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US 4,056,160 AGranted
Electrically powered vehicle with power steering
AssigneeLinde Aktiengesellschaft
InventorsTheodor Abels, Siegfried Puschel
Life of this patent
Estimating the term…
Abstract
An electrically powered vehicle, e.g. a forklift truck or other utility-type battery-powered vehicle, is provided with a hydraulic power-steering system with a pump driven by an electric motor. A circuit is provided to cut out the power-steering pump motor when the vehicle attains an elevated speed, thereby reducing battery drain during period in which power-steering is not normally required.
Claims11
A vehicle comprising a battery;
- an electrically-operated propulsion system;
- switch means for connecting said battery to said propulsion system and having a range of speeds including relatively low speeds and at least one relatively high speed and, corresponding thereto, a high speed position and at least one lower speed position;
- a hydraulically operable power steering mechanism for steering said vehicle, said mechanism including a hydraulic pump and an electric motor operatively connected to said pump for driving same upon energization of said motor;
- and
- circuit means connected between said switch means and said motor for connecting said motor to said battery for operation of said mechanism in a lower speed position of said switch means and decoupling same from said battery in said high speed position of said switch means, said circuit means including a time-delay network delaying the energization of said motor by said circuit means for a predetermined time period subsequent to the operation of said switch means at said high speed position.
2 more elements
A vehicle comprising a battery;
- an electrically-operated propulsion system;
- switch means for connecting said battery to said propulsion system and having a range of speeds including relatively low speeds and at least one relatively high speed, and corresponding thereto, a high speed position and at least one lower speed position;
- a hydraulically operable power steering mechanism for steering said vehicle, said mechanism including a hydraulic pump and an electric motor operatively connected to said pump for driving same upon energization of said motor;
- and
- circuit means connected between said switch means and said motor for connecting said motor to said battery for operation of said mechanism in a lower speed position of said switch means and decoupling same from said battery in said high speed position of said switch means, said switch means being a key switching arrangement having respective contacts for the speeds of said propulsion system, said circuit means responding to the control voltage of said switch means.
2 more elements
A vehicle comprising a battery;
- an electrically-operated propulsion system;
- switch means for connecting said battery to said propulsion system and having a range of speeds including relatively low speeds and at least one relatively high speed and, corresponding thereto, a high speed position and at least one lower speed position;
- a hydraulically operable power steering mechanism for steering said vehicle, said mechanism including a hydraulic pump and an electric motor operatively connected to said pump for driving same upon energization of said motor;
- and
- circuit means connected between said switch means and said motor for connecting said motor to said battery for operation of said mechanism in a lower speed position of said switch means and decoupling same from said battery in said high speed position of said switch means, said switch means being a key switching arrangement having respective contacts for the speeds of said propulsion system, said circuit means responding to the keying ratio of said switch means.
2 more elements
A vehicle comprising a battery;
- an electrically-operated propulsion system;
- switch means for connecting said battery to said propulsion system and having a range of speeds including relatively low speeds and at least one relatively high speed and, corresponding thereto, a high speed position and at least one lower speed position;
- a hydraulically operable power steering mechanism for steering said vehicle, said mechanism including a hydraulic pump and an electric motor operatively connected to said pump for driving same upon energization of said motor;
- and
- circuit means connected between said switch means and said motor for connecting said motor to said battery for operation of said mechanism in a lower speed position of said switch means and decoupling same from said battery in said high speed position of said switch means, said switch means being a pulse control switching arrangement for the speeds of said propulsion system, said circuit means responding to an electrical control voltage parameter of said switch arrangement.
2 more elements
Dependencies are inferred from the claim text.