US1211754A - Crystal-rectifier. - Google Patents

Description

P. C. RAWLS.

CRYSTAL RECTIFIER.

APPLICATION FILED DEc.3o, |914.

1,21 1,7 54. Patented Jan. 9,1917.

A PAUL C. RAWLS, 0F DES MOINES, IOWA.`

i cmrsTAL-ascrirmn.

Specication of Letters Patent.

Patented Jan. 9, 1917.

Originalapplication led July 6, 1914, Serial No. 849,298. Divided and this application led December 30,

' 1914. Serial No. 879,801.

To all lwhom. it may concern:

Be it known that I, PAUL C. RAwLs, a

citizen of the United States, and resident o Des Moines, in the county of Polk and State of Iowa, have invented a. certain new and useful Crystal-Rectifier, of which the following` is a specification.

My invention relates to crystal rectifiers used in high frequency oscillation detectors in wireless telegraphy or telephony.

The object of my invention is to provide an improved crystal rectifier of simple and inexpensive construction of increased efficiency and sensitiveness and of great durability or ruggedness, which is so mounted and arranged that it is not likely to get out of adjustment readily; and further in this connection to provide a crystal rectifier having a large number of points of maximum sensitiveness which may be easily found by the operator and maintained in working position.

My invention consists in the construction, arrangement and combination of the various parts of the device, whereby the objects contemplated are attained, as hereinafter more fully set forth, pointed out in my claims and illustrated in the accompanying drawings,

Y )usted by means of a set screw 29. The

in which;

Figure 1 shows a side elevation of a crystal rectifier and means for mounting the same, embodying my invention. Fig. 2

shows a vertical longitudinal sectional View,

of a portion of the mechanism. Fig. 3 shows an enlarged sectional view of the contacting portions of my improved crystal faces of the crystals of my improved crystal rectifier.

This application is a divisional of my copending application #7249,298, filed July 6, 1914.

It will, of course be understood that my improved crystal rectifier is employed as ,a part of a mechanism. for detecting oscillations in carrying on the operations of wireless telegraphy and telephony.

In the exempliflcation of my invention illustrated in the accompanying drawings, I have used the reference numerals 10 and 11 to indicate generally the binding posts of cup 15, which receives a zinkite crystal 16,

and which is retained within the cup 15 by means of a quantity of mercury amalgam 17 or the like. In the other binding post is a tube 18, having suitably mounted in it, a cylindrical body 19, which is provided with a rod 20, extending through the tube 18, and having on its end an operating head 21. An extensible coil spring 22 is received within the tube 18, and is adapted to yieldingly engage the body 19 and a stop 23 for yieldingly pressing the body 19 longitudinally in a direction toward the post 10.

0n the 'upper end of the body 19 is screwed a sleeve 24, on which is a laterally extending arm 25, which carries a chuck 26. The arm 25 extends in the opposite direction from the sleeve 24. At one end, the arm carries the chuck 26, and to its other end is secured a contractible coil 27, which is operatively connected with an adjustable collar 28 on the tube 18. The collar 28 may be adchuck 26 is designed to carry another crystal, which is preferably a piece of copper pyrites 30, which is mounted within a cup shaped container 32, and is held therein by means of a quantity of mercury amalgam 31. On the cup 32 is an arm 33 adapted toV be held and gripped by the chuck 26. posts 10 and 11 are connected by the wires 34 and 35 in a proper circuit.

Several improvements are accomplished by my improved crystal rectifier, one of them being the arrangement of the two counteracting springs 27 and 22, so arranged that when the arm 25 is slightly rotated, the spring 27 is stretched and after the copper pyrites crystal isin contact with the zinkite crystal, as shown for instance in Figs. 3 and 5, there-will be a'yielding pressure upon it,

'irstin a direction toward the zinkite crystal and second, in a rotary direction relative to its contact point on the zinkite crystal, whereby an improved contact point is made between the crystals. By rotating the head 14, any part of the zinkite vcrystal may be brought into actual contact with the copper pyrites crystal.

The

plished by my improved crystal rectifier, is

in the construction of the face, which is first attened and smoothed, and then it is cut or scored transversely in different directions, as illustrated for instance in Fig. 4, whereby the raised points are left between the grooves, or cuts, or scores. These raised oints are shown in exaggerated form 'in' gig. 5, and are indicated by the reference character 36. What I use is a zinkite crystal having an artificially smooth and polished surface, which is preferably artificial and regularly scarified or scored by means of draw filing or fine sand-papering in two or more different directions, whereby a plurality of very fine regular points are left on `.the polished surface. In this connection it may be mentioned that a number of smooth polished surfaces will give the same or bet ter results, but necessitates the use of a much reater ressure in holding the other memer of t e rectifier against the zinkite crystal, which will in many instances cause the other member, which is frequently of softer material than the zinlritev crystal to be crushed. The object in slightly scarifying the surfaces of the zinkite crystal is to obtain rectification with less pressure andwith the same or uniform result over the entire surface of the zinkite crystal.

I nd that improved results are obtainedV by using the copper pyrites crystal with a rounded point, as shown in Fig. 5, and the zinkite crystal with the large number of points 36, as shown in said figure, insomuch as that when the crystals are in `the form shown, all of the raised points of the zinkite crystal are uniformly sensitive, and it is therefore easy for the operator, in adjusting these two crystals relative to each other, to

readily obtain an adjustment of maximum efficiency and rectification.

It willy be understood that some changes may be made in the construction and the parts of my improved crystal rectieraparticularly in the method of mounting the crystals, without departing from the essential features and purposes of my invention,

and it is my intent to cover by this appli- 50 cation any such changes which may be included within the scope of my claims.

I claim as my invention.

1. In a crystal rectifier, the combination of a sleeve, means for supporting the sleeve, a body portion slidingly mounted in the sleeve, a spring for normally extending the body portion in one direction from the sleeve, a transverse arm on the outer end of" the body portion, a crystal holder at one end of the transyerse arm, and a spring connected to the arm and adjustably mounted on the, sleeve, for the purposes stated.

2. In a crystal rectifier, the combination of a crystal holder,.a spring for normally projecting it toward the opppsite crystal, and a second spring arranged 1n op osition to the rst an also capable of appying a lateral tension to the crystal.

3. A crystal rectifier, comprising the combination-l of two adjacent crystals, one having a relatively blunt point, andthe other having a smooth fiat polished surface provided with minute substantially regular and uniform projections, the blunt point being arranged to contact with said fiat surface.

p Des-Moines, Iowa, December 22, v1914.

PAUL o. RAwLs.

Witnesses J. MAHEB, A. SHERMAN.

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