US3617977A - Electrical device having snap together housing parts - Google Patents

Electrical device having snap together housing parts Download PDF

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Publication number
US3617977A
US3617977A US855506A US3617977DA US3617977A US 3617977 A US3617977 A US 3617977A US 855506 A US855506 A US 855506A US 3617977D A US3617977D A US 3617977DA US 3617977 A US3617977 A US 3617977A
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US
United States
Prior art keywords
groove
projection
electrical device
generally cylindrical
annular
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US855506A
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English (en)
Inventor
Adolf K Scheiterbauer
Helmut Stickdorn
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Bunker Ramo Corp
Allied Corp
EIDP Inc
Original Assignee
Bunker Ramo Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Bunker Ramo Corp filed Critical Bunker Ramo Corp
Application granted granted Critical
Publication of US3617977A publication Critical patent/US3617977A/en
Assigned to E.I. DU PONT DE NEMOURS AND COMPANY, A CORP. OF DE. reassignment E.I. DU PONT DE NEMOURS AND COMPANY, A CORP. OF DE. ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: EUSTICE, ALBERT L.
Assigned to ALLIED CORPORATION A CORP. OF NY reassignment ALLIED CORPORATION A CORP. OF NY ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: BUNKER RAMO CORPORATION A CORP. OF DE
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01C—RESISTORS
    • H01C10/00—Adjustable resistors
    • H01C10/30—Adjustable resistors the contact sliding along resistive element
    • H01C10/32—Adjustable resistors the contact sliding along resistive element the contact moving in an arcuate path
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01C—RESISTORS
    • H01C1/00—Details
    • H01C1/02—Housing; Enclosing; Embedding; Filling the housing or enclosure
    • H01C1/022—Housing; Enclosing; Embedding; Filling the housing or enclosure the housing or enclosure being openable or separable from the resistive element
    • 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
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S338/00—Electrical resistors
    • Y10S338/01—Worm gear drive

Definitions

  • This invention relates to an electrical device and more particularly to an electrical device having snap together housing parts to facilitate rapid assembly while providing a highly effective seal, the device being readily and economically manufacturable.
  • the invention is illustrated herein as applied to small adjustable potentiometers but it will be understood that the principles of the invention are applicable to capacitors, inductors and other forms of electrical impedance devices.
  • the assembly of prior art devices has required considerable time and has been otherwise difficult and expensive, especially where it is desired to provide a sealed housing for electrical impedances.
  • This invention was evolved with the general object of overcoming disadvantages of prior arrangements and of providing a device which can be readily and quickly assembled while an effective seal is obtained.
  • Another object of the invention is to provide a device which is durable while being readily and economically manufacturable.
  • first and second housing parts are provided, the first part having a chamber and an opening to the chamber while the second part has impedance means supported thereon and positioned in the chamber, the second part having a generally cylindrical outside surface snap fitted in sealed relation into a generally cylindrical inside surface of the first part.
  • one of the generally cylindrical surfaces has an annular projection adapted to snap into an annular groove formed in the other.
  • Another specific feature is in the formation of the groove and the projection with rounded cross-sectional shapes to facilitate assembly, preferably with the projection before assembly having a radius of curvature substantially greater than that of the groove before assembly such that upon assembly side portions of the groove of restricted areas are interengaged with the projection to obtain a high pressure per unit area and a highly effective seal.
  • a further specific feature relates to the provision of a tapered generally frustoconical portion on one end of one of the surfaces to facilitate assembly.
  • Still another feature of the invention relates to the combination of the snap together feature with an impedance adjustment arrangement wherein coupling means are interengaged upon assembly of the parts to connect a movable control element associated with the impedance means with a manually adjustable element on the other part, controllable from the outside thereof.
  • the control element is in the form of a worm gear rotatable about the axis of the cylindrical surfaces
  • the manually adjustable element is in the form of a rotatable shaft member having one end accessible for actuation from the outside
  • the coupling means is in the form of a worm on the opposite end of the rotatable member meshed with the worm gear in the assembled condition of the parts.
  • the worm gear is journaled about the axis of the generally cylindrical surfaces and is preferably connected directly to a wiper contact engaged with a resistance element extending arcuately about the axis of rotation.
  • FIG. I is a bottom plan view of a potentiometer unit having a snap together housing and constructed in accordance with the principles ofthis invention
  • FIG. 2 is a sectional view, on an enlarged scale, taken substantially along line lI-ll ofFIG. l;
  • FIG. 3 is a greatly enlarged cross-sectional view showing the relationship of a groove and a projection with the parts positioned in an initial step of assembly;
  • FIG. 4 is a view similar to FIG. 3, showing the relationship of the groove and the projection after assembly.
  • FIG. 5 is a top plan view of the potentiometer unit, with parts broken away to show the internal construction.
  • Reference numeral 10 generally designates a potentiometer unit constructed in accordance with the principles of this invention.
  • the unit 10 comprises a first housing part 11 having a chamber 12 therewithin and a second housing part 13 with impedance means being supported on the second part 13 to be positioned in the chamber 12, the impedance means being in the form of an arcuately extending resistance element 14 engaged by a rotatable wiper contact 15, the angular position of the contact 15 being adjustable by means of a manual adjustment element 16, projecting from the outside of the housing part 11.
  • the adjustment mechanism is described in detail hereinafter.
  • the contact 15 and end tenninals of the resistance element 14 are connected to terminal prongs l7, l8 and 19 projecting in parallel relation from the housing part 13, for connection of the unit in a circuit in which it is to be used.
  • the part 11 has an opening to the chamber 12 which has a generally cylindrical inside surface 21 and the part 13 has a generally cylindrical outside surface 22 which is snap fitted in sealed relation into the surface 21.
  • the surface 21 is formed with an annular groove 23 therein and the surface 22 is formed with an annular projection 24 which snaps into the groove 23 when the parts are assembled.
  • the surface 21 could be formed with a projection and the surface 22 with a groove although the illustrated arrangement is preferred in facilitating formation of the parts.
  • the surface 21 is formed with a tapered generally frustoconical portion 25 at the entrant end thereof to facilitate alignment of the parts and entry of the annular projection 14 into the groove 23 in assembly.
  • a cylindrical surface portion 26 may preferably be provided between the inner end of the portion 25 and the groove 23.
  • the groove 23 and the projection 24 have concavely and convexly rounded cross-sectional shapes which facilitates assembly of the parts.
  • the rounded outer surface of the projection 24 engages the tapered surface 25 and as the part 13 is moved into the part 11, a wedging or jamming action takes place in which the inside surface 21, at the portion 26, is deformed outwardly while the projection 24 is deformed inwardly.
  • FIG. 3 when the parts are being assembled, the rounded outer surface of the projection 24 engages the tapered surface 25 and as the part 13 is moved into the part 11, a wedging or jamming action takes place in which the inside surface 21, at the portion 26, is deformed outwardly while the projection 24 is deformed inwardly.
  • the radius of curvature of the groove 23, designated by R, is less than the radius of curvature of the projection 24, designated by R.
  • the effective width of the groove 23 should be substantially less than twice the radius of curvature thereof to obtain the desired relationship of the parts.
  • the inside surface 21, moves inwardly with respect to the groove 23 and includes a cylindrical portion 29 which may preferably have a diameter equal to that of the portion 26 while the surface 22 includes a cylindrical portion 30 in facing relation to the portion 29 when the parts are assembled, the portion 30 preferably having a diameter less than that of the portion 29.
  • the assembly of the parts results in a mechanical interconnection between the element 16 and the contact 15.
  • the element 16 is the form of a shaft journaled in a passage 32 in the part 11 for rotation therein.
  • a cross pin 33 is inserted after disposing of the element 16 in the passage 32 to extend into an annular groove 34 in the element 16 and to retain the element 16 against axial displacement while permitting rotation thereof.
  • the element 16 has a second groove 35 in which an O-ring seal member 36 is disposed to provide a seal.
  • a slot 38 is provided for engageability by a screwdriver blade or the like.
  • a helical thread 39 is formed to define a worm which is meshed with the teeth on the periphery of a worm gear 40 journaled within the chamber 12 for rotation about the axis of the generally cylindrical surfaces 21 and 22.
  • the worm gear 40 is journaled on a sleeve 41 which is fitted onto a stud 42 formed integrally with the part 13.
  • the worm gear 40 is provided with grooves or recesses 43 which interlock with projecting portions 44 of a specially formed member 45 of resilient sheet metal.
  • Member 45 is bent to provide two portions 46 and 47 in spaced parallel planes transverse to the axis of rotation of the gear 40, the projections 44 being formed integrally with the portion 46 which is engaged with a central portion of the gear 40 and the portion 47 being engaged with an enlarged diameter flange portion 48 of the sleeve 41.
  • a slot 50 is formed in the member 47 which extends generally arcuately around the portion 46, through approximately 270, to define a generally U-shaped portion 51 the ends of the legs of which are integrally connected to the portion 46 with the wiper contact being formed as an integral extension of the center of the bight of the portion 51.
  • the portion 51 is so bent as to obtain a certain pressure engagement between the contact 51 and the resistance means element 14.
  • the terminal prong 17 is formed with a radially inwardly extending portion 53 which is engaged with the sleeve 41 to obtain an electrical connection to the contact 15, the sleeve 41 being of metal.
  • An end terminal 54 of the resistance element 14 is connected in a similar fashion to the terminal prong 18 and another similar connection is provided between an opposite end terminal of the resistance element 14 and the terminal prong 19.
  • Both the part 13 and the part 11 are preferably formed of a thermoplastic material and the prongs 17-19 are so molded or fitted into the part 13 as to obtain a seal. It is noted that in the assembly of the parts, the teeth of the gear 40 may be meshed with the teeth of the worm 39 when the part 13 is initially inserted into the opening defined by the surface 21, i.e. when the parts are in relative positions as represented in FIG. 3, after which the part 13 is forced into place with the snap engagement of the projection 24 into the groove 23.
  • a housing comprising first and second parts, said first part having a chamber and an opening to said chamber, impedance means supported on said second part and positioned in said chamber, impedance means supported on said second part and positioned in said chamber, said second part having an effective cross-sectional area substantially less than the effective area of said opening, said opening having an inside surface and said second part having an outside surface, one of said surfaces having a groove of a given effective width and the other one of said surfaces having a projection of a given effective width substantially greater than said given width of said groove and snap fitted partially within said groove into engagement with opposite side portions thereof only along a pair of unbroken continuous lines of interengagement between said opposite side portions of said groove and opposite side portions of said projection to obtain a high pressure per unit area and an effective seal, said groove having a given effective depth and said projection having a given effective height substantially less than said given depth to provide a clearance space between said groove and the unen aged ortion of said projection within said groove.
  • said groove and projection having concavely and convexly rounded crosssectional shapes.
  • said projection having a radius of curvature substantially greater than that of said groove and being interengaged with side portions of said groove of restricted area to obtain a high pressure per unit area and an effective seal.
  • said one of said generally cylindrical surfaces including a tapered generally frustoconical portion at one end to facilitate alignment of the part and entry of said annular projection into said annular groove in assembly.
  • annular groove being provided in said generally cylindrical inside surface of said first part and said annular projection being provided on said generally cylindrical outside surface of said second part.
  • a movable control element associated with said impedance means for controlling the impedance thereof, a manually adjustable element on said first part manually controlled from the outside thereof, and coupling means connected to said manual adjustment element and engaged with said control element in the assembled condition of said parts.
  • control element being in the form of a worm gear
  • manually adjustable element being in the form of a rotatable shaft member having one end accessible for actuation from the outside of said first part
  • coupling means being in the form ofa worm on the opposite end portion of said rotatable member meshed with said worm gear in the initial assembly of said parts.
  • said worm gear being journaled about the axis of said generally cylindrical surfaces.
  • said impedance means comprising a resistance element extending arcuately about the axis ofsaid generally cylindrical surface, and a wiper contact engaged with said resistance element and supported for rotation about said axis.
  • said second part being of a molded plastic material and terminal prongs projecting from the outside of said second part and having ends electrically connected to said wiper contact and said resistance element.

Landscapes

  • Engineering & Computer Science (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Adjustable Resistors (AREA)
  • Details Of Connecting Devices For Male And Female Coupling (AREA)
  • Connector Housings Or Holding Contact Members (AREA)
US855506A 1969-09-05 1969-09-05 Electrical device having snap together housing parts Expired - Lifetime US3617977A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US85550669A 1969-09-05 1969-09-05

Publications (1)

Publication Number Publication Date
US3617977A true US3617977A (en) 1971-11-02

Family

ID=25321423

Family Applications (1)

Application Number Title Priority Date Filing Date
US855506A Expired - Lifetime US3617977A (en) 1969-09-05 1969-09-05 Electrical device having snap together housing parts

Country Status (9)

Country Link
US (1) US3617977A (xx)
CA (1) CA919279A (xx)
CH (1) CH526250A (xx)
DE (1) DE2043568C3 (xx)
FR (1) FR2061011A5 (xx)
GB (1) GB1324188A (xx)
IL (1) IL35172A (xx)
NL (1) NL7012895A (xx)
SE (1) SE361969B (xx)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4242947A (en) * 1978-07-28 1981-01-06 Renner And Lovelace, Inc. Hydraulic actuator
US5699037A (en) * 1994-09-28 1997-12-16 Murata Manufacturing Co., Ltd. Variable resistor having clutch mechanism
EP1111628A2 (en) * 1999-12-21 2001-06-27 AB Electronic Limited Potentiometric position sensors

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3324078A1 (de) * 1983-07-04 1985-01-17 Götz-Udo 6391 Grävenwiesbach Hartmann Isolierstoffgehaeuse

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2914744A (en) * 1958-02-27 1959-11-24 Beckman Instruments Inc Encased variable resistance device
US3378803A (en) * 1966-07-01 1968-04-16 Beckman Instruments Inc Variable resistance device
US3429980A (en) * 1966-02-17 1969-02-25 Wolf Guttmann Electronic component package and cover
US3512113A (en) * 1968-06-28 1970-05-12 Weston Instruments Inc Miniaturized rotary potentiometers

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2914744A (en) * 1958-02-27 1959-11-24 Beckman Instruments Inc Encased variable resistance device
US3429980A (en) * 1966-02-17 1969-02-25 Wolf Guttmann Electronic component package and cover
US3378803A (en) * 1966-07-01 1968-04-16 Beckman Instruments Inc Variable resistance device
US3512113A (en) * 1968-06-28 1970-05-12 Weston Instruments Inc Miniaturized rotary potentiometers

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4242947A (en) * 1978-07-28 1981-01-06 Renner And Lovelace, Inc. Hydraulic actuator
US5699037A (en) * 1994-09-28 1997-12-16 Murata Manufacturing Co., Ltd. Variable resistor having clutch mechanism
EP1111628A2 (en) * 1999-12-21 2001-06-27 AB Electronic Limited Potentiometric position sensors
EP1111628A3 (en) * 1999-12-21 2005-03-09 AB Electronic Limited Potentiometric position sensors

Also Published As

Publication number Publication date
SE361969B (xx) 1973-11-19
CH526250A (de) 1972-07-31
DE2043568A1 (de) 1971-03-11
DE2043568B2 (de) 1976-12-02
GB1324188A (en) 1973-07-18
IL35172A0 (en) 1970-10-30
DE2043568C3 (de) 1979-02-08
NL7012895A (xx) 1971-03-09
CA919279A (en) 1973-01-16
IL35172A (en) 1973-02-28
FR2061011A5 (xx) 1971-06-18

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Legal Events

Date Code Title Description
AS Assignment

Owner name: E.I. DU PONT DE NEMOURS AND COMPANY, WILMINGTON, D

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:EUSTICE, ALBERT L.;REEL/FRAME:004039/0727

Effective date: 19820407

AS Assignment

Owner name: ALLIED CORPORATION COLUMBIA ROAD AND PARK AVENUE,

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:BUNKER RAMO CORPORATION A CORP. OF DE;REEL/FRAME:004149/0365

Effective date: 19820922