Control of auxiliary movements on industrial trucks

Claim 2

In an industrial truck, the combination comprising: a plurality of auxiliary movement mechanisms, a motor; transmission means coupling said motor for driving the auxiliary movement mechanisms; control means having a plurality of selectable conditions, each of said conditions coupling the transmission means to a respective one of said movement mechanisms to effect operation thereof; pulse control means for said motor, said pulse control means having a control circuit determining the pulse rate of the pulse control means; said control circuit having a plurality of selectable conditions, in each of which the control circuit provides a respective pulse rate; and said control means being operative to select simultaneously a condition in the control circuit and a corresponding auxiliary movement for operation by said motor.

Claim 3

The structure as set forth in claim 1 wherein the pulse control means comprises a controlled rectifier means which when conductive provides energizing current for said motor, a pulse generator means operative to supply control pulses to the controlled rectifier means, the pulse generator having a timing circuit with a plurality of conditions, in each of which a different period between control pulses is provided, the timing circuit condition being selected by said control means.

Claim 4

An industrial truck having a plurality of auxiliary movement mechanisms, said mechanisms comprising a lift mechanism, a tilt mechanism, and a reach mechanism; first, second and third manually operable control elements for selecting operation of said mechanisms respectively, motor means operable to drive said mechanisms, means responsive to selective movement of said elements for coupling said mechanism for driving by said motor means, controllable supply means for supplying said motor means with pulses of current at a selectable rate, first means coupled to said first element and said controllable supply means for determining a first pulse rate in response to selective movement of said first element, second means coupled to said second element and said controllable supply means for determining a second pulse rate in response to selective movement of said second element; and third means coupled to said third element and said controllable supply means for determining a third pulse rate in response to selective movement of said third element.

Claim 5

An industrial truck having a plurality of auxiliary movement mechanisms, said mechanisms comprising a lift mechanism, a tilt mechanism, and a reach mechanism; first, second and third manually operable control elements for selecting operation of said mechanisms respectively, motor means operable to drive said mechanisms, means responsive to selective movement of said elements for coupling said mechanism for driving by said motor means, controllable supply means for supplying said motor means with pulses of current at a selectable rate, first means coupled to said first element and said controllable supply means for determining a first pulse rate in response to selective movement of said first element, second means coupled to said second element and said controllable supply means for determining a second pulse rate in response to selective movement of said second element; and third means coupled to said third element and said controllable supply means for determining a third pulse rate in response to selective movement of said third element.

Claim 6

An industrial truck as set forth in claim 3 additionally comprising switch means and means responsive to additional movement of said first lever for operating said switch means, said switcH means being operative to energize said motor means.

Claim 7

In an industrial truck, the combination comprising: a plurality of auxiliary movement mechanisms each having respective power requirements; a hydraulic circuit for actuating said mechanisms, said hydraulic circuit including a pump means for providing hydraulic pressure in the hydraulic circuit and selectively operable valve means for selective coupling of the hydraulic pressure to said auxiliary movement mechanisms; an electric motor means coupled for driving said pump means; pulse supply means for said electric motor means, said pulse supply means having a timing circuit having a plurality of selectable conditions each defining a respective one of a plurality of predetermined rates of supply of energizing pulses from said pulse supply means to said electric motor means, each of said predetermined rates of supply of energizing pulses corresponding to a respective one of said power requirements of said auxiliary movement mechanisms; a plurality of manually operable elements each coupled to a respective one of said valve means for selective operation thereof in response to selective movement of said elements; and means responsive to selective movement of each element for simultaneously selecting the respective condition of said timing circuit, whereby the rate of supply of energizing pulses to said electrical motor means corresponds to the power requirement of the auxiliary movement mechanism selected for operation.

Claim 8

In an industrial truck, the combination comprising: a plurality of auxiliary movement mechanisms each having respective power requirements; a hydraulic circuit for actuating said mechanisms, said hydraulic circuit including a pump means for providing hydraulic pressure in the hydraulic circuit and selectively operable valve means for selective coupling of the hydraulic pressure to said auxiliary movement mechanisms; an electric motor means coupled for driving said pump means; pulse supply means for said electric motor means, said pulse supply means having a timing circuit having a plurality of selectable conditions each defining a respective one of a plurality of predetermined rates of supply of energizing pulses from said pulse supply means to said electric motor means, each of said predetermined rates of supply of energizing pulses corresponding to a respective one of said power requirements of said auxiliary movement mechanisms; a plurality of manually operable elements each coupled to a respective one of said valve means for selective operation thereof in response to selective movement of said elements; and means responsive to selective movement of each element for simultaneously selecting the respective condition of said timing circuit, whereby the rate of supply of energizing pulses to said electrical motor means corresponds to the power requirement of the auxiliary movement mechanism selected for operation.

Claim 9

The combination as set forth in claim 5 in which said timing circuit includes a resistive network in circuit with a capacitor, the resistive network including a plurality of different selectable resistive paths, and in which said means responsive to selective movement of each element comprises switch means disposed for actuation by the respective elements and circuit means coupling said switch means for selecting a respective resistive path.

Claim 10

The combination as set forth in claim 5 in which said auxiliary movement mechanisms comprise lift, reach and tilt mechanisms.

Claim 11

The combination as set forth in claim 7 in which said manually operable elements comprise levers.

Claim 12

The combination as set forth in claim 6 in which said pulse supply means comprises a battery source, an electronic power switch coupled between the battery source and said electrical motor means, said electronic power switch having a control input, and pulse-generating means, including said timing circuit, coupled to said control input.