Electrical connection system for motors

Two pairs of contact strips are mounted on the respective bridge members of an integral web portion of the molded field case of a power tool or other motor-driven device. The forward ends of the contact strips are cantilever-mounted and automatically engage the respective terminals on the field, as the field is inserted into the field case and is secured in it. An annular wire harness is mounted on the rear bearing boss of the field case. Spaced contacts are carried by the wire harness and engage the respective ends of the first pair of contact strips. The respective ends of the second pair of contact strips are connected to terminals on the ends of the brush shunts. In a reversing embodiment, a third pair of contact strips is mounted on the bridge, and a rotatable reversing subassembly is mounted on the rear bearing boss in lieu of the wire harness.

CROSS-REFERENCE TO RELATED APPLICATION 
The subject matter of this patent application is related to that disclosed 
in corresponding U.S. patent application Ser. No. 480,725, filed on Mar. 
31, 1983, now U.S. Pat. No. 4,491,752, for Electrical Connection System 
for Switches, and assigned to the same assignee as the present 
application. 
FIELD OF THE INVENTION 
The present invention relates to an improved system for the electrical 
connection of electric motors, and more particularly, to the electrical 
connection of universal motors used in power tools and other devices. 
BACKGROUND OF THE INVENTION 
In power tools and related devices, the motor housing comprises a field 
case, which may be made from a dielectric or insulating material (such as 
a suitable plastic which may be injection molded for economy of 
manufacture). The field case may include an integral web portion having a 
rear bearing boss and further having a plurality of 
circumferentially-spaced bridge members joining the rear bearing boss to 
the generally-cylindrical main portion of the field case. The universal 
motor includes an armature and a field. The field is inserted within the 
field case and is secured in it. The armature is inserted within the field 
and has a shaft journaled in a bearing in the rear bearing boss. A 
commutator is carried on the armature shaft, and spring-loaded brushes are 
slidably received in respective brush holders mounted on the field case 
for engagement with the commutator. With this arrangement the motor 
wire-up must often be conducted by hand. 
Also, the prior art has resorted to various forms of manually-manipulatable 
reversing members. For example the reversing member may rotate a brush 
carrier pivotally mounted in the tool housing. Access to the reversing 
member is through an aperture in the tool housing. 
While generally practical for the purposes intended, these structures (with 
or without the separate reversing mechanisms) are not readily adaptable to 
a wide range of power tools, appliances and other motor-driven devices for 
standardization of manufacture and assembly. Moreover, the electrical 
connection of the motors within the final product involves various wires 
and connections which further delay the overall assembly time, and 
inhibits realization of many benefits associated with automation of the 
assembly processes. This is especially important during the assembly of a 
compact power tool having relatively high motor performance and further 
having an overall "double insulated" design. 
SUMMARY OF THE INVENTION 
It is an object of the present invention to correct the disadvantages and 
deficiencies of the prior art by providing an improved system for the 
electrical connection of motors used in power tools, appliances and other 
motor-driven devices. 
It is an additional object of the present invention to provide a set of 
contact strips uniquely configured to reduce motor "wire-up" time. 
It is another object of the present invention to provide a standardized 
motor "package" and its associated electrical connection means for a wide 
variety of power tools, appliances and other motor-driven devices. 
It is yet another objective of the present invention to provide a 
standardized motor "package" and its associated electrical connection 
means which is readily adapted to reversing or non-reversing applications. 
It is also an object of the present invention to provide a drive system 
having a reversible electrical motor and a transmission, in which 
compensating means operatively associated with a reversing switch 
accomodates a range of variations in the transmission, so that the drive 
shaft will rotate in a predetermined direction regardless of the number of 
transmission drive elements and driven elements. 
It is a further object of the present invention to reduce the assembly time 
of motors used in power tools and other products. 
It is also a further object of the present invention to effect a high 
degree of standardization, reduce motor assembly time, and effect overall 
manufacturing economies for a wide variety of power tools and other 
products, and to enhance opportunities for automated assembly. 
Another object of the present invention is to provide an electrical 
connection means which facilitates a convenient compliance with the 
rigorous requirements of double-insulated power tools. 
In accordance with the teachings of the present invention, at least two 
pairs of contact elements are fixedly mounted on one end of the motor 
housing, the housing being made of a suitable insulating material. A motor 
has a field which is inserted into the other end of the housing and is 
secured in it. The field has four terminals thereon, and these terminals 
automatically engage the respective contact elements as the field is 
inserted within the housing and is secured in it. A member which is made 
of insulating material is mounted on the housing. The member carries 
spaced contacts which automatically engage at least two of the contact 
elements as the member is mounted on the housing. 
In accordance with the further teachings of the present invention, the 
member includes an annular wire harness mounted on a rear bearing boss 
formed integrally with the housing. The respective rearwardly-projecting 
ends of a first pair of the contact elements are connected to respective 
terminals on the brush shunts (first means for connecting the rearward end 
portions of one of the pairs of contact elements to the respective 
brushes). A pair of spaced contacts on the wire harness engage the 
respective rearwardly-projecting ends of the other two of the contact 
elements. The spaced contacts on the wire harness are connected to 
respective wires, and the wires are then connected to the switch to 
complete the electrical connection of the motor. The wire harness thereby 
is one form of a second means for connecting the rearward end portions of 
the other of the pairs of contact elements to a source of electrical 
energy. 
Also in accordance with the further teachings of the present invention, the 
member may instead include a reversing subassembly mounted on the rear 
bearing boss for limited rotary movement. First, second and third pairs of 
contact elements are mounted on the motor housing. The forward ends of the 
first and second pairs of contact elements are connected to the respective 
terminal means on the field. The forward ends of the third pair of contact 
elements are connected to respective terminals on the brush shunts. The 
respective rearward ends of the first pair of contact elements are 
connected to the switch on the tool. When the reversing subassembly is 
mounted on the bearing boss, the respective rearward ends of the second 
and third pair of contact elements are automatically connected to a pair 
of spaced arcuate contacts carried by the reversing subassembly. The 
reversing subassembly has two alternate positions in the housing, whereby 
the respective rearward ends of the second and third pair of contact 
elements ae reversibly connected to each other, respectively. Therefore, 
the reversing subassembly is yet another form of the first means for 
connecting one of the first or second pairs of contact elements to the 
respective brushes. 
The motor housing comprises a molded field case having an integral web 
portion including a plurality of circumferentially-spaced bridge members 
joining the rear bearing boss to the generally-cylindrical main portion of 
the field case. Openings (or channels) are formed in the bridge members 
for mounting the respective contact elements. These contact elements are 
formed as bent contact strips, at least some of which are cantilever 
mounted on the respective bridge members. 
These and other objects of the present invention will become apparent from 
a reading of the following description, taken in conjunction with the 
enclosed drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
With reference to FIG. 1, there is illustrated a portable electric drill 
10. It will be appreciated by those skilled in the art, however, that the 
scope of the present invention is not restricted to it, but that the 
teachings of the present invention are equally applicable to a wide 
variety of power tools, appliances and other electric motor driven 
devices, and indeed, to a wide variety of electric motors, per se. With 
this in mind, the drill 10 generally comprises a motor housing 11, a gear 
case 12 secured forwardly of the motor housing, a chuck 13 forwardly of 
the gear case, a trigger switch 14 for controlling the energization of the 
tool, a rear handle cover 15 secured rearwardly of the motor housing, a 
pistol-grip handle 16 depending from the motor housing, and a strain 
relief means 17 depending from the handle, the strain relief means being 
associated with a line cord (not shown) for connection to a suitable power 
source. 
With reference to FIGS. 2-8, the motor housing comprises a field case 18 
formed from a suitable insulating or dielectric material. Preferably, the 
field case is injection molded from a suitable plastic material having 
relatively high impact strength and structural rigidity, as well as good 
electrical insulating qualities. The field case includes a 
generally-cylindrical main portion 19 and further includes a rear web 
portion (or spider) 20 formed integrally therewith. The web portion 20 
includes an annular rear bearing boss 21, and a plurality of 
circumferentially-spaced inclined bridge members 22 joining the bearing 
boss to the main portion of the field case, as shown in FIG. 8. The field 
case further has a rearwardly-projecting boss 23, as shown in FIG. 2, and 
the rear handle cover is secured by means of a fastener 24. 
An electric motor 25 is housed within the field case. The motor is of the 
universal type and includes a stator or field subassembly 26 and a rotor 
or armature subassembly 27 nested in it. The field subassembly includes a 
field core or stack of laminations 28 having longitudinal passageways 29 
for respective screws 30. The screws extend beyond the field stack, and a 
molded carrier 31 (for the brushes) is piloted on it. The field stack, 
together with the screws and brush carrier, is inserted within the open 
forward portion 32 of the field case and is seated in it; and the screws 
are received in respective holes 33 in the rearward portion of the field 
case. As a result, the field subassembly is secured within the field case, 
and the brush carrier is retained between the field subassembly and the 
field case. The carrier includes rearwardly-extending brush holders 34, 
diametrically opposite to one another as shown in FIG. 4, for receiving 
respective brushes 35. The brushes are resiliently biased by respective 
springs 36 retained within the holders. Each of the brushes has a shunt 
wire 37; the end of each shunt is provided with a terminal 38. The 
armature has a shaft 39 journaled in a bearing 40 in the rear bearing 
boss. The armature shaft carries a commutator 41 shown in FIGS. 2 and 4, 
for engagement with the brushes. The field subassembly also includes a 
terminal block 42 with terminal means. Preferably, the terminal means 
includes four terminals, one of which is shown at 43 in FIG. 5. The motor 
field is of the two-coil type, each of the coils having two leads (not 
shown) which are connected to the four terminals 43 in a suitable manner. 
In accordance with the teachings of the present invention, a plurality of 
contact elements 45, 46 are carried on the integral rearward portion of 
the inslulated field case. As shown in FIGS. 5 and 6, the respective 
bridge members have slots or openings 44 formed therein. Each of the 
openings 44 is formed in the upper portion of its respective bridge 
member, substantially adjacent to the main portion of the field case. As 
shown in FIG. 8, first and second contact elements, 45 and 46, 
respectively, are received in the respective openings in the bridge 
members. (These contact elements may be mounted on the housing in first 
and second pairs, respectively.) Each of the contact elements includes a 
suitably formed or bent contact strip. Each of the bridge members has a 
rearward ledge (or face) 47 and a forward ledge (or face) 48, adjacent to 
the respective openings and transverse to it. Each of the contact strips 
has a main body portion formed with a downwardly-projecting lanced-out tab 
49 and a downwardly-bent ledge 50. With this arrangement, and as shown 
more clearly in FIGS. 5 and 6, each contact strip may be inserted 
forwardly through its respective openings, such that its ledge 50 engages 
the rearward face 47, and such that its lanced-out tab springs down and 
engages the forward face 48, axially retaining each contact strip in its 
respective opening with respect to the respective bridge member. The 
contact strips are thus cantilever mounted and have forwardly-projecting 
ends or end portions 51. The terminals on the field are each provided with 
leaf-spring female sockets 52 (or other suitable socket means) for 
engagement with the respective forward ends of the contact strips, as 
shown more clearly in FIGS. 5 and 6, making electrical contact between the 
first and second pairs of contact strips 45, 46 and the coils on the field 
subassembly. This engagement and electrical connection between the contact 
strips and the field terminals occurs automatically upon the insertion of 
the field within the field case and the securing of the field in it. The 
first pair of contact strips have respective cantilevered 
rearwardly-projecting ends or end portions 53, as shown in FIG. 5. The 
second pair of contact strips 46 have respective downwardly-inclined 
rearward portions 54 supported in complementary channels 55 formed on the 
respective bridge members, as shown in FIGS. 6 and 7. These inclined 
rearward portions have respective rear ends 56, bent thereto, and disposed 
adjacent to the external annular surface of the rear bearing boss. 
A wire harness 57 is provided in accordance with the further teachings of 
the present invention. The wire harness 57 is made from an insulating 
material (such as a suitable molded plastic) and is annular in form, 
although it may take other forms as well, depending upon the shape of the 
motor housing. Spaced contacts 58 are mounted on the wire harness and are 
connected to respective conductors 59 carried on it. The annular wire 
harness is received on the rear bearing boss and may be press-fitted on 
it. As a result, the contacts on the wire harness engage the rearward ends 
of the second pair of contact strips, making electrical connection 
thereto, as the rearward ends of the contact strips are wedged between the 
bearing boss and the contacts on the wire harness (as shown in FIGS. 6, 9b 
and 9c). The wires on the wire harness are then connected to the switch 
(in a conventional manner), which is ultimately connected to a source of 
electrical energy. 
Thus, it will be appreciated that the first and second pairs of contact 
strips 45 and 46, respectively, in combination with the wire harness 57, 
greatly facilitate the connection of the field to the brushes and to the 
switch leading to the power source. The formed contact strips are easily 
inserted into the integral web portion of the field case; the terminals on 
the field automatically engage the respective contact strips when the 
field is inserted into the field case and is secured in it; the terminals 
on the brush shunts are readily slipped over two of the contact strips and 
connected to them; the wire harness is mounted on the rear bearing boss 
for automatic engagement with the remaining two contact strips on the web; 
and finally, the wires on the wire harness are connected to the switch in 
the usual manner. With this arrangement, a plethora of loose wires is 
eliminated; assembly and electrical connection time are substantially 
reduced; and the motor connections are standardized for a wide variety of 
power tools, appliances or other motor-driven devices. Thus opportunities 
for automated assembly are enhanced, since most of the assembly motions 
described above are in directions parallel to the axis of the motor. Thus 
each brush shunt is a first means for connecting the rearward end portions 
of one of the first or second contact elements (or pairs of contact 
elements) to at least one of the brushes; and the wire harness is a second 
means for connecting the rearward end portion of the other of the contact 
elements (or pairs of elements) to a source of electrical energy. 
With reference to FIGS. 9a, 9b, and 9c, the advantages and benefits of the 
improved apparatus and method of the present invention will be readily 
appreciated. As shown in FIG. 9a, the contact strips 45 and 46 are mounted 
on the rearward portion of the field case 18, being slipped into their 
respective openings 44 in the bridge members 22. The mounting screws 30 
are slipped into the field subassembly 26, extending through the brush 
carrier 31. The field subassembly (with the brush carrier) is inserted 
through the open forward portion 32 of the field case, is seated in it, 
and the screws are driven into the field caae. In this manner the four 
terminals 43 on the field automatically engage (and hence make electrical 
connection) to the cantilevered forward ends 51 of the four contact strips 
45, 46, as shown in FIGS. 6, 9b, and 9c. The armature 27 is inserted 
within the field, such that its commutator-end bearing 40 is received 
within the rear bearing boss 21, and when the armature is in place, the 
brushes 35 are released to engage the commutator 41. The brush shunt 
terminals 38 are connected to the cantilevered rearward ends 53 of the 
first pair of contact strips 45. The wire harness 57 is mounted on the 
rear bearing boss 21, such that its contacts 58 are wedged against (and 
hence make electrical connection with) the rear ends 56 of the remaining 
(second) pair of contact strips 46. The wires 59 on the wire harness 57 
are then connected to the switch. 
With reference to FIG. 10, a modified wire harness 57' includes means for 
retaining the annular harness or member on the housing, including a pair 
of substantially diametrically-opposed resilient latch members 60 formed 
integrally. These latch members define latch apertures 61 and project 
forwardly of the wire harness. The latch members 61 are sufficiently 
flexible, such that the latch member may be flexed slightly (outwardly) as 
the wire harness 57' is slipped over the rear bearing boss 21. The 
respective latch apertures 61 engage latch bosses 61a on the bearing boss 
(as shown in FIG. 8) and the wire harness 57' is retained on the bearing 
boss with a "snap action". Moreover, if desired, the wire harness 57' may 
be provided with a suitable key (not shown) for cooperation with a 
corresponding keyway on the bearing boss (again, not shown) to assure the 
proper circumferential position of the wire harness on the bearing boss 
for proper engagement between the contacts 58 and the ends 56 on the 
second pair of contact strips 46. Moreover, and again if desired, the 
shape of the wire harness could be other than annular, and could be 
fixedly mounted elsewhere within the housing. 
With reference to FIGS. 11-18, a second embodiment of the present invention 
is provided. In this second embodiment, a reversing subassembly 62 is used 
in lieu of a wire harness, and a third bent contact strip 63 is mounted on 
the bridge as shown in FIGS. 14 and 15. (Again, the third contact strip 
may be mounted on the housing in third pairs of contact elements). The 
reversing subassembly 62 includes an outer (or first) reversing member 62 
which is a support member preferably made from an insulating material, 
such as a suitable molded plastic. This first reversing member 64 has 
means for rotatably retaining the reversing subassembly on the rear 
portion of the housing, including a resilient plug 66 shown in FIG. 17, 
and which is engaged by a portion of the handle 15, as shown in FIG. 11. 
The resilient plug 66 therefore acts as a vibration isolation means 
between the handle and the rest of the tool. In this manner, the outer 
reversing member is mounted on the bearing boss for a limited rotary or 
pivoted movement, but is precluded from axial dislodgement. 
An inner (or second) reversing member 68 is nested within the outer 
reversing member, as shown in FIGS. 16 and 17, and is keyed to it (as at 
69) for conjoint limited rotary movement. This inner reversing member is 
also made from an insulating material, such as a suitable molded plastic. 
A pair of curved contact means, or spaced-apart arcuately-formed reversing 
contacts 70 are carried by the inner reversing member, and are mounted 
transverse to the plane of the reversing member. These reversing contacts 
70, as shown in FIG. 18, each have a central portion 71 and 
longitudinally-split bifurcated contact-engaging ends 72 and 73, 
respectively. Each of these ends are in turn provided with respective 
dimples 74 for engagement with the respective rearwardly-projecting ends 
of the second and third pair of contact strips, 46 and 63, respectively, 
as shown in FIG. 16. Also as shown in FIG. 16, this bifurcated 
configuration is part of a means for compensating for tolerance buildup 
associated with the potential differences in radial distances R.sub.1, 
R.sub.2 to the respective ends 56, 76 of the cantilever-mounted contacts 
46, 73. Where R.sub.1 does not equal R.sub.2, a single cantilever-mounted 
curved contact strip could engage strip 46, and be levered out of 
engagement with strip 63. Therefore by splitting contact strip 70 into two 
strips of different lengths, the strips are self-biased, more or less 
independently, against contact elements 46, 63, taking up variations in 
their respective radial distances from the axis "A" of the subassembly, 
and accommodating stress due to the amount of deflection in the free ends 
of the strips. Further, and as shown in FIG. 14, the rearwardly-projecting 
ends 53 of the first pair of contact strips 45 are connected to the switch 
(in a suitable manner); the forward ends 75 of the third pair of contact 
strips 63 (shown in FIGS. 14 and 15) are connected to the brush shunt 
terminals 38; and the forwardly-projecting ends of the first and second 
pairs of contact strips 45 and 46, respectively, automatically engage the 
four terminals 43 on the field (as in the first embodiment of FIGS. 2-8). 
The rearwardly-projecting respective ends 56 and 76 of the second and 
third pairs of contact strips, 46 and 63, are alternately connected to the 
arcuate reversing contacts 70 for reversing the electrical connections 
between the field and the armature for reversing the motor rotation in the 
conventional manner. Thus the reversing subassembly includes reversing 
means for selectively interconnecting the respective rearward end portions 
of the second and third pairs of contact elements to change the direction 
of rotation of the armature. However, it should be noted that reversing 
subassembly 62 need not include discrete reversing members 64, 68. 
Instead, members 64, 68 may be integrally molded as one unit. Thus the 
reversing subassembly is yet another form of the first means for 
connecting the rearward end portions of one of the first or second contact 
elements (or pairs of contact elements) to at least one of the brushes. 
With reference again to FIGS. 12-14, the reversing subassembly 62 has a 
radially-extending integral portion or switch operator 77 which is formed 
with a generally oval aperture 78 within which the rearwardly-projecting 
boss 23 on the field case is received. The integral portion 77 is further 
provided with a manually-manipulated portion or serrated reversing button 
79 which passes through an opening 80 in the rear switch cover and is 
nested within a dwell 81 therein (as shown in FIG. 13). The reversing 
subassembly also has a downwardly-projecting integral tab 82 for 
interlocking engagement with the switch, precluding movement of the 
reversing subassembly in the "on" position of the switch. As shown in FIG. 
17, if desired, a felt washer 83 may be trapped between the reversing 
subassembly and the field case to minimize the flow of dirt or dust 
particles to the reversing contacts and the rearwardly-projecting ends of 
the respective contact strips. 
With reference to the schematic diagrams of FIGS. 19a, 19b, and 19c, the 
electrical interconnection of the present invention will be further 
appreciated. In the non-reversing embodiment of FIG. 19a, the first 
contact element 45 connect the field coils 84, 85 to the brushes 35 on the 
armature 27, and the second contact elements 46 connect the field coils to 
the switch 14 (via the wire harness 57) to the power source 86. In the 
reversing embodiment shown in FIGS. 19b and 19c, the first contact 
elements 45 now connect the field coils 84, 85 to the switch 14, and the 
second contact elements 46 and third contact elements 63 reversibly 
connect the field coils 84, 85 to the brushes 35 via the reversing 
subassembly 62. The reversing subassembly has two alternate positions; the 
first or "forward" position is shown in FIG. 19b, and the second or 
"reverse" position is shown in FIG. 19c. 
Another advantage of the electrical interconnection and reversing systems 
of the present invention is the creation of a drive system having 
compensating means for causing the output shaft to rotate in a 
predetermined direction responsive to movement of the reversing switch 
from a first (forward) position to a second (reverse) position, for any 
given number of transmission drive elements. This feature is illustrated 
in FIGS. 20a and 20b, showing a double-reduction transmission 100, and in 
FIGS. 21a and 21b, which illustrate a triple-reduction transmission 102. 
The drive system schematically shown in FIG. 20a includes armature shaft 
39, which rotates in one direction indicated by arrow 104 (corresponding 
to the current direction indicated by arrow 106), when the reversing 
switch is in its "forward" or first position. The drive system further 
includes "N" number of drive elements 108 which form a transmission 
connecting the armature shaft 39 to the output shaft 110, which rotates in 
a predetermined direction indicated by arrow 112. Referring now to FIG. 
20b, when the reversing switch is moved to its second or "reverse" 
position, the current flow 106 is reversed, thus reversing the armature 
shaft direction of rotation 104 and the output shaft direction of rotation 
112. However, it is now necessary to address the problem posed when the 
drive system for a particular application includes "N+1", "N+2" or another 
number of drive elements 108, since changing the number of drive elements 
from one application to another will result in changing the direction of 
rotation 112 of the output shaft 110 for a given direction of current 
flow. Also it is desirable to maintain the orientation of the "forward" 
and "reverse" positions of switch reversing button 79 with respect to the 
housing configurations, as shown in FIG. 13, whether the particular power 
tool or other application contains a double- or triple-reduction 
transmission. The solution to the problem is the compensating means shown 
in FIGS. 21a and 21b, and in FIG. 16. Referring now to FIG. 16, an 
alternate keyway 69a is formed at diametrically opposite points on the 
inner (reversing) member 68, and is spaced circumferentially approximately 
25.degree. from keyway 69. Recalling that FIG. 16 is taken looking 
rearwardly from the field, and that FIGS. 20a, 20b, 21a and 21b are taken 
looking forwardly toward the field, it can be appreciated that if the 
subassembly of curved contact strips 70 and (inner) reversing member 68 is 
first rotated 25.degree., and then assembled so that alternate keyway 69a 
is now located at the position formerly occupied by keyway 69, the curved 
contact strips 70 will therefore be selectively oriented or locatable with 
respect to the respective contact elements 56, 76, (and to the first and 
second switch positions) as shown in FIGS. 21a and 21b. The result is a 
change in direction of current flow, as seen when comparing FIG. 21a with 
FIG. 20a, and FIG. 21b with FIG. 20b. Therefore, when it is desired to use 
the subject invention in conjunction with a triple-reduction reversing 
power tool instead of a double-reduction reversing power tool, the tool is 
assembled with a reversing subassembly utilizing keyway 69a as just 
described, yielding the same predetermined direction of rotation for 
output shaft 110 as was generated in the double-reduction system. This can 
be seen by again comparing FIG. 21a with FIG. 20a, and FIG. 21b with FIG. 
20b. It can be appreciated that this feature of the present invention is 
applicable not only to drive systems utilizing gear trains, but to belt 
drives, chain drives, rollers, threads, and others. 
However it should be noted then if the reversing subassembly 62 does not 
include two discrete members 64, 68, but rather is composed of a single 
integrally-molded member, compensation for variations in the number of 
transmission elements can be effected by molding two types of reversing 
members, such that one type orients the reversing contacts 25.degree. with 
respect to the other type. 
Thus it will be appreciated that the first and second pairs of contact 
elements (strips 45 and 46, respectively) are used in both embodiments, 
that is, the non-reversing embodiment of FIGS. 2-8, and reversing 
embodiment of FIGS. 11-18. In the non-reversing embodiment, the wire 
harness 57 (or 57') is used; and in the reversing embodiment, the 
reversing subassembly 62 is used in addition to the third pair of contact 
elements (strips 63). Preferably, both the wire harness 57b and the 
reversing subassembly 62 are mounted on the rear bearing boss. In each 
case, the pairs of respective contacts 58 and 70 carried by the wire 
harness and reversing subassembly, respectively automatically engage (and 
make electrical contact with) the respective rearward ends of the 
appropriate contact elements. The contact elements are mounted on the 
integral web portion of the field case; and in each case, the forward ends 
of two pairs of contact elements automatically engage (and make electrical 
contact with) the four terminals on the field, when the field is seated 
within the field case and is secured in it. As a result, the electrical 
connections for the motor are greatly simplified; standardization is 
assured for a wide variety of motors, both reversing and non-reversing; 
production economies are realized; and the quality, reliability and 
serviceability of the end product are substantially improved. 
Obviously, many modifications may be made without departing from the basic 
spirit of the present invention. Accordingly, it will be appreciated by 
those skilled in the art that within the scope of the appended claims, the 
invention may be practiced other than has been specifically described 
herein.