US1813591A - Electric coil - Google Patents

Description

(I T. ULREY ELECTRIC COIL July 7, 1931.

. Filed May 1. 1928 ll'l! To PUMP INVENTOR C.T. U EY Patented July 7, 1931 UNITED STATES PATENT; OFFICE CLAYTON TBIDLE ULREY, OF EAST ORANGE, NEW JERSEY, ASSIGNOR T WESTING- HOUSE LAD COMPANY, A- CORPORATION 01' PENNSYLVANIA.

ELECTRIC COIL Application filed Kay 1, 1828. $erla1 No. 874,181.

This invention relates to electric coils and more particularly to a coil for heating the metallic arts of electrical discharge devices such as -ray tubes, cathode ray tubes, radio receiving and transmitting tubes, etc. by high frequency induction current. It is not limited to such use, however, but may also be applied to electromagnetic coils.-

It is the usual practice, in such devices, to pretreat the electrodes and metal parts to remove the gases therefrom, which otherwise would be driven off during the operation of the device. This pretreatment in some instances can be accomplished bythe heating effect of an operating current, but onlya few P of the parts can be heated in this way and ordinarily it is necessary to resort to heating b means of high frequency currents induce in the metal arts by a coil disposed exteriorly of the device. In order to be most effective, such high frequency induction coil should be coupled as closely as possible to the arts to be heated.

eretofore, a helical coil has been generally employed for such heating and has been positioned about a portion of the envelope by passing the same over one end of the device. With straight sided envelopes of regular form, this may be readily accomplished, but

in many types of devices, such as X-ray tubes, the envelope is of irregular shape with one or more portions of small diameter connected by portions of larger diameter and ordinarily such heating is carried out while the device is sealed to an exhaust system. In such cases it is often impossible to heat certain portions of the device unless a coil is em loyed, of suflicient diameter to pass over t e parts of the envelope of maximum the objects of the present inven-' about the requlred portions-of the device.

' Other objects and advantages will hereinafter appear.

According to the present invention, I provide an induction coil having a plurality of turns, each consisting of two or more parts, hinged together or detachably secured together so that it ma be opened to allow the coil to be placed a out the envelope of a device undergoing treatment and to permit the parts of the coil to be reassembled in operative relation. l V

Reference is had gto the accom anying drawing for a full understanding 0 the invention. In the drawings;

Figure 1 is a side elevation of an X-ray or other form of discharge device undergoing exhaustion, having my induction coil disposed about the same.

Figure 2 is a perspective view of the coil in an opened position.

Figure 3 is a perspective view of the coil in a closed osition, and

Figure 4 1s an elevation, partly in section, of the coil and support therefor.

The vacuum device 1, to be exhausted, is shown in Figure 1, and is connected by glass tubing 2 to an exhaust manifold 3 connected to a vacuum pump not shown). The envelope of the vacuum evice com rises a large spherical central portion 4 an sections or arms 5 and 6 of smaller "diameter extending therefrom, to the latter of which is connecte the tubing 2 communicating with the exhaust system. The vacuum device is shown as an 8 is shown extending into the central portion of the envelope-from the op site arm 5.

During the exhausting 0 the device it is necessary to heat the metal parts to incandeyscence to drive out the gases therefrom and to allow such liberated gases to be removed from the envelope by the vacuum pump. The filamentary cathode may be heated by passage of current therethrough and the anode may be heated by electron bombardment from the cathode, but the anode and cathode supporting structure cannot be heated in this manner and it is necessary to resort to high frequency induction heating. For this purpose I have shown the coil 9 of 1 a high frequency induction heating appatwo sections 11 and 12 of arcuate shape.

ratus disposed about the arm 6 in closely cou led relation to the internal metal parts.

T e high frequency coil, shown in detail in Figures 2, 3 and 4, consists of a helix 10 of copper or other good conducting material havmg a number of turns, each consistin fif e sections 11 are supported in parallel spaced relation by insulating members 13 and 14 of bakelite, fiber or other suitable material. The insulating supports may consist of two abutting strips '15 and 16 recessed as at 17 k and clamped to the ends of the arcuate sections by screws 18 or other suitable fastening means. The sections 12 are similarly supported in spaced relation. The ends of each of the sections 12' are provided with tongues 19 a'da ted to be received in recesses 20 in the en s of the sections 11 to form a concesses may be provided with pivot pins 21,

forming a hinge so that the coil may be readily opened and closed and thus be disposed about. the narrow portion of the tube being exhausted. The 0 posite set of tongues and recesses are made to havea snug fit so as to form a ood electrical circuit when the coil is in close position. Terminal portions 22, extending at an angle to the face of the coil, are provided for each end thereof and ma be secured in sockets 23 and 24 carried by an insulating handle 25. The sockets are so constructed that one or both of the terminals may be swung into the socket upon closin of the coil. Conductors28 and 27 supply igh frequency current to the coil from any convenient source (not shown). v

Instead of having the coil formed in two sections, as shown, it is obvious that a larger number of sections may be employed and that various means for opening and closing the coil, or temporarily detachin one or more sections, may be provided, an I do not desire to be limited to the exact details of construction shown and described. By the term 'helix I desire to include coils oi both circular and non-circular form, suchas, for instance,-

triangular rectangular or other polygonal form. i

What is claimed is:

1. An electrical coil comprising a plutivity, a plurality of insulating members for I each of'said sets for supporting the sections in spaced parallel relation, the ends of one set ofsections overlapping with those of the other section to form a continuous multi-turn helix and being pivotally connected thereto at one end to permit the sets of sections of said helix to be opened and closed to encircle the object to be heated.

3. A coil for a high frequency induction heating apparatus comprising a multi-turn coil composed of two or more parts pivotally connected along one side of the coil to divide each turn of the coil into component parts and to enable the .coil to be opened and closed to enclose an object to be heated.

In testimony whereof, I have hereunto subscribed my name this 30th day of A ril 1928.

CLAYTON TRIDLE UIZREY.

Images