U.S. patent number RE34,001 [Application Number 07/368,192] was granted by the patent office on 1992-07-21 for enamelled wire connection for circuit boards.
This patent grant is currently assigned to Papst-Motoren GmbH & Co. KG. Invention is credited to Guenter Wrobel.
United States Patent |
RE34,001 |
Wrobel |
July 21, 1992 |
Enamelled wire connection for circuit boards
Abstract
Disclosed is an arrangement for providing an electrical
connection to the enamelled wire of a coil of an electrical motor.
The arrangement includes a circuit board carrying at least one
conductive component such as an electrical trace on the surface of
the circuit board. A conductive pin-type contact, also carried by
the circuit board, is electrically connected to the conductive
component. An insulating body is carried by the electrical motor
and includes passageways for receiving at least two pin-receiving
receptacle terminals. The receptacle terminals have
inwardly-extending rib members for engaging the enamelled wire when
the enamelled wire and the pin-type contact are inserted therein.
The rib members are operative to penetrate the enamel covering to
establish electrical contact with the wire.
Inventors: |
Wrobel; Guenter (Villingen,
DE) |
Assignee: |
Papst-Motoren GmbH & Co. KG
(Black Forest, DE)
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Family
ID: |
25829417 |
Appl.
No.: |
07/368,192 |
Filed: |
June 16, 1989 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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Reissue of: |
829623 |
Feb 13, 1986 |
04673834 |
Jun 16, 1987 |
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Foreign Application Priority Data
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Feb 14, 1985 [DE] |
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3505092 |
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Current U.S.
Class: |
310/71; 439/391;
439/426 |
Current CPC
Class: |
H01R
4/2412 (20130101); H02K 3/522 (20130101); H02K
2203/03 (20130101) |
Current International
Class: |
H02K
3/52 (20060101); H02K 3/46 (20060101); H01R
4/24 (20060101); H01R 011/20 () |
Field of
Search: |
;29/596,598,857,861,866
;310/42,68R,68D,71 ;439/391,426 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Stephan; Steven L.
Assistant Examiner: Rebsch; D. L.
Attorney, Agent or Firm: Fitch, Even, Tabin &
Flannery
Claims
I claim:
1. An arrangement for providing an electrical connection to the
enamelled wires of the coil of an electrical motor, comprising, in
combination:
a circuit board carrying at least one conductive component;
a conductive pin-type contact carried by said circuit board and
electrically connected to said conductive component;
an insulating body carried by said electrical motor, said
insulating body defining at least two receptacle-receiving
passageways therein; and
conductive-pin receiving terminals having wall means defining a
pin-receiving cavity and engaging means associated with said wall
for electrical engagement with one said enamelled wire and one said
pin-type contact inserted into said cavity, said engaging means
operative to penetrate the enamel covering said wire to establish
electrical contact with said wire and said pin.
2. The combination of claim 1 wherein said motor further includes
latching means carried by said insulating body for latching to said
circuit board, said receptacle terminals arranged to mate with said
pin-type contacts as said latching means are latched to said
circuit board.
3. The combination of claim 1 wherein said engaging means comprise
inwardly-extending rib members formed in said receptacle
terminal.
4. The combination of claim 1 wherein said receptacle terminal has
a pin-receiving end and defines a slot extending from said
pin-receiving end along at least two-thirds the length of said
receptacle terminal.
5. The combination of claim 1 wherein said insulating body is
supported by a stack of plates of the motor.
6. The combination of claim 1 wherein said engaging means comprises
an end section of said receiving terminal wall conically tapered in
the direction of insertion.
7. The combination of claim 3 wherein each said rib member has a
single edge for penetrating the enamel covering said wire.
8. The combination of claim 3 wherein each said rib member has two
edges for penetrating the enamel covering said wire.
9. The combination of claim 1 wherein said insulating body includes
wall means defining said receptacle-receiving passageways, said
wall means slotted along their length to produce a
resiliently-expandable passageway which augments the mating contact
force of said engaging means with said pin-type contact. .Iadd.
10. An arrangement for providing an electrical connection to the
enamelled wires of the coil of an electrical motor, comprising, in
combination:
a circuit board carrying at least one conductive component;
a conductive contact pin carried by said circuit board and
electrically connected to said conductive component;
an insulating body carried by said electrical motor, said
insulating body defining at least two receptacle-receiving
passageways therein; and
at least one conductive pin-receiving receptacle terminal having
wall means defining a pin-receiving cavity and engaging means
conductively associated with said wall means for electrical
engagement with one of said enamelled wires, said engaging means
operative to penetrate the enamel covering said wire to establish
electrical contact with said wire. .Iaddend. .Iadd.11. The
combination of claim 10 wherein the motor is a brushless direct
current motor. .Iaddend. .Iadd.12. The combination of claim 10
wherein said receptacle terminal has a pin-receiving end and
defines a slot extending from said pin-receiving end along at least
two-thirds the length of said receptacle terminal. .Iaddend.
Description
The invention concerns a device for producing an electrically
conductive connection between the enamelled wire ends of one or
several stator coils of an electrical motor, especially a direct
current motor without a collector, and electrical conductors with
contact pins, each of which, individually and in common with one or
several of the enamelled wires to be contacted, is, by producing a
radial compression, through which the enamel casing of the enamel
wire is in places penetrated or removed in a contacting manner,
inserted in the axial direction into the hollow space of an
insulating body.
With increased use of electronic components for the control or
power supply of devices which have electromagnetic enamelled wire
coils, such as, for example, relays, transformers, motors and the
like, the use of circuit boards also increases, and therewith as
well the technical problem of how to connect the Cu-enamelled wire
ends of the coils of these electromagnetic devices to the circuit
boards in serial sequence and with adequate contact security. In
this, the insulating enamel layer should, for reasons of cost, be
removed from the Cu-wire at the connecting place, and a firm
connection with the conductor track be produced at the same time.
Previously, this was done in such a way that the enamelled wire
section to be attached was soldered directly onto a conductor track
with a soldering bit. In this, the insulating enamel layer is
removed from the wire, and it is necessary that the hot soldering
bit be repeatedly guided with a certain bearing pressure over the
individual wire, so that the insulating enamel melts, and the
exposed wire surface has direct contact with the fluid soldering
material. This method is not only very time-consuming, but also
entails the danger that, particularly with very thin enamelled
wires, the wire section to be joined breaks, or that no electrical
contact occurs.
It is, of course, known to provide electrical circuit boards with
contact pins which are closely pressed into the borings of the
circuit boards, and soldered together with the other construction
elements of the circuit boards. These known contact pins are,
however, only used where a metallic plug socket which accommodates
the contact pin in a clamping manner is present as a fixed contact
element.
It is also already known (U.S. Pat. No. 3,014,140) to connect the
enamelled wire ends of the coil of a shaded pole motor in a
contacting manner with individual contact pins, through the fact
that a contact pin section provided with a threading is pressed
into a boring of an insulating casing together with an enamelled
wire section. Through this, the sharp-edged threads burrow into the
enamel casing up to contact with the wire. Connecting strands are
joined to the contact pins by means of attachable clamping
plates.
Apart from the fact that this manner of producing a contacting
connection is only suited for relatively thick enamelled wires, the
danger that the wire end, upon insertion of the contact pin into
the boring, will break is very great, since the end of the wire is
also drawn into the boring.
This task is, in accordance with the invention, solved through the
fact that, in circuit boards provided with electronic control
elements and attached to the insulating body, several contact pins
provided with smooth casing surfaces are attached in a contacting
manner, and that the plastic body has, in several borings, axially
parallel receptacle terminals of metal, each of which, serves to
accommodate one of the contact pins, the inner surfaces of which
slightly taper conically in the direction of insertion, and/or are
provided with riblike elevations which run essentially laterally to
the axial direction.
The principal advantage which is to be obtained through this is to
be seen in the fact that the electrical contact between the coil
wires and the conductive tracks of the printed circuit board and
the mechanical attachment of the circuit board occurs in the same
work process on the plastic body, and that the danger of breaking
or shearing is prevented by the fact that either no sharp-edged
parts come into contact with the wire, or that the elevations are
positioned on the part which does not move relative to the
insulated wire.
.[.The.]. .Iadd.Certain .Iaddend.developments of the invention
.[.in accordance with claim 2 or 3.]. are particularly of advantage
if thicker enamelled wires are to be contacted.
.[.The.]. .Iadd.Another .Iaddend.development of the invention .[.in
accordance with claim 4.]. not only facilitates the insertion of
the connecting enamelled wire ends and the contact pins into the
receptacle terminals, but it is also through this prevented that
the enamelled wire during the insertion of the contact pin into the
receptacle terminal, is drawn over the sharp edge, and thus be
possibly damaged.
The use of receptacle terminals .[.in accordance with claim 5.].
has the advantage that a higher radial elasticity can be attained,
through which the contacting of very thin enamelled wires becomes
more secure, and through which also enamelled wires with larger
differences of thickness can be contacted. Through this, it is
furthermore also possible to provide slotting over the entire
length of the receptacle terminal.
A very simple connection which corresponds in its motion to the
process of insertion of the contact pins into the receptacle
terminals can .Iadd.also .Iaddend.be carried out .[.through the
characteristics in accordance with claim 6.]..
.[.The.]. .Iadd.Another .Iaddend.development of the invention .[.in
accordance with claim 7.]. ensures its advantageous use,
particularly in the manufacture of electronically controlled direct
current motors without collectors, in which it was previously
necessary to connect four ends of winding wires by soldering
conductor tracks of a circuit board.
.[.Through the development in accordance with claim 8, in
connection with the development in accordance with claims 5 and 7,
the machine insertion of the winding ends into the receptacle
terminals is facilitated or made possible..].
The invention will now be illustrated in greater detail by means of
the diagram. These show:
FIG. 1: the stator of a brushless direct current motor in a lateral
view, with a circuit board;
FIG. 2: a view from above of FIG. 1, without the circuit board;
FIG. 3: a view III--III of FIG. 2;
FIG. 4: a view IV--IV of FIG. 2, in enlarged representation;
FIG. 5: in enlarged representation, the view from above of a pole
blade of the stator of FIGS. 1 and 2;
FIG. 6: a slotted receptacle terminal of metal according to the
section line VI--VI from FIG. 7;
FIG. 7: a receptacle terminal of FIG. 6 in an axial view from
above;
FIG. 8: another slotted receptacle terminal of metal in a lateral
perspective view;
FIG. 9: an enlarged longitudinal section of the receptacle terminal
depicted in FIG. 8.
In the stator (1) of a direct current motor depicted in FIGS. 1 and
2 in a lateral view and view from above, insulating cover plates (5
and 6) of plastic are positioned on both frontal sides (2 and 3) of
a stack of plates (4) which cover not only the annular internal
part (7), but also the radial bars (8) and the large part of the
segmented pole piece (9). On the radial bars (8), double coils (10)
are coiled the four enamelled wire ends of which (11, 12, 13, and
14) are to be connected with different conductive tracks of a
circuit board (15). For purposes of providing a clearly visible
illustration, wire ends (11, 12, 13 and 14) are shown over-sized in
the drawings. Accordingly, the figures, and especially FIG. 4 are
not drawn to scale, as wire diameters, smaller than those
illustrated, are employed in the present invention. The proper
sizing of the wire ends, relative to the components of the wire
contact connection, will become apparent upon considering the
following description. The printed circuit board (15) is fastened
by means of the latching catches (16) of fork-shaped slotted
supporting fingers (17 and 17/1) of the upper insulating cover
plate (5), which run parallel to that at a certain distance from
the stack of plates (4).
The slotted ends of the supporting finger (17 and 17/1) thereby
project into slot apertures (18) of the support plate (15) (see
FIGS. 4 to 6). The supporting fingers (17 and 17/1) are each formed
symmetrically with the middle axes (19 and 20) of the radial bars
(8) on the part sections (21) of the upper insulating covering
plate (5) in one piece and partially covering the pole piece (9),
which is likewise formed in segments, and formed as to extend in an
axial direction. While the two supporting fingers (17/1) are only
provided for the attachment of the circuit boards (15), the
supporting finger (17), as can best seen from FIGS. 2, 4 and 7, is
formed as one piece on both sides with symmetrical positioning to
the middle axes (19 and 20), each with two side parts (23), with
one boring or passageway (24), each running parallel to the axis of
the boring (22) of the stack of plates (4), and slotted receptacle
terminals (27 or 27/1) of metal are inserted in the upper expanded
section (25) in the form depicted in FIGS. 6 and 7 or in FIGS. 8
and 9 as individual parts. The receptacle terminals (27 and 27/1),
as well as the borings (24), are expanded on the upper ends in
funnel or trumpet shapes. The internal walls surface of the
receptacle terminal may include several annular corrugations or
ribs (28'), each of which has two edges (28/1) which can penetrate
the enamelled casing of the enamelled wire in a cutting manner
under radial compression pressure (see FIG. 9), or, in the
alternative, may include a few sharp annular reinforcing
corrugations or ribs (28), which are radially driven from the
outside to the inside (see FIG. 6). In FIGS. 8 and 9 three such
relatively sharp-edged annular corrugations (28') are depicted. The
receptacle terminal (27) of FIGS. 6 and 7 has, on the other hand,
five annular reinforced corrugations (28). The receptacle terminals
(27 and 27/1) are each produced from a rolled sheet, and provided
with a slot (29) extending in the axial direction over this entire
length, which effects a radial elasticity. The lateral parts (23)
are, like the receptacle terminals (27 and 27/1), provided with
penetrating axial slots (26) (FIG. 5), in order to also attain a
certain radial elasticity of the boring wall, and in order to be
able to insert the enamelled wire ends (11 to 14) more easily into
the receptacle terminals (27 and 27/1) by machine.
For insertion into the pin-receiving cavities of these receptacle
terminals (27 and 27/1), cylindrical contact pins (30) provided
with rounded, conical tips and smooth casing surfaces are attached
to the circuit board (15). These contact pins (30) each have in
their longitudinal center a stop collar (31), up to which they are
pressed from the lower side into the circuit board (15). Contact
pins (30) are soldered to a conductive component carried by the
circuit board, preferably a conductive track or conductive trace
located on the surface of the circuit board (15). In order to
attach the loose enamelled wire ends (11, 12, 13 and 14) into the
receptacle terminals (27 and 27/1) of the borings (24), and at the
same time to produce an electrically conductive connection to the
contact pins (30), the enamelled wire ends are each individually
inserted into one of the receptacle terminals (27 or 27/1) in the
manner depicted in FIG. 4, from above or from below, and the
contact pins (30), during the positioning of the circuit boards
(15) on the supporting finger (17 and 17/1) are subsequently thrust
into the receptacle terminal (27). Through this, the internal
diameter of the receptacle terminals (27 and 27/1) are so adjusted
to the external diameter of the contact pins (30) that a radial
clamping effect or compression arises, through which the enamelled
wire ends (11 to 14) are pressed against the relatively sharp edges
(28/1) of the annular corrugations (.[.28.]. .Iadd.28'.Iaddend.),
which then penetrate the enamelled wire layer, and produce a
conductive connection to the metal wire. Approximately the same
result also appears during the driving of the contact pin (30) into
the receptacle terminal (27), with the difference that the annular
reinforced corrugations (28) penetrate the enamelled casing of the
wire in less a cutting manner than in a squeezing manner, in order
to contact the wire, since they are blunter.
Through the fact that the upper ends of the receptacle terminals
(27 and 27/1) are expanded in a flared manner, the enamelled wire
ends, if they are inserted from above with a loose loop into the
receptacle terminals (27), upon insertion of the contact pins (30),
execute an axial motion, without the danger of their being damaged
at the edges of the receptacle terminals (27).
Since the contact pins (30) used together with the receptacle
terminals (27 and 27/1) have a smooth cylindrical casing surface
and conically rounded tips, which make an edgeless transition into
the cylindrical casing surface, no sharp edges are present on the
contact pins (30) themselves, which, in cooperation with the edges
(28/1) of the annular corrugations (28') or the reinforced
corrugations (28), exert a shearing effect, and can cut the
enamelled wire during insertion into the receptacle terminal (27 or
27/1).
While the receptacle terminals (27), with their elevations which
consist of reinforced corrugations (28), are suited for thin, as
well as for relatively thick enamelled wires, the receptacle
terminals (27/1) with the relatively sharp-edged annular
corrugations (28') are more advantageous for contacting extremely
thin enamelled wires.
It is also possible to use unslotted receptacle terminals, that is,
ones which are smooth all around, which have smooth internal wall
surfaces, together with likewise smooth contact pins (30), for
contacting with enamelled wires, if the diameter tolerances are
precisely dimensioned to the wire strength, and an increased
insertion force is tolerated. In this it is of advantage if the
smooth internal surfaces taper slightly conically in the direction
of insertion, and are, for example, on the insertion side, around a
wire thickness further than the end of the insertion length.
* * * * *