Delivery cart

• US 6,276,471 B1
• Filed: 01/12/2000
• Issued: 08/21/2001
• Est. Priority Date: 06/06/1997
• Status: Expired due to Term

• Current Assignee: Expresso Deutschland Transpotgeräte GmbH
• Original Assignee: Expresso Deutschland Transportgerate GmbH
• Inventors: Kratzenberg, Wolfgang, Stein, Siegfried
• Primary Examiner(s): Swann, J. J.
• Assistant Examiner(s): McClellan, James S.
• Application Number:
  US09/481,328
• Time in Patent Office: 587 Days
• Field of Search: 180/65.1, 180/65.8, 180/65.5, 180/6.48, 180/6.5, 180/19.1, 180/19.3, 180/6.2, 280/47.34, 477/3, 477/4
• US Class Current: 180/19.3
• CPC Class Codes: B60L 50/60 using power supplied by batteries in combination with fuel cells B60L50/75
• CPC Class Codes: B62B 5/0026 Propulsion aids
• CPC Class Codes: B62B 5/0073 Measuring a force
• CPC Class Codes: Y02T 10/64 Electric machine technologies in electromobility
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

A delivery cart including a chassis, one or two castors pivotable about a vertical axis and two support wheels for supporting the chassis on a ground, a substantially vertically extending displacement stirrup attached to the chassis, a gearless, load-actuated reversible electric motor, formed integrally with the respective wheels, and a control system for controlling power supply to the electric motors and including sensors for sensing a displacement force or a steering force applied to the cart, and a free-programmable control unit for controlling power supply to the electric motors, in accordance with the one of a displacement force and a steering force.

Claims

1. A delivery cart, comprising:

a chassis formed of longitudinal and cross-beams;

at least one castor pivotable about a vertical axis and two wheels for supporting the chassis on a ground;

a displacement stirrup attached to the chassis and towering above the chassis;

two gearless, load-actuated reversible electric motors associated with the two wheels and formed integrally with the two wheels;

a power source for the electric motors; and

control means for controlling power supply to the electric motors and including sensor means for sensing at least one of a displacement force and a steering force applied to the cart, and a free programmable, electronic control unit for controlling power supply to the electric motors in accordance with the one of said displacement force and said steering force,

wherein the control unit comprises an electronic computer and a free programmable memory associated with the computer 1 wherein the sensor means comprises at least two sensors, and wherein the computer has a separate input for each of the at least two sensors and a separate output for each of the two electric motors,

wherein the free programmable memory stores data used for actuating the electric motor means and for controlling power supply thereto, the data including an allowable force to be applied by the user and variably predetermined operational characteristics of the cart, and

wherein the computer comprises a further input for programming the free memory from outside, and the delivery cart further comprises computer means connectable with the further input for programming the free programmable memory.

2. A delivery cart as set forth in claim 1, wherein the free programmable memory is formed as a replaceable insert formed as one of a pin-on data carrier and a plug-in data carrier, and wherein the computer has an interface to be connected with the data carrier.

3. A delivery cart as set forth in claim 1, wherein the displacement stirrup is formed as shaft pole provided with a single handle, and wherein the sensor means is mounted in the handle and comprises a first pair of force meters for sensing displacement forces applied to the shaft pole in a longitudinal direction of the cart, and a second pair of force meters for sensing steering forces applied to the shaft pole in a direction transverse to the longitudinal direction of the cart.

4. A delivery cart as set forth in claim 3, wherein each of the force meters is formed of strips of a foil material an electrical resistance of which changes dependent on a pressure force applied to a horizontal surface thereof, wherein the handle has a grip bar comprising a vertically extending square-shaped member, and wherein the force meters of the first pair of force meters and the force meters of the second pair of the force meters are arranged opposite each other in a respective direction on the square-shaped member.

5. A delivery cart as set forth in claim 1, wherein the two electric motors are formed as wheel hub electric motors formed integrally with the two wheels, wherein the displacement stirrup is formed as a shaft pole with a single handle, and wherein the control unit is mounted on the handle and is connected with the two electric motors by control conduits provided with plug-in connection means.

6. A delivery cart as set forth in claim 1, wherein the displacement stirrup is provided with two, spaced from each other in a transverse direction, handles, wherein the sensor means comprises two pairs of force meters arranged in the two handles, respectively, opposite each other on an appropriate support for sensing displacement and pressure forces applied to respective handles, and wherein each of the force meter is formed of strips of a foil material an electrical resistance of which changes dependent on a pressure force applied to an entire surface thereof.

7. A delivery cart as set forth in claim 6, wherein the computer has a separate input associated with each of the two force meters mounted in a handle, and a separate output associated with a respective electric motor.

8. A delivery cart as set forth in claim 7, wherein each of the inputs and the outputs of the computer is formed as a plug-in connection interface, and wherein the cart further comprises first adapter means for connecting the handles with the stirrup and second adapter means for connecting the wheels, which are formed integrally with respective wheel hub electric motors, with the chassis.

9. A delivery cart as set forth in claim 7 wherein the computer comprises driving and end stages for connecting respective outputs with respective electric motors and connected with respective plug-in interfaces of the computer, and wherein the control means further comprises a switch for turning the electric motors off.

10. A delivery cart as set forth in claim 1, wherein the stirrup is provided with at least one handle, wherein the power source comprises accumulator means and wherein the cart further comprises display means mounted on the handle and showing an accumulator charge.

11. A delivery cart as set forth in claim 10, wherein the display means comprises a light-emitting code.

12. A delivery cart as set forth in claim 6, wherein each of the two handles comprises a grip bar provided with sheathing formed of an elastic material, and wherein each pair of force meters is mounted in the grip bar of a respective handle.

13. A delivery cart as set forth in claim 1, wherein the displacement stirrup is formed as substantially U-shaped member formed of a tubular material, wherein two legs of the U-shaped stirrup extend substantially vertically and have free ends thereof fixedly secured to the chassis, and wherein a base portion of the U-shaped stirrup is bent out toward a user, and wherein the sensor means comprises two sensors formed as one of torque meters and force meters and mounted, respectively, on the two legs of the U-shaped stirrup.

14. A delivery cart as set forth in claim 13, wherein the two sensors are mounted inside the legs for sensing forces acting in a longitudinal direction of the cart.

15. A delivery cart as set forth in claim 14, wherein each sensor is associated with an electric motor provided on a same side of the chassis as the sensor receiving leg of the U-shaped stirrup.

16. A delivery cart as set forth in claim 15, wherein the two sensors are formed as torque meters and are arranged in foot portions of the respective legs for generating control signals in accordance to torques applied to respective electric motors.

17. A delivery cart as set forth in claim 15, wherein the two sensors are formed as force meter and are arranged in portions of the leg adjacent to the base of the U-shaped stirrup for sensing forces applied to the base by a user and for generating control signals communicated to the control unit.

18. A delivery cart as set forth in claim 1, wherein the electric motors are wheel hub motors.