US2842626A - Switch mechanism - Google Patents

Description

y 1958 w. P. GALLAGHER ET AL 2,842,626

SWITCH MECHANISM Filed Nov. 25, 1953 3 Sheets-Sheet 1 lillllllll'llillHllHi HHIW'IIIHHIIIIII 2am INVENTORS.

July 8, 1 58 w. P. GALLAGHER ET AL 42, 2

} SWITCH MECHANISM Filed Nov. 23. 1953 3 SheecsSheet 2 INVENTOR-S'.

IWIHIHH IH HI 7 175M- 88 Mgw J ly 8, 1958 w. P. GALLAGHER ET AL 2,842,626

SWITCH MECHANISM Filed Nov. 25. 1953 5 Sheets-Sheet 3 INVENTORS. Q

United States Patent SWITCH MECHANISM William P. Gallagher, Anthony D. Stolle, and Robert B. Ellis, Chicago, Ill., assignors to International Register Company, Chicago, 111., a corporation of Illinois Application November 23, 1953, Serial No. 393,802 15 Claims. (Cl. 200-38) Our present invention relates generally to switch mechanisms, and, more specifically, is directed to time switch mechanisms.

Time switch mechanisms of the general character to which our present invention relates each comprises a cam having a track with an abrupt radial recess. The cam is rotated by power driven gear reduction means. The conventional switch further comprises a switch arm which is mounted for movement into and out of engagement with a contact for establishing and disestablishing an electrical circuit. The switch arm is generally formed with a projection, or the like, that engages the cam track for urging the switch arm into engagement with the contact.

The camis manually rotated for moving the projection into engagement with the cam track for energizing the power driven gear means and initiating the time cycle of the switch. Thereafter, the cam is power driven until rotated an amount corresponding to one cycle, at which time the projection is received in the cam track recess for deenergizing the power driven gear means and disestablishing the electrical circuit.

Early embodiments of known time switches proved unsatisfactory as arcing at the contact occurred each time the projection moved into the cam track recess. Such arcing was caused by the slow disengagement of the switch arm from the contact. To remedy this defect, lost motion was arranged between certain of the gears of the power drive mechanism to permit a quick break of the switch arm from engagement with the contact upon movement of the switch arm projection from the cam track into the cam track recess.

Although this construction eliminated the problem of arcing, it also created two new problems. First, the quick break away feature only operates when the switch arm projection enters the cam track recess in one direction of rotation of the switch actuating cam. Secondly, the provision of lost motion in the drive mechanism makes for a sloppy gear drive and thus prevents the switch mechanism from being employed for precise timing.

It is an object of our present invention to provide a time switch mechanism of the general character described wherein arcing at the contact is eliminated and precise timing may be obtained, with the latter features being effective in both directions of rotation of the switch actuating cam.

In the accomplishment of the foregoing object, we provide the switch arm with a pivotally floating cam follower which is engagable with the cam track for urging the switch arm into engagement with the switch contact. The floating cam follower is receivable in the cam track recess, and upon leaving the cam track and entering the recess, instantaneously flips or pivots to efiect a quick break away of the switch arm from engagement with the contact. By virtue of the provision of the pivotally floating cam follower, all lost motion may be eliminated in the power driven gear means, and thus precise timing may be accomplished with the switch mechanism of our present invention. Also, due to the flipping or pivoting action of the cam follower, the latter is equally effective in operation in both directions of rotation of the cam. The improvement of our present invention may be employed with one or more switch arms or contacts, as will be disclosed more fully hereinafter.

Now, in order to acquaint those skilled in the art with the manner of constructing and using time switches in accordance with the principles of our present invention, we shall describe in connection with the accompanying drawings preferred embodiments of our present invention.

In the drawings:

Figure l is an exploded view of one embodiment of time switch mechanism of our present invention having embodied therewith a clockwise power drive mechanism;

Figure 2 is a front elevational view of the time switch mechanism of Figure 1, with the cover member being broken away;

Figure 3 is an exploded view of the time switch mechanism of Figure 1, with certain of the elements thereof being reversed and having a counter clockwise power drive mechanism embodied therewith;

Figure 4 is a front elevational view of a modified form of time switch mechanism of our present invention, with the cover member being broken away;

Figure 5 is a front elevational view of still another embodiment of time switch mechanism of our present invention; with the cover member being broken away;

Figure 6 is a front elevational view of a further embodiment of time switch mechanism of our present invention, will the cover member being broken away;

Figures 7 through 10 illustrate the sequence of steps in manually pie-setting, in a counter-clockwise direction, the time switch mechanism of Figures 1 and 2; and

Figures 11, 12 and 13 illustrate the sequence of steps in manually pre-setting, in a clockwise direction, the time switch mechanism of Figures 1 and 2.

Referring now to Figures 1 and 2, there is shown one embodiment of switch mechanism of our present invention, indicated generally by the reference numeral 10, which comprises a generally rectangular insulating member 12 that provides support for the various elements of the switch mechanism. The rectangular insulating member 12 has a pair 'of parallel faces 14 and 16.

Formed in the upper half of the member 12 are spaced apart transverse rectangular apertures 18, 20 and 22, which are arranged in ascending stepped relation from left to right. Staked or positioned in the apertures 18, 20 and 22, respectively, are terminal post members 24, 26 and 28. The process by which the terminal post members 24, 26 and 28 are staked to the mounting 12 is disclosed in the co-pending application of William P. Gallagher, Anthony D. Stolle and Paul G. Bielik, Serial Number 366,842, filed July 8, 1953. The ends of the posts 24, 26 and 28, that project away from the face 16 of the member 12, are adapted to have suitable connection with various electrical devices, the sequences of operation of which it is desired to have timed.

Secured, as by riveting, to the ends of the posts 24 and 26, that project away from the face 14 of the mounting 12, are the one ends of switch arms 30 and 32. The other ends of the switch arms 30 and 32 have, respectively, mounted thereto contacts 34 and 36, the latter of which cooperates with a contact 38 secured to the terminal post 28. Movement of the switch arm 32 in one direction is limited by a pin stop 39. The switch arms 30 and 32 are preferably formed of spring material and flex at the terminal posts 24 and 26 as the contact 34 is moved toward the contact 36 and the contact 36 moved toward the contact 38.

Movement of the switch arms 30 and 32 is adapted to be effected by means of a revolvable cam 40 mounted on a shaft 42 which is journaled, at one end, in a central aperture 44 formed in the mounting member 12, and, at the other end, in a central aperture 46 formed in a cover member 48 having arm members 50. In the assembly of the switch mechanism of our present invention, lugs '52, which are formed at the ends of the arms 50 of the cover member 48, are inserted through rectangular openings 54 formed at the sides of the mounting member 12 and are then bent or twisted so as to lock the cover 48 to the member '12. A radial recess, having two steps 56 and 58, is formed in the peripheral track 60 of the cam 40 and functions in a manner to be described hereinafter.

Secured to the shaft 42, with the cam 40, is a gear 62 which has meshing engagement with a pinion 64 that projects through an aperture 66 formed in the mounting member 12. The gear 64 is drivingly connected through reduction gearing with a slow speed synchronous electric motor, the latter assembly being indicated generally by the reference numeral 68. The electric motor and reduction gearing assembly 68 is secured by screws 70, threaded into openings 71, to the face 16 of the member 12, with the electric motor being adapted to be placed in connection with an electric power source through lines 72 and 74.

Associated with the switch arm 30 is a floating C-shaped cam follower 76 which has a body portion 78 and arm portions 80. The switch arm 30, intermediate of the ends thereof, is formed at its opposite edges with spaced flanges '82 that project at right angles therefrom and toward the cam 40. Each flange 82 is formed in two parts which define a substantially V-shaped recess 84.

The V-shaped recesses 84 floatingly receive the -C-shaped cam follower 76 when the elements of the switch mechanism are in assembled relation, as shown in Figure 2. The arm portions 80 of the follower 76 partially envelop the switch arm 30 and intersect the plane of the latter so as to serve to limit endwise move- :ment of the follower 76 relative to the arm 30.

The body portion 78 of the follower 76 is adapted to engage the cam track 60 for flexing the switch arms 30 and 32 away from the cam so as thereby to urge the contact 34 into engagement with the contact 36 and the contact 36 into engagement with the contact 38.

The floating cam follower 76' is receivable in the stepped cam track recess to effect a quick break away of the switch arm 32 and contact 36 from engagement with the contact 38, :and the switch arm '30 and contact 34 from engagement with the contact 36.

Attention is directed to the fact that the cam follower 76 is mounted on the switch arm 39 at a point which is off-center or displaced from a plane passing through the axis of rotation of the cam 40 normal to the switch arm 30. This point of mounting is displaced oif-center from the aforesaid plane in the direction of motor driven rotation of the cam, i. e. to the right of said plane for the clockwise direction of motor driven rotation of the cam shown in Figures 2 and 4 to 13 inclusive.

This plane is designated x--x in Figure 7. Because of the continuous downward pressure which the switch arm 30 transmits through the cam follower 76 to the notched steps 56, 58 or to the periphery 60 of the cam 40, and because the point of application of this downward pressure is disposed to the right hand side of the diametrical plane xx, it follows that this downward pressure from the spring arm 30 normally exerts a slight torque on the cam 40 in a clockwise direction (Figure 7). The backlash in the gear train from the motor 68 to the cam 40 permits slight rotation of the cam 40 in this clockwise direction whenever theshaft 42 is released after a setting operation in which the cam .is rotated in a counterclockwise direction. There is a natural tendency for the cam follower 76 to flip over to the position shown in the cam follower pointing downwardly and toward the right of the diametrical plane x-x, and this flipping tendency is insured by the above clockwise rotation of the cam after each counterclockwise setting.

Since the cam follower 76 is floatingly mounted and has limited pivotal movement relative .to the switch arm 30, the follower 76, when moved to the cam track .60, is caused to be pivoted so as to point in the direction that the cam 46 is to be vpower rotated. For example, if the cam 40 is manually rotated counterclockwise, as viewed in Figure 2, the follower 76 will initially pivot clockwise from the position shown in Figure 7 and will ascend the right end of the step 58 of the cam track recess, as shown in Figure 8, thereby moving contact 34 into engagement with contact 36 for completing an electrical circuit between the terminal posts 24 and 26 and for establishing energizat-ion of the timer motor assembly 68. During further manual counter-clockwise rotation of the cam 40, which is permitted because of slippage of a friction clutch employed in the timer motor assembly 68, the follower 76 moves up the right incline of the step 58 to the landing of the step 56 and simultaneously snaps counter-clockwise to the solid line position shown in Figure 9. 'The snap action is obtained by the above described offsetting of the pivotal axis of the follower 7.6 from the axis of rotation of the cam 40. Still further manual counter-clockwise rotation of the cam 40 first causes the follower 76 to pivot clockwise to the position shown in dotted lines in Figure 9 so as to facilitate its travel up the right incline of the step 56 and then, as the follower 76 rides up the incline and reaches the landing of the cam track 60, effects .a snap pivot of the follower counter-clockwise to the position shown in Figure 10. At this point, the contact 36 is moved into engagement with the contact v38 for completing'an electrical circuit between the terminal posts 26 and 28.

It is to be understood that the length of the timed cycle will depend upon the extent of the counter-clockwise rotation of the cam 40. It is to be further noted that the .aforedescribed steps, which are taken in presetting the timer, are effected in a continuous smooth manner.

After the cam 40 has been rotated the desired amount in a counter-clockwise direction and after it has been manually released, the motor assembly 68 becomes effective for power rotating the cam in a clockwise direction.

As the cam 40 is rotated in a clockwise direction .by the motor assembly 68, the follower 76 remains inclined downwardly toward the right, as viewed in Figure 10, thereby maintaining the drag on the cam 40, and attendant wear, at a minimum.

The timed cycle is completed when the follower 76 enters the cam track recess. The follower 76, upon leaving the cam track 60 and entering the step 56 of the cam track recess, instantaneously .fiips or pivots in .a clockwise direction, so that the latter quickly drops for effecting a quick break ;of engagement between .the con tacts 36 and 38. As the :body portion 78 of the follower 76 engages the step 56, the follower 176 is returned or flips in a counter-clockwise direction to a position inclined downwardly and toward the right. Further rut-ation of the cam 40 causes the follower 76 to leave thestep 56 and enter the step 58 of the :cam track recess, :at which time the follower is again flipped instantaneously clockwise for permitting the latter to drop quickly .for effecting a quick break of engagement between the contacts 34 and 36.

The cam 40 may, as shown in Figures 11, 12 and 13,, be rotated manually in a clockwise direction'for {instituting a timed cycle of operation. As the cam 40 is manually rotated "clockwise from the position shown in Figure 11, the follower 7:6 initially tends to assume substantially the same angle as the left end of the step 58 Figure 7 with the cam'riding edge of V of the cam track recess, thus facilitating travel of the follower 76 up the incline to the cam track proper. As the follower 76 rides up the incline, as shown in Figure 12, the switch arm 30 is flexed and the contact 34 is moved into engagement with contact 36 for completing an electrical circuit between the terminal posts 24 and 26 and establishing energization of the timer motor assembly 68. Continued manual rotation of the cam in a clockwise direction moves the follower 76 to the cam track 60 at which point, as shown in Figure 13, the contact 36 is moved into engagement with the contact 38 for completing an electrical circuit between the terminal posts 26 and 28. After the follower 76 has been moved to the position shown in Figure 13, the motor assembly 68 takes over rotation of the cam 40. The selected time cycle is substantially completed after one revolution of the cam 40, at which time the follower 76 drops into the cam recess, in the manner described hereinbefore, thereby effecting snap separation of the contacts for opening the motor and dependent electrical circuits.

The above described cycles of operation may be repeated as desired. It will be understood by those skilled in the art that the cycles of operation may be varied by changing the arcuate length of the steps of the cam track recess or by increasing the number of recesses about the periphery of the cam.

It is to be further noted that since the follower 76 is fioatingly mounted, the switch mechanism will operate equally effectively and efficiently should the cam 40 be driven counter-clockwise, as viewed in Figure 2, rather than clockwise as described.

In commercial applications of the time switch mechanism of our present invention, it is sometimes required that a particular cycle of operation, which is predetermined by the configuration of the cam track and recess, be carried out by driving the shaft 42 and cam 40 in a clockwise direction, such as described in connection with Figure 2. Likewise, it is sometimes required that a particular cycle of operation, identical to that described in connection with Figure 2, be carried out by driving the shaft 42 and cam 40 in a counter-clockwise direction. Obviously, since the cam track recess is formed with steps 56 and 58, a mere reversal in the direction of drive of the cam 40 will not effect a cycle of operation identical to that attained during clockwise rotation of the cam 40.

To provide interchangeably for identical cycles of operation in both directions of drive of the shaft 42, the apertures in the mounting member 12 are so arranged that clockwise drive means 68 may be secured to the face 16, with the switch arms 30 and 32 arranged at the face 14, or the cam 40 may be reversed on the shaft 42 and counter-clockwise drive means, as shown at 86 in Figure 3, secured to the face 14, with the switch arms 30 and 32 arranged at the face 16. The counter-clockwise drive means 86 is adapted to have suitable connection with an electric power source through the lines 90 and 92 From the foregoing description, it will become apparent to those skilled in the art that with our present invention it is possible to employ a standard mounting member 12 for both clockwise and counter-clockwise direction drive means.

Referring now to Figure 4, wherein primed reference numerals have been employed to designate the elements which are the same or similar to those of Figure 1, there is shown a modified embodiment of our present invention. The switch mechanism of Figure 4 is substantially identical to the switch mechanism of Figures 1 and 2, except that no switch arm is arranged intermediate of the switch arm 30 and contact 38; the contact 34' is arranged to engage the contact 38' directly; and the cam track recess 57 is not stepped. The floating cam track follower 76' is receivable in the cam track recess 57 to effect a quick break away of the switch arm 30' from engagement with the contact 38.

7 connection with Figures 1 and 2 and is Referring now to Figure 5, there is shown another embodiment of time switch mechanism of our present invention. The time switch mechanism of Figure 5 comprises a generally rectangular planar mounting member in which are formed a plurality of spaced apertures 101, 102, 103 and 104. Staked within the apertures 101, 102, 103 and 104, respectively, are terminal post members 105, 106, 107 and 108. The one end of switch arms 110, 112 and 114- are secured, as by riveting, respectively to the terminal post members 105, 106 and 108. A contact 116 is secured to the terminal post member 107 and cooperates with a contact 118 secured to the free end of the switch arm 114. A contact 120 is secured to the free end of the switch arm 110 and cooperates with a contact 122 secured to the switch arm 112 intermediate of the ends thereof. Flexing of the switch arm 110 is limited in one direction by means of a stop pin 115.

The free end of the switch arm 112 is provided with an insulating button 124 that is adapted to engage the free end of the switch arm 114 for urging the contact 118 thereat into engagement with the contact 116. Movement of the switch arms 110, 112 and 114 is adapted to be effected by means of a revolvable cam 126 which is mounted on a shaft 128 that may be rotated for presetting the timer and by power driven gear reduction means indicated generally at 130 for completing a timed cycle. A recess 132 is formed in the cam track 134.

The switch arm 112 intermediate at the ends thereof is formed at its opposite edges with spaced flanges 136 that project at right angles therefrom and toward the cam 126. Each flange 136 is formed in two parts which define a substantially V-shaped recess 138. The V-shaped recesses 138 fioatingly receive a C-shaped cam follower 140 which is of the same configuration and arranged in the same manner as the cam follower 76 shown and described in connection with Figures 1 and 2.

The body portion of the follower 140 engages the cam track 134 upon initial manual rotation of the cam 126. As the cam follower 140 is moved from the cam recess 132 to the cam track 134, the contacts 120 and 122 are moved into engagement and the contacts 116 and 118 are likewise moved into engagement for completing various electrical circuits through the terminal posts 105, 106, 1 07 and 108. The cam follower 1 40 operates in the same manner as the cam follower 76 described in operable, when received in the cam track recess 132, for effecting a quick disengagement of the contacts 120 and 122 and the contacts 116 and 118.

In Figure 6, there is shown still another embodiment of time switch mechanism of our present invention, wherein addition contacts are provided for employment in complex electrical circuits. Switch arms 150, 152 and -154 are suitably secured, as by riveting, to terminal post members 156, 158 and 160, which are in turn staked in apertures formed in the generally rectangular planar member 162. Also staked to the mounting member 162 are terminal post members 164 and 166 which provide support, respectively for contacts 168 and 170. The contact 168 is adapted to be associated with a contact 172 secured to the free end of the switch arm 154, while the contact is associated with a contact 174 secured to the switch arm 154, intermediate of the ends thereof. A contact 176 is secured to the switch arm 150, intermediate of the ends thereof, and the contact 176 normally engages a contact 178 secured to the terminal post member 158.

The free end of the switch arm 152 has riveted thereto a relatively inflexible lever or switch arm 180, which, at one end, has a contact 182 engageable with the contact 172 at the free end of the switch arm 154, and, at the other end, engages an insulating button 184 mounted at the free end of the switch arm 150.

The switch arms 150, 152, 154 and are moved by 7. means of a revolvable cam 186 secured to a shaft 187 which may be rotated manually and by power driven gear means indicated generally at 188. Recesses 190 are formed in the cam track 192 at diametrically opposite points of the cam 186.

The switch arm 152, intermediate of its ends, is formed with spaced flange members 194, which are formed of two parts that define substantially V-shaped grooves 196. Received in the grooves 196 is a generally C-shaped pivotal floating cam follower 198. The body portion of the cam follower 198 is engageable with the cam track 192 and the cam track recesses 190. The mechanism is initially started by manually rotating the shaft 187 for moving the cam 186 clockwise which causes the cam track follower 198 to move from the recess 190 to the cam track proper. At this point in the operation of the timer mechanism, the contacts 170 and 174 and 176 and 178 are opened and the contacts 168, 172 and 182 are closed. Thereafter, the cam 186 is rotated by the power means 188. At the completion of approximately one-half revolution of the cam 186 the cam follower 198 moves from the cam track 192 into the cam track recess 190 at which time the cam follower 198 flips or pivots instantaneously to effect a quick break of engagement between the contacts 168, I72 and 182 and reestablishment of engagement of the contacts 170 and 174, and 176 and 178. The described cycle may be repeated when desired.

Now, while we have shown and described what we believe to be preferred embodiments of our present invention, it will be understood that various rearrangements and modifications may be made therein without departing from the spirit and scope of our present invention.

We claim:

1. In a switch assembly, the combination of a revolvable cam having a track with a radial recess, a switch arm mounted for movement into and out of engagement with a contact, a floating C-shaped cam follower associated with said switch arm and having a body portion engageable with said cam track for urging said switch arm into engagement with said contact, said cam follower being mounted ofl-center of a plane passing through the axis of rotation of said cam normal to said switch arm and the body portion of said floating cam follower being receivable in said cam track recess to effect a quick break away of said switch arm from engagement with said contact.

2 In a switch assembly, the combination of a revolvable cam having a track with a radial recess, said cam being'manually settable in either direction of rotation a switch arm mounted for movement into and out of engagement with a contact, a floating C-shaped cam follower partially encircling said switch arm, said cam follower having arm portions intersecting the plane of said switch arm and having a body portion engageable with said cam track for urging said switch arm into engagement with said contact, said cam follower being non-positively connected with said switch arm, and being mounted off-center of a plane passing through the axis of said cam normal to said switch arm, the body portion of said cam follower being receivable in said cam track recess to effect a quick-break away of said switch arm from engagement with said contact.

3. In a switch assembly, the combination of a revolvable cam having a track with a radial recess, a switch arm mounted for movement into and out of engagement with a contact, said switch arm having spaced flanges projecting at right angles therefrom and toward said cam, substantially V-shaped recesses formed in said flanges, a cam follower arranged in said V-shaped recesses for limited floating pivotal movement and being engageable with said cam track for urging said switch arm into engagement with said contact, said cam follower beingnonpositively connected with saidswitch arm, and said cam follower being receivable in said cam track recess to effect a quick break away of said switch arm from engagement with said contact.

7 4. In a switch assembly, the combination of a revolvable cam having a track with a radial recess, a switch arm mounted for movement into and out of engagement with a contact, said switch arm having spaced flanges projecting at right angles therefrom and towards said cam, subsantially V-shaped recesses formed in said flanges, a generally C-shaped cam follower partially encircling said switch arm and arranged in said V-shaped recesses for limited floating pivotal movement, said cam follower having arm portions intersecting the plane of said switch arm and a body portion engageable with said cam track for urging said switch arm into engagement with said contact, said cam follower being non-positively connected with said switch arm, and said floating cam follower being receivable in said cam track recess to eflfect a quick break away of said switch arm from engagement with said contact.

5. In a switch assembly, the combination of a revolvable cam having a track with a radial recess, said cam being manually settable in either direction of rotation a first switch arm mounted for movement into and out of engagement with a contact, a second switch arm mounted for movement into and out of engagement with said first switch arm, a floating C-shaped cam follower partially encircling said second switch arm, said cam follower having arm portions intersecting the plane of said second switch arm and having a body portion engageable with said cam track for urging said second switch arm into engagement with said first switch arm and said first switch arm into engagement with said contact, said cam follower being non-positively connected with said second switch arm, and being mounted offcenter of a plane passing through the axis of rotation of the cam normal to said switch arm, said floating cam follower being receivable in said cam track recess to effect a quick break away of said first switch arm from engagement with said contact and said second switch arm from engagement with said first switch arm.

6. In a time switch, the combination of a revolvable cam having a track with a radial recess, an electric motor, reduction gearing between said electric motor and said cam for driving the latter at a slow timing speed, a switch arm mounted for movement into and out of engagement with a contact, said switch arm having spaced flanges projecting at right angles therefrom and toward said cam, substantially V-shaped recesses formed in said flanges, a generally C-shaped cam follower partially encircling said switch arm and arranged in said V-shaped recesses for limited floating pivotal movement, said cam follower havingarm portions intersecting the plane of said switch arm and a body portion engageable with said cam track for urging said switch arm into engagement with said contact, said cam follower being non-positively connected with said switch arm, and said floating cam follower being receivable in said cam track recess to effect a quick break away of said switch arm from engagement with said contact. 7

7, In a time switch adapted to be driven by either clockwise rotatable power drive means or counter-clockwise rotatable power drive means, a mounting member having a pair of spaced apertures formed therein, a contact adapted to be staked in one of said apertures at one side of said. mounting member or the other, a switch arm adapted to be staked at one end in the other of said apertures at the said one side of said mounting or the other, said switch arm being movable into and out of engagement with said contact, a cam having a track with a radial recess, said cam being revolvably mounted in said mounting member at the said one side or the other, .1: cam follower associated with. said switch arm and engageable with said cam track for urging said switch arm into engagement with said contact, said cam follower being receivable in said cam track recess to effect a quick break away of said switch arm from engagement with said contact, means for securing said clockwise rotatable power drive means to the other side of said mounting member when said contact, switch arm and cam are arranged on the said one side of said mounting member, means for securing said counter-clockwise rotatable power drive means to the said one side of said mounting member when said contact, switch arm and cam are arranged on the said other side of said mounting member, and said mounting member serving to cooperate with either of said drive means to provide for the selective association of either of said drive means with said cam for driving the latter in either relative direction.

8. In a time switch adapted to be driven by either clockwise rotatable power drive means or counter-clockwise rotatable power drive means, a mounting member having a pair of spaced apertures formed therein, a contact adapted to be staked in one of said apertures at one side of said mounting member or the other, a switch arm adapted to be staked at one end in the other of said apertures at the said one side of said mounting or the other, said switch arm being movable into and out of engagement with said contact, a cam having a track with a radial recess, said cam being revolvably mounted in said mounting member at the said one side or the other, a floating C-shaped cam follower partially encircling said switch arm, said cam follower having arm portions intersecting the plane of said switch arm and having a body portion engageable with said cam track for urging said switch arm into engagement with said contact, said floating cam follower being receivable in said cam track recess to effect a quick break away of said switch arm from engagement with said contact, means for securing said clockwise rotatable power drive means to the other side of said mounting member when said contact, switch arm and cam are arranged on the said one side of said mounting member, means for securing said counter-clockwise rotatable power drive means to the said one side of said mounting member when said contact, switch arm and cam are arranged on the said other side of said mounting member, and said mounting member serving to cooperate with either of said drive means to provide for the selective association of either of said drive means with said cam for driving the latter in either relative direction.

9. In a switch assembly, the combination of a revolvable cam having a track with an abrupt radial recess, said cam being manually settable in either direction of rotation, a first switch arm mounted for movement into and out of engagement with a contact, a second switch arm mounted for movement into and out of engagement with said first switch arm, a floating cam follower associated with said second switch arm and engageable with said cam track for urging said second switch arm into engagement with said first switch arm and said first switch arm into engagement with said contact, said cam follower being associated with said second switch arm at a point displaced to one side of a plane passing through the axis of rotation of said cam normal to said second switch arm, said floating cam follower being receivable in said cam track recess to effect a quick break away of said first switsh arm from engagement with said contact and said second switch arm from engagement with said first switch arm, and stop means engageable by said first switch arm as the second switch arm moves away from the latter to prevent said first switch arm from following said second switch arm.

10. In a switch assembly, the combination of a revolvable cam having a track with an abrupt radial recess, a first switch arm mounted for movement into and out of engagement with a contact, a second switch arm mounted for movement into and out of engagement with said first switch arm, a floating C-shaped cam follower partially encircling said second switch arm, said cam follower having arm portions intersecting the plane of said second switch arm and having a body portion engageable with said cam track for urging said second switch arm into engagement with said first switch arm and said first switch arm into engagement with said contact, said floating cam follower being receivable in said cam track recess to effect a quick break away of said first switch arm from engagement with said contact and said second switch arm from engagement with said first switch arm, and stop means engageable by said first switch arm as the second switch arm moves away from the latter to prevent said first switch arm from following said second switch arm.

11. In a time switch, the combination of a rotatable cam having a track with a radial recess, drive means for driving said cam in one direction of rotation, a switch arm mounted for movement into and out of engagement with a contact, a floating cam follower associated with said switch arm and engageable with said cam track for urging said switch arm into engagement with said contact, said cam follower being mounted off-center of a plane passing through the axis of rotation of said cam normal to said switch arm, said cam follower being movable by manual rotation of said cam from said cam track recess to said cam track for initiating a timed sequence of operation, said cam follower being pivoted to point in the direction that the cam is to be driven when said cam is manually rotated in the direction that the cam is to be driven, the off-center mounting of said cam follower serving to cause the latter to snap pivot to point in the direction that the cam is to be driven when said cam is manually rotated in a direction opposite to that in which the cam is to be driven, and said floating cam follower being receivable in said cam track recess to effect a quick break away of said switch arm from engagement with said contact upon completion of said timed cycle.

12. In a time switch, the combination of a rotatable cam having a track with a radial recess, drive means for driving said cam in one direction of rotation, a switch arm mounted for movement into and out of engagement with a contact, a floating C-shaped cam follower partially encircling said switch arm, said cam follower having arm portions intersecting the plane of said switch arm, and having a body portion engageable with said cam track for urging said switch arm into engagement with said contact, said cam follower being mounted off-center of a plane passing through the axis of rotation of said cam normal to said switch arm, said cam follower being movable by manual rotation of said cam from said cam track recess to said cam track for initiating a timed sequence of operation, said cam follower being pivoted to point in the direction that the cam is to be driven when said cam is manually rotated in the direction that the cam is to be driven, the off-center mounting of said cam follower serving to cause the latter to snap pivot to point in the direction that the cam is to be driven when said cam is manually rotated in a direction opposite to that in which the cam is to be driven, and said floating cam follower being receivable in said cam track recess to effect a quick break away of said switch arm from engagement with said contact upon completion of said timed cycle.

13. In a time switch, the combination of a rotatable cam having a track with a radial recess, drive means for driving said cam in one direction of rotation, a switch arm mounted for movement into and out of engagement with a contact, said switch arm having spaced flanges projecting at right angles therefrom and towards said cam, said flanges having substantially V-shaped recesses formed therein, a generally C-shaped cam follower partially encircling said switch arm and arranged in said V-shaped recesses for limited floating pivotal movement,

11 said cam follower having arm portions intersecting the plane of said switch arm and having a body portion engag'eable with said cam track for urging said switch arm into engagement with said contact, said cam follower being mounted off-center of a plane passing through the axis of rotation of said cam normal to said switch arm, said cam follower being movable by manual rotation of said cam from said cam track recess to said cam track for initiating a timed sequence of operation, said cam follower being pivoted to point in the direction that the cam is to be driven when said cam is manually rotated in the direction that the cam is to be driven, the ofl-center mounting of said cam follower serving to cause the latter to snap pivot to point in the direction that the cam is to be driven when said cam is manually rotated in a direction opposite to that in which the cam is to be driven, and said floating cam follower being receivable in said cam track recess to elfect a quick break away of said switch arm from engagement with said contact upon completion of said timed cycle.

14. In a time switch, the combination of a rotatable cam, time driving means for normally driving said rotatable cam in one direction at a time driven rate, said cam being manually rotatable in either direction relativeiy to said time driving means to enable said cam to be given different timed settings, said cam having a pcripheral track, a recess in said peripheral track having relatively gradual slopes joining its leading end and its trailing end with said peripheral track with respect to the direction of time driven rotation of said cam, a movable switch arm, contacts responsive to movement of said switch arm, a cam follower carried by said switch arm and having a cam riding edge adapted to ride on said cam, and rockable mounting means for rockably supporting said cam follower on said switch arm in a free floating tiltable mounting which is unbiased in either direction so that with respect to said switch arm said cam follower is as free to tilt in one direction as it is in the other, the gradual slope of the leading and trailing ends of said recess and the freedom of the cam follower to tilt without bias in either direction permitting said cam to be given different time settings by manual rotation thereof in either direction and to any angular extent, said rockable mounting means mounting said cam follower in a position which is off center of a plane passing through the axis of rotation of said cam and normal to said switch arm, the offset being in the direction of 12 the time driven rotation of said cam, said cam follower operating to snap pivot when entering the leading end of said recess in the time driven rotation of said cam so as to effect a quick operation of said contacts.

, 15. 'In .a time switch, the combination of a rotatable cam, time driving means for normally driving said rotatable cam in one direction at a time driven rate, said cam being 'manua'lly rotatable in either direction relatively to said time driving means to enable said cam to be given different timed settings, said cam having a periph er-al track, a recess in said peripheral track having relatively gradual slopes joining its leading end and its trailing end with said peripheral track with respect to the direction of time driven rotation of said cam, 'a movable switch arm, contacts responsive to movement of said switch arm, a cam follower carried by said switch arm and having a cam riding edge adapted to ride on said cam, and rockable mounting means for rockably supporting said cam follower on said switch arm in a free floating tiltable mounting which is unbiased in either direction so that with respect to said switch arm said cam follower is as free to tilt in one direction as it is in the other, the gradual slope of the leading and trailing ends of said recess and the freedom of the cam follower to tilt without bias in either direction permitting said cam to be given different time settings by manual rotation thereof in either direction and to any angular extent, said rockaole mounting means mounting said cam follower in a position which is off center of a plane passing through the axis of rotation of said cam and normal to said switch arm.

References -Cited in the file of this patent STATES PATENTS

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