GB2149368A

GB2149368A - Driverless wheeled vehicle system

Info

Publication number: GB2149368A
Application number: GB08426267A
Authority: GB
Inventors: Robert A Hale
Original assignee: SI Handling Systems Inc
Current assignee: SI Handling Systems Inc
Priority date: 1983-10-28
Filing date: 1984-10-17
Publication date: 1985-06-12
Also published as: GB8426267D0; JPS60166555A; GB2149368B; DE3439052A1; SE8405382D0; SE8405382L; FR2554071A1

Abstract

A first driverless wheeled vehicle 10 is arranged to follow a trackless guide such as a wire 14. The vehicle is self-propelled e.g. battery-powered, and adapted to carry a second driverless wheeled vehicle 35. The second vehicle is adapted to ride on tracks 24, 26 or (48, 50), Fig. 1, and has a drive wheel 38 adapted to be driven frictionally by a drive shaft 28 or (52). <IMAGE>

Description

SPECIFICATION Driverless vehicle and conveyor system Background Of The Invention There are a number of different types of known driverless vehicles. A first type of driverless vehicle which follows a trackless guidepath defined by a wire is known. A second type of driverless vehicle is known and may be of the type disclosed in U.S. patent 3,818,837. The second type of driverless vehicle is adapted to ride on tracks and is propelled by frictional contact between a drive wheel and a drive shaft which rotates about its longitudinal axis.

There is a need for a system for transporting vehicles of the second type between spaced locations, We have decided that this is best accomplished by using a vehicle of the first type modified to transport vehicles of the second type. The present invention is directed to a solution of that problem.

Summary Of The Invention The present invention is directed to a driverless vehicle and a conveyor system incorporating the same. A first type of driverless vehicle arranged to follow a trackless guidepath is self-propelled and has support wheels for riding on a floor. The first vehicle supports a platform for receiving a second driverless vehicle. The platform has means for receiving support wheels on the second vehicle and a drive tube for frictional contact with a drive wheel of the second vehicle. The platform also includes a speed control device for cooperating with a drive wheel on the second vehicle to control the speed of the same. The first vehicle may be utilized as a shuttle for transporting vehicles of the second type between two conveyor systems incorporating vehicles of the second type.

For the purpose of illustrating the invention, there is shown in the drawings a form which is presently preferred; it being understood, however, that this invention is not limited to the precise arrangements and instrumentalities shown.

Figure 1 is a top plan view of a portion of a shuttle system wherein a driverless vehicle of the first type is used to shuttle vehicles of a second type.

Figure 2 is a sectional view taken along the line 2-2 in Figure 1.

Figure 3 is a view similar to Figure 1 showing another embodiment of the present invention.

Figure 4 is a sectional view taken along the line 4-4 in Figure 3.

Figure 5 is a diagramatic plan view showing two conveyor loops for vehicles of the second type interfaced with a guide loop for vehicles of the first type.

Detailed Description Referring to the drawings in detail, wherein like numerals indicate like elements, there is shown in Figures 1 and 2 a vehicle designated generally as 10. Vehicle 10 is a driverless vehicle adapted to follow a trackless guide path. The preferred guide path is defined by conductive wire 14. Wire 14 may be slightly above, on or embedded in the floor 1 5. It is known to couple wire 14 to an electrical potential.

The vehicle 10 includes a body 1 6 having support wheels 1 8. The support wheels 1 8 are adapted to ride on the floor 1 5. Wheels 1 8 are propelled by a battery 20 on the body 16. In a conventional manner, vehicle 10 will stop at predetermined locations along the wire 14. The body 16 has a platform 22. On platform 22, there is provided a pair of rails 24, 26. Between the rails, there is provided a drive shaft 28 adapted to rotate about its longitudinal axis. Tube 28 is rotated by an endless belt extending around a sheeve at the output end of a reversible DC motor. Motor 30 is driven by the battery 20. Motor 30 may be actuated in response to an electrical signal.

On the platform 22, there is provided a speed control device 32 and a switch 34.

Switch 34 is responsive to contact with a arm 36 depending downwardly from a driverless vehicle 35. Driverless vehicle 35 is preferably of the type disclosed in U.S. Patent 3,818,837. Vehicle 35 has a drive wheel 38 in frictional contact with the drive shaft 28.

Vehicle 35 also has a cam follower 40 connected to the drive wheel 38 and adapted to cooperate with the speed control device 32.

Thus, cam follower 40 is coupled to the drive wheel 38 to change its angular relationship with respect to the axis of drive shaft 28 due to contact with the speed control device 32.

Vehicle 10 is utilized as a shuttle for transporting vehicle 35 from one location along the wire 14 to another. Vehicle 10 may be caused to stop at predetermined locations along wire 14 in any manner including the use of an on-board programmed microprocessor. At one such location, the vehicle 10 receives vehicle 35 as it is transferred off the tracks 42, 44 while being propelled by the drive shaft 46. Tracks 42, 44 are at the same elevation as tracks 24, 26 and are provided with a selectively actuable speed control device 45. See the lower end of Figure 1.

Device 45 halts vehicle 35 when vehicle 10 is not present and in a receiving position. As the vehicle 35 transfers onto the vehicle 10, it is propelled by the rotation of drive shaft 28 until the speed control device 32 causes the vehicle 35 to halt on vehicle 10. Just prior to the vehicle 35 halting, arm 36 trips switch 34. When switch 34 is tripped, vehicle 10 is propelled by battery 20 to the second location defined by tracks 48 and 50. A drive shaft 52 is disposed between the tracks 48 and 50. At this location, battery 20 causes motor 30 to rotate the drive tube 28 in a direction so that vehicle 35 transferrs off track 24 and 26 and onto the tracks 48, 50. Also, battery 20 operates a motor such as a solenoid (not shown) to move device 32 to thereby release cam follower 40.

The drive wheel 38 transfers vehicle 35 off the drive shaft 28 and onto the drive shaft 52. The gap 54 between the ends of the tracks 24, 26 and 48, 50 respectively is very small such as 3mm. Hence, the drive shafts 28 and 50 do not contact one another. The gap 54 is sufficiently small so that the support wheels on vehicle 35 may easily bridge the gap. Vehicle 35 may be empty or may support a load thereon as it is being transported by the vehicle 1 0. Vehicle 10 may be caused to halt at various predetermined locations along the wire 11 by a variety of devices other than a microcomputer including a photocell, proximity sensor, etc.

In Figures 3 and 4, there is illustrated another embodiment wherein corresponding elements are provided with corresponding primed numerals. Vehicle 10' is identical with vehicle 10 except as follows.

On the vehicle 10', the platform 22' is movable with respect to the body 16'. Motor 55 is attached to a stationary rail 50'. A connecting member 58 extends from said motor 56 into an open bottom channel defined by bracket 59 on one side of the platform 22'. Platform 22' may be guided for horizontal reciprocation over a short distance of not more than about 5cm in any convenient manner. As illustrated, platform 22' has grooved wheels 60 attached to its bottom surface. Wheels 60 ride on tracks 62 which are triangular in section. Such movement of the platform 22' closes the gap 54' which may be on the order of 2 1/2 to 5cm. A friction pad is provided at the free end of at least one of shafts 28', 52'. Motor 56 pulls member 58 to the left in Figure 3 and member 58 engages bracket 59 to move platform 22' to close gap 54'.When the gap 54' is closed, the drive shaft 28' is coupled to and driven by the drive shaft 52' whereby the vehicle 35 is transferred off the vehicle 10' and onto the tracks 48', 50'. When the vehicle 35 has transferred onto the tracks 48', 50', it trips a switch not shown which reciprocates the platform 22' to the position shown in Figure 3.

In Figure 5 there is diagramatically illustrated two conveyor loops 64 and 66 designed to handle one or more vehicles 35.

Wire 14 is arranged in a loop 68 between the loops 64 and 66 so that vehicles 10 may act as a shuttle for transferring vehicles 35 from loop 64 to loop 66 and vica versa. In addition, a spur 70 may be provided and defined by the tracks 42, 44 with the drive shaft 46 therebetween. Loops 64 and 66 may be in separate buildings with loop 68 being in a third building between the first two buildings.

Alternatively, the loops 64, 66 and 68 may be in the same building with offices, production machinery, or the like disposed within the loop 68.

The present invention utilizes the advantages of the two different types of driverless vehicles and combines them in novel manner whereby discrete conveyor loops 64, 66 are interfaced in an automated manner which is inexpensive and practical. It is not practical to have a direct connection between the loops 64, 66 since tracks and drive tubes would block aisles. Vehicle 10 does not utilize tracks and therefore may move down existing aisles for long distances.

Claims

1. Apparatus comprising a first driverless vehicle arranged to follow a trackless guide path, said vehicle being self-propelled and having support wheels for riding on a floor, said vehicle supporting a platform for receiving a second driverless vehicle, said platform having track means for receiving support wheels of the second vehicle and a drive shaft for frictional contact with a drive wheel on the second vehicle, and a speed control means on said platform for cooperation with a drive wheel of the second vehicle for causing the second vehicle to halt on said first vehicle.

2. Apparatus in accordance with claim 1 wherein said trackless guide path for the first vehicle is defined by a wire adjacent to, on, or in a floor.

3. Apparatus in accordance with claim 1 or 2 wherein said platform is supported on said first vehicle for reciprocation horizontally in a direction transverse to the direction of movement of the first vehicle.

4. Apparatus in accordance with any previous claim wherein the first driverless vehicle is arranged to follow a trackless guide path in the form of a loop, a second loop adjacent said first-mentioned loop, said second loop being adapted to receive vehicles of the second type and including track means associated with a drive shaft rotatable about its longitudinal axis, the last-mentioned track means being at substantially the same elevation as the track means on said first vehicle.

5. Apparatus in accordance with claim 4 including a third loop, said third loop being of the same type as the second loop, said first mentioned vehicle and loop being arranged to shuttle vehicles of the second type between the second and third loops.

6. Apparatus in accordance with claim 4 wherein the ends of tracks on the first vehicle are spaced from the ends of the track means of the second loop by a distance of approximately 3mm.

7. Apparatus in accordance with claim 4 wherein the ends of tracks on the first vehicle are spaced from the track means of the second loop by a distance of about 2 1/2 to 5cm.

8. Automated apparatus comprising a first driverless vehicle arranged to follow a trackless guide path, said vehicle being self propelled and having support wheels, said vehicle supporting a platform for receiving a second driverless vehicle, said platform having a pair of tracks for receiving support wheels of the second vehicle and a drive shaft for frictional contact with a drive wheel on the second vehicle, a speed control means on said platform for cooperation with a drive wheel of the second vehicle for causing the second vehicle to halt on said first vehicle, a second pair of tracks at an angle to said guide path and at substantially the same elevation as said first mentioned pair of tracks, a drive shaft associated with said second second pair of tracks for frictional contact with a drive wheel on the second vehicle for propelling the second vehicle along the second pair of tracks, the ends of the first pair of tracks being spaced from the ends of the second pair of tracks by a distance less than 5cm.

9. Apparatus in accordance with claim 8 wherein said platform is mounted for reciprocation toward and away from the ends of said second set of tracks.

10. Apparatus in accordance with claim 8 or 9 wherein said guide path is a closed loop, said second pair of tracks being associated with a closed conveyor loop.

11. Apparatus in accordance with claim 8, 9 or 10 wherein said first vehicle is constructed to follow a guide path defined by an electrically conductive path supported by a floor.

1 2. A driverless vehicle substantially as hereinbefore described with reference to Figs.

1 and 2 or Figs. 3 and 4 of the accompanying drawings.

1 3. Automated apparatus substantially as hereinbefore described with reference to Figs.

1, 2 and 5 or Figs. 3, 4 and 5 of the accompanying drawings.