Voltage and rotation switching device

An operating voltage change and motor rotation reversal device for a dynamoelectric machine in the form of an induction motor having simplified structure and operational features. For single phase operation, a pre-configured jumper plug interconnects a multi-receptacle connector socket mounted to a terminal board for the motor to complete one of four unique circuit combination. For three phase applications, a different and separate jumper plug is used to provide two different mating relationships with the connector socket so as to provide two unique circuit combinations. Preferably, the terminal board is physically mounted within the motor housing so that when the single phase or three phase plug is mated with the connector socket, a vertically extending handle of the plug is positioned adjacent to an overlying motor housing cover plate having prearranged openings in it. The cover plate has functional information imprints adjacent the openings. The plug handle-cover plate sequence gives a reversal indication of the motor connection without having to disassemble motor components to obtain the connection information.

BACKGROUND OF THE INVENTION 
This invention relates to dynamoelectric machines, and in particular to 
electric motors employing a device to change voltage applied to the motor 
or to change direction of motor rotation, or both. 
In many applications, it is necessary or desirable to reverse the rotation 
of a motor, whether of split phase, capacitor start or run, or three phase 
designs. Interchanging one or more leads of the motor windings can produce 
the desired result. The lead interchange typically is accomplished on a 
terminal board located inside a terminal box attached to or a part of the 
motor housing. If the leads are not accessible from a terminal box, access 
to the interior of the motor may be necessary. External reversing switches 
are also used in some cases. 
Where a terminal board is used, spaced lugs mounted to the board with lead 
identification marked adjacent to each lug on the board frequently are 
used to permit motor rotation reversal by interchanging connections 
between two of the lugs. Visibility and access to the lugs and their 
identifying markings are generally less than desirable. Unless 
considerable care is exercised in effecting the reversal, particularly in 
single phase motor designs, the effort may be time consuming or 
frustrating or, more importantly, wrong. 
In addition to rotation reversal, it is often desirable or necessary to 
operate an appropriately designed motor at one or the other of two 
different voltages. Thus, if a motor is designed for dual voltage 
applications, it possible, by switching or changing winding connections, 
to change the operating voltage of the motor from 115 volts to 230 volts, 
for example. This is an important feature in many applications because a 
single motor may be stocked, that motor being usable in a variety of 
applications by field personnel. 
Whether considering dual voltage operation or rotation reversal or a 
combination of both, care must be exercised when changing circuit 
connections to avoid motor damage. Typically, information regarding 
connections required for each operating mode are identified on the motor 
housing or on a cover plate overlying an internal board where connections 
are made and changed. Where individual connections are required to effect 
circuit changes, the opportunities for connection errors and motor damage 
increase with the number of connections required, the extent to which 
access to the connections are physically limited, and the amount of 
information regarding the making of connections that is physically 
available immediately adjacent to the connectors where the changes will be 
made. 
The prior art has addressed the problem of providing easy and reliable 
field change of motor connections for a long time. For example, U.S. Pat. 
No. 4,748,355 discloses a universal motor connector unit that is usable 
with different three phase and single phase motors for connecting the 
motors to different source voltages. While the prior art in general works 
for its particular purpose, the present invention, unlike the prior art 
and the 4,748,355 patent in particular, utilizes different plug 
constructions for single phase and three phase applications, and thus 
provides an entirely different approach for a voltage change and motor 
reversal device, as will be explained in more detail below. By using 
separate plugs, visual indications of the resulting motor connection is 
available to the installer and end user. 
SUMMARY OF THE INVENTION 
Among the several objects and advantages of the present invention include: 
The provision of a voltage and rotation switching device which makes 
multiple motor connections in a reliable manner, and yet is releasably 
interlocked to permit separation and change as desired; 
The provision of the aforementioned voltage and rotation switching device 
which makes multiple motor circuit connections by simple manipulation of 
the switching device; 
The provision of the aforementioned voltage and rotation switching device 
which provides mistake-proof connections; 
The provision of the aforementioned voltage and rotation switching device 
which provides externally identifiable readings of the particular motor 
connection selected and/or in use; 
The provision of the aforementioned voltage and rotation switching device 
which provides different plug constructions and arrangement for single 
phase and three phase applications; and 
The provision of the aforementioned voltage and rotation switching device 
which is simple and economical to construct, is long lasting and durable 
in use, and is otherwise adapted for the purposes intended. 
The present invention employs a connector socket containing a rectangular 
matrix of female electrical receptacles, mounted in a connector housing. 
Respective ones of the electrical receptacles are electrically connected 
to preselected ones of the motor windings or motor circuit components, 
which, where appropriately connected at the other end of the electrical 
receptacle or at alternate locations on electrical lugs affixed to the 
terminal board and attached to the connector socket, determine the 
electrical operating conditions of the motor. In the preferred embodiment, 
the single phase version provides four operating combinations. A high 
voltage and clockwise rotation may be selected, a high voltage and 
counter-clockwise rotation may be selected, a low voltage and clockwise 
rotation may be selected, or a low voltage and counter-clockwise rotation 
may be selected. The connector socket of the present invention has five 
rows of three receptacles each arranged in an orthogonal relationship. The 
mating single phase jumper plug includes four shorting conductors, the 
ends of which comprise eight male jumper pins for insertion in the 
appropriate receptacles of the connector socket, to provide any 
preselected one of four mating relationships described above. For three 
phase application, the three phase plug has six jumpers interconnecting 
twelve male jumper pins, and the three phase plug mates with the connector 
socket in one of two positions to select high or low voltage operation. 
The jumper plug, for both single phase and three phase applications, 
includes a vertical handle extending upwardly from a surface of the plug 
on an opposite side of the plug from the and male jumper pins. The length 
of the handle is such that when the plug is inserted into the connector 
socket and a cover plate is secured to the motor housing, the cover plate 
will be close to the end of the handle so that the plug is held securely 
in the desired position until the cover plate is removed. Further, the 
cover plate for the single phase jumper plug has four apertures or 
openings located so that a portion of the top of the plug handle, will be 
visible through one of the apertures, depending upon which one of the four 
positions is chosen for the single phase jumper plug. Markings on the 
exterior surface of the cover plate, adjacent to each aperture, indicate 
the four possible positions of the single phase jumper plug relative to 
the four operating combinations of the motor. The cover plate, for three 
phase application, has two apertures to indicate high and low voltage 
connections, in a similar manner.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring now to the drawings of one illustrative embodiment of the 
connection device of this invention, FIGS. 1-13 show a single phase 
version of the connection device while FIGS. 14-17 show the three phase 
version thereof. 
As illustrated in FIG. 1, a portion of a motor 1 is shown to include a 
housing 12 in which the present invention is illustrated. Motor 1 
conventionally includes a stator assembly (not shown) and a rotor assembly 
R, shown diagrammatically in FIGS. 9 and 17. The stator assembly carries 
the motor windings W, described in greater detail below. The rotor 
assembly is mounted for rotation on suitable bearings, not shown, and a 
shaft S extends outwardly of the motor to convert the electrical input to 
the motor 1 to mechanical work. The above structure all is conventional 
and forms no part of the present invention. Conventionally, the windings W 
are connected to a source of electrical energy at a terminal board 24. In 
the preferred embodiment, the above structure is contained in the housing 
12. 
A cover plate 16, secured to the motor housing 12 by means of machine 
screws 18, closes an opening 14 in the motor housing 12 during normal 
operation of the motor. The opening 14 provides access to the terminal 
board 24, which, as indicated, is mounted within the motor housing 12, and 
supports a connector socket 32. A single phase jumper plug 40 is shown 
inserted in the socket 32. The cover plate 16 has apertures or openings 20 
located so that at least one aperture overlays a handle 44 of the single 
phase plug 40 when it is in one of the four possible connection 
relationships with the connector socket 32. Preferably, information is 
imprinted or otherwise carried on the cover plate 16 adjacent to each 
aperture 20 in order to reveal or permit observation of the actual motor 
rotation and operating voltage connections, without removing the cover 
plate 16. This is an important feature of the present invention, in that 
it allows the installer or end user to check visually the motor operation 
connection at any time. 
As shown in FIG. 2, the connector socket 32 is mounted to the terminal 
board 24. The terminal board 24, in turn, is secured to the motor housing 
12 by any convenient method. Conventional threaded fasteners work well, 
for example. As indicated, when the single phase jumper plug 40 is 
inserted in the connector socket 32, the handle 44 will be juxtaposed 
immediately beneath one of the apertures 20 in the cover plate 16. 
The motor circuit leads 33, shown in FIG. 2, enter the rear of the 
connector socket 32, where the leads are secured to respective, 
preselected ones of an end 39 of individual ones of a plurality of 
receptacles 38, as shown in the FIG. 5. Also clearly shown in FIG. 2 is a 
function tang 48 which extends outwardly from a face of the jumper plug 
40. The function tang 48 is intended to extend normal to and passing 
through the terminal board 24, by way of a specific function slot 29 in 
the board 24. 
The connector socket 32 is provided on opposite sides with opposed, 
flexible wedge retainers 34, for releasable locking engagement with the 
terminal board 24, along with orientation wedges 35, which are provided on 
the other two opposed sides of the rectangular-shaped connector socket 32. 
The two flexible wedge retainers 34, located on two of the opposite sides 
of the connector socket 32, as shown in FIG. 2, extend through the 
terminal board 24. When the connector socket 32 is placed in an opening 28 
of the terminal board 24, best seen in FIG. 2, the flexible retainers 34 
are collapsed against the side of the connector socket 32, from which they 
extend. After passing through the terminal board 24, the flexible 
retainers 34 spring outward from the connector socket 32 to releasably 
secure it to the terminal board 24, in conjunction with at least one stop 
5 positioned on an opposite side of the terminal board 24 material 
thickness. The opposed orientation wedges 35, 35 also act in 
guiding/orienting the connector socket 32 into alignment with opening 28, 
as shown in FIG. 4. 
In FIG. 3, a plurality of electrical connection arms 25 are shown affixed 
to the terminal board 24 by means of the bolts 27, which are secured by 
the nuts 26. The arms 25 are used to connect a source of electrical power, 
not shown, to the motor 1 at the terminal board 24. The single phase 
jumper plug 40 is shown as being connected to the connector socket 32, 
with the function tang 48 extending down through the terminal board 24 at 
the function slot 29 identified as 115 volts and counter-clockwise (CCW) 
rotation. The configuration of the terminal board 24 in FIG. 3 is shown as 
providing 115 volts or 230 volts, and clockwise (CW) or counter-clockwise 
(CCW) rotation of the motor shaft. FIG. 3 also shows the raised portion 46 
of the handle 44 which is observable through the respective apertures 20 
of the cover plate 16, showing in FIG. 1, where the cover plate 16 is 
imprinted with the voltage and direction of motor rotation, adjacent to 
the apertures 20. 
The functional relationship between the single phase jumper plug 40 and the 
connector socket 32 is shown in FIG. 5. The U-shaped jumpers 42 are molded 
within the single phase jumper plug 40, each jumper 42 delimiting a pair 
of connected jumper pins 43, which extend centrally through and out of an 
insulation stem 41 integrally molded in the single phase jumper plug 40. 
Another view of the jumper pins 43 exiting the single phase jumper plug 40 
is shown in FIG. 8. When the single phase jumper plug 40 is interconnected 
to the connector 32, the jumper pins 43 of the single phase jumper plug 40 
are frictionally secured within respective U-shaped electrical receptacles 
38 mounted in the connector socket 32. The connector sockets 32 in turn 
secure motor leads 33. The electrical receptacles 38 themselves are 
received within cylindrical openings 37 formed in the connector socket 32. 
It will be seen in FIG. 5 that the positioning stems 41 of the jumper plug 
40 are constructed to be guidingly received by the cylindrical openings 37 
and are formed to ensure proper electrical separation between the 
receptacles 38 and the mating plug 40. At the same time, each jumper pin 
43 is releasably secured by the spring fingers of the U-shaped receptacles 
38, to provide the desired electrical connection between the single phase 
jumper plug 40 and leads 33, when the connector and plugs are mated to one 
another. 
As indicated above, the function tang 48 is located at the side of the 
single phase jumper plug 40 and extends downwardly in the same direction 
as the jumper pins 43, as is visible in FIGS. 6-8. The function tang 48 is 
arranged to be received by an appropriate function slot 29 in the terminal 
board 24. Specifically, the single phase jumper plug 40 has four motor 
operating modes to complete four unique circuit combinations. These four 
motor operating modes are determined by the position of the single phase 
jumper plug 40 relative to the connector socket 32. The function tang 48 
of the single phase jumper plug 40 may be releasably associated with any 
one of the four function slots 29 providing, as best seen in FIG. 3, 115 
volts and counter-clockwise motor rotation or 115 volts and clockwise 
motor rotation or, upon rotating the single phase jumper plug 40 
180.degree., 230 volts and clockwise motor rotation or 230 volts and 
counter-clockwise motor rotation. 
Referring now to FIG. 6, it may be observed that not all positions of the 
plug 40 have pins 43 extending from them. Rather, pins 43 extend from 
positions 1', 2', 3', 4', 5', 6', 8' and 11'. These are arranged so that 
the U-shaped receptacle is shorted between 3' and 6', 2' and 5', 1' and 4' 
and 8' and 11'. 
An electrical schematic showing all connections from the motor winding 
circuits to the fifteen receptacle connector socket 32 for a single phase, 
dual voltage and reversible rotation motor is illustrated in FIG. 9. One 
side of input voltage line 61 is connected to a protector 53. Protector 53 
also is connected to one side of a main winding part 50 and to receptacle 
R6 of connector socket 32. A start capacitor 54 is connected to an a 
connection point 60 and to a receptacle R11 of connector socket 32. The 
second side of main winding part 50 is connected to receptacles R1, R7 and 
R13 of connector socket 32. A first side of a second main winding part 51 
is connected to the point 60. Point 60 conventionally is one of the 
connection arms 25 located on terminal board 25. The second source lead 12 
also is connected to point 60. Point 60 in turn is connected to the 
receptacle R4 of connector socket 32. A second side of main winding part 
is connected to receptacles R9, R3, R5 and R10 of connector socket 32. A 
first side of an auxiliary winding 52 is connected to receptacles R8 of 
connector socket 32, while a second side of winding 52 to connected to 
receptacles R14 and R2 of connector socket 32, all as shown in FIG. 9. 
While single winding representations are shown in the drawings, those 
skilled in the art will recognize that the single windings shown may 
represent multiple pole windings in actual embodiments of the invention. 
As thus shown, the motor windings W are connected to all receptacles 38 of 
the socket 32 except receptacles R12 and R15, which are intentionally left 
open. As thus is configured, it is possible to use the single eight pin 
plug 40 with the jumpers 42 connected as described above to complete the 
circuits appearing in FIG. 10 for 115 volt and counter-clockwise rotation, 
FIG. 11 for 115 volt and clockwise rotation, FIG. 12 for 230 volt and 
clockwise rotation and FIG. 13 for 230 volt and counter-clockwise 
rotation. In FIG. 10, the single phase jumper plug 40 connects receptacles 
R1 and R4, R2 and R5, R3 and R6, and R8 and R11 of connector socket 32 to 
make the winding connections shown in that FIG. 10. In FIG. 11, the single 
phase jumper plug 40 connects receptacles 4 and 7, 5 and 8, 6 and 9, and 
11 and 14, to make the winding connections shown and provide 115 volt, 
counter-clockwise operation. In FIGS. 12 and 13, the single phase jumper 
plug 40 is turned 180 degrees to provide two additional operating modes 
for the motor. In FIG. 12, the single phase jumper plug 40 connects 
receptacles R5 and R8, R10 and R13, R11 and R14, and 12 and 15 to make the 
winding connections shown and provide 230 volt clockwise operation. In 
FIG. 13, the single phase jumper plug 40 joins receptacles R2 and R5, R7 
and R10, R8 and R11, and R9 and R12 to make the winding connections shown 
and provide 230 volt, counter-clockwise operation. The changes to motor 
operation can be made quickly easily and correctly by field personnel 
without fear of motor damage due to improper lead connections. 
FIGS. 14-19 illustrate the poly or three phase operation of the connection 
device of this invention. Like reference numerals are used for like parts. 
Where appropriate, the suffix "a" is used to distinguish from the single 
phase operation. 
In FIG. 14, the cover plate 16a has apertures 20a located above the handle 
44a of the three phase jumper plug 40a, configured with jumpers 42a (not 
shown) configuring to form pins 43A as shown in FIG. 16 for dual voltage, 
dual rotation operation of a three phase motor. The terminal board 24a has 
a layout accommodating two function operation. Thus, in FIG. 15, two 
function slots 29a, one for 230 volt and the second for 460 volt 
operation, are provided to assure proper orientation of the jumper plug 
40a by receiving the function tang 48a. FIG. 16 illustrates the three 
phase plug. As there shown, the pins 43A are arranged in three rows of 
four pins. As also shown, a row 100 is shorted to a row 102 while a row 
103 is shorted to corresponding ones of the pins 43A in the row 104. 
The poly phase windings are connected to the connector socket 32a so as to 
permit dual voltage operation of the motor. Thus, a first side of a 
winding 60 is connected to receptacle R7. A second side of winding 60 is 
connected to a source of voltage via lead L1 and to receptacle R1. A first 
side of a winding 61 is connected to receptacle R4 while a second side of 
the winding 61 is connected to protector P. 
A first side of a winding 63 is connected to a source of voltage via lead 
L2 and to receptacle R2. A second side of winding 63 is connected to 
receptacle R8. A first side of winding 62 is connected to receptacle R5, 
while its second side is connected to protector P. 
A first side of a winding 65 is connected to a source of voltage via lead 
L3 and to receptacle R3. A second side of winding 63 is connected to 
receptacle R9. A first side of winding 64 is connected to a receptacle R6 
while a second side is connected to protector P. Protector P, in turn, is 
connected to receptacles R12, R10 and R11. 
The jumper plug 40a can be inserted into the connector socket 32a to 
connect the three phase motor winding circuits in FIG. 17 by joining 
receptacles 38a in receptacle positions R1 and R4, R2 and R5, R3 and R6, 
R7 and R10, R8 and R11, and R9 and R12 to produce a parallel Y circuit for 
low voltage operation. The receptacle positions 13, 14 and 15 are 
intentionally left open. In the low voltage (230 volts) operating mode, 
the windings 60 and 61 are connected in parallel, as are the windings 62 
and 63, and the windings 64 and 65 (FIG. 17). Likewise, by moving jumper 
plug 40a down one row of receptacles in connector socket 32a, receptacle 
positions R4 and R7 are joined as are R5 and R8, R6 and R9, R10 and R13, 
R11 and R14, and R12 and R15. Since receptacle positions R13, R14 and R15 
are open, the motor circuit produced is a series Y winding arrangement for 
high voltage operation. In the high voltage (460 volts) operating mode, 
the windings 60 and 61 are connected in series, as are the windings 62 and 
63 and the windings 64 and 65, as shown in FIG. 17. Rotation may be 
reversed merely by interchanging one of the L1, L2 or L3 leads on the 
terminal board 24 itself. 
The terminal board 24 is preferably fabricated from 0.94 inch thick 
phenolic fiber board and has functional information imprinted adjacent to 
each function slot 29. The connector socket 32 is an AMP MAT-N-LOK 15 pin 
socket and the single phase jumper plug 40 and three phase jumper plug 40a 
are molded from suitable material such as Valox 420 SEO plastic material, 
with the function tang 48 molded as an integral part of the plug, in both 
cases. Jumpers 42 are made from electrically conductive material such as 
copper alloy, for example. 
In view of the above, it will be seen that the several objects and features 
of this invention are achieved and other advantageous results have been 
obtained. 
As various changes could be made in the above constructions without 
departing from the scope of the invention, it is intended that all matter 
contained in the above description or shown in the accompanying drawings 
shall be interpreted as illustrative and not in a limiting sense. For 
example, the design and location of the connector socket 32 may be altered 
in other embodiments of this invention. Likewise, the location of function 
tang 48 may be altered, if desired. Though described as being preferably 
mounted on the terminal board 24, other locations for the socket 32 may be 
utilized if desired. Likewise, the design of the receptacles 38 or the 
pins 43 may be altered in other embodiments of the invention. While 
certain materials are described as preferred, other materials may be 
substituted. These variations are merely illustrative.