US2831153A - Centrifugal switch mechanism - Google Patents

Description

' April 15, 1958 A. F. DEMING EI'AL CENTRIFUGAL swn ca mommzsu Filed Nov. 19, 1956 INVENTORS ANDREW F. osmm D. HOUK RICHARD 8W United States Patent 2,831,153 CENTRIFUGAL SWITCH MECHANISM Andrew F. Deming and Richard D. Honk, Alliance, Ghio, assignors to The Alliance Manufacturing Company, Division of Consolidated Electronics Industries Corporation, Wilmington, Del.

Application November 19, 1956, Serial No. 623,199

16 Claims. (Cl. 318-207) reversing switches attempted to combine the two func- Itions of switching from forward to reverse conditions and :also to hold closed temporarily contacts for the starting winding of an electric motor. Such prior art switches :were subject to several defects, however, in that they attempted to use rotary motion of the motor shaft to provide the reverse switching function and attempted to use an axial motion as imparted by a centrifugal force mechanism to give the starting function, with both of zthese functions being embodied in a single switch part.

'This single switch part then had to have both arcuate movement and axial movement, and-to be successful there had to be sufiicient arcuate friction to cause arcuate movement of the switch part, yet there had to be sufficiently low axial friction to permit axial movement by means of the centrifugal mechanism. This dual function was impossible of achievement to any degree of satisfaction because attempts to increase the arcuate friction also increased the axial friction, and the motor switch would either hang up in the open position, thus refusing to start,

.or would hang up in the closed position, thus burning out the starting windings of the motor.

Accordingly, an object of the present invention is to provide an improved reversing switch for an electric :motor.

Another object of the invention is to provide a dependable combined starting and reversing switch for an electric motor.

Another object of the invention is to provide a switch mechanism wherein one part has axial movement and :another part has arcuate movement, both parts actuating .contact means.

Another object of the invention is to provide a switch mechanism wherein rotatively movable means are separate from axially movable means so that the friction of each is independent and wherein the friction affecting the axially movable means is less than that affecting the rotatively movable means. i k

Another object of the invention is toprovide a switch mechanism wherein a part moves rotatively and another .part moves axially to lock and unlock the rotatively movable means. a

Another object of the invention is to provide a switch mechanism utilizinga plurality of contacts wherein the circuit is made and broken at only a single set of contacts so that this set of contacts needs to be high -quality Patented Apr. 15, 1958 to resist burning and pitting and the remaining contacts may be made of more economical material.

Another object of the invention is to provide a switch mechanism having a rotative part and an axially movable part, with one of these parts actuating first and second double-throw contacts and the other part locking and unlocking the first part.

Another object of the invention is to provide a switch having two separate switching functions, one of which is actuated by rotative friction and the other of which is actuated by centrifugal force means, with these two means of actuation being separate and independent.

Other objects and a fuller understanding of this invention may be had by referring to the following description and claims, taken in conjunction with the accompanying drawings, in which:

Figure 1 is a side elevation view of the switch mechanism according to the invention which for illustration is incorporated in an electric motor;

Figure 2 is an end elevation view of the switch mechanism removed from the motor of Figure 1 and schematically showing the wiring connections;

' Figure 3 is a sectional view on the line 3-3 of Fig ure 2; and

Figure 4 is a sectional view on the line 44 of Figure 2.

The invention pertains to a switch mechanism 11 which may take many forms but which in the preferred embodiment shown incorporates three main parts; namely, a stationary plate 12, a rotatively movable cam 13, and an axially movable :cam 14. The stationary plate 12 has first and second faces 16 and 17 and carries the contact means of the switch 11. The stationary plate 12 may be mounted at the mounting holes 18 in any suitable manner to the support, which in this case is the frame 19 of an electric motor 20. This motor 20 has a shaft 21 journalled in a bearing 22 carried by the frame 19, and the stationary plate 12 has an aperture 23 surrounding the shaft 21.

The rotatively movable cam 13 has a sleeve 27 journalled on the shaft 21, with the stationary plate 12 engaging this sleeve 27 as a form ofbearing so thatthe rotatively movable cam 13 is journalled between the 'stationary shaft 12 and the shaft 21. The stationary plate 12 has a sleeve portion 28 coaxial with the shaft 21 and extending from the second face 17. This sleeve portion 28 carries the axially movable cam 14 for axially sliding movements. A centrifugal force mechanism 29 is fixed to the shaft 21 and coacts with the axially movable cam 14 to provide axial movement thereto.

The contact means carried on the stationary plate 12 include a main contact 32 and a main leaf spring contact 33 having an end 34 fixed to the stationary plate 12 and carrying a movable contact 35 for cooperation with the main contact 32. The outboard end 36 of the leaf spring 33 extends into the path of movement of the axially movable cam 14 to be actuatable thereby. First and second fixed contacts 39 and 40 are mounted on the stationary plate 12 on one side of the main contact 32, and first and second leaf spring contacts 41 and 42 cooperate therewith. Third and fourth fixed contacts 43 and 44 are mounted on the stationary plate on the other side of the main contact 32, and third and fourth leaf spring contacts 45 and 46 cooperate therewith. Each of the leaf spring contacts 41, 42, 45, and 46 carries a cam follower 47 which is adapted to be actuated by the rotative- 1y movable cam 13. A conductive strap 49 interconnects the main contact 32 and the second and third fixed contacts 40 and 43. A conductive strap 50 interconnects the first and fourth fixed contacts 39 and 44 with an car 51 connected to the strap 50 for external electrical conneceam 14 to the right to its second limit position.

3 tion. All of the fixed contacts 32, 39, 40, 43, and 44 are on the second face of the stationary plate 12, which facilitates ease of manufacture.

The rotatively movable cam may be considered as an arcuately movable switch piece because limit pins 54 and 55 are engaged by a tail piece 56 to establish first and second arcuate or rotational limit positions. A first arcuate limit position is shown in Figure 2, and in this position the rotatively movable cam 13 has a cam face 58 which engages the cam followers 47 on the first and second leaf spring contacts 41 and 42 to open circuit the first and second sets of contacts. This is as shown in Figures 1 and 4. The second rotational limit position of the cam 13 would be when the other side of the tail piece 56 engages the limit pin 54, and in that position the cam face 58 would engage the cam followers 47 on the third and fourth leaf spring contacts 45 and 46 to open circuit the third and fourth sets of contacts. At this time the first and second sets of contacts would be closed by the resiliency of the first and second leaf spring contacts 41 and 42.

The axially movable cam 14 is generally cylindrical to slide along the axis or parallel to the axis of the shaft 21 by sliding on the sleeve portion 28. This axially movable cam 14 has a planar face 60 for cooperation with the centrifugal force mechanism and has an abutment surface 61 to abut the outboard end 36 of the main leaf spring contact 33. A lock pin 62 extends from this abutment surface 61 and is parallel to the axis 64 of the shaft 21. This lock pin extends through an aperture 65 in the stationary plate 12 and is adapted to extend into first and second locking apertures 66 and 67, respectively, in the rotatively movable cam 13. The lock pin 62 extends into the first locking aperture 66 when the rotatively movable cam 13 is in the first limit positon as shown in Figures 2 and 3, and this lock pin 62 may extend into the second locking aperture 67 when the cam 13 is in the second rotational limit position.

The axially movable cam 14 has first and second axial limit positions, with the first limit position being that shown in Figures 1 and 3, and with the second axial limit position being when the cam 14 is moved to the right against a lock ring 69. In this second axial limit position the lock pin 62 will still engage the aperture 65 but will not engage either locking aperture 66 or 67. A coil spring '73 surrounds a collar portion 72 of the axially movable cam 14 and acts between this cam 14 and the stationary plate 12 to urge the cam 14- to the right to the second limit position, shown in dot-dash lines in Figure 3.

weighted rollers 74 carried on arms 75 pivoted at'76 on a carrier 77 which rotates with the shaft 21. A spring 78 urges the arms 75 toward the shaft 21 but the action of centrifugal force, when the motor 20 is running at or near normal running speed, is enough to cause the rollers 74 and arms 75 to swing outwardly to the dotdash line position, as shown in Figure 1. moves the rollers 74 to the right as viewed in Figure l and permits the coil spring 71 to urge the axially movable When the shaft 21 and centrifugal force mechanism 29 is stationary as shown in full linesin Figures 1, the spring 78 overcomes the coil spring 71, thus urging the axially movable cam 14 to the left to the first limit position.

The switch mechanism 11 may be used for several purposes, but one specific use is shown schematically in Figure 2'wherein this switch mechanism 11 is connected to control 'energization to the motor 20. Single phase alternating current supply'liues 81 and 82 may be connectedthrough a switch S3 to the running winding 84 The centrifugal force mechanism includes This axially of the permanent-split capacitor type, or other suitable types known to the skilled in the art. The starting winding 85 has first and second terminals 86 and 87, with the first terminal 86 connected to the first and third leaf spring contacts 41 and 45 and with the second terminal 87 connected to the second and fourth leaf spring contacts 42 and The main leaf spring contact 33 is connected through the line switch 83 to the line 32.

Operation The rotatively movable cam 13 is rotatively or arcuately movable between the first limit position shown and a second limit position to provide forward and reverse energization to the motor 20. This is by selective actuation of the first and second sets of contacts 39-42 and the third and fourth sets of contacts 43-46. The axially movable cam 14 moves between the first axial limit position shown in full lines in Figure 3 and the second limit position shown dot-dash lines, with this cam 14 providing two separate functions. When this cam 14 is in the left-hand or first limit positon, the lock pin 62 engages either one or the other of the locking apertures 66 and 67 to prevent any rotative movement of the rotatively movable cam 13. Also, at this time the abutment surface 61 causes the main contacts 32 and 35 to close. This provides energization to the motor 20, assuming the switch 83 to be closed. Energization is, of course, supplied to the running winding 84, and the line 82 is connected through the main contacts 32 and 35 and through the third contacts 43 and 45 to the first terminal 86 of the starting winding 85. The other terminal 87 of the starting winding 85 is connected through the fourth contacts 44 and 46 and the car 51 to the line 81. This causes rotation of motor 20 in one direction, for example, the forward rotation. As the motor accelerates and comes up to a preset speed, the centrifugal force mechanism 29 is actuated so that the rollers 74 move to the dot-dash position shown in Figure 1, whereupon the coil spring 71 moves the axial cam 14 to the right to the second limit position, shown in dot dash in Figure 3, to first open circuit the main contacts 32 and 35, and subsequently to unlock the rotatively movable cam 13. The opening of the main contacts 32 and 35 completely de-cnergizes the starting winding 85 so that this starting winding is only energized during the short time of acceleration of the motor 20. The unlocking of the rotatively movable cam 13 by with drawal of the lock pin 62 permits arcuate movement of this cam 13. This arcuate movements is effected by friction between the shaft 21 and the sleeve 27. This friction quickly causes rotative movement of the rotatively movable cam 13 to the second limit position with the tail piece 56 against limit pin 54, but the opening of the third and fourth sets of contacts 43-46 and the closing of the first and second sets of contacts 3942 has no eifect because the main contacts 32 and 35 are already opened. The fact that the main contacts 32 and 35 are opened before opening of any of the first through fourth contacts means that only the main contacts 32 and 35 need be of high quality material to withstand the arcing so as to prevent pitting and burning. The first through fourth fixed contacts and the first through fourth leaf spring contacts may be made of low quality economical material since they do not make or break current flow in the circuit.

The lock pin 62 maintains the switch mechanism in the selected one of the forward and reverse, or double-throw, conditions so that vibration or jarring will not change the position of this switch mechanism. The motor continues to run in the forward direction until the switch 83 is opened to de-energize the running winding 84.

'Wh'en next the switch 83 is closed, the motor 20 is energized in the reverse direction because now the rotatively movable cam 13 is in the second arcuate limit position wherein the starting winding 86 is energized in a reverse condition from that previously established. The motor again accelerates, this time in the reverse direction, and as it accelerates, the centrifugal force mechanism opens up to move the axially movable cam to the right to the second limit position to first break the circuit to the starting winding 85 at the main contacts 32 and 35 and subsequently to unlock the rotatively movable cam 13 so that it returns to the first arcuate limit position shown in Figure 2,

Whenever the switch 83 is opened for either direction of rotation, the motor willde'celerate, and as it decelerates, the centrifugal force mechanism 29 will collapse, with the rollers 74 urging the axially movable cam 14 to the left to the first limit position to first lock the rotatively movable cam 13 in its selected position and to subsequently close the main contacts 32 and 35 so that the switch mechanism 11 will be ready for its next starting function.

The axially movable cam 14 slides on the sleeve portion 28 and has an inherent friction therewith which friction is separate from, and independent of, the friction from the shaft 21 to the sleeve 27 which is a part of the rotatively movable cam. This means that the friction between sleeve 27 and shaft 21 may be increased to a satisfactory operating point without affecting the axial friction between axially movable cam 14 and the sleeve portion 28. Therefore, the friction on this axially movable cam 14 may be made quite low and much less than the friction acting on the rotatively movable cam 13.

It will be noted that the rotative cam 13 actuates the contact means, and also the axial cam 14 actuates the contact means. In the embodiment shown, these are two separate switching functions, one providing a reversing switching function or double-throw switching function, and the other performing a starting switch function of momentary or short duration until the motor accelerates to near running speed. Also, of these two movable cams, one performs a double-throw switching function and the other performs a locking function to lock and unlock the other.

Although this invention has been described in its preferred form with a certain degree of particularity, it is understood that the present disclosure of the preferred form has been made only by way of example and that numerous changes in the details of construction and the combination and arrangement of parts may be resorted to without departing from the spirit and the scope of the invention as hereinafter claimed.

What is claimed is:

l. A switch mechanism having a rotatable shaft, comprising, contact means carried in said switch mechanism, rotatively movable means, axially movable means, first mounting means to mount said rotatively movable means for rotation between first and second rotational positions, second mounting means to mount said axially movable means for movement generally parallel to the axis of said shaft between first and second axial positions, friction means to actuate one of said movable means between said first and second positions and to actuate said contact means thereby, lock means coacting between said axially movable means and'said rotatively movable means to lock and unlock said one of said movable means upon the other of said movable means being in said first and second limit positions, respectively, and centrifugal force means separate from said friction means and acting from rotational movement of said shaft to actuate the other of said movable means and hence actuate said lock means.

2. A switch mechanism having a rotatable shaft, comprising, contact means, rotatively movable means, axially movable means, first mounting means to mount said rotatively movable means for rotation between first and second arcuate limits, second mounting means to mount said axially movable means for movement parallel to the axis of said shaft between first and second axial limits, means to actuate said contact means in accordance with the firstand second limit position of one of said movable means, means to actuate said contact means in accordance with the first and second limit positions of the other of said movable means, centrifugal force means, means for actuating said centrifugal force means from the rotation of said shaft to provide first and second conditions of said centrifugal force means in accordance with the stationary condition and at least one moving condition of said shaft, respectively, means for connecting said centrifugal force means to move said axially movable means between said first and second limit positions for said first and second conditions of said centrifugal force means, drive means coacting with said shaft and said rotatively movable means at said first mounting means to rotate said rotatively means between said first and second arcuate limits in accordance with the rotational direction of said shaft, and said second mounting means being separate from said first mounting means to be independent of said drive means.

3. A switch mechanism having a rotatable shaft, comprising, contact means, rotatively movable means, axially movable means, first mounting means to mount said rotatively movable means for rotation between first and second arcuate'limits, second mounting means to mount said axially movable means for movement parallel to the axis of said shaft between first and second axial limits, means to actuate said contact means in accordance with the first and second limit position of one of said movable means, lock means coacting between said axially movable means and said rotatively movable means to lock said one of said movable means upon the other of said movable means being in said first limit position, centrifugal force means, means for actuating said centrifugal force means from the rotation of said shaft to provide first and second conditions of said'centrifugal force means in accordance with the stationary condition and at least one moving condition of said shaft, respectively, means for connecting said centrifugal force means to move said axially movable means between said first and second limit positions for said first and second conditions of said centrifugal force means, drive means coacting with said shaft and said rotatively movable means at said first mounting means to rotate said rotatively movable means between said first and second arcuate limits in accordance with the rotational direction of said shaft, and said second mounting means'being separate from said first mounting means to be independent of said drive means.

4. A switch mechanism for an electric motor having a rotatable shaft, said switch mechanism, comprising, contact means carried in said switch mechanism, rotatively movable means, axially movable means, first mounting means coaxial with said shaft to mount said rotatively movable means for rotation between first and second arcuate limits, second mounting means coaxial with said shaft tomount said axially movable means for movement parallel to the axis of said shaft between first and second axial limits, means to connect said contact means to said motor, means to actuate said contact means in accordance with the first and second limit position of one of said movable means, means coacting between said axially movable means and said rotatively movable means upon the other of said movable means being in said first limit positions, centrifugal force means, means for actuating said centrifugal force means from the rotation of said shaft to provide first and second conditions of said centrifugal force means in accordance with the stationary condition and at least one running condition of said motor shaft, respectively, means for connecting said centrifugal force means to move said axially movable means between said first and second limit positions for said first and second conditions of said centrifugal force means, first friction means coacting with said shaft and said rotatively movable means at said first mounting means to rotate said rotatively movable means between said'first and second arcuate limits in accordance with the rotational 7 direction of said shaft, and said second mounting means being separate from said first mounting means to be independent of said first friction means.

5. A'starting and automatic reversing switch mechanism for an electric motor having a starting winding and a rotatable shaft, said switch mechanism, comprising, contact means including forward and reverse contacts, rotatively movable means, axially movable means, first mounting means coaxial with said shaft to mount said rotatively movable means for rotation between first and second arcuate limits, second mounting means coaxial with said shaft to mount said axially movable means for movement along the axis of said shaft between first and second axial limits, means to connect said forward and reverse contacts to said starting winding, means to selectively actuate said forward and reverse contacts to the closed circuit condition in accordance with the first and second limit position, respectively, of one of said movable means, means to actuate said contact means in accordance with movement of the other of said movable means, lock means coacting between said axially movable means and said rotatively movable means to lock and unlock said one of said movable means upon the other of said movable means being in said first and second limit positions, respectively, combined spring and centrifugal force means, means for actuating said centrifugal force means from the rotation of said shaft to provide first and second conditions of said combined spring and centrifugal force means in accordance with the stationary condition and at least one running condition of said motor shaft, respectively, means for connecting said combined spring and centrifugal force means to move said axially movable means between said first and second limit positions for said first and second conditions, respectively, of said combined spring and centrifugal force means, said first mounting means being separate from said second mounting means, first friction means coacting with said shaft and said rotatively movable means at said first mounting means to rotate said rotatively movable means between said first and second arcuate limits in accordance with the rotational direction of said shaft, and said second mounting means being independent of said first friction means and'having an inherent friction less than said first friction means.

6. A starting and automatic reversing switch mechanism for an electric motor having a starting winding and a rotatable shaft, said switch mechanism, comprising, contact means including a main contact and forward and reverse contacts, rotatively movable means, axially movable means, first mounting means coaxial with said shaft to mount said rotatively movable means for rotation between first and second arcuate limits, second mounting means coaxial with said shaft to mount said axially movable means for movement along the axis of said shaft be tween first and second axial limits, means to connect said forward and reverse contacts to said starting winding, means to selectively actuate said forward and reverse confacts to the closed circuit condition in accordance with the first and second limit position, respectively, of one of said movable means, lock means coacting between said axially movable means and said rotatively movable means to lock and unlock said one of said movable means upon the other of said movable means being in said first and second limit positions, respectively, means to selectively actuate said main contact in accordance with movement of the other of said movable means from one of said limits to the other thereof prior in time to the unlocking of said lock means, whereby the electrical circuit'to said motor is made and broken at said main Contact rather than at said forward and reverse contacts, combined spring and centrifugal force means, means foractuating said centrifugal force means from the rotation of said shaft to provide first and second conditions ofsa'id combined spring and centrifugal force means in'accordance With'the stationary condition and a running condition of Cir said motor shaft, respectively, means for connectin'g'said axially movable means and said combined spring and centrifugal force means to move said axially movable means between said first and second limit positions for said first and second conditions, respectively, of said combined spring and centrifugal force means, said first mounting means being separate from said second mounting means, firstfriction'means coacting with said shaft and said rotatively movable means at said first mounting m ns to rotate said rotatively movable means between said first and second arcuate limits in accordance with the rotational direction of said shaft, and said second mounting means being independent of said first friction means and having an inherent friction less than said first friction means.

7. A double-throw switch mechanism having first and second conditions and operable from an arcuately movable shaft, said switch mechanism, comprising, first and second contacts, rotative means, first frictionmeans coacting with said shaft and said rotative means to rotate same between first and second arcuate limits in accord ance with the rotational direction of said shaft, means to selectively actuate said first and second contacts in accordance with rotative positioning of said rotative means at said first and second arcuate limits, respectively, axial means separate from said rota'tive means and movable parallel to the axis of said shaft between first and second axial limits, entrifugal force means, means for actuating said centrifugal force means from the rotation of said shaft to provide first and second conditions of said centrifugal force means in accordance with the stationary condition and at least one moving condition of said shaft, means for connecting said centrifugal force means to move said axial means between said first and second limit positions for said first and second conditions of said centrifugal force means, mounting means to mount said axial means for said axial movement and inherently having friction which is independent of said first friction means, and means coacting between said axial and rotative means when said axial means is in said first limit position.

8. A double-throw switch mechanism having first and second conditions and operable from an arcuately movable shaft, said switch mechanism, comprising, contact means including first and second contacts, rotative means, first friction means coasting with said shaft and said rotative means to rotate :same between first and second arcuate limits in accordance with the rotational direction of said shaft, means to selectively actuate said first and second contacts in accordance with rotative positioning of said rotative means at said first and second arcuate limits, respectively, axial means separate from said rotative means and movable parallel to the axis of said shaft between first and second axial limits, centrifugal force means, means for actuating said centrifugal force means from the rotation of said shaft to provide first and second conditions of said centrifugal force means in ac cordance with the stationary condition and at least one moving condition of said shaft,'means for connecting said centrifugal force means to move said axial means between said first and second limit positions for said first and second conditions of said centrifugal force means, mounting means to mount said axial means for said axial movement and inherently having friction which is less than and independent of said first friction means, and means to actuate said contact means from said axial means.

9. An automatic reversing switch mechanism for an electric motor having a rotatable shaft, said switch mechanism, comprising, forward and reverse contacts, rotative means, first friction means coacting with said shaft and said rotative means to rotate same between first and second arcuate limits in accordance with the rotational direction ofsaid shaft, means to connect said forward and reverse contacts to said motor to govern the rotational direction thereof, means to selectively actuate said for- 9 r ward and reverse contacts in accordance with rotative positioning of said rotative means at said first and second arcuate limits, respectively, axially moving means separate from said rotative means and movable parallel to the axis of said shaft between first and second axial limits, lock means coacting between said axially moving means and said rotative means to rotativcly lock said rotative means upon said axially moving means being in said first limit position and said lock means adapted to free said rotative means for rotation when said axially moving means is in said second limit position, centrifugal force means, means for actuating said centrifugal force means from the rotation of said shaft to provide first and second conditionsof said centrifugal force means in accordance with the stationary condition and at least one rotating condition of said motor shaft, means connecting said axially movable means and said centrifugal force means tomove said axially moving means between said first and second limit positions for said first and second conditions of said centrifugal force means, and mounting means to mount said axially moving means for said axial movement and inherently having friction therein which is less than and independent of said first friction means.

10. An automatic reversing switch mechanism for an electric motor having a rotatable shaft, said switch mechanism, comprising, forward and reverse contacts, rotative means, first friction means coacting with said shaft and said rotative means to rotate same between first and second arcuate limits in accordance with the rotational direction of said shaft, means to connect said forward and reverse contacts to said motor to govern the rotational direction thereof, means to selectively actuate said forward and reverse contacts in accordance with rotative positioning of said rotative means at said first and second arcuate limits, respectively, axially moving means separate from said rotative means and movable parallel to the axis of said shaft between first and second axial limits, lock means coacting between said axially moving means and said rotative means to rotatively lock said rotative means upon said axially moving means being in said first limit position and said lock means adapted to free said rotative means for rotation when said axially moving means is in said second limit position, combined spring and centrifugal force means, means for actuating said centrifugal force means from the rotation of said shaft to provide first and second conditions of said combined spring and centrifugal force means in accordance with the stationary condition and at least one rotating condition of said motor shaft, means for establishing coaction between said axially movable means and said combined spring and centrifugal force means to move said axially moving means between said first and second limit positions for said first and second conditions of said combined spring and centrifugal force means, and mounting means to mount said axially moving means for said axial movement and inherently having friction therein which is less than and independent of said first friction means.

11. A starting and automatic reversing switch mechanism for an electric motor having a starting winding and a rotatable shaft, said switch mechanism, comprising, forward and reverse contacts, rotative means, first friction means enacting with said shaft and said rotative means to rotate same between first and second arcuate limits in accordance with the rotational direction of said shaft, means to connect said forward and reverse contacts to said starting winding, means to selectively actu ate said forward and reverse contacts to the closed circuit condition in accordance with rotative positioning of said rotative means at said first and second arcuate limits, respectively, axially moving means separate from said rotative means and movable parallel to the axis of said shaft between first and second axial limits, lock means coacting between said axially moving means and said rotative means to rotatively lock said rotative means upon said axially moving means being in said first limit 10 7 position and said lock means freeing said rotative means for rotation when said axially moving means is in said second limit position, combined spring and centrifugal force means, means for actuating said centrifugal force means from the rotation of said shaft to provide first and second conditions of said combined spring and centrifugal force means in accordance with stationary and normal running conditions of said motor, respectively, means for establishing coaction between said axially movable means and said combined spring and centrifugal force means to move said axially moving means between said first and second limit positions for said first and second conditions, respectively, of said combined spring and centrifugal force means, and second friction means in said switch mechanism independent of said first friction means and acting on the axial movement of said axially movable means.

12. A starting and automatic reversing switch mechanism for an electric motor having a starting winding and a rotatable shaft, said switch mechanism, comprising, contact means including a main contact and forward and reverse contacts, rotative means, first friction means coacting with said shaft and said rotative means to rotate same between first and second arcuate limits in accordance withthe rotational direction of said shaft, means to connect said forward and reverse contacts through said main contact to said starting winding, means to selectively actuate said forward and reverse contacts to the closed circuit condition, in accordance with rotative positioning of said rotative means at said first and second arcuate limits, respectively, axially moving means separate from said rotative means and movable parallel to the axis of said shaft between first and second axial limits, lock means coacting between said axially moving means and saidsrotative means to rotatively lock said rotative meansupon said axially moving means being in said first limit position and said lock means freeing said rotative means for rotation when said axially moving means is in said second limit position, combined spring and centrifugal force means means for actuating said centrifugal force means from the rotation of said shaft to provide first and second conditions of said combined spring and centrifugal force means in accordance with stationary and normal running conditions of said motor, respectively, means for, establishing coaction between said axially movable means and said combined spring and centrifugal force means to move said axially moving means between said first and second limit positions for said first and second conditions, respectively, of said combined spring and centrifugal force means, second friction means in said switch mechanism independent of said first friction means and acting on said axially movable means in axial movement thereof, and means to open said main con tact from said axially moving means in movement from said first limit to said second limit prior in time to the unlocking of said rotative means, whereby the electrical circuit is made and broken at said main contact rather than at said forward and reverse contacts.

13. v A switch mechanism having a rotatable shaft, comprising, a stationary plate, contact means carried on said stationary plate, an arcuately movable cam, friction means acting between said shaft and said cam to move same between first and second positions to actuate said contact means, an axially movable cam having first and second axial positions and cooperating to actuate said contact means, centrifugal force means operating from said shaft and having a stationary and a rotating condition with said stationary condition acting to urge said axially movable cam to said first position, and said rotating condition acting to urge said axially movable cam to said second position.

14. A starting and automatic reversing switch for a reversible motor having a rotatable shaft, said switch, comprising, a stationary plate, rotational selection contacts and a main contact connected to said motor and 11 carried on said stationary plate, an arcuately movable cam, friction means acting between said shaft and said cam to move same between first and second positions to alternately select actuation of said rotational selection contacts to provide alternate forward and reverse rotation of said motor, an axially movable actuator having first and second positions and cooperating with said arcuately movable cam, means for actuating said main contacts to a closed condition upon said actuator being in said first position, combined centrifugal and spring means having a stationary and a rotating condition with said stationary condition acting to urge said actuator to said first position, and said rotating condition acting to urge said actuator tosaid second position to first open said main contact and secondly to permit said friction means to rotate said arcuately movable cam whereby the circuit is made and broken at said main contact rather than at said rotational selection contacts.

15. A starting and automatic reversing switch for a reversible induction motor having a rotatable shaft, said switch, comprising, a stationary plate, rotational selection contacts and a main contact connected to said motor and carried on said stationary plate, an arcuately movable cam, friction means acting between said shaft and said cam to move same between first and second limit positions to alternately select actuation of said rotational selection contacts to provide alternate forward and reverse rotation of said motor, an axially movable locking cam having first and second limit positions and cooperating with said arcuately movable cam to lock same in a fixed position when said locking cam isin the first limit position, means for actuating said main contacts to a closed condition upon said locking cam being in said first limit position, first spring means urging said locking cam axially to said second limit position, combined centrifugal and second spring means driven from said shaft and having a stationary and a rotating condition with said stationary condition acting on said locking cam to overpower said first spring means and urge said locking cam to said first limit position, and said rotating condition permitting said first spring means to urge said locking cam to said second limit position Whereat said arcuately moving cam is free to rotate by said friction means to move same between said first and second limit positions in accordance with the rotational direction of said shaft, and movement of said locking cam from said first limit position to said second limit position first opening said main contact and secondly releasing the lock on said arcuately movable cam whereby the circuit is made and broken at said main contact rather than at said rotational selection contacts.

16. A starting and automatic reversing switch for a single split phase induction motor having a rotatable shaft and run and start windings, comprising, a stationary insulating switch plate having first and second faces and mounted at one end of said motor perpendicular to the shaft axis, a main fixed contact mounted on said stationary plate, a main leaf spring contact mounted on said stationary plate for cooperation with said main contact, first and second fixed contacts mounted on said stationary plate on one side of said main contact and third and fourth fixed contacts mounted on said stationary plate on the other said of said main contact, first,'second, third, and

fourth leaf spring contacts mounted on said stationary plate for cooperation with said first, second, third, and fourth contacts, respectively, means for connecting together said second, third, and main fixed contacts, means for connecting together said first and fourth fixed contacts, first conductor means for energizing said run winding from first and second terminals of an alternating current source, second conductor means for connecting said main leaf spring contact to said first terminal of said alternating current source, third conductor means for connecting said first and third leaf spring contacts to one end of said start winding, fourth conductorsmeans for connecting said second and fourth leaf spring contacts to the other end of said start winding, all said contacts mounted on said second face of said stationary plate, an

arcuately movable cam mounted on said shaft adjacent said first face of said stationary plate, means providing arcuate friction between said shaft and said cam to tend to rotate said ram in either of two directions according to the selected rotation of said shaft to first and second arcuate limit positions, a cam follower on each of said first and second leaf spring contacts extending through apertures in said stationary plate and being engaged by said arcuate cam in said first limit position to position said first and second left spring contacts out of engagement with said first and second fixed contacts, respectively, a cam follower on each of said third and fourth leaf spring contacts extending through apertures in said stationary plate and being engaged by said arcuate cam in said second limit position to position said third and fourth leaf spring contacts out of engagement with said third and fourth fixed contacts, respectively, a sleeve portion coaxial with said shaft and fixedly attached to said second face of said stationary plate, an axially moving lock cam surrounding and axially movable on said sleeve portion, an axially parallel aperture in said stationary plate, first and second locking apertures in said arcuate cam, an axially parallel pin carried by said locking cam and ex tending into said axially parallel aperture and being aligned with said first and second locking apertures upon said arcuate cam being in said first and second limit positions, respectively, a coil spring surrounding said sleeve portion and engaging said stationary plate second face andsaid lock cam to urge said lock cam away from said second face to a position whereat said pin engages neither of said locking apertures, centrifugal roller means carried on said shaft to cooperate with said lock cam to urge said lock cam axially toward said stationary plate with said pin extending into the selected one of said locking apertures when said shaft is stationary and upon rotation of said shaft at normal motor running speed to cease said urging to permit said coil spring to move said lock cam pin out of engagement with the selected locking aperture whereby said friction means arcuately moves said arcu- 1 ate cam from one limit position to the other to establish electrical connections for reversed rotation of said motor upon subsequent de-energization and re-energization.

References Cited in the file of this patent UNITED STATES PATENTS 2,701,855 Hammes Feb. 8, 1955

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