US1235087A - Electric-motor drive. - Google Patents

Description

I. E. WHITT.

ELECTRIC MOTOR DRIVE.

APPuqmoM FILED-"L12. 1915.-

1 235,087. Patented July 31, 1917.

2 SHEETSSHEET 1.

- INVENTOR J5 Wf/lff ATTORNEY J. E. WHITT.

ELECTRIC MOTOR DRIVE. APPLICATION FILED K1211915- 1 235,087. I Patented July 31, 1917.

2 SHEET 8-SHEET 2.

INVENTOR effW/V/TT.

UNITED STATES PATENT OFFICE.

JOSEPH E. WHIT'I, OF ITALY, TEXAS.

ELECTRIC-MOTOR nerve.

Application filed April 12, 1915.

To all whom it may concern:

Be it lm'own that I, Josnrrr E. WHITT, citizen of the United States, residing at Italy, in the county of Ellis and State of Texas, have invented certain new and useful Improvements in Electric-\lo'tor Drives, of which the following is a specification.

This invention pertains to improvements in electric motor drives. The purpose of the invention is to provide an electric motor drive particularly adapted for use in connection with a cotton tramper. I

In carrying out the invention a driving device of the unit type has been provided and includes mechanism for automatically reversing the motor drive by reversing the motor itself.

Another object of the invention resides in means cooperating with the motor for increasing the application of power to the tramper head as the same approaches the lower end of its stroke, thus increasing the pressure exerted by the tramper head on the cotton proportionate to the resistance offered by the latter; whereby a substantially uniform load is placed on the motor.

A still further object is to provide a manually operated switch arranged to reverse the motor so that the tramper head may be carried up and down rapidly and at will; and also the provision of automatic means for operating said switch and stopping the motor at each end of the stroke of the tramper head in case the operator should fail to do so manually.

Another object of the invention is to provide a controlling device for the motor switch having a normally neutral position at which the motor is idle; and also provision of means for arresting and holding the tramper stationary in the position which it occupies when the controlling device is moved to neutral, but constructed to release the tramper head when said device is moved into one of its operative positions.

A further object of the invention is to provide a device of the character described that will be strong, durable, and eflicient, and comparatively inexpensive to construct, simple to operate, "and one in which the several parts will not be likely to get out of working order.

With the above and other objects in view the invention has relation to certain novel features of construction and operation, an example of which is described in the follow- Specification of Letters Patent.

Patented J uly 31, 1917.

serial No. 20,744..

111g specification and illustrated in the accompanying drawings, wherein:

lligure 1 is a view of a portion of a cotton baling press with portions in elevation and section and showing in section the tramper apparatus herein described, said latter sect1on being taken on the line 00'% of Fig. 2,

F g. 2 is a plan view of the same,

Fig. 3 is a diagrammatical view of the tramper head indicating the positions of the eccentric drum at each end of the stroke,

F g. 4 is a detail of the brake mechanism,

F1g. '5 is a di'agrammatical view of the switch and motor circuits, and

F 1g. 6 is a sectional detail of the control shaft stop.

In the drawings the numeral 1 designates the tramper sills which are supported on uprights 2 and 3. On the sills 1 a pair of metal beams A are secured longitudinally of the sills. The entire tramping apparatus is mounted on and carried by these beams and thus may be installed on any make of cotton press.

A super frame 5 is mounted on the beams 4 and carries cross bars 6 and 7 which support at right angles bars 8. A vertically disposed plunger 9 is confined against lateral 'displacement between the bars by guide rollers 10 and 11 mounted on the bars 8 and engaging the plunger on opposite sides. The guide rollers are flanged as shown, there being one roller 10 and a pair of rollers 11, the latter being separated. At the bottom 01 the beams cross bars 12 and 13 are mounted similar to the bars 6 and 7 and support bars 1 1 at right angles similar to the bars 8. Guide rollers 15 and 16 engage opposite sides of the plunger, there being a pair of rollers 16 and a single roller 15.

A cable 17 has one end secured to a bracket 18 fixed to the upper end of the plunger 9. This cable extends down and is *coiled around a drum 19 eccentrically fixed on a shaft 20 suitably mounted on the beams 4. The cable is attached at a proper point to the drum so as not to slip. The same cable passes oil of the drum and is carried down to an eye bolt 21 yieldably mounted in the ramper head 22 carried by the plunger 9. The rollers 11 and 16 are arranged in separated pairs to permit the free passage of the cable, and the yieldable eye bolt connection is provided to compensate any overthrow of the drum when the tramper head has reached the limit of its upward stroke By observing Figs. 1 and 3 it will be noted that when the tramper head is at the center of its stroke the drum 19 is positioned so that the cable 17'- is unwinding from the high side or at its point of least leverage. When motion is imparted to the drum and the plunger is started down at its slowest speed, the drum being at its point of greatest leverage the cable is unwinding from the low side. The speed is gradually increased so that at the center of the down stroke the greatest speed is attained and the cable is paying ofi the high side as indicated in dottedlines in Fig. 3. After passing the center point the speed is gradually decreased but the power applied is increased, the maximum being reached when the low side of the drum is reached at which point the plunger and tramper head will be at the end of the down stroke. By this arrangement the power is increased by increasing the leverage and in proportion to the increase of the resistance offered by the cotton being packed; thereby permitting the use of a motor of minimum horse-power, as very little if any extra horse-power will be required from the motor when the peak of the load is reached. It is apparent that without this mechanism or its equivalent the motor would be subjected to an unequal load and would not operate satisfactorily.

The shaft 20 is driven by a large sprocket 23 fixed thereon and which is driven by an endless chain 24 passing about a smaller sprocket 25 fixed on a counter shaft 26 suitably mounted in bearings on the beams 4. A large gear 27 is fixed on the shaft 26 and meshes with a pinion 28 fixed on a drive shaft 29 suitably mounted in bearings on the beams 4. A large sprocket wheel 30 is fixed on the drive shaft and is driven by an endless chain 31 passing about the smaller sprocket 32 attached direct to the shaft of a motor 33. By observing Fig. 1 it will be evident that quite a speed reduction is had by the gearing arrangement just described. This is necessary in order to operate the tramper head at a comparatively slow rate of speed and use a direct motor drive.

In tramping cotton in a press box the tramper head 22 is vertically reciprocated and where a motor is employed means for reversing said motor as well as automatically stopping it must be employed. The motor 33 is of the 3-phase type and is mounted on a cross plate 34 connecting the beams. Below the plate 34 a double-throw oil switch 35 of approved construction is mounted on a cross plate 36 extending between the beams 4 as shown in Fig. 1. In Fig. 5 a diagrammatical view of the switch and motor circuits are shown in which A designates the power circuit which leads to the poles of a switch lever 37. A motor circuit B leads from contacts on one side of the switch lever to the motor; while a re versed circuit 0 leads from contacts on the opposite side of said lever to the motor.

Normally the lever 37 occupies an intermediate or neutral position whereby the motor is idle and it is obvious that when said lever is swung to one side the motor will be energized and when swung in the opposite direction the first circuit will be broken and the circuit on the other side closed whereby the motor is reversed, but should the lever be arrested after breaking either contact the motor will stop.

For operating and controlling the switch a controlling device is provided. This de vice comprises a neck shaft 38 having its inner end bearing in a hanger 39 depending from a bar 40 carried by the super frame 5. The forward end of the shaft projects over the front beam 4 and has fixed thereon a depending lever 41 by which the shaft may be manually rocked. As shown in Figs. 2 and 6 the hanger 39 has a collar 42 pro vided with an arcuate slot 43 into which a pin 44 projects from the shaft 38. It is obvious that the ends of the slot 43 limit the rocking movement of the shaft 38. An arm 45 is fixed on the rock shaft and depends therefrom in line with the lever 41. A link 46 is pivotally connected to and extends between the lower end of the arm 45 and the upper end of the switch lever 37. The operator by grasping the lever 41 and swinging the same rocks the shaft 38 and through the agency of the arm 45 and link 46 throws the lever 37 of the switch 35 into engage ment with one of the contacts and closes one of the circuits whereby the motor is energized, the motor being reversed by swinging the lever 41 in the opposite direction.

hen the motor is energized motion is transmitted to the drum 19 through the gearing herein before oescribed and the plunger 9 reciprocated by the cable 17 whereby the tramper head 22 packs the cotton in the press box thereunder, -t is obvious that automatic means must be provided for stopping the motor at each end of the stroke of the plunger 9, because should the operator not swing the lever 41 at the proper time the plunger would continue to travel and tear up the machine. For ac complishing this an arm 47 fixed on the shaft 38 projects horizontally from the same and has pivotal connection at its outer end with the lower end of a link 48 pivoted at its upper end to a horizontal lever 49 which is mounted on an upright 50 extending between the cross bars 7 and 13 as shown in Fig. 1. The lever 49 extends across the plunger 9 in the path of pins 51 projecting from said plunger. These pins are positioned so as to engage the lever 49 at the extremities of the plunger stroke. Referring to Fig. 1. it will be seen that if the rock shaft is swung so that the arm 45 is moved to the right and the motor circuit B closed the free end of the lever 49 will be swung up and motion imparted to the parts so that the plunger 9 will be carried downward. lVhen the tramper head reaches the extremity of its downward stroke should the operator forget or fail to swing the lever al to reverse the motor the upper pin 51 would engage the free end of the lever 49 and force it downward whereby the shaft 88 would be rocked and the switch lever swung to its neutral position and the motor stopped. It is obvious that should the operator attempt to swing the lever 41 so as to swing the lever 37 back into the same contact he would be unable to do so as the pin 51 locks the lever as against upward movement; thus the lever 11 can only be swung to the other contact whereby the motor is reversed and the plunger started on its upward stroke.

It will be apparent that some means for holding the tramper head in the position at which it is arrested when the motor is stopped, must be provided. For this purpose a brake-wheel 52 is fixed on the drive shaft 29. A pair of hinged brake shoes 53 surround the wheel and are pivoted on a bracket 5% projecting from one of the beams 1. The shoes are connected by a spring tension device 55 which causes them to normally bind on the wheel and hold the shaft 29 against rotation whereby the tramper head 22 is held in its arrested or suspended position. A pair of jaws 56 extend from the brake shoes and embrace a double-face cam 57 fixed on the rock shaft 38. When the rock shaft is swung in either direction the cam spreads the jaws 56 thus spreading the brake shoes and releasing the wheel 52 and the shaft 29. The brake acts when the motor is idle, but is released simultaneously with the energizing of the motor. lVhen the switch 35 is neutral the brake is holding the tramper head by restraining the gearing, and when the switch is thrown by swinging the lever 41, the brake is released. It will be observed that the brake is applied when either of the pins 51 stop the motor.

The operation of the apparatus is the same as in all trampers; the cotton being fed to the press box and the lever 41 being swung to start the motor and reverse it to reciprocate the tramper to pack the cotton in the press box. The mounting of the motor directly on the tramper gives a unit power drive which is both economic and desirable.

The invention is presented as including all such modifications and changes as fall within the scope of the appended claims.

What I claim, is:

1. The combination of a reciprocating member, a driving member connected with the reciprocating member for reciprocating the latter, an electric motor connected with the driving member for operating the latter, a reversing switch normally neutral and connected in the power circuit of the motor, a manual operating device connected with the switch, and means on the reciprocating member for engaging the switch operating device at each end of the stroke of said reciprocating member.

2. The combination of a reciprocating member, a driving member connected with the reciprocating member for reciprocating the latter, an electric motor connected with the driving member for operating the latter, a reversing switch normally neutral and connected in the power circuit of the motor, a manual operating device connected with the switch, means on the reciprocating member for engaging the switch operating device at each end of the stroke of said reciprocating member, a brake for arresting the motion of the reciprocating member, and means on the switch operating device for operating the brake.

3. The combination of a reciprocating member, a driving member connected with the reciprocating member, an electric motor connected with the driving member, a reversing switch connected in the power circuit of the motor, a switch operating device, a hand operated element connected directly with the switch operating device, and means mounted on the reciprocating member positioned so as to operate the switch operating device at each end of the stroke of said member.

4. The combination with a reciprocating member and an electric motor for driving the member, of a reversing switch connected in the power circuit of the motor, a switch operating member, a hand lever mounted on the operating member, a brake correlated with the reciprocating member, a brake operating device connected with the switch operating member, emergency stops at each end of the reciprocating member, and an operating connection in the path of the stops and connected with the switch operating member, the switch operating member being operatable by either the hand lever or the emergency connection and the brake operating device being operated whenever the switch operating member is actuated.

In testimony whereof I aflix my signature.

JOSEPH E. WHITT.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G.

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