US1448207A - Wireless-telephone receiving apparatus - Google Patents

Wireless-telephone receiving apparatus Download PDF

Info

Publication number
US1448207A
US1448207A US560036A US56003622A US1448207A US 1448207 A US1448207 A US 1448207A US 560036 A US560036 A US 560036A US 56003622 A US56003622 A US 56003622A US 1448207 A US1448207 A US 1448207A
Authority
US
United States
Prior art keywords
spindle
contact arm
switch
tuning coil
cover
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
US560036A
Inventor
William F Gehrig
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.)
ESSEX SPECIALTY Co Inc
Original Assignee
ESSEX SPECIALTY CO 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 ESSEX SPECIALTY CO Inc filed Critical ESSEX SPECIALTY CO Inc
Priority to US560036A priority Critical patent/US1448207A/en
Application granted granted Critical
Publication of US1448207A publication Critical patent/US1448207A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04BTRANSMISSION
    • H04B1/00Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
    • H04B1/06Receivers
    • H04B1/08Constructional details, e.g. cabinet

Definitions

  • This invention relates, generally, to improvements in wireless telephone apparatus; and, more particularly, to a novel arrangement and mounting of tuning coil and detector devices for wireless telephone receiving sets.
  • the invention has for its principal object to provide a novel and simple arrangement and mounting of cylindrical tuning coil together with a novel rotary slider switch for cooperation therewith; and the invention has for a further object to provide a neat, simple, cheap and eiiicient arrange ment and mounting of said tuning coil devices together with suitable detector devices for association therewith.
  • the same consists, primarily, in the novel-tuning coil and detector set for wireless telephone receivin apparatus herein after set forth; and, Furthermore, the invention consists in the novel arrangements and combinations of the various devices and parts, as well as in the details of the construction thereof, all of which will be hereinafter more fully described and claimed.
  • Figure 2 is a plan view of the apparatus.
  • Figure 3 is a bottom plan view of the 1922.
  • Figure 4 is a detail fragmentary vertical longitudinal section, taken on line 4-4 in Figure 2,- the same being drawn on an enlarged scale.
  • Figure 5 is a bottom plan view of the rotary slider switch handle and its pointer member.
  • Figure 6 is a perspective view of a spacer block used in connection with the means for fastening the tuning coil element to the underside of the casing top or cover.
  • Figure 7 is a perspective view of the switch or contact arm of the rotary slider switch element. 1 v
  • the reference character 8 indicates'a suitable casing-or box, the upper open end of which is closed by a top or. cover member 9, which fits said upper open end and which may be suitably secured thereto.
  • the reference character 10 indicates a suitable hollow cylindrical core, made of insulating material, upon which the wire windings 11 of the tuning coil element are supported. Said core 10 is secured to the underside of said top or cover member 9, so as to be suitably suspended and spaced therefrom, in such manner that the tuning coil element is enclosed within the interior of the casing or box 8 beneath the top or cover member 9.
  • the meansfor so mounting the tuning coil element within the casing comprises a pair of bolts 12 and 12' which pass downwardly through the top or cover member 9. Arranged upon the shanks of said bolts are the respective perforate spacer pieces or blocks 13 and 13' which abut upon the under side ofsaid top or cover member 9.
  • the tuning coil element is so disposed that the upper surface of its coil windings 11 are spaced from the underside of said cover or top member.
  • a rotary slider or tuning switch mechanism adapted to cooperate with thetuning coil element.
  • This mechanism comprises a verticalspindle 16 journaled in a bearing opening 17 provided in said cover or top member, and suitably located relative to the position of the tuning coil so as to be disposed in off-set relation to one side thereof opposite a point intermediate the ends of the same.
  • the upper endof said. spindle 16, which projects exteriorly from said casing, is provided with a threaded extension 18 of reduced diameter.
  • the reference character 19 indicates a handle or knob of insulating material, which possesses, in imbedded relation to its lower end, a centrally alined internally threaded socket piece 20, into which said threaded extension 18 screws to operatively attach the handle or knob 19 to the exterior end of said spindle 13.
  • a pointer plate 21 Engaged against the bottom of said handle or knob 19 is a pointer plate 21, hav ing a central perforation 22 and a pair of upwardly pressed tits or studs 23.
  • a pointer arm 24 Integrally connected with said pointer plate to extend outwardly therefrom.
  • Said pointer plate is secured to the bandle or knob and to the spindle, so as to turn therewith, bv, passing the spindle extension 18 upwardly through the central perforation 22, so as to engage and clamp the pointer plate between the bottomof the handle or knob and the shoulder 25 at the juncture of the spindle body and its extension 18, the
  • tits or studs 23 being countersunk in the body of the handle or knob to thereby prevent turning of the pointer plate and its pointer arm relative to the handle or knob and the spindle.
  • a washer 26 Disposed between the underside of said pointer plate and the upper surface of said top or cover member 9 is a washer 26.
  • a contact plate 27 Arranged against the underside of said top or cover member 9 is a contact plate 27 having a perforate end 28 through which the spindle 16 extends.
  • Said spindle is provided with a transverse opening 29 adjacent to its lower inner end adapted to receive the butt 30 of a laterally projecting switch or contact arm 31, which extends over the upper side of the tuning coil element so as to be movably and electrically en-' gageable with wire windings 11 thereof.
  • a washer 32 Arranged upon said spindle 16 above the butt 30 of said switch or contact arm 31 is a washer 32, and arranged around said spindle 16, intermediate the perforate end 28 of said contact plate 27 and the washer 32 is a coiled compression spring 33, which normally exerts a downward thrusting pressure upon said spindle 16, whereby the switch or contact arm 31 is yieldably held iii-flexed ponaeaaor sition to maintain the same tensionally engaged with the windings of the tuning coil element.
  • a scale plate 34 Fixed upon the upper surface of the top or cover member 9, in position to cooperate with the pointer arm 24- is a scale plate 34:, whereby the pointer indicates the adjusted position of the switch or contact arm relative to the windings of the tuning coil element.
  • a pair of stop pins 35 which limit the movement of the pointer arm in each direction, and con sequently limit the rotation of the handle and spindle to determine the limit of adjustment of the switch or contact arm 31 toward each end of the tuning coil element.
  • a crystal detector body 36 and holder 37 therefor therefor, together with an adjustable cat-whisker contact arm 38 and holder or mounting 39 therefor.
  • binding posts d0 and 41-1 Fixed upon said top or cover member 9, at one side thereof are binding posts d0 and 41-1, and at the opposite side additional binding posts 42 and 13.
  • the binding post 10 is connected by a suitable lead to the holder 37 of the dectector body 36, and by an additional lead a0 to one end of the windings 11 of the tuning coil element.
  • the cat whisker contact arm holder or mounting 39 is connected by a suitable lead to the holder 37 of the dectector body 36, and by an additional lead a0 to one end of the windings 11 of the tuning coil element.
  • a suitable lead 42 is connected by a suitable lead 42 with the binding post 12.
  • Tnterconnecting the binding post 13 with the binding post n is a ground Wire lead 44 which crosses over the contact plate 2?, and which is secured in fixed electrical engagement with the latter by soldering the same thereto.
  • the incoming conductor 15 leading from the aerial or antennae of a wireless telephone receiving outfit is connected with the binding post i0, so that the wave impulses are caused to enter the detector body 36 through the lead 40, passing thence through the cat whisker contact arm and its holder by way of the lead 12 to the binding post 42; at the same time said wave impulses are carried to the tuning coil windings 11 through the lead 40", passing thence through the switch or contact arm 31 to the spindle 16 and contact plate 27, and through the. ground wire lead 4 1 to the binding post 41, which is connected to a suitable ground by the conductor 16.
  • the phones (not shown) are connected at one side by the conductor 47 with the binding post 12, and at the other side, by the conductor lfilwith the binding post 13 being thence grounded through the ground lead wire 44, binding post 41 and conductor 46 upon a suitable ground connection.
  • a cover for said casin a cylindrical tuning coil element, means or supporting said tuning coil element within said casing from the under side of said cover but spaced downwardly from the latter, a vertical spindle journaled .
  • said cover aknob on the exterior end of said spindle for turning the same, a laterally projecting switch con-, tact arm on the interior end of said spindle having its free end portion tensionally hearing on the upper surface of the windings of said tuning coil and adjustably movable from end to end of the latter when said spindle is turned, and means for connecting said spindle and switch contact arm with ground;
  • a casing a cover for said casing, a c lindrical tuning coil element secured to t e under side of said cover within said casing, means for spacing said tuning coil element from the under surface ofsaid cover, a vertical spindle journaled in said cover, 'a knob on the exterior end of said spindle, a contact plate on the under side of said" cover through which said spindle extends, a laterally projecting switch contact armon the interior end of said spindle having its free end portion tensionally bearing on the upper ing coil element secured to the under side of said cover within said casing, means forspacing saidtuning coil element from the under surface of said cover, a vertical spindle journaled in said cover, a knob on the exterior end of said spindle, a contact plate on the under side of said cover through which said spindle extends, a laterally projecting switch contact arm on the interior end of said spindle having its free end portion tensionally bearing on the upper surface
  • a supporting member 'a cylindrical tuning; coil secured to the under side of said supporting member in downwardly spaced re lation thereto, a vertical spindle 'journaled in said supporting member, a knob on the exterior end of said spindle a laterally pro jecting switch contact arm on the interior end of said spindle having its free end portion tensionally bearing on the upper surface of the windings of said tuning coil, a compression spring around said spindle intermediate said supporting member and the butt of said switch contact arm to thrust downwardly on said spindle to augment the tension of said switch contact arm relative to said tuning coil, means for connecting said spindle and switch contact arm to ground, and cooperating means connected with said knob and the upper side of said supporting member to indicate the adjusted position of said switch contact arm relative to said tuning coil.

Description

Mar. 13, 1923. 1,448,207 w. F. GEHRIG WIRELESS TELEPHONE RECEIVING APPARATUS Filed May 11 1922 2 sheetssheet l INSULATION W. F. GEHRIG WIRELESS TELEPHONE RECEIVING APPARATUS Mar. 13, 1923.
Filed May 11, 1922 2 sheets-sheet 2 IN VE IV TOR Vz/p lamifi g g BY (J flaw ATTORNEKF Patented Mar. 13, 1923.
UNITED STATES PATENT OFFHCE.
WILLIAM F. GEHRIG, OF NEWARK, NEW JERSEY, INC., OF BERKLEY HEIGHTS, NEW JERSEY, A
ASSIGNOR- TO ESSEX SPECIALTY 30.,
CORPORATION OF HEY? 3 WIRELESS-TELEPHONE RECEIVING APPARATUS.
Application filed May 11,
To all whom it may concern:
Be it known that I, WILLIAM F. GEHRIG, a citizen of the United States, residing at Newark, in the county of Essex and State of New Jersey, have invented certain new and useful Improvements in Wireless-Telephone Receiving Apparatus; and I do hereby declare the followin to be a full, clear, and exact description 0 the invention, such as will enable Others skilled in the art to which it appertains to make and use the same, reference being bad to the accompanying drawings, and to characters of reference marked thereon, which form a part of this specification.
This invention'relates, generally, to improvements in wireless telephone apparatus; and, more particularly, to a novel arrangement and mounting of tuning coil and detector devices for wireless telephone receiving sets.
The invention has for its principal object to provide a novel and simple arrangement and mounting of cylindrical tuning coil together with a novel rotary slider switch for cooperation therewith; and the invention has for a further object to provide a neat, simple, cheap and eiiicient arrange ment and mounting of said tuning coil devices together with suitable detector devices for association therewith.
Other objects of this invention,- not at this time more particularly enumerated,will be clearly understood from the following detailed description of the same.
With the various objects of this invention in view, the same consists, primarily, in the novel-tuning coil and detector set for wireless telephone receivin apparatus herein after set forth; and, Furthermore, the invention consists in the novel arrangements and combinations of the various devices and parts, as well as in the details of the construction thereof, all of which will be hereinafter more fully described and claimed.
The invention is clearly illustrated in the accompanying drawings, in which Figure l is a side elevation of the apparatus made according to and embodying the principles of this invention, a part of the casing being shown in vertical section -to disclose the parts enclosed within the same.
Figure 2 is a plan view of the apparatus. Figure 3 is a bottom plan view of the 1922. Serial No. 560,036.
casing top or cover upon which the apparatus is mounted.
Figure 4 is a detail fragmentary vertical longitudinal section, taken on line 4-4 in Figure 2,- the same being drawn on an enlarged scale.
Figure 5 is a bottom plan view of the rotary slider switch handle and its pointer member.
Figure 6 is a perspective view of a spacer block used in connection with the means for fastening the tuning coil element to the underside of the casing top or cover.
Figure 7 is a perspective view of the switch or contact arm of the rotary slider switch element. 1 v
Similar characters of reference are employed in all of the hereinabove described views, "to indicate corresponding parts.
Referring now to said drawings, the reference character 8 indicates'a suitable casing-or box, the upper open end of which is closed by a top or. cover member 9, which fits said upper open end and which may be suitably secured thereto.
The reference character 10 indicates a suitable hollow cylindrical core, made of insulating material, upon which the wire windings 11 of the tuning coil element are supported. Said core 10 is secured to the underside of said top or cover member 9, so as to be suitably suspended and spaced therefrom, in such manner that the tuning coil element is enclosed within the interior of the casing or box 8 beneath the top or cover member 9. The meansfor so mounting the tuning coil element within the casing, comprises a pair of bolts 12 and 12' which pass downwardly through the top or cover member 9. Arranged upon the shanks of said bolts are the respective perforate spacer pieces or blocks 13 and 13' which abut upon the under side ofsaid top or cover member 9. The free lower ends of the bolts 12 and 12 extend through the walls of the core 10, adjacent to the respective ends of the latter, and the said core is secured against displacement from the ends of the bolts by the respective curvilinear washer members or clips 14 and the fastening nuts 15 screwed upon the shanks of said bolts. As thus secured to the cover or top member 9, and suspended from the under or inner side thereof, the tuning coil element is so disposed that the upper surface of its coil windings 11 are spaced from the underside of said cover or top member.
Mounted in connection with said cover or top member 9 is a rotary slider or tuning switch mechanism adapted to cooperate with thetuning coil element. This mechanism comprises a verticalspindle 16 journaled in a bearing opening 17 provided in said cover or top member, and suitably located relative to the position of the tuning coil so as to be disposed in off-set relation to one side thereof opposite a point intermediate the ends of the same. The upper endof said. spindle 16, which projects exteriorly from said casing, is provided with a threaded extension 18 of reduced diameter. The reference character 19 indicates a handle or knob of insulating material, which possesses, in imbedded relation to its lower end, a centrally alined internally threaded socket piece 20, into which said threaded extension 18 screws to operatively attach the handle or knob 19 to the exterior end of said spindle 13. Engaged against the bottom of said handle or knob 19 is a pointer plate 21, hav ing a central perforation 22 and a pair of upwardly pressed tits or studs 23. Integrally connected with said pointer plate to extend outwardly therefrom is a pointer arm 24. Said pointer plate is secured to the bandle or knob and to the spindle, so as to turn therewith, bv, passing the spindle extension 18 upwardly through the central perforation 22, so as to engage and clamp the pointer plate between the bottomof the handle or knob and the shoulder 25 at the juncture of the spindle body and its extension 18, the
tits or studs 23 being countersunk in the body of the handle or knob to thereby prevent turning of the pointer plate and its pointer arm relative to the handle or knob and the spindle. Disposed between the underside of said pointer plate and the upper surface of said top or cover member 9 is a washer 26. Arranged against the underside of said top or cover member 9 is a contact plate 27 having a perforate end 28 through which the spindle 16 extends. Said spindle is provided with a transverse opening 29 adjacent to its lower inner end adapted to receive the butt 30 of a laterally projecting switch or contact arm 31, which extends over the upper side of the tuning coil element so as to be movably and electrically en-' gageable with wire windings 11 thereof. Arranged upon said spindle 16 above the butt 30 of said switch or contact arm 31 is a washer 32, and arranged around said spindle 16, intermediate the perforate end 28 of said contact plate 27 and the washer 32 is a coiled compression spring 33, which normally exerts a downward thrusting pressure upon said spindle 16, whereby the switch or contact arm 31 is yieldably held iii-flexed ponaeaaor sition to maintain the same tensionally engaged with the windings of the tuning coil element. Fixed upon the upper surface of the top or cover member 9, in position to cooperate with the pointer arm 24- is a scale plate 34:, whereby the pointer indicates the adjusted position of the switch or contact arm relative to the windings of the tuning coil element. There are also mounted on the upper side of the top or cover member 9, one on either side of the pointer arm 24:, a pair of stop pins 35 which limit the movement of the pointer arm in each direction, and con sequently limit the rotation of the handle and spindle to determine the limit of adjustment of the switch or contact arm 31 toward each end of the tuning coil element.
Mounted upon the upper surface of said top or cover member 9 is a crystal detector body 36 and holder 37 therefor, together with an adjustable cat-whisker contact arm 38 and holder or mounting 39 therefor.
Fixed upon said top or cover member 9, at one side thereof are binding posts d0 and 41-1, and at the opposite side additional binding posts 42 and 13. The binding post 10 is connected by a suitable lead to the holder 37 of the dectector body 36, and by an additional lead a0 to one end of the windings 11 of the tuning coil element. The cat whisker contact arm holder or mounting 39,
is connected by a suitable lead 42 with the binding post 12. Tnterconnecting the binding post 13 with the binding post n is a ground Wire lead 44 which crosses over the contact plate 2?, and which is secured in fixed electrical engagement with the latter by soldering the same thereto.
The incoming conductor 15 leading from the aerial or antennae of a wireless telephone receiving outfit is connected with the binding post i0, so that the wave impulses are caused to enter the detector body 36 through the lead 40, passing thence through the cat whisker contact arm and its holder by way of the lead 12 to the binding post 42; at the same time said wave impulses are carried to the tuning coil windings 11 through the lead 40", passing thence through the switch or contact arm 31 to the spindle 16 and contact plate 27, and through the. ground wire lead 4 1 to the binding post 41, which is connected to a suitable ground by the conductor 16. The phones (not shown) are connected at one side by the conductor 47 with the binding post 12, and at the other side, by the conductor lfilwith the binding post 13 being thence grounded through the ground lead wire 44, binding post 41 and conductor 46 upon a suitable ground connection.
From the above description it will be apparent that the present invention provides a very neat, compact and simple constructlon, arrangement and hook-up of tuning from view.
coil and detector devices for Wireless telephone receiving sets.
One of the important advantages afforded by the novel structure lies in the provision of the rotary slider switch adapted to cooperate with the windings 11 of the tuning coil. The novel arrangement of such feature permits the enjoyment of allthe convenience and simplicity of operation entailed in turning a: knob or handle, as against the more crude and inconvenientarms-length or longitudinal slider and bar arrangement, While at the same time permitting the enclosure and protection of the coil and its windings within a casing and concealed The inherent tension of the switch or contact arm 31, together with the auxiliary tens-ion applied thereto through the coiled compression spring 33. assures a perfect electrical enga ement of the switch or contact arm with windingsof the longitudinal coil, in all positions of said switch or contact arm relative to said windings, while at the same time the indication of the adjusted position of the switchor contact arm relative to said windings is conveniently and visibly shown by the positionof the pointer arm 24 relative to the scale plate 34.
I am aware that some changes may be made in the various arrangements and combinations of the devices and parts, as well as in the details of the construction of the same, without departing from the scope of this invention as set forth in the. foregoing specification, and as defined in the appended claims. Hence, I do not limit myinvention to the exact arrangements and combinations of the various devices and parts as described in said specification, nor do I confine myself to the exact details of the construction of said parts as illustrated in the accompanyingdrawings.
I claim 1. In a device f the kind described, a
casing, a cover for said casin a cylindrical tuning coil element, means or supporting said tuning coil element within said casing from the under side of said cover but spaced downwardly from the latter, a vertical spindle journaled .in said cover, aknob on the exterior end of said spindle for turning the same, a laterally projecting switch con-, tact arm on the interior end of said spindle having its free end portion tensionally hearing on the upper surface of the windings of said tuning coil and adjustably movable from end to end of the latter when said spindle is turned, and means for connecting said spindle and switch contact arm with ground;
2. In a device of the kind described, a casing, a cover for said casing, a c lindrical tuning coil element secured to t e under side of said cover within said casing, means for spacing said tuning coil element from the under surface ofsaid cover, a vertical spindle journaled in said cover, 'a knob on the exterior end of said spindle, a contact plate on the under side of said" cover through which said spindle extends, a laterally projecting switch contact armon the interior end of said spindle having its free end portion tensionally bearing on the upper ing coil element secured to the under side of said cover within said casing, means forspacing saidtuning coil element from the under surface of said cover, a vertical spindle journaled in said cover, a knob on the exterior end of said spindle, a contact plate on the under side of said cover through which said spindle extends, a laterally projecting switch contact arm on the interior end of said spindle having its free end portion tensionally bearing on the upper surface of the windings of said tuning coil, a compression spring around said spindle intermediate said contact plate and the butt of said switch contact arm to thrust downwardly on said spindle to augment the tension of said switch contact arm relative to said tuning coil element, said contact plate serving to receive theattachment of a ground lead in electrical connection with said spindle and its switch contact arm, and co operating means connected with said knob and the outer surface of said cover to indicate the adjusted position of said switch face of the windings of said tuning coil, a
compression spring around said spindle 'intermediate said supporting member and the butt of said switch contact arm to thrust downwardly on said spindle to augment the tension of said switch contact arm relative to said tuning coil, and means for connect-v ing said spindle and switch contact arm to ground.
lit
5. In a device of the hind described, a supporting member, 'a cylindrical tuning; coil secured to the under side of said supporting member in downwardly spaced re lation thereto, a vertical spindle 'journaled in said supporting member, a knob on the exterior end of said spindle a laterally pro jecting switch contact arm on the interior end of said spindle having its free end portion tensionally bearing on the upper surface of the windings of said tuning coil, a compression spring around said spindle intermediate said supporting member and the butt of said switch contact arm to thrust downwardly on said spindle to augment the tension of said switch contact arm relative to said tuning coil, means for connecting said spindle and switch contact arm to ground, and cooperating means connected with said knob and the upper side of said supporting member to indicate the adjusted position of said switch contact arm relative to said tuning coil.
6. The combination with a cylindrical tuning coil of a rotary slider switch comprising a vertical spindle having a laterally projecting resilient contact arm connected therewith, the free end portion of said contact arm being adapted to tensionally bear upon the windings of said coil, spring means for exerting an axial thrust upon said spindle to augment the tension of said contact arm, and a knob on said spindle tor turning the same.
7. The combination with a cylindrical nccaao? tuning coil off a rotary slider switch comprising a vertical spindle having a laterally projecting resilient contact arm connected therewith, the free end portion of said contact arm being adapted to tensiona-lly bear upon the windings of said coil, spring means for exerting an axial thrust upon said spindle to augment the tension of said contact arm, a knob on said spindle for turning the same, and means for connecting said dicator means associated with said spindle and its knob for showing'the adjusted position of said contact arm relative to said tuning coil.
in testimony, that l claim the invention set forth above l have hereunto set my hand this 2nd day ct May, 1922.
WLLIAM F. Gldl-lllltllG Witnesses:
Gnonon D. lPtrcrranns, FLORA Mrnnnn.
US560036A 1922-05-11 1922-05-11 Wireless-telephone receiving apparatus Expired - Lifetime US1448207A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US560036A US1448207A (en) 1922-05-11 1922-05-11 Wireless-telephone receiving apparatus

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US560036A US1448207A (en) 1922-05-11 1922-05-11 Wireless-telephone receiving apparatus

Publications (1)

Publication Number Publication Date
US1448207A true US1448207A (en) 1923-03-13

Family

ID=24236089

Family Applications (1)

Application Number Title Priority Date Filing Date
US560036A Expired - Lifetime US1448207A (en) 1922-05-11 1922-05-11 Wireless-telephone receiving apparatus

Country Status (1)

Country Link
US (1) US1448207A (en)

Similar Documents

Publication Publication Date Title
US1442999A (en) Automatic reel for electric devices
US2277671A (en) Electrical switch
US2676225A (en) Electric trailer brake actuator
US1448207A (en) Wireless-telephone receiving apparatus
US2545965A (en) Master switch
US2814900A (en) Electric fishing signal device bite buzz light
US2611016A (en) Portable fire alarm unit
US2506208A (en) Switch
US2472604A (en) Rheostat with switch
US2291019A (en) Snap action switch
US1415534A (en) Variable resistance
US3968337A (en) Door-actuated alarm switch
US2274870A (en) Burglar alarm
US2024060A (en) Electric current control device
US1947681A (en) Electric switch
US2229520A (en) Combination radio aerial and turn indicator for automobiles
US1477375A (en) Electrically-operated warning horn
US1839916A (en) Starting motor switch
US2702328A (en) Inertia switch
US1873658A (en) Tuning coil shifter
US2423610A (en) Electric burglar alarm
US1731003A (en) Electric-circuit-control device
US2004207A (en) Switch
US2274990A (en) Hand brake signal
US1633468A (en) Burglar alarm