US3614690A

US3614690A - Solenoid

Info

Publication number: US3614690A
Application number: US14113A
Authority: US
Inventors: David C Jencks
Original assignee: Detroit Coil Co
Current assignee: Detroit Coil Co
Priority date: 1970-02-25
Filing date: 1970-02-25
Publication date: 1971-10-19
Anticipated expiration: 1988-10-19
Also published as: JPS4922623B1; DE7042101U; GB1260787A

Abstract

The coil bobbin which is received within the stator is provided with a pair of end flanges, one of which is shaped to define a pair of catches which are depressed when the bobbin is inserted in the stator, and when the bobbin is in its proper position the catches spring out to retain the bobbin in operating position.

Description

United States Patent David C. Jencks Troy, Mich.

Feb. 25, 1970 Oct. 19, 1971 Detroit Coil Company Ferndale, Mich.

Inventor Appl. No. Filed Patented Assignee SOLENOID 10 Claims, 5 Drawing Figs.

US. Cl

Int. Cl Field of Search.

282, 299, 261, 262; 336/199, 208, 210,197, 65; 24/73 B, 230 CF; 248/361 TF [56] References Cited UNITED STATES PATENTS 2,326,903 8/1943 Tinnerman 248/361 TF 2,466,592 4/1949 Jencks 336/197 X 3,134,467 5/1964 Blyth 24/73 B X 3,191,135 6/1965 Hazelquist 336/65 Primary ExaminerBernard A. Gilheany Assistant ExaminerF. E. Bell Attarney--Burton and Parker ABSTRACT: The coil bobbin which is received within the stator is provided with a pair of end flanges, one of which is shaped to define a pair of catches which are depressed when the bobbin is inserted in the stator, and when the bobbin is in its proper position the catches spring out to retain the bobbin in operating position.

PATENTEDucT 19 l97| FIG.3

F'IG.5

I NVENTOR 0A W0 c uavcxs ATTO R N EYS SOLENOID FIELD OF INVENTION This invention relates to improvements in alternating current solenoids, particularly industrial-type solenoids. Specifically the improvements relate to the solenoid coil bobbin.

BACKGROUND OF THE INVENTION Heretofore the solenoid coil of an alternating current industrial-type solenoid has been retained in the stator in various ways. For example, in 0.8. Pat. No. 2,466,592, the coil is provided with oppositely projecting extensions which abut the stator and/or the side plates to retain the coil in the stator. U.S. Pat. Nos. 3,017,547 and 3,195,024 suggest the use of spring clips which are adapted to embrace a portion of the coil structure and also engage the stator for the purpose of retaining the coil therein. Where the construction of the solenoid does not provide for the insertion of the coil in the stator and the subsequent securement of sideplates so that the coil is locked in place, the coil retaining concept disclosed in the first-mentioned patent cannot be utilized, and the clips disclosed in the latter two patents occupy space within the coil receiving opening in the stator thereby reducing the space available for coil windings.

It is the object of this invention to provide means for retaining a solenoid coil wrapped on a bobbin within the stator without reliance upon sideplates or spring clips, such as shown in the prior art, and provide a solenoid structure capable of exerting a greater force for its size than the prior art solenoid utilizing clips because a greater number of turns can be provided in the winding.

Other objects, advantages and meritorious features will become apparent from the following specification, claims and drawing wherein:

FIG. 1, is a side elevation of a solenoid embodying the invention;

FIG. 2, is a front elevation of the solenoid shown in FIG. 1;

FIG. 3, is a view similar to FIG. 1 but with the stator, plunger and coil removed and showing only the bobbin and one of the terminals;

FIG. 4 is a cross-sectional view taken on a line 4-4 of FIG. 3; and

FIG. 5, is a top view looking in the direction of arrow 5 of FIG. 3.

A solenoid embodying the invention includes, as shown in FIGS. I and 2, a stator 10, a plunger 12, and a coil assembly 14, the latter being received within an aperture 16 opening through opposite faces of the stator. Upon energization of the coil, the plunger 12 is drawn inwardly to the position shown in FIG. 2 and upon deenergization of the coil, the plunger may shift outwardly (upwardly in FIGS. 1 and 2). Both the stator and plunger are formed by a series of laminations and the laminations are secured together as by rivets 18 in the plunger and 20 in the stator as and for reasons well understood in the prior art. The outer laminations of the stator and plunger may be and preferably are of greater thickness to provide what is termed in the trade as rivetting plates, such plates being shown at 22 for the plunger and 24 for the stator.

The plunger 12 may be of T-shaped configuration with a head portion 26 and a shank portion 28. Those portions of the head extending beyond opposite sides of the shank have stator abutting surfaces 30 and 32 which are adapted, when the coil is energized, to rest upon the upper end of the stator as shown in FIG. 2.

As shown in FIG. 2, the stator, or as it is often termed in the trade, the C-stack, is a generally C-shaped structure having a bight portion 42 through which an aperture 44 extends for the reception of a pushpin (not shown) which is adapted to be abutted by the lower end of the plunger shank for transmitting the force of the plunger to a device to be actuated by the solenoid. A pair of upstanding

side arm portions

46 and 48 project upwardly from the bight portion 42 and terminate in opposed laterally extending arms 50 and 52 which overhang in spaced relation the bight portion 42 and are spaced apart at their inner ends to provide a passageway through which the plunger shank extends. The lower end of the plunger shank is spaced slightly from the bight portion 42 to provide an airgap when the faces 30 and 32 of the plunger head abut the overhanging arms 50 and 52.

The solenoid coil assembly includes a bobbin 54 upon which is wrapped the wire comprising the coil. The bobbin is made of a resistingly flexible insulating material such as nylon and, if desired, the nylon may be reinforced with suitable material such as glass fibers. The bobbin is an integral structure including a rectangular tube portion 56 and end flanges 58 and 60. The wire is wrapped about the tube between the flanges and contained by the flanges. The wire, when completely wrapped, is shown schematically in FIGS. I and 2 at 62. The flange 58 may be provided with a pair of raised

ribs

64 and 66 which provide bearing surfaces for engaging the underside of the overhanging arms 50 and 52 of the stator when the bobbin is slid into position as shown in FIGS. 1 and 2. Preferably the axial dimension of the bobbin is such that the bobbin is under a slight axial compression, i.e., it is a press fit, in the stator.

Flange 60 is provided with a pair of spaced sockets, such as the socket 68 shown in FIG. 3 within which are press-fitted a pair of

terminal strips

70 and 72 to which the ends of the coil wire are secured in any suitable fashion. The lead wires for energizing the coil may also be connected to these terminals in any suitable fashion.

Flange 60 is also provided with means for insulating or isolating the inner wire end 76 from the turns of the coil. Such means comprise a slot 80 which opens outwardly at 82 through an edge of the flange and also axially inwardly of the bobbin at 84 through the face of the flange against which the wire turns are wrapped. As a consequence of the construction, the inner end 76 of the coil wire, as shown in FIG. 4, may be lead through the slot to the terminal 72 and is thereby isolated or insulated from the turns of the winding and also trapped to hold such end during the coil-winding operation.

The bobbin is also provided with integral means for retaining the coil in the stator. As shown in FIG. 3 and 4, flange 60 is provided with a pair of slots 86 and 88 which extend inwardly from the flange edge 90 spaced from the

opposite edges

92 and 94 and defining with such edges a pair of resistingly flexible catches or

tongues

96 and 98. The

edges

92 and 94 are shaped at the tongues to provide shoulders I00 and tapered cam surfaces 102. The flange at its outer face 104 is provided with a stepped portion 106 with a step or shoulder 108 which faces the shoulders of catches 100. As a consequence of this construction, when the coil is inserted into the stator in the direction of arrow 11 1 of FIG. 1, the step 108 will engage one side of the stator when the coil reaches its operating position and during the insertion the cam surfaces 102 will cause the

tongues

96 and 98 to be pressed inwardly so that the tongues pass through the opening 16 of the stator, and when the coil reaches its operating position, the tongues spring out with the shoulders locking on the opposite side of the stator from that abutted by the shoulder 108. As a consequence, the shoulder 108 and the catches 100 serve to center the coil in the stator and retain it against dislodgement.

If desired the flange 58 may be provided with a shoulder 110, similar to the shoulder I08 on flange 58. Shoulder 110 will abut the stator arms 50 and 52 when the coil is inserted to its operating position. I have found that the two shoulders I08 and 110 together with the

catches

96 and 98 will adequately hold the coil in stator. Also, if desired, the flange 58 may be provided with catches similar to those in flange 60 though I have not found such to be essential in normal applications.

I claim:

1. In a solenoid, a flux-conducting stator having a coilreceiving aperture opening outwardly through opposite faces of the stator, a solenoid coil mounted on a flanged bobbin and disposed in said aperture, a flange of the bobbin having a portion thereof overlying in abutting relation one of said faces of the stator, and a flange of the bobbin having an integral resistingly deflectable catch overlying in abutting relation the opposite face of the stator whereby said solenoid coil and bobbin are retained in the stator in trapped relation between said flange portion and catch.

2. The invention defined in claim 1 characterized in that said catch is integral with that flange of the bobbin which overlies said one face of the stator.

3. The invention defined in claim 1 characterized in that each flange of the bobbin lies adjacent and overlies one face of the stator, and one of said flanges includes said integral catch.

4. The invention defined in claim 1 characterized in that there are two catches, one at each edge of the flange and each overlying in abutting relation the opposite face of the stator.

5. The invention defined in claim 4 characterized in that each flange of the bobbin has a portion which overlies in abutting relation said one face of the stator in opposition to the two catches.

6. In a solenoid coil assembly, a bobbin having a flange at each end, a coil wrapped on the bobbin between the flanges thereof, one of said flanges having an abutment shoulder for engaging one side of a stator in which the coil assembly is to be mounted for limiting insertion of the bobbin therein, and one of said flanges having an integral resistingly deflectable catch portion yielding to permit insertion of the coil assembly in a stator and biased to a position providing a shoulder facing oppositely to said abutment shoulder to engage an opposite face of a stator in which the coil assembly is received whereby the bobbin embraces opposite faces thereof to be retained therein.

7. The invention defined in claim 6 characterized in that each flange of said bobbin includes an abutment shoulder for overlying one face of a stator in which the coil assembly is to be mounted.

8. The invention defined in claim 7 characterized in that one of said flanges includes two of said integral catches.

9. A bobbin for a solenoid coil comprising a tubular portion having opposite end flanges, at least one of said flanges having an abutment shoulder facing toward the axis of the bobbin for limiting insertion of the bobbin into a stator, and one of said flanges having an integral resilient catch portion providing a shoulder facing oppositely to said abutment shoulder, said shoulders adapted to overlie opposite faces of a solenoid stator in which the bobbin is adapted to be mounted.

10. The invention defined in claim 9 characterized in that there are abutment shoulders on each flange facing the axis of the bobbin and each intended to overlie a face of a stator in which the bobbin is adapted to be mounted.