire connected to said base and said movable contact and normally biasing said movable contact away from said fixed contact, means biasing said movable contact to engage said fixed contact, a relay including an operating coil on said core and a movable metal armature pivoted on said frame, a circuit including a metal frame supporting said fixed contact, a metal core connected to said frame said fixed contact, said resistance wire, said movable contact, and said coil in series rela tion, effective to heat said resistance wire to expand the latter, a first relay energizing circuit, in shunt with said resistance wire, and including said fixed contact and said movable contact, in engagement when the resistance wire expands, and said relay coil, said armature carrying a third contact engageable with said movable contact when said coil is energized, and a second relay energizing circuit, in shunt with said resistance wire, and including said third contact, said movable contact, and said relay coil, said armature swinging toward said movable contact as the latter is retracted by contraction of said high resistance wire so that said movable contact and said third contact wipe over each other, and said movable contact disengaging said third contact to break said second shunt circuit, in the fully retracted position of said movable contact, to deencrgiz-e said relay coil, and spring means connected to said frame and armature and operable to bias said armature away from said movable contact when said relay coil is deenergized.

3. A flasher comprising, in combination, a di electric base, a metal relay frame mounted on said base, a relay coil mounted in said frame, a metal core connected to said frame and mounted in said coil, a metal armature hingedly mounted on said frame in conductive relation therewith and carrying a first contact, a metal spring member mounted on said base and extending toward said armature, said spring member having a second contact extending therealong in a direction substantially perpendicular to said first contact in the operated position of said armature, a high resistance wire connected to said spring memher and said base and normally biasing said spring member to a position retaining said second contact out of the line of movement of said first contact, a fixed contact carried by said relay frame and engageable by said second contact under the bias influence of said spring member when said resistance wire is heated and expands, the fixed contact being disposed inwardly of the edge of said second contact nearest said first contact whereby said first contact, when said armature is operated, will ngage only the outer edge of said second contact, a circuit including said fixed contact, said resistance wire, said second contact, and said coil in series relation, effective to heat said resistance wire to expand the latter, a first relay energizing circuit, in shunt with said resistance Wire, and including said fixed contact and said second contact, in engagement when the resistance wire expands, and said relay coil, and a second relay energizing circuit, in shunt with said resistance wire, and including said first contact, said second contact, and said relay coil, said armature swinging toward said spring member as the latter is retracted by contraction of said high resistance wire so that said first contact and said second contact wipe over each other, and said second contact disengaging said first contact, in the fully contracted condition of said resistance wire, to break the relay energizing circuit, and spring means operable to bias said armature away from said second contact when said relay coil is deenergized.

4. A fiasher comprising, in combination, a dielectric base, a metal relay frame mounted on said base, a relay coil mounted in said frame, a metal core connected to said frame and mounted in said coil, a metal armature hingedly mounted on said frame in conductive relation therewith and carrying a first contact, a metal spring mema ber mounted on said base and extending toward said armature, said spring member having a second contact extending therealong in a direction substantially perpendicular to said first contact in the operated position of said armature, a high resistance wire connected to said spring member and said base and normally biasing said spring member to a position retaining said second contact out of the line of movement of said first contact, a fixed contact carried by said relay frame and engageable by said second contact under the bias influence of said spring member when said resistance wire is heated and expands, the fixed contact being disposed inwardly of the edge of said second contact nearest said first contact whereby said first contact, when said armature is operated, will engage only the outer edge of said second contact, a circuit including said fixed contact, said resistance wire, said second contact, and said coil in series relation, efiective to heat said resistance wire to expand the latter, a first relay energizing circuit, in shunt with said resistance wire, and including said fixed contact and said second contact, in engagement when the resistance wire expands, and said relay coil, a second relay energizing circuit, in shunt with said resistance wire, and including said first contact, said second contact, and said relay coil, said armature swinging toward said spring member as the latter is retracted by contraction of said high resistance wire so that said first contact and said second contact wipe over each other, and said second contact disengaging said first contact, in the fully contracted condition of said resistance wire, to break the relay energizing circuit, spring means operable to bias said armature away from said second contact when said relay coil is deenergized, a third contact carried by said armature, and a second fixed contact supported on said base engageable by said third contact, when said armature is operated, to close an auxiliary circuit including said armature.

5. A flasher comprising, in combination, a dielectric base, a metal relay frame mounted on said base, a relay coil mounted in said frame, a metal core connected to said frame and mounted in said coil, a metal armature hingedly mounted on said frame in conductive relation therewith and carrying a first contact, a metal spring member mounted on said base and extending toward said armature, said spring member having a second contact extending therealong in a direction substantially perpendicular to said first contact in the operated position of said armature, a high resistance wire connected between the free end of said spring member and a terminal on said base, a fixed contact carried by said relay frame and engageable by said second contact under the bias influence of said spring member when said resistance wire is heated and expands, the fixed contact being disposed inwardly of the edge of said second contact nearest said first contact whereby said first contact, when said armature is operated, will engage only the outer edge of said second contact, a conductor connecting said fixed contact to said terminal, a circuit including said fixed contact, said conductor, said resistance wire, said second contact, and said coil in series relation, effective to heat said resistance wire to expand the latter, a first relay energizing circuit, in shunt with said resistance wire, and including said fixed contact and said second contact, in engagement when the resistance wire expands, and said relay coil, and a second relay energizing circuit,

in shunt with said resistance wire, and including said first con tact, said second contact, and said relay coil, said armature swinging toward said spring member as the latter is retracted by contraction of said high resistance wire so that said first contact and said second contact wipe over each other, and said second contact disengaging said first contact, in the fully contracted condition of said resistance wire, to break the relay energizing circuit, and spring means connected to said frame and armature and operable to bias said armature away from said second contact when said relay coil is deenergized.

6. A flasher comprising, in combination, a dielectric base, a metal frame mounted on said base, a relay coil mounted on a metal core secured to said frame and extending outwardly therefrom, an L-shaped metal armature having one arm plvotally connected at its outer end to the frame and extending parallel to the core, and its other arm extending across the outer end of the core, a first contact on the outer end of said other arm, a frame arm extending parallel to the core on the opposite side thereof from said first armature arm, a fixed contact extending along the outer surface of the outer end of said frame a spring member mounted on said and extending in parallel spaced relation to such other arm and biased toward the same, a second con tact extending along the inner surface of the outer end of said spring member and arranged to engage said first contact, said second contact extending outwardly beyond said fixed contact whereby said first contact, when said armature is operated, will engage only the outer edge of said second contact, a high resistance wire connected between the free end of said spring member and a terminal on said base, a conductor connecting said fixed contact to said terminal, a circuit including said fixed contact, said conductor, said resistance wire, said second contact, said coil in series relation, effective to heat said resistance wire to expand the latter, a first relay energizing circuit, in shunt with said resistance wire, and including said fixed contact and said second contact, in engagement when the resistance wire expands, and said relay coil, and a second relay energizing circuit, in shunt with said resistance wire, and including said first contact, said second contact, and said relay coil, said armature ing toward said spring member as the latter is retracted by contraction of said high resistance wire so that said first contact and second contact wipe over each other, and said second contact disengaging said first contact, in the fully contracted condition of said resistance wire, to break the relay energizing circuit, and spring means connected to said frame and armature and operable to bias said armature away from said second contact when said relay coil is deenergized.

7. A flasher comprising, in combination, a dielectric base, a metal relay frame mounted on said base, a relay coil mounted in said frame, a metal core connected to said frame and mounted in said coil, a metal armature hingedly mounted on said frame in conductive relation therewith and carrying a first contact, a metal spring member mounted on said base and extending toward said armature, said spring member having sec ond contact extending therealong in a direction substantially perpendicular to said first contact in the operated position of said armature, a hi h resistance wire connected between the free end of said spring member and a terminal on said base,

a fixed contact carried by said relay frame and 'engageable by said second contact under the bias influence of said spring member when said resistance wire is heated and expands, the fixed contact being disposed inwardly of the edge of said second contact nearest said first contact whereby said first contact, when said armature is operated, will engage only the outer edge of said second contact, a conductor connecting said fixed contact to said terminal, a circuit including said fixed contact, said conductor, said resistance wire, said second contact, and said coil in series relation, effective to heat said resistance wire to expand the latter, a first relay energizing circuit, in shunt with said resistance wire, and including said fixed contact and said second contact, in engagement when the resistance wire expands, and said relay coil, a second relay energizing circuit, in shunt with said resistance wire, and including said first contact, said second contact, and said relay coil, said armature swinging toward said spring memher as the latter is retracted by contraction of said high resistance wire so that said first contact and said second contact wipe over each other, and said second contact disengaging said first contact, in the fully contracted condition of said resistance wire, to break the relay energizing circuit, spring means connected to said frame and armature and operable to bias said armature away from said second contact when said relay coil is deenergized, a third contact carried by said armature, and a second fixed contact supported on said base engageable by said third contact, when said armature is operated, to close an auxiliary circuit including said armature.

8. A flasher comprising, in combination, a dielectric base, a metal relay frame mounted on said base, a relay coil mounted in said frame, a metal core connected to said frame and mounted in said coil, a metal armature hingedly mounted on said frame in conductive relation therewith and carrying a first contact, a metal spring member mounted on said base and extending toward said armature, said spring memher having a second contact extending therealong in a direction substantially perpendicular to said first contact in the operated position of said armature, a high resistance Wire connected to said spring member and said base and normally biasing said spring member to a position retaining said second contact out of the line of movement of said first contact, a fixed contact carried by said relay frame and engageable by said second contact under the bias influence of said spring member when said resistance wire is heated and expands, the fixed contact being disposed inwardly of the edge of said second contact nearest said first contact whereby said first contact, when said armature is operated, will engage only the outer edge of said second contact, a circuit including said fixed contact, said resistance wire, said second contact, and said coil in series relation, effective to heat said resistance wire to expand the latter, a first relay energizing circuit, in shunt with said resistance wire, and including said fixed contact and said second contact, in engagement when the resistance wire expands, and said relay coil, a second relay energizing circuit, in shunt with said resistance wire, and including said first contact, said second contact, and said relay coil, said armature swinging toward said spring member as the latter is retracted by contraction of said high resistance wire so that said first contact and said second contact wipe over each other, and said second contact disengaging said first contact, in the fully contracted condition of said resistance wire, to break the relay energizing circuit, spring means connected to said frame and armature and operable to bias said armature away from said second contact when said relay coil is deenergized, a third contact carried by said armature, and a second fixed contact supported on said base engageable by said third contact, when said armature is operated, to close an auxiliary circuit including said armature, a fourth contact carried by said armature, and a third fixed contact carried by and insulated from said frame engageable by said fourth contact, when the armature is retracted, to close a second auxiliary circuit including said armature.

References Cited in the file of this patent UNITED STATES PATENTS Number