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Publication numberUS888191 A
Publication typeGrant
Publication dateMay 19, 1908
Filing dateNov 9, 1907
Priority dateMar 9, 1907
Publication numberUS 888191 A, US 888191A, US-A-888191, US888191 A, US888191A
InventorsGreenleaf Whittier Pickard
Original AssigneeGreenleaf Whittier Pickard
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
US 888191 A
Abstract  available in
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Description  (OCR text may contain errors)






r5 WM A ty test: 4 M WW4 tion of a compl v I low conductivity, provided that the contact The permanent leads, A,

' conductivity.



Patented. May 19, 1908.

1907, Serial No. 361,444. Divided and this application filed November-9, 1907.

Serial No. 401,363.

polished, and providing a device which is ,more useful in circuits of low impedance. The polishing of the operative surface of mem- No. 888,191. Specification of Letters Patentl Original application filed March 9,

To all whom it may concern:

Be it known that I, GREENLEAF Wnrrrrnn PioKAaD,

a citizen of the United States of America-and a resident of the town of Ameser B apparently emphasizes the rectification bury, State of Massachusetts, have invented property of the material such that the resultcertain new and useful Improvements in )s ant effective current consists ofthe oscillacillation-Receivers, the principles of which tions in the direction which is least oppose are set forth in the following specification and by the material; as distinguished from the accompanying drawings, which disclose the thermo-electric property of the material, the form of the invention which I now consider to resultant of the action of which is apparen y be the best of the various forms in which an electromotive force in the other direction. these principles may be embodied. This rectification action is apparently also accentuated by the enormous difference in specific conductivity between the brass member A and member B.

The member B is placed in a liquefied offusible metal M in a conducting cu P, so that'when the metal M cools and so 'difies, the member B will be embedded therein in good conductin relation therewith. he cup P rests on t ie metallic plate K, held on the base I by the pin N. Hence the cup This application is a division of my applicationSerial Number 361,444, filed March9, 1907.

This invention relates to improvements in oscillation receivers, f or use in receiving communications transmitted by electromagnetic waves, and for similar uses.

The object of the invention is a commercially stable and sensitive device of the kind specified.


The invention involves an oscillation remay be slid around on K, as desired, to ceiver having as one member a conductor instantly present different parts of its pplossessing the property of one of those speciished surface to the end of member A, t at lied in-said original application. end being electrically small as compared wit drawings, Figure 1 is a vertical secete' embodiment of the invention, Fig. 2 is a plan of the same, both figures being on a two to one scale, in respect of a commercial device.

Of the the other contacts in series.

The member A is carrie which is vertically movable in a guide G of a bracket Z secured to base I; The spring S is held in the sleeve L by the cup 0, and the in a sleeve L In Fig. 1 the two solid conductors appear s ringi presses member A down on member at Aand B: The binding posts for the cir- In use, the telegraph or other operator cuit terminals are shown at E and E Fig. 2. rapidly moves the sleeve up and down in this position of maximum sensitiveness. at

from member A,- and B from member B, he in the insulating base I, in holes drilled horizontally from the recesses for the heads of screws H and D to the recesses for the heads of the screws of the binding posts. .Each of the conductors A and release 0 and B may be any suitable conductor of electhat particular pressure of spring S. Finally tricity, provided that at least one of them is a the operator moves the cup P "around on solid possessing the property of rectifying super-base K until the most sensitive art electrical oscillations, and the two conductors of the polished surface of member is preferably having a wide difference in specific The member A may for examle be of brass and the member B a mass of the natural element silicon having extremely 2. A member of an oscillation surface of the silicon member with which the terminal T J of member A is to enga e, or at least apart of that surface, is polished, thereby requiring lower optimum pressure of spring S on member. A, and providing a lower resistance at junction T J than when unchemical element silicon having a polished surface.

1. An oscillation receiver, which consists receiver, which consists of a mass of the non-metallic usual telephone 3. Anoscillation receiver, which consists f a mass of silicon having a olished surface, of two electrical conduct0rs,'.one of which is said conductors operatively aving good and a, mass of silicon having a'polished surface, small-areaed contact with each other and the other of which is a conductor of sub- 'GREENLEAF WHITTIER PIOKARD. 5 stant ially higher specific conductivlty. Witnesses:

4'. An oscillation receiver, which consists l EDWARD H. RoWELL, of two electrical conductors, one of which is l MYRA S. ROWELL.

Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US2629767 *Aug 31, 1949Feb 24, 1953Rca CorpSemiconductor amplifier or oscillator device
US2649560 *May 17, 1951Aug 18, 1953Bell Telephone Labor IncMotor system for controlling pressure
Cooperative ClassificationH01L29/00