US2405053A - Controller for electric motordriven traveling machines - Google Patents

Description

July 39, 1946. J PQSSELT '2,405,053

CONTROLLER FOR ELECTRIC MOTOR DRIVEN TRAVELING MACHINES Filed March 18, 1944 Tor?! Patented July 30, 1946 CONTROLLER FOR ELECTRIC IVIOTOR- DRIVEN TRAVELING MACHINES Edward J. Posselt, Fox Point, Wis., assignor to Cutler-Hammer, Inc., Milwaukee, Wis., a corporation of Delaware Application March 18, 1944, Serial No. 527,058

4 Claims. 1

This invention relates to controllers for electric motor driven traveling machines using trolleys.

The invention while not limited thereto is particularly advantageous for controllers for coal and ore bridges having alternating current control, the invention having among its objects reduction to a minimum of the trolley wires from the pilot device to the control panel, this in the case of coal and ore bridges and other traveling mechanisms being frequently highly important.

Another object of the invention is to provide a control system having the aforementioned advantageous characteristic and also that of enabling use in conjunction with the electrical overload devices auxiliary control windings, as for holding them in tripped position, Without any complication of connections.

Other objects and advantages will hereinafter appear.

The accompanying drawing illustrates diagrammatically in simplified form one embodiment of the invention which will now be described, it being understood that the embodiment illustrated is susceptible of various modifications without departing from the scope of the appended claims.

Referring to the drawing, the same shows an alternating current motor M of suitable type supplied from alternating current lines L L and L through selectively operable reversing switches F and R. The reversing connections are of conventional form, the switches F and R each being of the triple pole electromagnetic type. Also as is quite customary the motor has associated therewith overload devices IOL, ZQL having tripped windings a and a respectively, included in series with the motor upon connection thereof to the line through either of the reversing switches.

The switch F has three pairs of stationary contacts and three bridging contacts I, 2 and 3, nory disengaged from their respective stationary contacts, and being operable jointly by an electromagnetic winding 4 to engage their respective stationary contacts. The switch R has similar sets of contacts including bridging contacts 1 2 and 3 and a similar operating winding 2 The windings 4 and 4 are adapted to be connected selectively across lines L and L by relays to be described. and the energizing connections of said windings have included therein in series normally engaged contacts b and b of the afore mentioned overload switches [5L and 29L, respectively. The contacts b and b are adapted to be disengaged by response of the overload windings a and a aforementioned.

The windings 4 and 4 of switches F and B, respectively, are controlled by relays PR and RR, respectively. The relay FR has normally disengaged contacts 0 connected between the winding 4 and line L and said relay has a winding d which when energized engages said contacts. The relay RR has similar contacts 0 and a winding the contacts c being included in circuit between winding 4 and line L The switches and relays thus far described comprise elements of the stationary control panel for the traveling mechanism, the relays PR. and RR bei g under the control of pilot contacts to be carried by the traveling mechanism. The pilot contacts may comprise contacts of a control drum D and are so illustrated, although it is to be understood that they may assume any desired form. While in practice the drum D would ordinarily comprise contacts in addition to the contacts required to control relays FR and RR. only the latter contacts are shown in the drawing. These contacts comprise normally disengaged contacts 5 and 6 which are engaged when the drum is moved in reversing direction as to the position X and similar contacts 1 and 8 which are engaged when the drum is moved in forward direction as to position X X and X may be considered as cams to engage their respective sets of contacts. releasing them to disengage when the drum is moved to 01f position. The contacts 5 and 1 respectively have trolley connections T and T to lines L and L respectively. Contacts 6 and 8 are interconnected and have a trolley connection T to a conductor 9 which interconnects opposed rectifiers l0 and H.

The rectifiers IE3 and H are respectively connected to the windings cl and d and through said windings to lines L and L respectively. However, even though the windings cZ and d have permanent connections with lines L and L respectively, current flow therethrough in series is blocked by the opposed rectifiers l0 and II.

As shown the connection between conductor 9 and the pilot contacts includes windings e and e for the overload relays lfiL and 20L, respectively, the purpose of which windings will be later set forth.

As will now be apparent, although windings d and d have a common connection to the pilot contacts, the pilot contacts and the rectifiers Ill and I nevertheless jointly afiord selective energization of the normally deenergized relays FR and DR. Thus when pilot contacts 1 and 8 are engaged current will flow only through the winding cl, winding d and rectifier I I being shortcircuited. The energizing circuit for winding (1 comprises its connection to line L and its connection to line L through rectifier Ill and contacts 8 and I of the drum, the latter connection extending from winding (2 to and through windings e and e in series to trolley connection 'I and thence to and through contacts 8 and I and trolley connection T to line L On the other hand, when contacts 5 and 6 are engaged only winding al will be energized, the winding :1 and rectifier In being short-circuited. The energizing circuit of winding (1 comprises its connection to line L and its connection to line L through rectifier i i and drum contacts 6 and 5, the latter connection extending from winding d to and through windings e and e to trolley connection T and thence to and through contacts 6 and 5 to trolley connection T, which as explained is connected to line L Hence as will be apparent, selective control of relays FR and RR is obtained with a minimum number of trolley connections, whereas the trolley connections T and T are available for use in various other circuits commonly desired in the control of coal and ore bridges and other traveling mechanisms. Such being the case, selective control for the windings d and d to afford reversals of the motor at will may be said to involve only the addition of the single trolley connection T Considering now windings e and c the same may be employed to hold their respective overload switches against resetting after tripping thereof by the windings in series with the motor. With windings e and e so utilized it will be apparent that if either overload switch is tripped it will be held in tripped position pending return of the drum D to off position to interrupt the connection of conductor 9 with line L When such disconnection occurs both windings e and e are deenergized to permit resetting of the overload switch or switches preparatory to further operation of the motor. Such control of the overload switches is often highly desirable, and as will be apparent it is obtainable in the system shown without any complications or need of additional contacts.

On the other hand, it will be apparent that the system disclosed is in nowise dependent upon the presence of the coils e and e and that if such coils are not desired a direct connection from the trolley T to conductor 9 may be made which will afford the same selective control of the forward and reverse relays as that aforedescribed.

What I claim as new and desire to secure by Letters Patent is:

1. In a controller for a motor driven traveling machine, in combination, a supply circuit, a reversing controller for the machine to be mounted in fixed position and comprising electroresponsive windings to be energized selectively for drive reversals according to line connection of a single supply lead common to said windings, pilot contacts to travel with the traveling machine and having trolley connections with difierent lines of 4 said supply circuit and with said common supply lead of said windings, and rectifiers in circuit with said windings to render their energization dependent upon selective setting of said pilot contacts.

2. In a controller for a motor driven traveling machine, in combination, an alternating current circuit, a reversing controller for the machine to be mounted in a fixed position and comprising electr-oresponsive windings to be energized selectively for drive reversals, said windings being connected between different lines of said circuit and a common supply lead, pilot contacts to travel with the traveling machine and having trolley connections with said different supply lines respectively, an additional trolley connection between said pilot contacts and said common supply lead of said windings, and rectifiers respectively in series with said windings and being oppositely disposed to block an effective current flow through said windings in series but enabling energization of said windings selectively by said pilot contacts.

3. In a controller for a motor driven traveling machine, in combination, an alternating current supply circuit, a reversing controller for the motor to be mounted in fixed position, said controller comprising electroresponsive windings to be energized selectively for motor reversals and comprising a motor protective device having operating means and a holding winding, all of said windings having certain common connections, pilot contacts to travel with the traveling machine and having trolley connections with said supply circuit and with said common connections of said windings, and rectifiers respectively in circuit with said first mentioned windings to necessitate energization thereof selectively and to enable control of all of said windings by said pilot contacts through a singl trolley connection with selectivity of control of the first mentioned windings.

4. In a controller for a motor driven traveling machine, in combination, an alternating current supply circuit, a reversing controller for the motor to be mounted in fixed position, said controller comprising electroresponsive windings to be energized selectively for motor reversals and comprising a motor protective device having operating means and a holding winding, pilot contacts to travel with the traveling machine and having trolley connections with said supply circuit, a trolley connection common to said pilot contacts, said first mentioned windings and said holding winding, and rectifiers respectively in series with said first mentioned windings to necessitate energization thereof selectively and to enable their energization selectively by said pilot contacts through said common trolley connection, said holding winding being traversed by and responsive to the current thus supplied to either of said first mentioned windings.

EDWARD J POSSELT.

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