US3648208A

US3648208A - Coil form

Info

Publication number: US3648208A
Application number: US8363A
Authority: US
Inventors: Helmut Rolf
Original assignee: International Standard Electric Corp
Current assignee: Alcatel Lucent NV
Priority date: 1969-02-26
Filing date: 1970-02-03
Publication date: 1972-03-07
Anticipated expiration: 1989-03-07
Also published as: GB1249616A; NL7002546A; FR2033087A5; DE6907606U

Abstract

A double-flanged coil form with a hollow core part is provided with an uninterrupted slot running through the core part in axial direction and through the flanges in the radial direction. The slot is as broad as the diameter or the breadth of the core part. The coil form can be die-cast or molded as a whole, avoiding the use of slides and a put-in core.

Description

United States Patent Hultgren ..336/198 X Rolf Mar. 7, 1972 [54] COIL FORM 3,019,375 1/1962 Geyer et al ..336/208 X 3,112,898 12/1963 Stahl ...336/198 X I [72] Invent Numberg' Germany 3,218,592 11/1965 Banrick ..336/208 x 73 A :It ti lStaddElectriC l 1 'j ffmfii' c FOREIGN PATENTS OR APPLICATIONS F 3 97 932,732 9/1955 Germany ..336/198 [22] ed eh 0 25,339 7/1956 Germany ..336/208 [21] Appl. No.: 8,363 Y Primary Examinen-Thomas J Kozma AttorneyC. Cornell Remsen, .lr., Walter J. Baum, Percy P. [30] Foreign Application Monty Data Lantzy, J. Warren Whitesel, Delbert P. Warner and James B.

Feb. 26, 1969 Germany ..G 69 07 606 Raden [52] US. Cl ..336/208 [57] ABSTRACT f A double-flanged coil form with a hollow core part is provided with an uninterrupted slot running through the core part in axial direction and through the flanges in the radial direction. [56] References Clted The slot is as broad as the diameter or the breadth of the core UNITED STATES PATENTS part. The coil form can be die-cast or molded as a whole,

avoiding the use of slides and a put-in core. 708,220 9/ 1902 Gill ..336/208 X 1 Claim, 1 Drawing Figure PATENTEDMAR "/1912 3,648,208

INVENTOR Helmut Rolf ATTORNEY COIL FORM The present invention relates to a coil form made from a die-cast or molded compound, and includes a hollow core part and two end flanges extending vertically in relation to the coil axis. Such types of coil forms are required, for example, for relay coils used in telecommunication and telephone systems, as well as in other communications systems, and in controlling, measuring and regulating arrangements.

In the known prior art the hollow core part serves to receive an iron core or else one or more protective tubes of reed relays. The hollow core part, therefore, just like each of the end flanges, may be shaped in accordance with the purpose of practical use of the coil form. Thus, for example, there are known cylindrical types of coil forms in which the hollow core part is a hollow cylinder, and in which the end flanges consist of rings. Moreover, there are known coil forms having a square shape, in which the hollow core part consists of a square box, and in which the end flanges are formed by square frames.

in cases where the known coil forms are intended to be manufactured as die-cast or molded parts, the latter must be designed in such a way that the removal from the mold will not cause any difficulties. in conventional types of coil forms there are provided undercut portions, extending rectangularly in relation to the mold removal direction, by arranging laterally movable mold elements which are actuated prior to the opening of the planes of the molds. in order to avoid the use of molds with sideway drawers or slides, coil forms are often composed of halves of identical shape (German Pat. application No. P 25 339 Ville/21g). The known type of method, however, does not provide the possibility of manufacturing coil forms quickly and inexpensively as die-cast or molded parts.

The present innovation is based on the problem of providing a coil form which, by avoiding slider molds, and, if so required, an inserted or put-in type core, can be die-cast or molded as a whole. In the case of a coil form made from a diecast or compression molding compound, consisting of a hollow core part and two end flanges extending vertically in relation to the coil axis, this problem is solved in accordance with the present innovation, in that the coil form, in the manner known per se, comprises an uninterrupted slot extending in the axial direction through the core part and, in the radial direction, through the flanges, and in that the slot in the core part is at least as wide as the diameter thereof or the largest width thereof respectively.

So-called double flanged coil forms comprising a hollow core part and slotted end flanges are known per se (German Auslegeschrift (DAS) 1 I09 268). in the known case, however, there is concerned an uninterrupted narrow slot extending in both the core part and the flanges, serving to avoid the occurrence of eddy currents when using a coil form of magnetizable sheet metal. Such types of coil forms, however, cannot be manufactured by using a sideway slideless die-cast or compression mold.

in distinction thereto, the present innovation provides a coil fonn in which the end flanges which hitherto formed a more or less closed ring or frame, and in which the core part comprises wide slots or recesses in a regular arrangement of such a type that the slots or recesses are at least just as wide as the diameter or the largest width of the core part respectively. in this way the coil forms may be removed from the mold either in the axial direction or in the radial direction which is more advantageous owing to the short path of removal from the mold, without requiring the use of sideway drawers or slides and a special core. Accordingly, the expensive slider molds which are susceptible to interferences, and which were necessary hitherto, may be replaced by more inexpensive slideless molds operating more precisely and reliably. in this way there is also safeguarded a more simple construction of the necessary multiple molds. Coil forms according to the present innovation may thus be manufactured in a substantially more rapid succession and more inexpensively than in the conventional cases.

Moreover, coil forms according to the innovation, by maintaining the embodiment and the arrangement of the slots, may have any arbitrary shape which, above all, is dependent upon whether the hollow core part serves as an airgap, for receiving an iron core of certain shape, or one or more protective tubes of reed relays. It may preferably be of cylindrical, but also of a square shape. If the coil form, for example, forms part of a reed relay comprising a protective tube positioned within the hollow core part, a cylindrical coil form will be more advantageous for spatial reasons, than a square one, especially since also a hollow cylinder is more torsion-proof than a square box. If, however, several protective tubes lying next to each other are supposed to be supported inside the hollow core part, it will be generally preferred to use the square shape because it safeguards a smaller build-in volume with a lower overall height.

As regards the manufacture of the die-cast or compression mold it is of advantage when the slot in the core part is in alignment with the slots in the flanges. For example, if the core part forms a hollow semicylinder, each flange comprises a correspondingly designed U-shaped recess which is not closed on the side neighboring the open side of the core part.

Moreover, it is of advantage to the outer circumferential surface of the end flanges to be designed at least on one side, in particular on the side neighboring the closed side of the core part, to have the shape of a plane supporting surface. This substantially facilitates the installation of the coil form in a printed circuit.

Likewise under the aspect of an economical production, the coil forms may either be die-cast from thermoplastic materials or compression-molded from thermosetting plastics.

Further advantages and details of the innovation will now be explained with reference to the copending drawing from which there may be taken one particularly advantageous example of an embodiment relating to the innovation. The single drawing shows in a perspective representation one coil form according to the innovation.

The shown coil form consists of the hollow core part I, and of two

end flanges

2,3 extending vertically in relation to the coil axis. Since in the preferred example of embodiment of the innovation, the coil form has a cylindrical shape, the core part 1 forms a hollow semicylinder, whereas the two

end flanges

2,3 are designed as U-shaped frames, which are not closed on the side neighboring the open side of the core part. For this reason, both

end flanges

2,3 are provided with U-shaped slots 2' or 3' respectively, extending in the radial direction. The widths of the slots 2',3' are chosen thus that they, on one hand, are in alignment with the slot provided in the core part 1 and, on the other hand, that their widths are at least just as large as the diameter of the hollow semicylinder. The outer circumferential area of the

end flanges

2,3, on the side neighboring the closed side of the core part 1, is designed as an even supporting surface 2", 3".

From the enclosed drawing it may be taken that the outer circumferential area of the end ,

flanges

2,3 is preferably designed to have a square shape. The

end flanges

2,3, together with the hollow core part 1, i.e., half the hollow cylinder, form a winding body for electrical coils, whereas the hollow space 1 may serve, for example, to receive one or more not shown protective tubes, as is known per se.

Moreover, it may be taken from the drawing that the slots 2', 3 and the slot (hollow space 1') in the core part 1 are designed to have equal shapes. in this way it is possible for the corresponding die-cast or compression mold. to be manufactured in a more simple and, consequently, more economical way.

What is claimed is:

l. A coil form made from a single piece of molding compound, comprising a one-piece hollow core in the form of a hollow cylinder terminating in open ends, an uninterrupted slot extending along the length of the hollow cylinder parallel to a longitudinal axis and interconnecting the open ends, an end flange at each end of the hollow cylinder integral to the hollow cylinder and extending vertically to the longitudinal the flanges and being substantially in alignment with each of those slots to form a continuous slot along one side of the coil form, the flanges providing plane supporting surfaces around the cylinder at the ends of the hollow cylinder.

Claims

1. A coil form made from a single piece of molding compound, comprising a one-piece hollow core in the form of a hollow cylinder terminating in open ends, an uninterrupted slot extending along the length of the hollow cylinder parallel to a longitudinal axis and interconnecting the open ends, an end flange at each end of the hollow cylinder integral to the hollow cylinder and extending vertically to the longitudinal axis of the cylinder from an open end of the cylinder, each of said flanges extending substantially an equal distance in each direction from the open end of the cylinder, a slot extending radially through each of the flanges, the slot in the cylinder having a width substantially equal to that of the slot in each of the flanges and being substantially in alignment with each of those slots to form a continuous slot along one side of the coil form, the flanges providing plane supporting surfaces around the cylinder at the ends of the hollow cylinder.