US1835072A

US1835072A - Electric pick-up device

Info

Publication number: US1835072A
Application number: US411317A
Authority: US
Inventors: Mcclatchie Stanley
Original assignee: Individual
Current assignee: Individual
Priority date: 1929-08-08
Filing date: 1929-12-03
Publication date: 1931-12-08
Anticipated expiration: 1948-12-08

Description

Dec. 8, 1931. s. MCCLATCHIE ELECTRIC PICK-UP DEVICE Filed Dec. 5, 1929 R O T m V Nu stahleg mc Clahzhie W W RTTORHEY,

Patented Dec. 8, 1931 UNITED. STATES STANLEY MCGLA'IGHIE, on vBERLIN-wImvrnnsnonr, GERMANY ELECTRIC PICK-UP DEVICE Application filed December 3, 1929, Serial No. 411,317,:and in Germany August 8, 1929.

This invention relates to electric pick-up devices, and is more particularly concerned with magnetic sound pick-up devices such as are used in phonographs for reproduction'of 6 sound or speech recorded upon a phonograph record. 7 v

The first object of the invention is to provide a sound box or pick-up for a phonograph with an oscillating magnetic armature of minimum weight, wherebya faithfulreproduction of the sound is obtained.

Another object of the invention is to provide a pick-up device for a phonograph which is of small cost.

Another object of the invention is to provide means in connection-with an electric" pick-up device for phonographs and the like by which the life of the records as well as the needles-may be increased.

Still another object is to provide apick-up device which enables a ready and easy replacement of a used needle.

The variousfeatures and further objects of my invention will become apparent as the following detailed description proceeds, with reference to the accompanying drawings. I wish it to be understood that the specific embodiment of my invention as illustrated by the drawings is illustrative only of the novel idea underlying my invention and should not have the effect of allowing a narrow interpretation of the invention, short of its broad scope as expressed by the terms of the appended claims. Similar reference numbers refer to similar elements throughout the different views of the drawings.

Figure 1 of the drawings shows in cross-section a sound boX in accordance with my in vention taken along the section line I-I of Figure 2. r

' Figure 2 is a section taken along line IIII of Figure 1. V

Figure 3 shows a longitudinal section taken along section line IIIIII of Figure 2.

According to the invention, the pickup armature is provided with a flange held between damping surfaces of rubber or similar resilient material. r V V The armature may have different forms.

which is easy and simple to manufacture and According to a preferred embodiment of the invention, the armature has the form of a metal tube for receiving the phonograph needle. This tube is provided at one. end with a flange held between gaskets of cushioningor damping material. In this embodiment, the needle is held in a simple manner merely by the oblique pressure of the pick-up, whichforces the needle angularly into opposing V-shaped portions of the tube. This con-. struction eliminates the necessity for a clamp ing screw and the necessary guiding elements therefor, and results in a further reduction of the weight of the oscillating mass.

Referring to the drawings, afield magnet 1 (only partially shown) is arranged within a casing 2. This magnet is provided with pole pieces 4 which are mounted on an interme diate wall 6 between the main casing 2 and a detachable cup-shaped lower casing 7. 5 is the spool for the coil 3. The cup 7 is attached to casing 2 by

screws

9 and 10, with a resilient gasket 8, and the spool flange 8 interposed. a

The armature 11 is in the form of an iron 7 sleeve and is provided at its lower end, with a flange or ring-shaped extension 12 which is resiliently mounted between andheld in position by resilient gaskets 13 and 1 1.- The armature tube 11 has preferably a rhomboidal cross-section, as shown at 11 in Figure 2. In operation, the needle is forced by the weight of the pick-up into a slightly oblique position within the armature tube, and is thuswedged into firm engagement with the armature without the use of a retaining screw. This con struction is very simple in itself, simplifies the interchangeof needles and relieves the armature of the undesirable additional weight of a set-screw with accompanyingretaining walls. The needle is prevented from falling out when the pick-up does not rest on the recordeither by friction at the mouth of-the gasket 14, or by the inherent magnetic at? traction of the armature. The gaskets 13, 14:, together with a washer 17 and cover-plate 17' are fastened together and connected to the lower wall of the cup-shaped casing part 7 by means of rivets 16. The gasket 8 between the lower part 7 of the casing and the intermediate wall 6 serves to allow the adjustment of the armature between the pole pieces 4 by means of the set-screw 10.

Although the invention has been specifically described in reference to the showing of the drawings, it is obvious that it may be applied in other ways.

\Vhat I claim is:

1. A sound reproducing device for phonographs and the like, comprising in combina tion, a supporting member, an armature adapted to engage a stylus, a supporting flange on said armature, and a resilient cushion carried by said supporting member and engaging the armature-flange so as to support the armature and at the same time damp oscillations of the same.

2. A sound reproducing device for phonographs and the like, comprising in combination, a supporting member, resilient gaskets held by said member, a tubular armature adapted to engage a stylus, and a flange on said armature which is clamped between the said gaskets in such manner as to support the armature and to damp oscillations.

3. In an electro-magnetic sound reproducing device for phonographs and the like, comprising in combination, a casing structure, a magnet associated with said structure, pole pieces for said magnet, a phonograph needle to be subjected to mechanical oscillations corresponding to the oscillations of sound to be reproduced, a sleeve of magnetic material for holding said needle arranged between said pole pieces and serving as the armature of said pick-up device, a flange of said sleeve and means for elastically mounting said sleeve, said means consisting of sheets of elastic material carried by said casing structure, said flange being clamped between said sheets.

4. In an electro-magnetic sound reproducing pick-up device for phonographs and the like comprising in combination, a casing structure, a magnet associated with said casing, pole pieces of said magnet, a phonograph needle to be subjected to mechanical oscillations corresponding to the oscillations of sound to be reproduced, a sleeve element with an inner cross-section gradually decreasing in two opposite radial directions until below the thickness of said needle, to hold said needle by clamping action, said sleeve being arranged between said pole pieces to serve as operating armature of said pick-up device, a flange of said sleeve and means elastically mounting said sleeve, said means consisting of rubber sheets, fastened together and carried by said casing, said flange being clamped between said sheets.

5. In an electro-magnetic sound reproducing pick-up device for phonographs and the like, comprising in combination, a casing structure, a magnet carried by said structure, pole pieces of said magnet, a phonograph needle to be subjected to mechanical oscillations corresponding to the oscillations of sound to be reproduced, a tube of magnetic material squeezed in opposite directions from its center in respect to its cross-section to an outside width just below the thickness of said needle, so that said needle can be clamped between the corners of said tube in its operating position, said tube being arranged between said pole pieces to serve as operating armature of said pick-up device, a flange of said tube and means for elastically mounting said tube, said means consisting of rubber sheets fastened together and carried by said casing, said flange being clamped between said sheets.

6. In an electro-magnetic sound reproducing pick-up device for phonographs and the like, as described in claim 5, in which said needle is prevented from falling out of its holding sleeve by means of an elastic lock washer covering the opening of said sleeve.

7. In an electro-magnetic sound reproducing pick-up device for phonographs and the like, as described in claim 6, in which said needle is prevented from falling out of its holding tube by means of an elastic lock washer covering the opening of said tube.

8. In an electro-magnetic sound reproducing pick-up device for phonographs and the like, comprising in combination, a main casing structure, a magnet carried by said struc ture, pole pieces of said magnet, a detachable member of said casing structure, sheets of elastic material held together and carried by said detachable member, a phonograph needle passing through an opening of said sheets, said needle being subjected to mechanical oscillations corresponding to the oscillations of sound to be reproduced, means for elastically mounting said needle, said means comprising a tube of magnetic mate rial surrounding and holding said needle by clamping action and arranged between said pole pieces to simultaneously serve as operating armature of said pick-up device and a flange of said tube, said flange being clamped between said sheets.

9. In an electro-magnetic sound reproducing pick-up device for phonographs and the like comprising in combination, a main casing structure, a magnet carried by said casing structure, pole pieces of said magnet, a detachable member of said casing structure, sheets of rubber held together and carried by said detachable member, a phonograph needle passing through an opening of said sheets, said needle being subjected to mechanical oscillations corresponding to the oscillations of sound to be reproduced, means for elastically mounting said needle, said means comprising a tube of magnetic mate rial arranged between said pole pieces to serve as an operating armature of said pickup device with an inner cross-section gradually decreasing in two opposite radial directions until below the thickness of said needle for holding said needle by clamping action in its operating position and a flange of said tube at its lower end, said flange being held in clamping position between said rubber sheets.

10. In an electro-magnetic pick-up device as described in claim 8, wherein said needle is prevented from falling out of its holding tube by means of a lock washer of flexible material covering the opening of said tube.

11. In an electro-magnetic pick-up device, as described in claim 9, wherein said needle r is prevented from falling out of its holding tube by means of a lock washer of flexible material covering the opening of said tube.

12. In an electro-magnetic sound reproducing phonograph pick-up device, as described in claim 8, in which one of said elastic sheets has a perforation corresponding to the thickness of said needle passing same to serve as a lock washer for said needle to prevent it from falling out of said tube.

13. In an electro-magnetic sound reproducing phonograph pick-up device, as described in claim 9, in which one of said elastic sheets has a perforation just corresponding to the thickness of said needle passing same to serve as a lock washer for said needle to pervent it from falling out of said tube.

14. In combination with a device transforming mechanical movements into corresponding magnetic variations, a stylus subjected to said mechanical movements, a supporting member, a magnet carried by said member, pole pieces of said magnet, a metal sleeve arranged between said pole pieces for holding said stylus in a clamped position to hold and to serve as an armature of said magnet, a flange of said sleeve and means for elastically mounting said sleeve, said means including a number of sheets of wield ing material carried by said member, said flange being clamped between said sheets.

15. In combination with an arrangement for transforming mechanical movements into corresponding magnetic variations, a stylus subjected to said mechanical movements, a supporting member, a magnet carried by said member, pole pieces of said magnet, a metal tube of magnetic material arranged between said pole pieces to serve as an armature of said magnet and having an inner cross-section gradually decreasing in two opposite radial directions until below the thickness of said stylus for holding said stylus in aclamped operating position, a flange of said tube and means for elastically mounting said tube, said means including at least two sheets of yielding material carried by said member,

said flange being clamped between said sheets. 7

16. In a pick-up device as described in claim 15, wherein said stylus is prevented from falling out of its holding tube by means of elastic lock washer covering the opening of said tube.

17. In combination with an arrangement for transforming mechanical movements into corresponding magnetic variations, a stylus subjected to said mechanical movements, a supporting member, a main casing structure, a magnet carried by said structure, pole pieces of said magnet, a detachable part of said casing structure, sheets of rubber material held together and carried by said detachable part, said phonograph needle passing through an opening of said sheets, and means for elastically mounting said needle, said means comprising a tube of magntic material surrounding and holding said needle in clamped position and arranged between said pole pieces for simultaneously serving as operating armature of said magnet and the flange of said tube, said flange being clamped between said sheets.

18. In combination with an arrangement for transforming mechanical movements into correspondingmagnetic variations, a stylus subjected to said mechanical movements, a main casing structure, a detachable part of said structure, a magnet carried by said main structure, pole pieces of said magnet and means for holding said stylus in operating position, said means comprising a metal tube of magnetic material having an inner cross-section decreasing towards two radial opposite directions until below the thickness of said stylus for holding said needle in a clamped operating position, saidmetal tube being arranged between said pole pieces to serve as operating armature of said, magnet, a flange of said metal tube, at least two sheetsof rubber material carried by said detachable part of said main structure, said flange being clamped between said rubber sheets.

19. In a pick-up device as described in claim 18, in which elastic means are arranged between said detachable part andsaidmain casing for adjusting said armature tube to a central position between the pole pieces.

In testimony whereof I affix my signature.

STANLEY MoOLATGI-IIE.