Crown Equipment Corporation

Allen Thomas Trego

Robert J Henshaw

Donald E Luebrecht

John Ivan Koeper

Michael P Gallagher

Steven R Pulskamp

Philip D Palermo

Daniel C Magoto

Timothy S Quellhorst

Daniel Carl Magoto

James Francis Schloemer

Brent A Bergman

Forrest A Haverfield

Supplemental walk along control for walkie/rider pallet trucks is provided by supplemental controllers such as jog and coast release switches and/or twist grips (or other drive motor speed controllers) provided adjacent the base of load carrying forks. The supplemental controllers are enabled during coasting operation so that operators can advance to the base of the forks to accelerate the trucks between closely spaced picks located along substantially straight portions of pick routes. For application of the trucks' brakes, the operators activate the coast release switches to release the coast mode and enable deadman brake mechanisms to brake the trucks and/or by plug braking with the twist grips. A steering direction detector is provided to determine the direction of the steered wheel so that if the steered wheel is not directed substantially straight ahead, then operation of the truck from the supplemental controls is disabled.

Supplemental jog and/or twist grip or other drive motor speed walk along controllers for walkie/rider pallet trucks

Supplemental walk along control for walkie/rider pallet trucks is provided by supplemental jog switches and coast release switches provided adjacent to the base of load carrying forks. The supplemental jog switches are enabled during coasting operation so that operators can advance to the base of the forks to accelerate the trucks between closely spaced picks located along substantially straight portions of pick routes. For application of the trucks' brakes, the operators activate the coast release switches to release the coast mode and enable deadman brake mechanisms to brake the trucks. A steering direction detector is provided to determine the direction of the steered wheel so that if the steered wheel is not directed substantially straight ahead, then operation of the truck from the supplemental jog switches is disabled.

Supplemental walk along control for walkie/rider pallet trucks

A knurled wheel is coupled to a sensor mounted to one mast member and the wheel is forced into another mast member so that the wheel/sensor rotate upon mast movement. The sensor generates signals, corresponding to mast movement, which are processed conventionally to determine mast height, etc. The knurled wheel forms a track on the contacted mast member and the knurl engages the track. The wheel can be forced into the mast member with a force of six to nine pounds. To enhance the versatility of the mast height sensing device, the thickness of the wheel can be made less than &frac18; inch, for example {fraction (1/16)} inch. The sensor can be an encoder or a sensor bearing and a heater can be provided for operation in cold environments to ensure rotation of the sensor under such conditions.

Materials handling vehicle mast height sensor

A coast control device for a walkie/rider pallet truck locks the position of a steering arm of the truck to prevent movement by a deadman mechanism. The disclosed locking device is a brake: an armature plate mounted to the steering arm; and an electromagnet coupled to a steering head that is operated to activate coasting operation. The brake force can be overcome by an operator to manually apply the truck brake or to reposition the steering arm to a new position where it is again locked. For controlling coasting operation, the brake is manually engaged by an actuator mounted adjacent to or on a grab bar that is to be gripped by an operator riding on the truck. With the actuator so located, coasting operation can be conveniently engaged while the operator is walking beside the truck.

Coast control for walkie/rider pallet truck

A fork lift truck includes a body, a drive mechanism supported on the body for effecting movement of the body, and a fork carrying assembly carrying forks which can be moved in height between a lowered position and desired raised positions. A tilt cylinder is provided for tilting the forks through a fork tilt range. The truck further includes a pressure sensor capable of generating signals indicative of the weight of a load on the forks, a fork tilt position sensor capable of being activated when the forks are tilted to extremes of the fork tilt range, and a controller. The controller is coupled to the drive mechanism, the pressure sensor and the fork tilt position sensor. It causes the drive mechanism to effect movement of the body up to a first maximum speed when at least one of the pressure sensor generates a signal indicative of a load on the forks having a weight above a predetermined value and the tilt position sensor is activated, and causes the drive mechanism to effect movement of the body up to a second maximum speed which is greater than the first maximum speed when the pressure sensor generates a signal indicative of no load or a load on the forks having a weight below the predetermined value and the tilt position sensor is inactivated. The lowering speed of the forks can also or alternatively be increased under the same operating conditions.

Travel and fork lowering speed control based on fork load weight/tilt

A handle mounted generally horizontally on a fork lift truck for controlling forward and reverse speed of movement of the truck and raising and lowering forks is carried by a control device. The control device includes a shaft with a centrally positioned spherical section contained in a socket in a support member. The shaft is therefore free to rotate about the center of the sphere. A ramp cam is mounted on the support member surrounding the shaft. A slider mounted on the shaft is pressed against the cam by action of a spring. This arrangement assures that the shaft and control handle remain centered until acted upon by an operator of the truck. Two linear potentiometers provide electrical output signals representing the X (horizontal) and Y (vertical) positions of the end of the shaft opposite the control handle. The cam is provided with four distinct compound surfaces. For vertical movement of the handle, the slopes of the two lower surfaces are greater than the slopes of the two upper surfaces. The slopes of each surface are also different in the forward and reverse direction. This arrangement provides the illusion that the same force is required to move the handle in any direction. A detent in the center of the cam requires a slightly greater force to move the handle from the center position.

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Hampshire, IL, United States of America

Allen Thomas Trego