U.S. patent number 3,691,493 [Application Number 05/185,102] was granted by the patent office on 1972-09-12 for coil plate assembly.
This patent grant is currently assigned to Allen-Bradley Company. Invention is credited to Gerd C. Boysen, Raymond H. Hannula.
United States Patent |
3,691,493 |
Boysen , et al. |
September 12, 1972 |
COIL PLATE ASSEMBLY
Abstract
A coil plate assembly having a pair of coil plates with an
electrical coil interposed therebetween to position the coil in a
molding die for encapsulation in an insulating material. The coil
plates each have a pair of side shrouds extending alongside the
coil and a boss is formed on the remote end of each shroud. A
terminal clasp encircles each pair of bosses of adjacent shrouds to
connect the shrouds of the two plates together. In addition, the
terminal clasps are electrically connected to the coil and extend
outward from the coil plates to act as terminals for making
connection in a circuit.
Inventors: |
Boysen; Gerd C. (Milwaukee,
WI), Hannula; Raymond H. (West Allis, WI) |
Assignee: |
Allen-Bradley Company
(Milwaukee, WI)
|
Family
ID: |
22679600 |
Appl.
No.: |
05/185,102 |
Filed: |
September 30, 1971 |
Current U.S.
Class: |
336/65; 336/192;
336/96; 336/208 |
Current CPC
Class: |
H01F
5/06 (20130101); H01F 5/00 (20130101) |
Current International
Class: |
H01F
5/06 (20060101); H01F 5/00 (20060101); H01f
015/02 (); H01f 027/30 () |
Field of
Search: |
;336/65,96,192,198,208 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Kozma; Thomas J.
Claims
We claim:
1. In a coil plate assembly for a coil having opposite ends and an
opening extending between the ends, the combination comprising:
a pair of coil plates between which the coil is disposed, such
plates each having:
an open center panel portion lying over an end of the coil with the
open center overlying the coil opening,
alignment lugs extending from the panel portion into the coil
opening to position the panel portion with the coil,
a pair of side shrouds at opposite margins of the panel portion
that turn and extend alongside coil sides, and that have outer ends
that abut shrouds of the other coil plate, and
a protruberance at the outer end of each side shroud that is
positioned adjacent a protruberance of an abutting side shroud of
the other coil plate; and
a pair of terminals, each having a clasp portion encircling
adjacent protruberances of abutting side shrouds to capture the
same in position, and a projecting extremity for making connection
in a circuit.
2. A coil plate assembly as in claim 1 in which each of said
protruberances has an overhanging lip and a catch, and each
terminal clasp portion slides under the lip and is held in place by
the catch to temporarily maintain the parts in position.
3. A coil plate assembly as in claim 1 wherein the assembly is
encapsulated in a molding material.
4. In a coil plate assembly to position a coil in a molding die
cavity for encapsulation in an insulating material, the combination
comprising:
a pair of coil plates between which the coil is disposed; each
plate including:
an end panel lying over the coil end,
die contact means on the end panel to space said assembly from die
cavity walls,
a pair of side shrouds at opposite ends of the panel and each
extending alongside of the coil, and
a boss formed on one end of each side shroud for spacing said
assembly from the sidewalls of said cavity; and
a pair of locking means each embracing the bosses of the shrouds on
one side of the coil to connect the coil support plates together,
which means are electrically connected with the coil ends and have
terminal portions which project outward from the coil plates.
5. A coil plate assembly as in claim 4 in which the shrouds of one
plate extend toward the shrouds of the other plate to abut against
one another, and the locking means comprises a clasp portion with
an opening in which the bosses of the abutting shrouds are
received, and a projection that extends outward from the
shrouds.
6. A coil plate assembly as in claim 4 in which each end panel has
a central aperture and alignment means which align said coil with
the panel.
7. A coil plate assembly as in claim 6 in which the alignment means
comprises a plurality of lugs that protrude from the periphery of
each panel aperture to extend partially into said coil.
8. In a coil plate assembly for positioning a coil in a die cavity
for encapsulation in an insulating material, the combination
comprising:
a pair of coil plates between which the coil is disposed, and each
having a center panel with two side members that extend alongside
the coil to abut with side members of the other coil plate, each
side member has a boss at a remote end that protrudes above said
side member with a front inclined face, an opposite rear inclined
face, and a lip above said front face, and bosses of two abutting
side members match with one another to define a generally
rectangular outline; and
a pair of terminal clasps, each electrically connected to the coil
and each having a clasp portion with a rectangular opening that
conforms to the outline of two matching bosses, and a connection
end, said clasp portion is adapted to hook under the lips of two
matching bosses and pivot down the opposite inclined faces of said
matching bosses to seat flat upon the side members associated with
said matching bosses, snugly clamping the matching bosses together,
said connection end extends outward from said side members and
serves as a terminal for connecting said coil into a circuit.
9. A coil plate assembly as in claim 8 in which each boss has a
flexible rib at a rear corner and has a catch protruding from the
flexible rib, and the ribs of said matching bosses are spaced from
one another to allow the ribs to be slightly deflected inward as
the clasp portion of the terminal clasp engages and slides over the
catches of the matching bosses while pivoting down upon the side
members, said catches thereafter maintaining the terminal clasp in
place.
Description
BACKGROUND OF THE INVENTION
It is of advantage to encapsulate electrical coils in molding
material to protect the individual turns and to minimize the
shifting of turns in response to magnetic forces. Appearance is
also greatly improved by the encapsulating of wound coils in
resinous materials, and it has now become a common practice to
cover coils with molding material. To properly position a wound
coil within a molding die cavity during the encapsulation process,
so as to cover the coil with a uniform coating, some form of
positioning of the coil within the molding die is required. The
space between the coil and the cavity walls must be maintained in
the presence of the flow of the molding material, and uneven
pressures that are occasioned by the material flow.
At the present, some positioning means for coils are formed of a
pair of support plates between which the coil is interposed, and
the plates have protrusions that bear against cavity walls with a
snug enough fit to hold the coil properly positioned throughout the
molding process. The plates are connected together by locking
elements that are completely covered by the encapsulating material,
and separate and distinct terminals are employed that protrude from
the completed, encapsulated coil, to serve as means for making
electrical connection. In addition to necessarily being
electrically connected to the coil, these terminals must also have
some type of connecting relationship with the support plates to fix
them in a proper position during the encapsulation process. Such a
prior structure is shown in U.S. Pat. No. 3,544,937 dated Dec. 1,
1970, and the present invention provides an improved departure from
the coil support disclosed in that patent.
SUMMARY OF THE INVENTION
The present invention relates to a coil supporting plate assembly
particularly useful for positioning an electrical coil in a molding
die cavity during encapsulation, and it more particularly resides
in a pair of coil support plates having panels on opposite ends of
the coil with coil alignment means to hold the coil in a fixed
position with respect to the plates, side shrouds, that continue
integrally from the panels and overlie the coil sides,
protruberances formed on the side shrouds, and terminals that clasp
the protruberances of adjacent shrouds together to hold the parts
assembled.
A preferred form of the invention has a pair of support plates with
central apertures that conform to and are aligned with the central
opening of the associated coil. Alignment lugs are mounted on the
periphery of the apertures that protrude into the coil core to
maintain the coil in proper registry with the plates, and the
plates have small protruding pins that engage cavity walls. This
engagement holds the coil assembly in place during molding. To
maintain the coil plates in assembled relation with the coil
preliminary to, and during, encapsulation, novel use is made of the
terminals. They not only function for making electrical connection,
but they also clasp the coil plates in a firm, assembled relation.
In doing so, the terminals also position themselves. A simplified
structure thus results that does not require extra, or complicated
parts for making a pre-assembly prior to the encapsulating process.
Means that are separate from the terminals for holding the coil
supporting plates and coil in pre-assembled relation are thus
eliminated.
It is an object of this invention to provide a coil supporting
plate assembly that can readily be assembled to position a coil
within a molding die cavity for encapsulation to establish the
desired degree of coverage of encapsulating material about the
assembly.
It is a further object to provide a coil supporting plate assembly
that is coupled together by dual purpose locking means that are
electrically connected to the coil and protrude from the
encapsulated coil assembly to act as terminals for electrically
connecting the coil into a circuit.
The foregoing and other objects and advantages of the invention
will appear from the following description. In the description
reference is made to the accompanying drawings, which form a part
hereof, and in which there is shown by way of illustration, and not
of limitation, a specific form in which the invention may be
embodied. Such embodiment does not represent the full scope of the
invention, but rather the invention may be employed in a variety of
embodiments, and reference is made to the claims herein for
interpreting the breadth of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 and 2 are perspective views of two coil plates which form a
part of this invention,
FIG. 3 is a perspective view of a terminal forming a part of the
invention,
FIG. 4 is a front view partially in section of the coil plates of
FIGS. 1 and 2 and of a pair of terminals as in FIG. 3 all assembled
in a pre-assembly with a coil,
FIG. 5 is a side view of the assembly of FIG. 4,
FIG. 6 is an enlarged fragmentary view in section taken through the
plane 6--6 indicated in FIG. 5,
FIG. 7 is a view in section taken through the plane 7--7 in FIG. 3,
and showing the pre-assembly in a molding die for encapsulation,
and
FIG. 8 is a perspective view of a completed, encapsulated coil
embodying the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings, FIGS. 1 and 2 are perspective views
of two identicaL coil plates 1 that mirror one another. Each plate
1 has a substantially rectangular end panel 2 which has a large
central aperture 3. As shown in FIG. 2, there are a number of short
pins 4 projecting from the outer face of each end panel 1, which
function to bear against the walls of a cavity of a molding die.
Each end panel 2 also has a plurality of small openings 5 through
which molding material may flow during an encapsulation
process.
As most clearly seen in FIGS. 1, 2 and 4, each panel 2 has a set of
four inwardly projecting alignment lugs 6 that are located at the
corners of its aperture 3. Each alignment lug 6 turns around a
corner of the aperture 3 to have a generally L-shaped appearance,
and each lug 6 is also offset from the periphery of the aperture 3,
so that the outer faces 7 of the lugs 6 are co-planar with the
aperture periphery. Each coil plate 1 also has a pair of side
shrouds 8. These shrouds turn at right angles from the end panels 1
in an inward direction and have a generally rectangular appearance.
Each shroud 8 has an integral boss 9 formed at a corner remote from
the end panel 2.
Each boss 9 os of a complex configuration that protrudes above the
outer surface of its associated side shroud 8 and is particularly
characterized by a lip 10 that is raised above and overhangs beyond
an edge of the shroud 8. As most clearly shown in FIG. 6, there is
a front inclined face 11 beneath the lip 10, and a rear inclined
face 12 at the opposite end of the boss 9 which parallels the front
inclined face 11. Each boss 9 is further characterized in
appearance, when viewed from a position as in FIG. 5, as being
generally "L" shaped in outline with a thin rib 24 extending
rearward from the lip 10. The inclined face 12 forms the rear edge
of the rib 24, and a nib like catch 25 protrudes from one side of
the rib 24. When the two coil plates 1 are brought up against each
other, as in FIG. 5, the bosses 9 of abutting shrouds 8 match with
one another to present a rectangular outline with the ribs 24 of
the two bosses 9 forming two opposite sides of the rectangle. The
nib like catches 25 face outward from the rectangular
configuration, and the ribs 24 are spaced from one another with a
gap therebetween, so that they can be flexed toward one
another.
As illustrated in FIGS. 4 and 5, the coil plates 1 are designed to
overlie the ends of an electrical coil 13, with the side shrouds 8
extending alongside opposite sides of the coil 13. The remote end
of each shroud 8 abuts with the like end of an opposite shroud 8 of
the other plate 1, to thereby form a frame around the coil 13. This
frame is to act as a support for the coil 13 when the sub-assembly
being described is inserted into a mold cavity. The bosses 9 of two
abutting shrouds 8 are juxtaposed and thereby define a composite
member on each side of the assembly.
Two juxtaposed bosses 9 are secured together by a terminal clasp 14
that serves as a locking means. Such a terminal clasp 14 is shown
in FIG. 3, and has a clasp portion 15 with rectangular opening 16
in which a pair of juxtaposed bosses 9 are snugly received, so as
to be clamped together. When a pair of bosses 9 are thus encircled
by a terminal clasp 14 on each side of the assembly, the plates 1
are joined with one another to snugly cradle the coil 13. Each
terminal clasp 14 is electrically connected to an end wire 17 of
the coil 13, and each terminal clasp 14 also has a connection end
18 which extends radially outward of the coil 13 for connecting the
coil into a circuit.
Referring now to FIG. 6, which is an enlarged section view of the
terminal clasp 14 and one of the bosses 9, it can be seen that the
clasp 14 is placed in position with a part thereof under the lip
10. The clasp 14 is then pivoted to have the clasp portion 15
seated flat upon the shrouds 8, in which position the rectangular
opening 16 of the clasp 15 fits snugly about the bosses 9 to firmly
hold all parts in position. The pivoting motion is facilitated by
the provision of the inclined faces 11 and 12 of the bosses 9.
Referring again to FIG. 5, as the terminal clasp 14 pivots, it
engages the catches 25 on the rear corners of the bosses 9. Due to
the gap between the ribs 24, the rear corners of the ribs 24 on
which the nib like catches 25 are formed are deflected inward to
allow the clasp portion 15 of the terminal clasp 14 to pass over
the catches 25. Thereupon, the bosses 9 resume their natural shape
and the catches 25 act to hold the clasp portion 15 in place.
The coil 13 is wound around a hollow forming core 19, as seen in
FIGS. 4 and 7. Then the coil plates 1 are positioned around the
coil 13 the alignment lugs 6 extend into the hollow core 19 with a
snug fit to hold the coil 13 in a fixed position with respect to
the plates 1. Also, the periphery of the plate aperture 3 matches
with the opening of the core 19.
Turning now to FIG. 7, there is illustrated the insertion of the
coil supporting sub-assembly within a molding die comprising a
lower die member 20 and an upper die member 21 which cooperate to
define a mold cavity 22. When the coil supporting sub-assembly 10
is placed within the cavity 22 the die contact pins 4 of the plates
1 engage cavity walls to vertically space the assembly parts from
the die surfaces. In order to provide longitudinal registration of
the sub-assembly within the cavity 22, the bosses 9 engage the
cavity side walls. The thickness of the encapsulating coating is
thereby controlled.
Once the coil sub-assembly is properly positioned within the mold
cavity 22, molten encapsulating material is injected into the
cavity to flow about the assembly and through the openings 5 to
entirely impregnate the coil 13, and to form a molded shape in
accordance with the cavity design. The finished product, when
removed from the cavity 22, may then have an appearance as in FIG.
8.
As can be seen, the connection ends 18 of the terminal clasps 14
extend from opposite sides of the final product, and a terminal
clamp 23 may be secured on each end 18.
By employing the terminal clasps 14 to serve the dual functions of
first, holding the coil supporting sub-assembly together before
encapsulation, and, second, serving as terminals after
encapsulation, the assembly of the present invention uses a minimum
of parts. Also, the parts may be rapidly and easily assembled
simply by hooking the terminal clasps 14 over the bosses 9, thus
coupling the coil plates 1 to one another.
Although a support assembly for a single coil has been shown and
described herein as a preferred embodiment of the present
invention, it should be understood that the invention is not so
limited and may be readily adapted to support two or more coils for
encapsulation.
* * * * *