CA1242482A - Electric motors and method of manufacturing and operating same - Google Patents

Abstract

ELECTRIC MOTORS AND METHOD OF
MANUFACTURING AND OPERATING SAME
ABSTRACT OF THE DISCLOSURE
Motor has outboard switch compartment with components therein such as a capacitor, thermal protector, terminal board, motor circuit controlling switch assembly, a manual switch, a thermal plastic molded cover for the compartment fastened with axially directed screws, and an optional rain shroud positively positioned on the end shield. The switch assembly is designed to have accurate contact alignment which will be maintained over the life of the switch; a wiping action of the contacts; a high amount of contact travel in terms of percentage of switch actuator travel; protected contact blade arms; and a multiple heighth mounting feature which assures a more optimum location of the switch at final assembly with respect to the location of the switch operating mechanism. Switch arms are essentially parallel and have contacts positioned directly in line with the actuating arm line of a switch actuator and an operating mechanism. A switch arm support is a molded synthetic material housing which with a synthetic material molded switch actuator, provide precise and accurate preloading of the contact arms.
Non-stick actuator features are included. Also included is novel cover attaching approach and method, as well as switch assembly variable height mounting means and methods.

Description

~2~ .c ELECTRIC MOTORS AND METHOD OF
MANUFACTURING AND OPERATING SAME
BACKGROUND OF T~E INVENTION
This application is a division of canadian Application Serial No. 460,399 filed August 3, 1984.
The present inventions relate generally to electric motors, and, more particularly, to motors of the type wherein the energization of motor windings are controlled by switch mechanisms carried on the 10. motor which are actuated by axially movable switch actuating members; to mot.ors of the type that are to be exposed to moist.ure such as, for example, moisture conditions such as are encountered in outdoor environment.s to motors having what are known in the art as outboard switch or accessory device compartments; and to motors wherein it is desirable to provide a motor carried, externally accessible, switch for determining the operational mode or condition of such mot.or.
As will be understood by persons of ordinary skill in the art, single phase induction motors may be of many different types. Thus, there are resist.ance start, reactor start, capacitor start, permanent split capacitor, and capacitor start-capacitor run motors to name but a few. These different types of motors are characterized by different speed-torque ~.~

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characteristics, and of course are capable of being designed to have different theoretical maximum efflciencies. For many applications, and especially those where high starting torque is required, it is necessary for part of the windings in the motor to be designed and arranged to be an auxiliary or starting winding which is energized during initial excitation of the motor but which is de-energized as the motor comes up to a predetermined speed.
One particular reference work that describes motor characteristics and gives specific application information regarding different motors is the C. G. Veinott book entitled, "Fractional and Subfractional Horsepower Electric Motors", published by McGraw-Hill Book Company. For more information on this subject, the reader is directed, for example, to the third edition of the ~einott book which was copyrighted in 1970 by McGraw Hill.
In many applications, it is known to use a centrifugally or otherwise actuated switch as~embly or de-energizing the auxiliary or starting winding as the motor comes up to speed, and it is desirable to optimize such assemblies in terms of material content, assembly cost, and reliability. Some problems with some switch assembly designs that have been used heretofore, are believed to have been associated with a condition wherein the switch contacts have been "open" to their environment and subject to damage, or to lodging of foreign material on or about such contacts. Another continuing concern for all types of motor circuit controlling switches is the question of accessibility or serviceability of such switches as well as the cost associated with replacing such switches. It thus also would be desirable to provide a new and improved switch of non-complex design which is reliable in operation.

In switches of the type here contemplated, the long term maintenance of desired dimensional relationships of different switch parts and components is important, in order that desired switch action characteristics result, such as: good contact wiping action; cont.act self-cleaning action; controlled and limited lost motion relative travel of two or more switch parts; reliable switch action notwi.thstanding dimensional tolerance accumulations; colinear relationship of contacts and actuator line of travel;
weld breaking action; and near-parallel relationship of two contacts.
Accordingly, one of the objects of the present invention is to provide a new and improved switch which is simple in design, is capable of simple installation to provide good contact wiping action, self-cleaning characteristics, and which does not require adjustment over the.life of the swit.ch.
Another object of the invention is to provide a new and improved motor circuit. controlling switch having limited and controlled lost motion travel between the switch actuator and a switch contact itself, and improved control of the switching action.
Still another object of t.he present invention is to provide a new and improved switch wherein such switch may be readily mount.ed to provide an optimum switching action notwithstanding an accummulation of dimensional tolerances of other motor parts.
Other objects of the present invention are to provide a switch assembly wherein: switch contact faces can act in essentially a parallel condition, switch contacts are positioned in close pro~imity to : 35 the switch mechanism actuating line; spring return forces are applied on actuator driven mechanisms to limit upset reactions and switch sticking; switch contact alignment is positively established and maintained; wherein provisions are made for a weld breaking action during movement of the switch arms;
potential for sticking as a result of dirt and dust is reduced; and switch blades or arms and contacts are encased in order to provide protection Eor such elements.
In some applications, and especially those applications of motors used to drive pumps such as jet pumps or swimming pool pumps, circuit controlling switches are mounted outboard of one of the motor end frames to facilitate access thereto. In many pump applications, there may be concern regarding moisture, and it is desirable, e.g., in vertical applications, to provide rain shrouds to prevent rain from entering motor ventilation openings. It thus is another object of the present invention to provide a new and improved rain shroud arrangement which is a single piece which can be interfitted in a positive manner with other parts of a motor and yet wherein the rain shroud itself does not cause water to be trapped inside the outboard switch compartment. It is also an object of the invention to provide a new and improved cover for an outboard switch compartment, as well as means for ensuring drainage of moisture from within such compartment when the motor is positioned for horizontal shaft applications.
Also in some applications, one of which may be, e.g., a swimming pool pump application, it is desirable to have a manually selectable two speed motor. An object of the present invention is to provide a motor having an outboard switch compartment arranged to accommodate therein a manually selectable switch, a capacitor, a thermal protector, and a starting switch.

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SUMMARY OF THE INVENTION
In carrying out the above and other objects of the invention, in one preferred form t,hereof, I
provide a new and improved motor having an outboard switch compartment with a number of component.s arranged and disposed therein. Such components may incl.ude, for example, a starting capacitor, a thermal protector, a terminal board and motor circuit controlling switch assembly (e.g., a starting switch assembly), and a manually actuable switch. In a preferred form, a starting switch assembly is utilized which includes not only a switch assembly per se but also a terminal board and wherein t.he motor circuit controllin~ switch may be adapted to control either a single speed or two speed motor.
In accordance with other aspects of t.he invent.ion, I provide a t.hermal plastic molded cover for the outboard swit.ch compartment which preferably is fastened to the motor with axially directed mounting screws.
In accordance with still other Eeatures of the present invent.ion, I have provided a new and improved thermal plastic rain guard or shroud which may be assembled with a slip fit over an end shield and captured by the switch compartment cover.
Preferably, means are utilized to positively position the rain shroud on the end shield.
In accordance with still other inventive features, a new and improved switching mechanism is provided which is designed for a high level of quality and reliability by having accurate contact alignment which will be maintained over the life of the switch;
a wiping action of the contacts; a high amount oE
contact travel in terms of percentage of switch actuator travel; protected contact blade arms; and a multiple heighth mounting feature which assures a more optimum location of the switch at final assembly wit.h respect to the location of the switch operating mechanism.
Swit.ches embodying inventive features include essentially parallel, i..e., overlying switch arms having contacts thereon positioned directly in line with the actuating line of a switch actuator.
Moreover, at least two of such switch arms are carried by a switch arm support that preferably is in the form of a molded synthetic material housing which both protects such arms and maintains the parallal alignment of such arms. A synthetic material molded switch actuator and molded switch arm mounting structure provide precise and accurate preloading of the contact arms while at least one of the contact arms in turn cooperates t.o ensure that a molded switch actuator i9 urged toward a switch operating mechanism when the motor is stopped. Still other preferred features include means built into the switch assembly 2n to control the contact gap and provide weld breaking action, means for guiding an act.uator relative to the actuator support that also minimize potential for sticking and binding; and means for variable level or height mounting of a switch assembly.
The subject matter which I regard as my invention is set forth in the appended claims. The invention itself, however, together with further objects and advantages thereof may be better understood by referring to the following more det.ailed description taken in conjunction with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
Eigure 1 is a perspective view of a vertically arranged motor embodying the present invention in one preferred form thereof;
Figure 2 is a perspective view, with parts removed, of a horizontally disposed motor embodying other features of the present invention;
Figure 3 is a plan view of the motor shown in Figure 1, with parts removed therefrom;
Figure 4 is a cross-sectional view, with parts removed, looking in the direction of arrows 4-4 in Figure 3;
Figure 5 is a fragment of a view looking in the direction of arrows 5-5 in Figure 3;
Figure 6 is a view fragment looking in the direction of arrows 6-6 in Figure 3;
Figure 7 is a cross-sectional view, with parts removed and parts broken away, looking in the direction of arrows 7-7 in Figure 3;
Figure 8 is a view corresponding to Figure 7 except that it shows the compartment cover in place on the motor end frame;
Figure 9 is a plan view of the rain shroud shown in assembled relationship with the motor in Figure l;
Figure 10 is a cross-sectional view t.aken in the direction of arrows 10-10 in Figure 9;
Figure 11 is a cross-sectional view taken in the direction of arrows 11-11 in Figure 9;
Figure 12 is a cross-sectional view taken in the direction of arrows 12-12 in Figure 9;
Figure 13 is a det.ail showing t.he assembled relationship of the rain shroud of Figure 9, the compartment cover best shown in FigUre l; the motor shell, and the motor end shield which accommodates the rain shroud;
Figure 14 is an enlarged perspective view, with parts broken away, of part of the molded portion of the switch assemblies shown in Figures 2, 3, and 15;
Figure 15 is an end view looking into the end of the motor shown in Figure 14;
Figure 16 is a detailed view of the switch ?~

and terminal board shown in Figure 16;
Figure 17 is a view taken in the direction of arrows 17-17 in Figure 16;
Figure 18 is a view subst.antially similar to Figure 16 except that it illustrates a modified mounting position (i,.e., height) of the switch and terminal board with respect to mounting posts on the end frame;
Figure 19 is a view taken in the direction of arrows 19-19 in Figure 18;
Figure 20 is an enlarged view of a portion of the switch shown in Figures 16 and 17;
Figure 21 is a cross-sectional view taken in the direction of arrows 21-21 in Figure 20;
Figure 22 is a view of a portion of the structure shown in Figure 21 but with the switch arms and contact.s in a different position due to actuation of the switch plunger or actuator;
Figure 23 is an enlarged view of a portion of the switch mechanism shown in Figure 3;
Figure 24 is a cross-sectional view taken in the direction of arrows 24-24 in Figure 23;
Figure 25 is a view showing a portion of the mechanism of Figure 24 with the switch actuator in an intermediate actuating position;
Figure 26 is a view of the same structure shown in Figure 25 but wherein the switch actuator has travelled further so that two pairs of contact have been closed;
Figure 27 is a connection diagram for motors utilizing the switching arrangement shown in Figures 15 and 16;
Figure 28 is a connection diagram for motors using the switching arrangement shown in Figures 3 and 23;
~ Figure 29 is a view taken in the direction of arrows 29-29 in Figure 18 and providing a typical representation of the multiple mounting surface technique used in switch assemblies illustrated in Figures 16 and 23;
Figure 30 is a view talcen in the direction of arrows 30-30 in Figure 29;
Figure 31 is an enlarged view illustrating the mounting of a manually selectable switch in motors embodying the present invention;
Figure 32 is an enlarged perspective view of the switch actuator or plunger that forms part of the switch assemblies shown in Figures 15-28; and Figure 33 is a cross-sectional view through part of the motor cover showing a fastening scheme ernployed in preferred embodiments of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
With reference now to the drawings and with particular reference to Figures 1 and 2, the structure thereshown will be described with particular emphasis being placed upon the new and useful features and parts thereof.
Figure 1 illustrates a motor 40 arranged in what is co~monly referred to as a vertical shaft down position. As will be understood, the shaft 41 projecting from the motor will be coupled with a pump impeller or any other load that is to be driven by the ; motor. The motor 40 includes the shell 42 having upper vent holes 43 therein, an upper end frame which is hidden from view in Figure 1 by a rain or drip shroud 44, and a lower end frame 46. The lower end ; frame includes a number of internally threaded bosses 47 by means of which the motor 40 may be assembled with a pump assembly.
Also visible in Figure 1 is a novel switch compartment cover 48 which is fastened to the upper end frame by means of a palr of axially oriented screw ~ ~r~3?

fasteners 49, an electrical conduit fitting 51 threaded into a tapped hole 52 (see Figure 2) of the upper end frame, and a winding energization control switch boot 53 (best seen in Figure 31).
The rain shroud 44 is held in assembled relationship as part of the complete motor 40 by means of the cover 48, all as will be explained in more detail hereinafter. Thus, separate fastening ~eans are not required for holding the rain shroud on the motor. Moreover, for applications where a rain shroud is neither needed nor desired, the shroud can be dispensed with and in such an event, a motor arrangement as shown in Figure 2 will result where the rain shroud has in fact been dispensed with.
Referring now to Figure 2, the motor 54 thereshown is substantially the same as the motor 40 with the exception that it is a single speed rather than a two speed motor, it does not include a rain shroud, and a speed or energization selection switch 53 is not included. Because of this, the cover 56 is slightly different from the cover 48 in that no provision is made therein for a switch which ; would protrude therefrom. Such a switch may be provided when the motor is to be operable at two different speeds, or when it is desired to have a line disconnecting switch at the motor.
A manually operable switch, in the form of a toggle switch, is shown at 57 in Figures 3 and 31 where it will be seen that the switch is trapped by means of a pair of nuts 58 on a switch bracket 59 which in turn is fastened to the end frame 61 by means of a pair of self tapping screws 62. The bracket 59 is dimensioned so that when the cover 48 is placed on the motor 40, the recessed surface 63 will fit about exposed threads on the switch body. The rubber ; boot 53, having a threaded nut molded therein, then is ~ Z

threaded onto the switch to provide a waterproof arrangement..
With reference now to Figure 3, the aluminum die cast end frame 61 (as is the case also with the end frame 64 shown in Figure 2) is fastened t.o the opposite end frame by means of clamp bolts 66 which pass through holes 67 (see Figure 4) that are provided in reinforcing bosses 68 which are molded as unitary parts of the end frame.
Also revealed in Figure 3 is a two speed switch assembly generally denoted by the reference numeral 69 which is mounted to the end frame by means of three self tapping screws 71. The switch portion of the switch assembly 69 is illustrated in detail herein in Figures 23-26 and a detailed discussion of such assembly will be provided on conjunction with a discussion of such figures hereinbelow. The terminal block portion of the switch assembly 69, on the other hand, is essentially the same as the terminal block portion of t.he single speed switch assembly 72 illustrated in detail in Figures 16-19, 29, and 30.
Because of this, a descript.ion of the terminal block and mounting portion of the switch assembly 69 will be described in detail hereinafter in conjunct.ion with the terminal block portion of the switch assembly 72.
Figure 3 further reveals the conduit fitting mounting leg 73, grounding screw 74, centrifugal switch actuating or operating mechanism 76, a start capacitor 77, and a pair of cast bosses 78, and cast bosses 79, 81, and 82. The bosses 78 surround tapped holes 83 which accommodate axially directed screw fasteners that are used to secure the cover 48 to the end frame 61. The boss 79, on the other hand, has a hole therein in which a self tapping screw 86 may be fastened to hold a capacitor clamp 87 in place which of course holds the capacitor 77 in place on the end frame. Underlying the capacitor 77 and holding the capacitor in spaced relation to the end shield are four cast bosses or capacitor standoff legs 88, two of which may be best seen in Figure 2.
At this point, it should be noted that, although the end shields 61 and 64 are di~ferent due to the provision of holes which are used to mount a manually operable switch, the end shields are otherwise identical, and thus like reference numerals have been used to denote like parts and portions of such end frames. Furthermore, in order to simpli~y the drawings and avoid confusion, lead wires and jumper leads have not been shown in any of the views.
However, persons skilled in the art will understand that lead wires 91 and appropriate jumper wires interconnect the capacitor 77, terminals on the terminal block portion of the switch assembly, and thermal protectors, such as the protector 92 (see Figure 2) - assuming such a protector is provided.
Thus such wires are appropriately interconnected before the cover 48 or cover 46 is placed on the motor. The appropriate connection of such wires and jumpers will be apparent from Figures 27 and 28 herein, and will be described hereinbelow in conjunction with a discussion of Figure 27 and Figure 28 wiring diagrams.
Continuing now with a description of Figure 3, it will be noted t-hat the boss 81 is provided with a centrally located hole while the boss 82 is provided with a centrally located pin 80 projecting upwardly therefrom (as viewed in Figure 3). The use and function of the bosses 81 and 82 in conjunction with mounting the thermal protector 92 of Figure 2 will be best appreciated by also considering Figure 15. Thus, one ear of a protector 92 is caught on pin 80, while the other ear of the protector is fastened to boss 81 by means of a self-tapping screw which is threaded into the hole 85 which is cast in the boss 81. By this means, the protector 92 may be positively mounted quickly and yet with a single mounting screw.
Considering together Figures 3-8 and Figures 9-13, the interrelationship of the shroud 44, end shield 61, cover 48, and motor shell 42 will be described in detail. With reference first to Figure 13, it will be understood that the end shield 61 includes a rabbet surface 93 along which the cover 48 fits. Also formed in the end shield are a number of notches generally denoted by the reference numeral 94 which accommodate tabs 96 (see Figure 9) formed on the shroud 44. ThUS, in order to assemble the shroud with the motor, the shroud is slipped along the rabbet surface of the end shield 61 so that the tabs 96 thereon are received in the notches 94.
Subsequent assembly of the plastic cover 48 traps and holds the shroud 44 in place.
It will be seen from Figure 9 that four tabs 96 are provided cn the shroud 44. However, the number of tabs provided is not critical, so long as a sufficient number are provided to securely hold the shroud in place and prevent it from being inadvertently separated or torn from a motor to which it is attached.
Preferably, the shroud is molded from any suitable engineering plastic material. In actual reductions to practice of the invention, NorylR
HS 2000 phenylene oxide resin purchased from the General Electric Company was used for molding the shroud 44.
Figure 10 represents a ~typical"
cross-section of the shroud 44. However, in order to provide added strength and rigidity to the shroud, a :

numher of ribs 97 (see Figure 12) are molded ir~to the shroud at a number or spaced apart locations. It also will be noted that two notches are provided in the shroud, the first one being generally identified at 98 to provide a clearance for the conduit leg portion of the end shield, and a second notch 99 (see Figure 11) is provided to accommodate an oil filler tube plug 101 carried by the end frame (see Figures 2 and 3).
Figures 4 and 5 reveal that the notches 94 are relatively small. For example, suitable results have been obtained when the notches were approximately 0.375 inches wide (measured across Figure 5) and about 0.060 inches deep (measured across Figure 4), An additional notch 102 will also be noted in the rabbet surface 93 (see Figures 3 and 6). The notch 102 is wider than the notches 94 and has been made, in actual reductions to practice, to be approximately 0.500 inches wide (across Figure 6) and approximately 0.035 inches deep. Moreover, this notch is located as shown in Figures 7 and ~ so that when a cover 48 or 56 is positioned on the end frame, a labyrinth drain passage 103 will be defined between the machined surface of the end shield and the switch compartment cover. This labyrinth drain passage is of particular value and use for horizontal shaft applications. In such applications, the motor is relatively positioned as shown for example in Figure 3 ; with the oil well filler cap 101 at the top of the motor and the drain notch 102 located at the bottom of the motor. With this arrangement/ any moisture that might condense or otherwise occur inside the switch compartmen~ will be able to readily drain out of the motor and yet the passageway will be sufficiently small to inhibit entry of insects.
The covers 48 and 56 preferably are molded ' : ~

plastic for reasons of simplicity, economy, corrosion resistance, general durability, and electrical isolation. Although substantially any desired engineerin~ plastic material may be used, ~e*e~
embodiment.s have utilized NorylR HS2000 ~re~ef~e t.hermoplastic material purchased from General Elect.ric Company in making the covers 48 and 56.
With reference now to Figures 15-19, mounting of the switch assemblies 72 and 69 will be explained. It will be noted from Figures 17 and 19 that the die cast aluminum and frames have two mounting posts 104, 106 cast therein as well as a standoff post 105. AS will be best appreciated from a review of Figures 18, 29, 17, and 19, the terminal board portion of the switch assembly 72 is provided with a multiple mounting surface design and thus mounting surfaces 107 or 108 may be positioned on top of the mounting posts 104, 106, and post 105. In the case of Figure 17, mounting surfaces 107 are resting on the top of posts 104 and standoff. On the other hand, in the case of Figure 19, mounting surfaces 108 are resting on the top of the posts and standoff.
With an arrangement such has gthh~at illustrat.ed, it is possible to vary the ~ of the switch assembly above the top of the end frame as viewed in Figures 17 and 19. This is desirable for reasons that are explained hereinbelow. For the moment however, it is sufficient to note that assembly of a switch assembly 69 or 72 with an end frame can be readily accomplished with the assembly at different predetermined heighths above the end shield in different motors simply by choosing t.o use mounting holes 110 (in which case surfaces 108 will rest upon end shield supporting surfaces) or by using mounting holes 111 (in which case surfaces 107 will rest upon end shield supporting surfaces).

The provision of an elongated slot 109 facilitates assembly, and whereas relatively short screws 71 are shown fast.ening the switch assemblies to the mounting post.s 104, 106, a relatively longer screw 100 is threaded into the end frame.
The variable level or height mounting just described may be accomplished to vary the height of the switch assembly 69 or 72, above the end frame without having any effect on the interaction between the switch operating mechanism and the switch assemblies 69, 72. The reason for this is that the holes 110, 111 are located along an arc of a circle having its center at the centers of the switch contacts which are essentially co-incident with the point 113 along which actuating forces are applied to the switch assembly. Similarly, t.he slot 109 has its center located along a circle that is concentric with the arc defined by the centers of holes 110 and 111.
Of course, the mounting posts or bosses 104, 106, and ; 20 the holes therein lie along an arc congruent with the arc that locat.es the centers of holes 110 and 111.
While two discret.e steps have been illustrated such that mounting surfaces 107, 108 result, it should be understood that three or more surfaces could be provided to provide either a greater overall range of mounting heighth adjustments or n finer n graduated adjustments. Moreover, while discrete steps have been shown and are preferred for providing variable heighth mounting surfaces, it should be understood that one could provide a smooth inclined plane mounting surfaces, it should be understood that one could provide a smooth inclined plane mounting surface (along with slots rather than discrete holes 110, 111) so that infinitely variable mounting heighths could be provided within the range \~

of heighths afforded by the two ends of such inclined plane mounting surfaces.
Before leaving Figures 16-19, it is further noted that the various terminal 116 and line terminals Ll and L2 are formed from conventional electrical brass material. on the other hand, the molded portions of the switch assembly and terminal board which will now be described in even more detail, are preferably formed from any suitable engineering plastic. In preferred forms, the switch assemblies illustrated and described herein have been formed from ValoxR 420 thermoplastic material purchased from the General Electric Company.
The molded portions of the switch assemblies and terminal boards 69, 72 are virtually identical.
Moreover, all of the parts utilized in the switch assembly 72 (now to be described in detail) are also present in the switch assembly 69 except for the fact ; that one o~ the switch arms in the switch assembly 69 is elongated as compared to its corresponding arm in the assembly 72.
It will be appreciated from a review of Figures 16 and 17, that the switch assembly 72 includes a terminal board portion which includes the mounting surfaces previously described, an electrical isolation wall 117 separating the terminals Ll and L2, and a reinforcing and protecting wall 118. Also included is a switch arm mounting section which is best viewed in the upper portion of Figure 16 and which portion further includes a switch actuator retaining means. The arrangement of these means will be better appreciated by referrring to Figures 20-22 wherein 119 generally denotes the switch arm supporting section and the reference numeral 121 is used to denote a bore defining distal portion which functions as an actuator retainer means and is 4~

illustrated in the form of a barrel.
Comparing Figures 20 and 21 for a moment, it will be seen that the supporting section 119 includes a channel defined between a pair of walls 122 and a floor 123. Moreover, disposed within such channel is a switch arm 124 which is fastened to the floor of the channel by means of a rivet 126. The end of arm 124 is folded back upon itself as illustrated, and the extending double thickness portion thereof forms a spade terminal 116 for connection to a female connector. As will be seen from Figure 21 the arm 124 carries a switch contact 127. Overlying the switch arm 124 and within at least part of the previously mentioned channel is a second switch arm 128 which carries a contact 129 at one location and which is folded upon itself to form a spade terminal 116, and fastened to the switch arm supporting section by a rivet 131. Since the connection of the switch arms, rivets, and molded substrates to one another by means of a rivet approach is known in the art, further discussion of such connections i5 not presented herein.
A perspective detail of the barrel 121 is presented in Figure 14 and it will be noted that the barrel includes front and rear slots 132, 133. With the switch arms shown in Figures 20-22, it will be appreciated that both of these arms project along the slot 132. Disposed within the barrel 121 is an acutator 134 which is best shown in Figure 32. The actuator 134 includes front and rear slots 136, 137 respectively, two upper flanges 138, and a force transmitting centrally disposed actuating rib or switch arm driver 139.
As best revealed in Figure 22, the actuator serves as a plunger having a relatively thick in cross-section (for wear purposes) bottom reaction wall that coacts with a switch mechanism, and side wall portions that are somewhat less thick in cross-section. As will be appreciat.ed from ~igures 20-22, the molded actuator and switch arm support jointly establish a maximum open contact. gap between the cont.acts 127, 129.
~ hen assembling the swit.ch assembly 72, an actuator 134 is disposed in the barrel 121 and slots 136, 137 (of the actuator) are aligned with the slots 132, 133 of the barrel 121. Thereafter, the cont.act and switch blade 124 are positioned in the channel defined by walls 122 and the switch arm 124 is permanently secured to the floor 123 with the rivet 126. When this is accomplished, the tension on the normally flat switch arm 124 holds the actuator 134 in place in the barrel 121.
~ ith reference to Figure 21, it will be noted that the difference in height. between the floor 124 and the t.op edge or surface 141 of t.he rib 139 will determine the amount of preload that is placed upon the switch arm 124. This preferably is considered since the switch arm 124 provides the restoring force t.o the actuator during swit.ch operation. After the actuator, swit.ch arm 124 and rivet 126 have all been assembled with the switch supporting section 119, the second or upper switch arm 128 is positioned along the slots 132, 133 of the barrel 121 and rivet 131 is used to attach the upper switch arm 128 to the switch arm supporting section 119. An abutment surface 117 locates the free end of arm 128 so as to preload this arm. The amount of such preload is determined as will be understood, by the mold cavity dimensions which determine the relative locations of surface 147 and the surface 130.
: It will be noted that rib guides 142, which : 35 act as spacers, are molded to project from the axially ~ ext.ending interior surface of barrel 121. The outer surface of actuator 134 rides along these ribs and the space thus provided between the outer surface of actuator 134 and mos~ of the interior walls of barrel 121 helps assure that dust, dirt, or other debris will not cause sticking of the plunger or act.uator 134 within barrel 121 and thus disturb reliable and consistent switch operation When the motor 54 (see Figure 2) is not running, the convent.ional centrifugal mechanism 76 ~see Figure 15) will be positioned so that the actuating tongue 143 thereof (see Figure 22) biases the actuator 134 upwardly as best shown in Figure 22.
In this condit.ion, the contact.s 127 and 129 are engaged with one another and power thus would be supplied to an auxiliary or starting winding when it is applied across line terminals Ll and L2 of the swit.ch assembly 72. It will be not.ed that when the switch arms 128, 124 are in the deflected positions thereof shown in Figure 2, there is a force exerted

2~ from both of such arms downwardly against the actuator rib 139. Moreover, it will be noted that. when t.he switch arm 12~ is in the position thereof illustrated in Figure 22, a dist.al portion 146 thereof is spaced from a blade stopping surface 147 that is formed as part of the barrel 121. Then, when t.he motor 54 is energized, as it comes up to speed, the centrifugal ; mechanism 76 will, with a snap action, pull the tongue 143 downwardly in the direction of arrow 148 ; (see Figure 22) a distance sufficient that actuator 134 will not contact tongue 143 even when the flange 138 of the actuat.or is resting on t.he upper surface of the barrel 121.
During motor operation, as the tongue 143 (see Figure 22) snaps downwardly, the switch arms 124 and 128 immediately snap the actuator 134 downwardly.
;~ However, as the actuat.or 134 and switch arms 124, 128 are moving, portion 146 of switch arm 128 impacts the switch arm stopping surface 147 and the contact 127 carried by switch arm 124 thereupon separates from the contact 129 so that they attain their relative positions thereof as viewed in Figure 21.
It is desirable that plunger 134 and contact 127 travel as far as possible during a switch breaking action since the tension or spring force tending to aid breaking is a function of and proportional to the amount of deflection of arm 124.
Such deflection, in turn, is a function of and proportional to the amount of travel of plunger 134.
It will be appreciated that t.ongue 143 undergoes only a finite amount of travel for any given switch operating mechanism. However, wit.h switches designed as shown herein, maximum utilization of the travel of the switch operating mechanism is attained. ThUS, the travel of plunger 134 can be, if desired, 100% of the travel of tongue 143. This desirable result occurs because the movements of contacts 127, 129, plunger 134, and tongue 143 are essentially collinear.
With reference now to the connection diagram illustrated in Figure 27, the auxiliary winding 149 and main windings 151, 152 of motor 42 are normally not energiæed when power is not supplied to line terminals Ll and L2. However, at that instant in time, switch arms 128 and 124 of the switch assembly 72 are positioned so that the contacts thereof re closed. Thus, as soon as power is supplied to line t.erminals Ll and L2, power will be supplied to the auxiliary winding 149 through capacitor 77 and to both main windings 151, 152. Subsequently, when power is supplied to line terminals Ll, L2, the motor 54 : will start, come up to speed, and the centrifugal switch actuating mechanism will cause the actuator 134 to move so that the contacts carried on contact arms 124, 128 will separate, thus breaking the supply of power to the auxiliary winding 149. However, main winding sections 151, 152 will continue to receive power through the thermal protector 92 and the mot.or will continue to run. Later, when the motor is de-energized, the centrifugal mechanism will reset and the tongue 143 thereof will once again close the switch in switch assembly 72.
It should be understood that the capacitor 77 has been shown in the wiring diagram of Figure 27 and in other views in the drawings herein for purposes of illustration. However, it should be understood that the switch assembly 72 and switch assembly 96 may be used with types of motors that do not utilize start capacitors such as, for example, resistance split phase motors.
With reference now to Figures 23-26, it is noted that the molded port.ions of the switch assembly 69 there shown are identical t.o the molded ' 20 portions of the switch assembly 72 shown in Figures 20-22 and the relative movement and operation of such parts are also identical. ~lowever, in the switch assembly 69, the lower or first switch are 153 is no longer than the switch arm 124 of switch assembly 72. Moreover, the lower switch arm 153 carries not only a first contact 127 (which is arranged to engage contact 129 on switch arm 128) but lower switch arm 153 also carries a second contact 154. The extended portion of switch arm 153 passes along the notches or slots 137 and 133 previously described. Thus, as was the case also with the switch arms in the switch assembly 72, the parallel alignment of the switch arms 153 and 128 in the switch assembly 69 are maintained by means of the channel established by the walls 122 as well as due to the fact that the switch arms pass along and are -confined by the notches 136, 137 of the actuator 134.
The switch assembly 69 further differs from the swit.ch assembly 72 in that a bifurcated third switch arm structure 156, carrying a contact 157 is provided. The two legs of switch arm 156 straddle the other t.wo arms and are attached to the switch arm supporting section 119 by means of rivet.s 158 which pass through the holes 159 in the supporting section 119. The rivets 158 may also fasten a terminal tnot visible in Figure 23) to the supporting section for connection to a lead wire. Alternately, such wire may be welded or soldered directly to the end of the arm.
Attention is now d.irected to Figures 20 and 32 and the abutments posts 159 that are molded as part of the barrel 121. ~hese abutment.s posts or ears serve as stops for the switch arm 156 and limit.
downward travel of swit.ch arm 156 when the actuator 134 moves downwardly to the "open switch~
; 20 position thereof. Operation of the switch assembly 69, upon movement of the switch mechanism tongue 143 (see Figure 26) is the same as described in conjunction with the operation oE switch assembly 72.
Thus~ with reference first to ~igure 26, prior to the time the motor 40 is energized, both pairs of contacts 127, 129 and 154, 157 are closed. However, when the motor is energized and as it comes up to speed, the mechanism tongue 143 snaps downwardly in - the direction of arrow 148 as viewed in Figure 26, with the result that the actuator 134 snaps through the position shown in Figure 25 to the open switch position shown in Figure 24. With the arragnement illustrated in Figures 23-26, the switch arm 156 cont.acts the abutment post 159 so that cont.acts 154 and 154 separate from one another with a weld breaking action and thereupon the dist.al or end portion 146 of the contact arm 128 contacts the blade stopping surface 147 of the barrel 121 whereupon further movement of the switch arm 128 is arrested and contacts 127 and 129 separate wit.h a weld breaking action. This same action also occurs with the structure shown in Figures 20-22.
With reference now to Figure 28, a connection diagram for the switch assembly 69 in conjunction with motor 40 will be described. In this case, the motor 40 is a two speed motor capable of operation either at two pole speed (3450 rpm) or four pole speed (1725 rpm). In Figure 28, the two pole start winding 161 is connected to the switch arm 156 while the two pole main winding 162 is connected to the switch arm 128, whereas one side of the four pole main winding 163 is connected to lowermost, first switch arm 153. The other side of all three windings 161, 162, and 163 are connected through a thermal protector, embedded in the winding end turns, t.o line terminal L2 and thus to one side of the line when line power is supplied to terminal Ll and L2.
The four pole main winding 163 (which is connected to the switch arm 153) is also connected, through a line 16~, to the low speed terminal of the toggle switch 57. The high speed terminal of the ` toggle switch 57 on the other hand is connect.ed to the same bald terminal as the end of the two pole main winding 162 - i.e., the terminal connected to switch arm 128. For high speed operation, the toggle switch will be in the solid line position thereof illustrated in Figure 28. ThUs, when power is supplied to the line, line Ll is connected through the movable contactor of the toggle switch 57 to the contact blade 128. At this instant in time, two pairs of contacts of the switch assembly 69 are closed as shown in Figure 26. Thus, power will be supplied at that instant to all three of the windings 161, 162, and 163. However, as the motor comes up to speed bot.h contact pairs open as represented in Figure 24 with the result that neither the two pole auxiliary winding nor the four pole main winding are supplied power Erom the switch arm 128. Thus, the motor 40 will have only the two pole main winding 162 thereof energized and it will operate at high speed.
When the toggle switch 57 is switched to the low speed configuration thereof as represented by dashed lines in Figure 28, power is supplied to line terminal Ll and thence through line 164 to the four pole main winding 163 as well as to the switch arm 153.. Since the condition of the switch assembly 69 at starting is as shown in Figure 26, power thus will be supplied from line Ll through the switch arm 153 and contact pairs shown in Figure 26 through the switch arms 128 and 156 to both the two pole auxiliary winding and the two pole main winding.
Thus, for low speed operation the motor will start as a t.wo pole high speed motor. However, as the motor comes up to speed, the cont.act pairs separate and the switch assembly 69 is in the confi.guration as illustrated in Figure 24. At this time the t.hree 25 switch arms 128, 153, and 156 are electrically isolated from one anot.her so that the two pole auxiliary winding and two pole main winding are no longer energized. ThUs, the motor 40 will continue to run as a four pole, low speed motor.
With reference now to Figure 33, the mode of attaching covers 48 and 56 to the motors 40 and 54 will be described. It is believed that, heretofore, covers have been made of metallic material and fastened with radially directed screws. The arrangements shown herein, however, utilize axially directed screws which is more convenient in the field. Moreover, enlarged posts 201 resist the collapsing force resulting from tightening the screws 49. AS will be seen from Figure 33, provision is made to prevent the cover from being cracked or otherwise damaged by screw 49. ThUs, the tapped hole 202 in the end frame is dimensioned so that screw 49 will bottom out therein. The screw 49 and cover 4B are in turn dimensioned so that the head of the screw and common steel washer 204 thereunder, when considered alone, would not apply any compressive force on the cover even when the screw is bottomed in hole 202. However, limited, non-damaging compressive force, coupled with a waster selaing effect is provided by a compression washer 206 trapped between 15 the steel washer 204 and cover 48, any suitable compression washer or elastomeric material may be used, and in an actual reduction to practice of ths invention, 50 durometer rubber having a nominal ; uncompressed thickness of 0.100 of an inch was used.
20 The dimensions of the hole 202, cover 48, screw 49, and washer 204 were such that the washer 206 was compressed to a thickness of about 0.045 of an inch;
with the screw 49 being dimensioned to a tolerance of plus or minus 0.010 of an inch.
In this manner, the plastic covers are protected from damage caused by overtightening of screws 48 and a water repelling seal about the screws is provided by a single means - i.e., the compression washer.
Study of Figure 33 will also revel detents 209 molded in the internal diameter of hole 202. When the screw 49 is placed in hole 202, it can be threaded past detents 2090 However, when the cover 48 is removed in the field, the detents prevent screws 48 from falling out of the cover.
It should now be understood that I have B~

described and shown herein numerous preferred embodiments of new and novel motor constructions and operating techniques. Moreover, new and improved methods of assembling and adjusting switch assemblies have been described as well as new and improved methods of assembling novel switch assembly components.
Accordingly, while I have now shown and described preferred and alternate forms of motors and assemblies thereof, as well as methods pertaining thereto, the disclosure contained herein should be construed as being exemplary, and the invention itself should be limited only by the scope of the claims that are appended hereto and that form part of this disclosure.

Claims (5)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. In an electric motor having a motor shell, at least one end frame, a cover attached to the at least one end frame and defining an outboard switch compartment therebetween, and including a capacitor, thermal protector, switch assembly, and terminal board in said outboard compartment, the improvement wherein the motor further comprises a manually operable switch disposed within said outboard compartment and said cover is contoured to accommodate said capacitor and switch assembly while also accommodating the manually accessible actuator of the manual switch without enlarging the overall length profile of the motor.

2. In an electric motor having a motor shell, at least one end frame, a cover attached to the at least one end frame and defining an outboard switch compartment therebetween, and including a capacitor, thermal protector, switch assembly, and terminal board in said outboard comparatment, the improvement wherein the cover includes at least two bosses that extend axially therein and have screw accommodating passages therein; wherein screw fasteners are disposed in said passages; and wherein the walls of the screw accommodating passages include means for preventing inadvertent removal of the screw fasteners therefrom.

3. In an electric motor having a motor shell, at least one end frame, a cover attached to the at least one end frame and defining an outboard switch compartment therebetween, and including a capacitor, thermal protector, switch assembly, and terminal board in said outboard compartment, the improvement comprising: said end frame having a rabbet surface with at least one notch formed therein, said cover fitting on the rabbet surface and closing at least a portion of the at least one notch so that labyrinth drain passage is defined by he walls of the notch and the cover.

4. In an electric motor having a motor shell, at least one end frame, a cover attached to the at least one end frame and defining an outboard switch compartment therebetween, and including a capacitor, thermal protector, switch assembly, and terminal board in said outboard compartment, the improvement wherein said end frame having a rabbet surface extending around the circumference thereof and having a plurality of notches formed in said rabbet surface; and wherein the motor further includes a rain shroud positioned about the end frame and having tabs thereof disposed in a plurality of said notches, and wherein said cover interfits with said rabbet surface and traps the tabs of said rain shroud in said slots whereby the rain shroud is held fast to the motor by the cover.

5. A method of manufacturing a motor having an outboard switch compartment established at least in part by an end frame, and having an axially moveable switch operating mechanism and a switch assembly disposed with said compartment, the method comprising:
positioning the switch assembly in overlying relationship with respect to the operating mechanism, determining a preferred mounting height for the switch assembly with respect to the operating mechanism and end frame from at least two different possible mounting hights and thereafter fastening this switch assembly in place in the compartment at the preferred mounting height.