Electricity: magnetically operated switches – magnets – and electr – Electromagnetically actuated switches – Polarity-responsive
Patent
1996-06-10
1999-03-09
Donovan, Lincoln
Electricity: magnetically operated switches, magnets, and electr
Electromagnetically actuated switches
Polarity-responsive
335128, H01H 5122
Patent
active
058806539
DESCRIPTION:
BRIEF SUMMARY
FIELD OF THE INVENTION
The present invention relates to an electromagnetic relay and to its manufacture.
DESCRIPTION OF THE PRIOR ART
An electromagnetic relay according to the prior art typically comprises an electromagnet block 2 and armature 3 placed in sequence in a box-shaped base block 1 and then enclosed by fitting a case 4 to the base block 1 as shown in FIGS. 28-31.
More specifically, this is accomplished by first manufacturing from a hoop material by stamping and bending a lead frame 8 comprising on both long sides thereof coil terminals 6a, fixed contact terminals 6b comprising fixed contacts 7, and common terminals 6c as shown in FIG. 29. After positioning this lead frame 8 inside the cavity of a mold (not shown in the figures), said cavity is filled with a resin material to cast the base block 1. The coil terminals 6a and common terminals 6c are severed from the lead frame 8 (FIG. 30) and then bent, and the electromagnet block 2 and armature 3 are positioned in sequence inside the base block 1. The fixed contact terminals 6b are severed from the lead frame 8 and then bent, and the base block 1 is finally fit to the base block 1 to complete the manufacture and assembly of the electromagnetic relay.
The problem with this manufacturing method is related to the fixed contact terminals 6b functioning to connect the base block 1 to the lead frame 8. This prevents the fixed contact terminals 6b from being cut from the lead frame 8 during the assembly process, and electrical inspections cannot be conducted with the fixed contact terminals 6b connecting the base block 1 to the lead frame 8.
In addition, the aging treatment for eliminating the residual stress of the fixed contact terminals 6b resulting from the bending process cannot be accomplished with the base block 1 connected to the lead frame 8. A separate process is therefore required for aging the fixed contact terminals 6b, thus complicating the manufacturing process.
If in this manufacturing method the fixed contact terminals 6b are severed from the lead frame 8 after assembling the electromagnet block 2 and armature block 3 to the base block 1, deformation of the semifinished product to which the electromagnet block 2 and armature 3 are assembled may occur, reducing assembly precision. Because the fixed contacts 7 of the fixed contact terminals 6b are also hidden below the armature 3 when the severed fixed contact terminals 6b are bent, it is not possible to hold the fixed contacts 7 and it is therefore also difficult to position the fixed contacts 7 with high precision.
Low productivity also results with this manufacturing method because the case 4 cannot be fit to the base block 1 while the base block 1 remains connected to the lead frame 8, and assembly of the case 4 cannot follow continuously upon assembly of the electromagnet block 2 and armature 3.
Furthermore, after assembling the electromagnet block 2 and armature 3, and then fitting the case 4 to the box-shaped base block 1 as shown in FIG. 28, the electromagnetic relay described above must then be turned over as shown in FIG. 31 to seal the electromagnetic relay assembly by injecting a sealing agent 5 to the gap between the base block 1 and case 4 by means of an injection nozzle 9.
However, an electromagnetic relay according to the prior art as described above further comprises channels 1a and 1b formed continuously in a vertical direction in the exterior sides of the base block 1 as shown in FIG. 28. The terminals 6a, 6b, and 6c reside within these channels 1a and 1b. The presence of these channels 1a and 1b also results in a discontinuous contact face between the base block 1 and the case 4. It is therefore easy for the injected sealing agent 5 to flow through the channels 1a and 1b into the base block 1, and solidify therein. The solidified sealing agent 5 then interferes with the operation of the armature block 3, easily inducing inoperation of the electromagnetic relay. The amount of sealing agent 5 injected to the gap between the outside of the base block 1 and the inside f
REFERENCES:
patent: 4703293 (1987-10-01), Ono et al.
patent: 5153543 (1992-10-01), Hitachi et al.
patent: 5184102 (1993-02-01), Mueller
patent: 5673011 (1997-09-01), Okihara et al.
Ishibashi Senjiro
Kawai Mitsuhiro
Kuzukawa Kiyoaki
Miyaura Hiroyuki
Nakano Hitoshi
Donovan Lincoln
Omron Corporation
LandOfFree
Electromagnetic relay and its manufacture does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Electromagnetic relay and its manufacture, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Electromagnetic relay and its manufacture will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1325419