US3440032A - Method and apparatus for making dimpled reed capsules - Google Patents

Method and apparatus for making dimpled reed capsules Download PDF

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Publication number
US3440032A
US3440032A US479736A US3440032DA US3440032A US 3440032 A US3440032 A US 3440032A US 479736 A US479736 A US 479736A US 3440032D A US3440032D A US 3440032DA US 3440032 A US3440032 A US 3440032A
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Prior art keywords
relay
reed
contacts
dimple
operate
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US479736A
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English (en)
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Bates C Cook Jr
Richard M Rovnyak
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Automatic Electric Laboratories Inc
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Automatic Electric Laboratories Inc
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H11/00—Apparatus or processes specially adapted for the manufacture of electric switches
    • H01H11/005—Apparatus or processes specially adapted for the manufacture of electric switches of reed switches
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T29/00—Metal working
    • Y10T29/49—Method of mechanical manufacture
    • Y10T29/49002—Electrical device making
    • Y10T29/49105—Switch making

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  • FIG.3 VNYAK United States Patent 3,440,032 METHOD AND APPARATUS FOR MAKING DIMPLED REED CAPSULES Bates C. Cook, Jr., Chicago, and Richard M. Rovnyak,
  • a dimple is placed in the glass envelope of a reed switch adjacent each reed contact to prevent stray magnetic fields from closing reed contacts which vibrate upon release.
  • the process for forming the dimples is controlled by apparatus which simulates operation under stray magnetic field conditions and which continuously monitors the progress of dimple formation.
  • the control apparatus includes circuits for operating a reed switch under adverse stray field conditions, control circuits for operating gas fueled torches heat the envelope and CRT displays for visually monitoring dimple formation.
  • This invention relates to glass encapsulated reed switches and more particularly to techniques for preventing malfunction of such switches due to vibrations of the reeds.
  • Another object of this invention is to provide a new and improved process to manufacture substantially vibration free reed switches.
  • Still another object of this invention is to provide apparatus to control the creation of dimples or indents placed in the envelopes of reed switches which dampen vibrations occurring in their reed members.
  • the dimples are formed in the glass envelope in a position such that a fiat portion of the reed contact blades opposite the contact surfaces will rest against them during the time the contacts are unoperated.
  • the dimples prevent the reed blades fro-m swinging past What would normally be their equilibrium position in a conventional undimpled reed capsule.
  • the reed is dampened or stopped before beginning the first oscillation of its normal vibration cycle.
  • a feature of the process and apparatus according to the present embodiment is the application of a high tempera- 3,440,032 Patented Apr. 22, 1969 F ice ture source to a capsule at the points desired for location of a dimple, and the utilization of the difference in the atmospheric or surrounding pressure and the pressure existing in a standard reed capsule, which is usually less than atmospheric, to push in and balloon the softened glass against the reed blades to create symmetrical indents or dimples.
  • Any external pressure which is greater than the internal pressure of the envelope is meant to be included within the scope of the aforementioned term atmospheric.
  • An important feature of the invention consists in that the production of the dimple or dimples is controlled, and preferably automatically controlled by electrically detecting, in a simulated operation of the reed switch, the vibrations of the reed or reeds as the dimple or dimples are formed.
  • Another feature of this invention is the detection of the dampening effect on a vibrating reed member of a dimple being formed in an envelope of a reed switch, by supplying alternate operate and reclosure pulses to a coil surrounding the reed switch as the dimple is being formed, and observing the cessation of the reclosure of the reeds due to the reclosure pulse as the dimple reaches its correct depth.
  • Still another feature of this invention is the detection of the dampening effect on a vibrating reed member of a dimple being formed in an envelope of a reed switch by supplying operate pulses periodically to a coil surrounding the reed switch as the dimple is being formed, and during the time no pulse is supplied, observing the voltage induced in the coil due to the vibrating reed until this vibration ceases and a predetermined amount of induced voltage is present.
  • Another fegorge of this invention is apparatus which automatically controls the dimple depth by removing the source of heat creating the dimple when it has been found, through analysis by the detection methods mentioned above, that dampening of the vibrations of the reeds has occurred.
  • FIG. 1 is a diagram illustrating the apparatus used to form indentations or dimples in reed switch envelopes
  • FIGS. 6-l1 are graphical illustrations to aid the reader in the understanding of the invention.
  • FIG. 12 is a diagram showing the manner in which FIGS. 3, 4 and 5 are oriented.
  • carriage 11 is a movable device which is part of the mechanical apparatus disclosed in application Reed Switch Dimpling Machine, W. E. Neese filed on even date, Ser. No. 479,911, filed Aug. 16, 1965, assigned to the same assignee as the present invention, to position reed switch within split coil 314 and 317.
  • Control 13 is for supervising the operation of torches TOA and TOB which heat portions of the envelope of reed switch 10 to form the dimples by the pressure dilference within and outside of the envelope.
  • Electromagnets 312 and 313 are for locking carriage 11 into position X or Y before the dimple forming operation begins.
  • FIG. 2 shows a dimpled reed switch 22 comprising envelope 23, reed members and 21, and dimples 24 and 25 conforming to the fiat surfaces of the reeds 20 and 21 to dampen vibrations thereof.
  • FIGS. 3, 4 and 5 show the apparatus used to control the formation of a dimple in the envelope.
  • contacts 309, 310, or 308, 311, electromagnets 312 or 313, and relays ERM, D, LR, ST and S begin the process.
  • Oscillator 320 and relays P and G are used to pulse split coil 314, 317.
  • a Hewlett Packard Type 200 J audio oscillator is used with its frequency set at 33 c.p.s.
  • Relay AB in conjunction with relays A and B regulates the formation of the dimples by controlling both solenoids SOLA and SOLB to move the torches TOA and TOB, shown in FIG. 1, into position to heat the reed switch envelope, and the pulsing means mentioned above.
  • the torches used in the above mentioned embodiment are #23 hypodermic needles having their tips ground, and are fueled by two Henes Model S gas generators supplying a mixture of H and O and booster units which entrain alcohol vapor in the gas to increase the Btu. output of the torches.
  • One gas supply is set at about 0.7 p.s.i. and the other at about 0.6 p.s.i.
  • the solenoids, SOLA and SOLB used to drive the torches TOA and TOB into position, include solenoid controlled tour-way air valves 14 and 15.
  • Oscilloscopes 316, the drive scope, 315, the monitor scope, and limiter circuit LIM comprise a detecting means which determines When the dimples being formed have reached a depth to sufiiciently dampen the vibrations set up in the reeds by means of the pulsating coil. Scope 316 is connected to relay C which sustains the process until the detecting means finds that the dimple has reached a correct depth.
  • the Oscilloscopes preferred for usein the above mentioned embodiment are a Tektronix Type 535 with a Type Z pre-amplifier for the monitor scope 315 because of its high dynamic scale, and a Type 532-37 Tektronix oscilloscope with a Type O operational amplifier having three functional circuits; a conventional output to the CRT vertical and two independent operational amplifiers for the drive scope 316.
  • the scopes 315, 316 are interconnected by a limiter circuit LIM including a pair of oppositely conducting diodes D3, D4, used in a Zener capacity to limit the voltage across the pair to less than one volt maximum in either direction.
  • LIM limiter circuit
  • a circuit shown in FIG. 5, comprising relay TR and its contacts, TR-S and TR-6, transistor (unijunction) 510, and various resistances, is energized at the start of each dimple making process to see that the process does not continue longer than a predetermined length of time.
  • Another circuit comprising peg-count meter 511, the TR relay and its contacts TR-l TR-4 counts the number of reed switches which have had their envelopes dimpled.
  • Still another circuit comprising relay R and its contacts R-1R-9, operated peg-count meter 512 which counts the reed switches that have been rejected during the process and buzzer 513 which sounds when a rejection occurs. If a rejection does occur, due to the process taking an abnormally long time or for some other reason, the cycle is ended by relay R and the circuit must be manually reset at switch SW-2 to begin the cycle again.
  • FIG. 6 shows a wave form appearing on scope 316, the drive scope, which displays normal reed contact reclosure while making the first dimple in the reed switch envelope.
  • FIG. 7 shows a wave form appearing on scope 315, the monitor scope, While the second dimple is being formed which shows the normal voltage induced in the coil by vibration of a reed member, located in an undimpled envelope if the other reed member has been dampened by a well seated first dimple.
  • FIG. 8 displays a gated signal from monitor scopes 315 vertical output into drive scope 316.
  • FIG. 9 shows monitor scope 315 trace of an abnormal voltage induced in the split coil 314, 317.
  • FIG. 10 illustrates a trace on monitor scope 315 showing normal coil voltage of an adequately dimpled capsule.
  • FIG. 11 shows the pulsing supplied to the coil 314, 317, and to gated amplifier AMP-2.
  • Trace A shows the operate pulses OP and reclosure pulses RP supplied to split coil 314, 317 during the formation of the first dimple.
  • Time T denotes that the reeds separate 0.15 ms. after the operate pulse OP ends.
  • Time T denotes that the reclosure RP pulse starts about 0.5 ms. after the operate pulse OP ends, although it is not necessary time T indicates that the reclosure pulse RP ends 0.5 ms. before the beginning of the next operate pulse OP.
  • Traces B and C show tht the gating pulse DP occurs an interval T after the ending of operate pulse OP during the formation of the second dimple.
  • the dimple operation begins by placing a reed switch 10 on carriage 11.
  • control 13 energizes solenoid SOLA to operate piston PIA to move torch TOA into position to heat a portion of the reed switch envelope, beginning the first dimple cycle.
  • the principle used to form and control the first dimple is to apply the torch TOA and at the same time supply alternate operate and reclosure pulses to coil 314, 317.
  • the reclosure pulse is of less magnitude than the operate pulse, but is of a sufficient strength to cause a reclosure of the reed contacts when applied immediately after the operate pulse. This is due to the natural vibration of the reeds following their release after the operate pulse.
  • the atmospheric or surrounding pressure which is greater than the pressure within the envelope R i.e. approximately 0.6 atmospheres, begins to form the first dimple.
  • the dimple forms the heated portion of the envelope moves inward until it touches and conforms to the flat surface of the pertinent reed blade 17 with sufficient force to dampen its natural vibration.
  • blade 17 no longer swings close enough to the other blade 16 to allow the reclosure during the application of a reclosure pulse and automatically withdraws torch TOA.
  • control 13 After the first dimple is completed, control 13 immediately and automatically applies torch TOB, in the same manner as torch TOA, to begin forming the second dimple. Since the reclosure pulse used on the first dimple will not operate the reed contacts because the blade 17 associated with the first dimple has been dampened, a different sensing of the completion of the second dimple is used. This time an operate pulse is applied to coil 314, 317 and then immediately thereafter the voltage induced by the remanent magnetism of the single vibrating reed blade 16 within coil 314, 317 is detected. As the second dimple moves inward and begins to dampen the vibration of reed blade 16, the magnitude of the induced voltage begins to drop oil.
  • control B withdraws torch TOB.
  • carriage 11 is moved out of its position X or Y and the reed switch is manually removed. Then the process can begin again with another undimpled, reed switch being placed into the carriage.
  • FIGS. 3, 4 and 5 control 13 of FIG. 1 will make it clear just how the control apparatus used to supervise the formation of the dimples, operates.
  • power is supplied from the DC. source DCS to power bus PB by way of normally closed switch SW-Z, relay contacts R-G, R-7 and switch SW-l. Tracing the bus PB further (through FIG. 4) lamp L3 is lighted to indicate that power is available to the control circuitry. In a similar fashion power is supplied to light lamp L4 to indicate that solenoid power is available to the control circuitry. Solenoid power is fed to contact LR-1 via SW-3, SW-1 and solenoid power bus SPB.
  • FIG. 1 As carriage 11, FIG. 1, is positioned in position X or Y, spring contacts 309, 310 or 308, 311 are closed. When either of those sets of contacts are closed, a ground is supplied by way of the winding of electrical magnet 312 'or 313, 'to operate relay ERM.
  • Contacts ERM-1 and ERM-Z or ERM-2 and ERM-3 in turn supply a ground to pulse stretching relay D to operate it, and contacts ERM-4 and ERM-5 or ERM5 and ERM-6 operate relay LR.
  • relay -D As relay -D operates, it sends a ground pulse to momentarily operate relay ST via contacts D1 and D-2.
  • Relay ST in turn sends battery via contacts ST-3 and ST-4 to operate relay S.
  • relay S supplies battery via contacts S5 and S-6 to operate relay TR to start the timing circuit.
  • Relay AB operates by means of battery and ground supplied by relay ST by contacts ST-3 and ST-4 and ST-S and ST-6, respectively, and locks up by its contacts AB-10, AB-11 and contacts 8-7, 8-8 and C-1, C-2 before relay S releases.
  • relay AB supplies the power necessary, via contacts AB-12 and AB-13 to operate solenoid SOLA to in turn bring torch TOA close to the reed switch envelope to heat a portion thereof and to begin to form the first dimple.
  • oscillator 320 pulses relay P which in turn supplies alternate operate OP and reclosure pulses RP (FIG. 11, trace A) to split coil 314, 317 (e.g. operate pulse via contacts P2 and P-3, RES-1, FC, winding 314, 317 to ground, reclosure pulse via contacts P-1 and P2, AB-8 and AB9, diode D1, RES2 and connection FC).
  • RP alternate operate OP and reclosure pulses RP (FIG. 11, trace A) to split coil 314, 317 (e.g. operate pulse via contacts P2 and P-3, RES-1, FC, winding 314, 317 to ground, reclosure pulse via contacts P-1 and P2, AB-8 and AB9, diode D1, RES2 and connection FC).
  • the reclosure pulses cause contacts 16 and 17 of the reed switch to close as long as the vibrations caused by the operate pulse have not been dampened by the oncoming dimple.
  • relay C Due to the closing of the reed contacts 16 and -17 upon impression of the reclosure pulse, relay C is held operated by CAP-3 to sustain the cycle. Relay C is operated via power from PB through contacts P1 and P-2, AB8 and AB9, RES-3 GC, reed contacts 16 and 17, BC, AB-15 and AB-16 and AMP-1 of drive scope 316 (see normal reed contact reclosure trace, FIG. 6).
  • Relay C in turn keeps holding power on relay S via contacts C-1 and C-2 and S-7 and 8-8.
  • the aforementioned path opens, the C relay drops out and the S relay is released, ending the cycle for the formation of the first dimple.
  • contacts S-9 and 8-10 open and remove power to the torch TOA, moving it away from the envelope.
  • Relay LR is released via contacts S-1 and S2, and relay AB is released by the opening of contacts S-7 and S8.
  • Relay S is now operated again via relay C because of relay P, which is still being pulsed by oscillator 320 as will be explained below.
  • relay LR is again operated over a previously mentioned circuit.
  • relay AB remains unoperated.
  • Torch TOB is now brought near to the envelope of the reed switch getting power supplied to solenoid SOLB via contacts S9 and S- and AB-13 and AB-14.
  • a different technique is employed.
  • relay P When time as relay P is pulsed, it in turn pulses coil 314, 317 with operating pulses OP (FIG. 11, trace B) via path contacts P2 and P-3, RES-1, and FC, and the undampened reed blade begins to vibrate.
  • the vibrating reed induces a voltage (FIG. 7) in the split coil between the pulses via the aforementioned path.
  • This -voltage due to the vibrating reed within coil 314, 317, is detected by AMP-4 in monitor scope 315, and the output 6 of 315 is fed through limiter circuit LIM into drive scope 316.
  • Simultaneously relay P sends a pulse via contacts P-1 and P-2 and AB-7 and AB-8 to pulse relay G, which provides delayed pulse DP, FIG. 11, trace C, via its contacts G1 and G2 and RES4, to gate the limiter LIM output through AMP2.
  • This in turn is fed through AMP-3 (see FIG. 8), and by way of AB-16 and AB-17 is inverted to AMP-1, to operate relay C.
  • relay C is no longer pulsed. It once again drops out, opening the circuit to relay S, withdrawing torch TOB.
  • capacitor CAPI Since the output from drive scope 315, in forming both dimples, may not be immediately effective to pulse relay C, capacitor CAPI is connected to contacts AB1 and AB-Z, and is charged upon operating switch SW-l, via PB. If relay C does not operate to close its contacts C1 and C-2 to hold relay S operate, CAP-1 discharges upon operation of relay AB, via contacts AB-2 and AB-3 to operate relay A which sends, via contacts A-1 and A-2, battery to relay S to operate it, until relay C is operated. Likewise, CAP2 has a similar function as CAPI in operating, relay S during the time between forming the 1st and second dimple, via contacts AB-4 and AB-S to operate relay B which sends battery to relay S via contacts B1 and B2.
  • relay TR When relay TR was first operated, it supplied battery by contacts TR-1 and TRZ to operate counter 511. Ground is also supplied by way of contacts TR-3 and TR-4 to light lamp L1. Battery is supplied via contacts TR-S and TR6, RES5, RES6, for charging CAP-4. If the formation of the dimples is sufiiciently long to allow CAP-4 to charge to a predetermined value, transistor 510 will operate and supply an enabling pulse to the gate of silicon controlled rectifier 520.
  • relay R When silicon controlled rectifier 520 conducts, ground is supplied therethrough to operate relay R which has power connected to its other side via contacts S-3 and S4 and SW-Z.
  • relay R When relay R operates, contacts R1 and R2, supply power to operate buzzer 513, contacts R3 and R4 supply holding power for relay R, contacts R5 and R6 close, placing power on reject counter contacts R8 and R9, light lamp L2, and contacts R6 and R7 open, removing power from PB, immediately ending the cycle at this point.
  • the process may be performed with detection being made by observing the monitor scope as the torch heats the envelope and then by manually removing the torch when the scope trace indicates that the dimple has damped the vibrations in the reeds.
  • the detection could also be made visually through a microscope focused on the portion of the envelope being heated by the torch, and removal of the torch effected when the dimple was observed to be of a proper depth.
  • Apparatus for forming an indentation in an evacuated envelope having a plurality of spring contacts therein comprising: coil means; means to position said envelope adjacent said coil means; a source of heat; switch means operated by said envelope positioning means; means operated by said switch means and including means for energizing said coil means to cause at least one of said spring contacts to vibrate and means to position said heat source adjacent an area of said envelope near said one contact for heating said area to a plastic state allowing the pressure difference due to the evacuated condition of said envelope to form an indentation therein, the vibrations being dampened by said indentation; and vibration detecting means coupled to said one contact and effective after said vibrations have been dampened to a predetermined level to operate said heat source positioning means to remove said heat source from said envelope.
  • Apparatus for forming a dimple in an evacuated envelope having a pair of reed contacts therein comprising: a heating means to heat a portion of said envelope to a plastic state so that the difference in air pressure will form a dimple thereat; means to vibrate at least one of said reed contacts; vibration detecting means coupled to said contact; and means operated by said detecting means after said vibrations have been reduced to a predetermined level due to the dampening effect of said dimple to remove the heat from said portion when the vibrations are dampened to said predetermined level.

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3670131A (en) * 1969-06-06 1972-06-13 Hasler Ag Adjusting and controlling reed relays
US5173101A (en) * 1990-01-31 1992-12-22 Ladislav Novotny Method of preparation miniaturized sensors on basis of fluids and arrangement of the measuring system

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2523903A (en) * 1948-04-15 1950-09-26 Bell Telephone Labor Inc Jig
US3124670A (en) * 1961-09-25 1964-03-10 Reed switch having improved reed positioning means
US3240897A (en) * 1964-06-19 1966-03-15 Clare & Co C P Sealed magnetic switch and method of manufacture
US3322524A (en) * 1963-10-28 1967-05-30 Clare & Co C P Method of and an apparatus for making sealed switches
US3369882A (en) * 1963-10-28 1968-02-20 Clare & Co C P Method of forming projections in reed switch assemblies by selective heat softening

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2523903A (en) * 1948-04-15 1950-09-26 Bell Telephone Labor Inc Jig
US3124670A (en) * 1961-09-25 1964-03-10 Reed switch having improved reed positioning means
US3322524A (en) * 1963-10-28 1967-05-30 Clare & Co C P Method of and an apparatus for making sealed switches
US3369882A (en) * 1963-10-28 1968-02-20 Clare & Co C P Method of forming projections in reed switch assemblies by selective heat softening
US3240897A (en) * 1964-06-19 1966-03-15 Clare & Co C P Sealed magnetic switch and method of manufacture

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3670131A (en) * 1969-06-06 1972-06-13 Hasler Ag Adjusting and controlling reed relays
US5173101A (en) * 1990-01-31 1992-12-22 Ladislav Novotny Method of preparation miniaturized sensors on basis of fluids and arrangement of the measuring system

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