US2142355A - Combination plug-in resistor and switch - Google Patents

Combination plug-in resistor and switch Download PDF

Info

Publication number
US2142355A
US2142355A US159697A US15969737A US2142355A US 2142355 A US2142355 A US 2142355A US 159697 A US159697 A US 159697A US 15969737 A US15969737 A US 15969737A US 2142355 A US2142355 A US 2142355A
Authority
US
United States
Prior art keywords
resistor
disc
switch
terminal plate
plugs
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
US159697A
Inventor
Hastings Donald Francis
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.)
HARDWICK HINDLE Inc
Original Assignee
HARDWICK HINDLE Inc
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 HARDWICK HINDLE Inc filed Critical HARDWICK HINDLE Inc
Priority to US159697A priority Critical patent/US2142355A/en
Application granted granted Critical
Publication of US2142355A publication Critical patent/US2142355A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01RELECTRICALLY-CONDUCTIVE CONNECTIONS; STRUCTURAL ASSOCIATIONS OF A PLURALITY OF MUTUALLY-INSULATED ELECTRICAL CONNECTING ELEMENTS; COUPLING DEVICES; CURRENT COLLECTORS
    • H01R13/00Details of coupling devices of the kinds covered by groups H01R12/70 or H01R24/00 - H01R33/00
    • H01R13/66Structural association with built-in electrical component

Definitions

  • This invention relates to a combination plug-in resistor and switch, in which the resistor and switch portions are relatively adjustable, one with respect to the other, whereby the output voltage from the device may be adjusted to meet the requirements of the apparatus which is connected to the device.
  • Figure 1 is an elevational view of the completely assembled device, on a reduced scale.
  • Figure 2 is a Vertical, sectional view on an enlarged scale through the device shown in Figure 1, the view being taken at right angles to the plane of the paper.
  • Figure 3 is a plan view of the top of Figure 2.
  • Figure 4 is a view on the line 4-4 of Figure 2.
  • Figure 5 is a view on the line 5-5 of Figure 2.
  • Figure 6 is a View on the line B-Ii of Figure 2.
  • Figure 7 is an elevational view of the resistor per se.
  • Figure 8 is a diagram of the circuit arrangement through the resistor and switch.
  • I is a resistor composed of a suitable core portion 2 of porcelain or some other high heat-resisting material, on which is placed a winding embedded in a slip 3 of vitreous material which is baked after the winding is put in position.
  • a winding embedded in a slip 3 of vitreous material which is baked after the winding is put in position.
  • taps 4 are indicated as coming therefrom.
  • the resistor I is mounted between two circularshaped discs 5 and 6 which are preferably of suitable insulating material.
  • This mounting includes a pair of clamps l and 8 preferably of metal and somewhat cup-shaped, so that the cup portion thereof fits Within the hollow portion of the resistor shell 2.
  • a spacing member 9 preferably of strong insulating material, such as hard fiber, and through this and the members l and 8 passes a bolt I Il lhaving a head I I set in a recess in the member 5.
  • the opposite end of the bolt I0 is threaded and a nut I2 is seated on the threaded portion to draw the clamp Il against the end of the core 2.
  • the member 5 carries a pair of contact members I3 and I4. As shown,
  • the members I3 and I4 are somewhat U-shaped, the arms passing through holes I5 and I6 in the member 5, while the bottom of the U portions lie in grooves in the outer face of the member 5.
  • the other arms of the U-shaped members pass in- 5 Wardly through holes provided in the member 5 and are adapted to be attached in any satisfactory manner, as by soldering or spot-welding to connectors II and I8 which extend to the taps 4 on the resistor I. 10
  • insulator I 9 Placed over the top of the insulator 5 is another insulator I 9 which may be fastened thereto in any satisfactory manner as by screws 20.
  • 'I'he member I9 has slots 2
  • On the insulator 6 are mounted a plurality of contact members 22 which are preferably in the form of eyelets as shown in Figure 2 and which have projections or fingers 23 which are bent inwardly and pass through openings 24 for the purpose of making electrical engagement with the taps 4 on 25 the resistor I.
  • These connections may be made in any satisfactory manner as by soldering or welding.
  • the connections to the taps 4 may likewise be made by soldering or welding.
  • a washer 25 of high heat-resisting material such as mica Positioned closely adjacent the disc S is a terminal plate 26 to which is attached a pair of contact prongs or plugs 2l. One end of the plugs 2'I is 35 counter-bored to give the effect of an eyelet which is spun over at 28 to clamp the plugs securely to the insulator 26. Positioned in the hollow or counter-bored portion of the plugs 2l are springs 29 which are adapted to press against balls 30 40 which thus act as contact members for electrical engagement means between the plugs 2l and the eyelets 22 on the disc 6. The co-action between the eyelets 22 and the balls 30 acts to form a positive switch-positioning means. 45
  • a bushing 3i Positioned in the terminal plate 26 is a bushing 3i which acts as a bearing for the bolt I0.
  • the inner end of the bushing 3I engages the dise 6 so that when the nut 32 on the bolt I0 is drawn up', the discs 5 and 8 are held in operated position and 50 the resistor unit, including the resistor I and the discs 5 and 6 with cooperating contacts, is held in resilient contact engagement with the balls 30.
  • a casing member 33 preferably having a plurality of Ventilating holes 55 34 therein.
  • the casing member 33 may be formed by rolling up a piece of metal which has been perforated as explained, and then passing over the ends thereof collars or bands 35 and 36 which preferably are of metal and act to hold the shell 33 in position.
  • the collars 35 and 36 are fastened to the member 33 in any satisfactory manner as by riveting, welding or some equivalent means.
  • one end of the casing member 33 embraces the disc 5, while the opposite end rests against the disc 6 and the collar 36 preferably engages the inner face of the terminal plate 26 so that it may act as an out-board guide or support for the resistor unit.
  • the plate I9 overlaps the collar 35, thereby making a more finished appearance of this end of the device.
  • the disc I9 acts to hold the contact members I3 and I4 in position in their respective slots in the disc 5.
  • the resistor with its associated parts, including the casing forms a unit which is rotatable about the terminal plate 26 so that various taps on the resistor I may be connected to the plugs 2'I as indicated in the diagram in Figure 8.
  • one portion 3'I of the resistor I is connected in shunt across the load terminals I3 and I4 at all times. This is desirable for certain types of load such as a dryshave razor, but for Vother types of load this shunt resistance may not be required.
  • the collar 36 With the voltage to be delivered by the device at the different taps as indicated in Figure 1.
  • the manner of making an operating connection between the casing 33 and either the disc 5 or disc 6 may be of any suitable kind.
  • the disc 6 may have a projection which will extend into the space 38 betwen the edges of the rolled up casing member 33 when the bands 35 and 36 are not used; or the projection may extend into a slot or notch in the band 36 when the bands are used; or a pin may be inserted through one of the perforations into the disc 5.
  • the projecting ends may be rectangular in shape.
  • the collars or bands 35 and 36 may be eliminated entirely by suitably extending one end of the casing 33, if desired, into engagement with the terminal plate 26.
  • a resistor having a plurality of taps, a pair of discs of insulating material disposed one at each end of the resistor, one of said discs having slots therein, contact members carried by said disc in operative'pcsition with relation to said slots so plug terminals inserted through said slots will engage gaging the contacts on said second mentioned disc, and means for rotatably mounting said discs and resistor on said terminal plate.
  • a device asset forth in claim'l further characterized in that the means for rotatably mounting the discs and resistor include the following parts, a clamp at and engaging each end of the resistor, a spacer between the Clear-mentioned disc and its associated clamp, a bushing located in the terminal plate and engaging the second-mentioned disc, an insulator between the disc and the other adjacent clamp, and a bolt going through said parts for clamping them in operative position.
  • a device as set forth in claim 1 further characterized in that the resistor and discs are housed Within a perforated casing member composed of a rolled up perforated sheet held together at its opposite ends by circular bands, the oneV atrthe terminal plate end engaging the terminal plate and thereby acting as an annular guiding support for the rotatable structure of which it is a part.
  • a device as set forth in claim 1 further characterized in that the resistor and discs are housed Within a cylindrical casing member one end of which may engage on the second mentioned disc While the other end embraces the first mentioned disc, a circular band at each end of said casing, the band at said terminal plate end having its edge engaging said terminal plate as an annular guide for the rotatable structure.
  • a device as set forth in claim 1 further characterized in that the resistor and discs are housed within a cylindrical casing member one end of Which may engage on the second mentioned disc while the other end embraces the first mentioned disc, a circular band at each end of said casing, the band at said terminal plate end having its edge engaging said terminal plate as an annular guide for the rotatable structure, and an insulator overlying and fastened to the first-mentioned disc and having slots therein in alignment with the slots in said disc.
  • a device as set forth in, claim 1 further characterized in that the resistor and discs are housed within a perforated casing member composed of a rolled up perforated sheet held together at its opposite ends by circular bands, the one at the terminal plate end engaging the terminal plate and thereby acting as an annular guiding support for the rotatable structure of which it is a part, said band adjacent the terminal plate bearing indica for indicating the output voltage at which the device is set.
  • a device as set forth in claim 1 further characterized in that the terminal plugs carried by said terminal plate each has a counterbore therein within which a spring and ball is positioned, the balls acting as the contact members to engage the contacts on the second-mentioned disc, the contacts on this disc being eyelets, the said balls being adapted to seat therein thereby positively positioning the switch part of the device in any set position, said eyelets having fingers bent around and through openings in the disc whereby they may be connected to the taps on the resistor.
  • a combination plug-in and resistor and switch including a resistor having a plurality of taps, a casing for the resistor, a pair of internally positioned contact members mounted adjacent one end Yof the resistor on an insulator form-V ing one end of the casing and adapted to have a plug inserted through openings inv the insulator into engagement with the -contact member, a pair of external plug members mounted adjacent the opposite end of the resistor on a disc-shaped insulator forming the other end of thecasing, a
  • a double ended resistor plug switch including, a casing closed at both ends by separate insulating means fastened thereto, the insulating means at one end carrying plug-in contacts and the insulating means at the opposite end carrying arcuately positioned contact members, an insulator located closely adjacent said last mentioned insulating means, and carrying externally extending plugs with means directly contacting With the inner ends of the plugs for engaging said Contact members as the latter are moved across the inner ends of the plugs, a resistor mounted at its ends between said end insulating means and having taps connected to said contact members and means for rotatably mounting the resistor, casing and said insulating means on the insulator carrying the plugs.

Landscapes

  • Details Of Connecting Devices For Male And Female Coupling (AREA)

Description

'Jan'. 3, 1939.
D. F. HAsTlNGs 2,142,355
COMBINATION PLUG-IN RESISTOR AND SWITCH Filed Aug. 18, 1937 i d INVENToR F3- ATTORNEY Patented Jan. 3, 1939 UNITED STATES COMBINATION PLUG-IN RESISTOR AND SWITCH Donald Francis Hastings, Fairlawn, N. J., assignor to Hardwick, Hindle, Inc., Newark, N. J.
Application August 18, 1937, Serial No. 159,697
9 Claims.
This invention relates to a combination plug-in resistor and switch, in which the resistor and switch portions are relatively adjustable, one with respect to the other, whereby the output voltage from the device may be adjusted to meet the requirements of the apparatus which is connected to the device.
It is the principal object of my invention to provide what may be termed a relatively simple and compact plug-in resistor and switch which will act as a line voltage reducer for use in connection with appliances of different types and in which, in some cases, speed changes may be desirable.
- Other ancillary objects will appear on reading 1.5 the specication taken in connection with the annexed drawing, wherein:
Figure 1 is an elevational view of the completely assembled device, on a reduced scale.
Figure 2 is a Vertical, sectional view on an enlarged scale through the device shown in Figure 1, the view being taken at right angles to the plane of the paper.
Figure 3 is a plan view of the top of Figure 2.
Figure 4 is a view on the line 4-4 of Figure 2.
Figure 5 is a view on the line 5-5 of Figure 2.
Figure 6 is a View on the line B-Ii of Figure 2.
Figure 7 is an elevational view of the resistor per se.
Figure 8 is a diagram of the circuit arrangement through the resistor and switch.
In the various views, wherein like numbers refer to corresponding parts, I is a resistor composed of a suitable core portion 2 of porcelain or some other high heat-resisting material, on which is placed a winding embedded in a slip 3 of vitreous material which is baked after the winding is put in position. In the drawing no attempt has been made to show the winding, but taps 4 are indicated as coming therefrom.
The resistor I is mounted between two circularshaped discs 5 and 6 which are preferably of suitable insulating material. This mounting includes a pair of clamps l and 8 preferably of metal and somewhat cup-shaped, so that the cup portion thereof fits Within the hollow portion of the resistor shell 2. Between the clamps I and 8, and the member 5, there is positioned a spacing member 9, preferably of strong insulating material, such as hard fiber, and through this and the members l and 8 passes a bolt I Il lhaving a head I I set in a recess in the member 5. The opposite end of the bolt I0 is threaded and a nut I2 is seated on the threaded portion to draw the clamp Il against the end of the core 2. The member 5 carries a pair of contact members I3 and I4. As shown,
the members I3 and I4 are somewhat U-shaped, the arms passing through holes I5 and I6 in the member 5, while the bottom of the U portions lie in grooves in the outer face of the member 5. The other arms of the U-shaped members pass in- 5 Wardly through holes provided in the member 5 and are adapted to be attached in any satisfactory manner, as by soldering or spot-welding to connectors II and I8 which extend to the taps 4 on the resistor I. 10
Placed over the top of the insulator 5 is another insulator I 9 which may be fastened thereto in any satisfactory manner as by screws 20. 'I'he member I9 has slots 2| therein which are in alignment with the slots I5 and IB in the member 5, so that a plug attached to a supply cord coming from the device to be operated by the electric current may be inserted through these slots or openings into engagement with the contact members I3 and I4. On the insulator 6 are mounted a plurality of contact members 22 which are preferably in the form of eyelets as shown in Figure 2 and which have projections or fingers 23 which are bent inwardly and pass through openings 24 for the purpose of making electrical engagement with the taps 4 on 25 the resistor I. These connections may be made in any satisfactory manner as by soldering or welding. The connections to the taps 4 may likewise be made by soldering or welding.
To prevent the clamp 8 from contacting with 30 the inner faces of the eyelets 22, there is a washer 25 of high heat-resisting material such as mica. Positioned closely adjacent the disc S is a terminal plate 26 to which is attached a pair of contact prongs or plugs 2l. One end of the plugs 2'I is 35 counter-bored to give the effect of an eyelet which is spun over at 28 to clamp the plugs securely to the insulator 26. Positioned in the hollow or counter-bored portion of the plugs 2l are springs 29 which are adapted to press against balls 30 40 which thus act as contact members for electrical engagement means between the plugs 2l and the eyelets 22 on the disc 6. The co-action between the eyelets 22 and the balls 30 acts to form a positive switch-positioning means. 45
Positioned in the terminal plate 26 is a bushing 3i which acts as a bearing for the bolt I0. The inner end of the bushing 3I engages the dise 6 so that when the nut 32 on the bolt I0 is drawn up', the discs 5 and 8 are held in operated position and 50 the resistor unit, including the resistor I and the discs 5 and 6 with cooperating contacts, is held in resilient contact engagement with the balls 30.
Enclosing the resistor I, is a casing member 33 preferably having a plurality of Ventilating holes 55 34 therein. The casing member 33 may be formed by rolling up a piece of metal which has been perforated as explained, and then passing over the ends thereof collars or bands 35 and 36 which preferably are of metal and act to hold the shell 33 in position. The collars 35 and 36 are fastened to the member 33 in any satisfactory manner as by riveting, welding or some equivalent means.
As shown in Figure 2, one end of the casing member 33 embraces the disc 5, while the opposite end rests against the disc 6 and the collar 36 preferably engages the inner face of the terminal plate 26 so that it may act as an out-board guide or support for the resistor unit. It will also be noted that the plate I9 overlaps the collar 35, thereby making a more finished appearance of this end of the device. In addition, it will be noted that the disc I9 acts to hold the contact members I3 and I4 in position in their respective slots in the disc 5.
From the construction as described, it will be understood that the resistor with its associated parts, including the casing, forms a unit which is rotatable about the terminal plate 26 so that various taps on the resistor I may be connected to the plugs 2'I as indicated in the diagram in Figure 8. As shown in this diagram, one portion 3'I of the resistor I is connected in shunt across the load terminals I3 and I4 at all times. This is desirable for certain types of load such as a dryshave razor, but for Vother types of load this shunt resistance may not be required.
To indicate the voltage that the device is set to deliver, I prefer to calibrate the collar 36 With the voltage to be delivered by the device at the different taps as indicated in Figure 1. 'Ihe manner of making an operating connection between the casing 33 and either the disc 5 or disc 6 may be of any suitable kind. For example, the disc 6 may have a projection which will extend into the space 38 betwen the edges of the rolled up casing member 33 when the bands 35 and 36 are not used; or the projection may extend into a slot or notch in the band 36 when the bands are used; or a pin may be inserted through one of the perforations into the disc 5.
While I have shown round types of plugs 21, the projecting ends may be rectangular in shape. Furthermore, the collars or bands 35 and 36 may be eliminated entirely by suitably extending one end of the casing 33, if desired, into engagement with the terminal plate 26.
Other details may` likewise be varied Without departing from the spirit of my invention or the scope of the appended claims.
What I claim is:
l. In a device of the class described, a resistor having a plurality of taps, a pair of discs of insulating material disposed one at each end of the resistor, one of said discs having slots therein, contact members carried by said disc in operative'pcsition with relation to said slots so plug terminals inserted through said slots will engage gaging the contacts on said second mentioned disc, and means for rotatably mounting said discs and resistor on said terminal plate.
2. A device asset forth in claim'l further characterized in that the means for rotatably mounting the discs and resistor include the following parts, a clamp at and engaging each end of the resistor, a spacer between the Erst-mentioned disc and its associated clamp, a bushing located in the terminal plate and engaging the second-mentioned disc, an insulator between the disc and the other adjacent clamp, and a bolt going through said parts for clamping them in operative position.
3. A device as set forth in claim 1 further characterized in that the resistor and discs are housed Within a perforated casing member composed of a rolled up perforated sheet held together at its opposite ends by circular bands, the oneV atrthe terminal plate end engaging the terminal plate and thereby acting as an annular guiding support for the rotatable structure of which it is a part. v
Ll. A device as set forth in claim 1 further characterized in that the resistor and discs are housed Within a cylindrical casing member one end of which may engage on the second mentioned disc While the other end embraces the first mentioned disc, a circular band at each end of said casing, the band at said terminal plate end having its edge engaging said terminal plate as an annular guide for the rotatable structure.
5. A device as set forth in claim 1 further characterized in that the resistor and discs are housed within a cylindrical casing member one end of Which may engage on the second mentioned disc while the other end embraces the first mentioned disc, a circular band at each end of said casing, the band at said terminal plate end having its edge engaging said terminal plate as an annular guide for the rotatable structure, and an insulator overlying and fastened to the first-mentioned disc and having slots therein in alignment with the slots in said disc.
6. A device as set forth in, claim 1 further characterized in that the resistor and discs are housed within a perforated casing member composed of a rolled up perforated sheet held together at its opposite ends by circular bands, the one at the terminal plate end engaging the terminal plate and thereby acting as an annular guiding support for the rotatable structure of which it is a part, said band adjacent the terminal plate bearing indica for indicating the output voltage at which the device is set. Y
'7. A device as set forth in claim 1 further characterized in that the terminal plugs carried by said terminal plate each has a counterbore therein within which a spring and ball is positioned, the balls acting as the contact members to engage the contacts on the second-mentioned disc, the contacts on this disc being eyelets, the said balls being adapted to seat therein thereby positively positioning the switch part of the device in any set position, said eyelets having fingers bent around and through openings in the disc whereby they may be connected to the taps on the resistor.
8. A combination plug-in and resistor and switch including a resistor having a plurality of taps, a casing for the resistor, a pair of internally positioned contact members mounted adjacent one end Yof the resistor on an insulator form-V ing one end of the casing and adapted to have a plug inserted through openings inv the insulator into engagement with the -contact member, a pair of external plug members mounted adjacent the opposite end of the resistor on a disc-shaped insulator forming the other end of thecasing, a
plurality of arcuately arranged contacts mounted on another disc-shaped insulator positioned in an adjacent plane parallel to but intermediate the insulator carrying the external plugs and the end of the resistor, means for making resilient engagement between the plugs and said arcuately arranged contacts, and means for attaching the resistor and other parts to the. mounting carrying said external plugs so the resistor and associated parts may be rotated on said mounting.
9. A double ended resistor plug switch including, a casing closed at both ends by separate insulating means fastened thereto, the insulating means at one end carrying plug-in contacts and the insulating means at the opposite end carrying arcuately positioned contact members, an insulator located closely adjacent said last mentioned insulating means, and carrying externally extending plugs with means directly contacting With the inner ends of the plugs for engaging said Contact members as the latter are moved across the inner ends of the plugs, a resistor mounted at its ends between said end insulating means and having taps connected to said contact members and means for rotatably mounting the resistor, casing and said insulating means on the insulator carrying the plugs.
DONALD FRANCIS HASTINGS.
US159697A 1937-08-18 1937-08-18 Combination plug-in resistor and switch Expired - Lifetime US2142355A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US159697A US2142355A (en) 1937-08-18 1937-08-18 Combination plug-in resistor and switch

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US159697A US2142355A (en) 1937-08-18 1937-08-18 Combination plug-in resistor and switch

Publications (1)

Publication Number Publication Date
US2142355A true US2142355A (en) 1939-01-03

Family

ID=22573619

Family Applications (1)

Application Number Title Priority Date Filing Date
US159697A Expired - Lifetime US2142355A (en) 1937-08-18 1937-08-18 Combination plug-in resistor and switch

Country Status (1)

Country Link
US (1) US2142355A (en)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2506067A (en) * 1947-11-28 1950-05-02 Charles E Cohn Plug-in electrical unit
US2670422A (en) * 1952-09-15 1954-02-23 Goodyear Aircraft Corp Electric plug in decade resistance unit
US2960673A (en) * 1959-08-04 1960-11-15 Leonard P Young Resistance devices
US3748532A (en) * 1971-12-15 1973-07-24 Leviton Manufacturing Co Removable dimmer attachment for a portable lamp
DE2843967A1 (en) * 1978-10-09 1980-04-10 Ford Werke Ag PRE-CONTROL RESISTOR FOR HEATING FAN, ESPECIALLY FOR MOTOR VEHICLES
US4843326A (en) * 1987-08-17 1989-06-27 Smythe Robert H Electrical testing device for the power input to automobile telephone installations

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2506067A (en) * 1947-11-28 1950-05-02 Charles E Cohn Plug-in electrical unit
US2670422A (en) * 1952-09-15 1954-02-23 Goodyear Aircraft Corp Electric plug in decade resistance unit
US2960673A (en) * 1959-08-04 1960-11-15 Leonard P Young Resistance devices
US3748532A (en) * 1971-12-15 1973-07-24 Leviton Manufacturing Co Removable dimmer attachment for a portable lamp
DE2843967A1 (en) * 1978-10-09 1980-04-10 Ford Werke Ag PRE-CONTROL RESISTOR FOR HEATING FAN, ESPECIALLY FOR MOTOR VEHICLES
US4843326A (en) * 1987-08-17 1989-06-27 Smythe Robert H Electrical testing device for the power input to automobile telephone installations

Similar Documents

Publication Publication Date Title
US2142355A (en) Combination plug-in resistor and switch
US1908800A (en) Electrical rectifier
US2451810A (en) Electromagnetic controller
US2273245A (en) Electrical transformer
US2090505A (en) Rotary switch
US3025452A (en) Electrical apparatus
US2677777A (en) Holder for brush element or elements
US2466900A (en) Two-voltage shaver motor
US1950341A (en) Rheostat
US1935947A (en) Multiple fuse plug
US3035163A (en) Apparatus for rotating and operating light blubs
US1628569A (en) Screening of coils carrying high-frequency current
US2215029A (en) Multivoltage sadiron
US1752873A (en) Variable-voltage transformer
GB973778A (en) Temperature sensing device and manufacture thereof
US2245266A (en) Variable transformer
US1599124A (en) Electric-current cord holder
US1841864A (en) Variable resistance device
US1807381A (en) Cut-out for series incandescent street-lighting circuits and the like
US1778306A (en) Rheostat
US2026303A (en) Connecting device
US2225030A (en) Resistor
US3537051A (en) Adjustable sliding brush transformer
US1739942A (en) Rheostat
US1781593A (en) Safety fuse and circuit tester