GB2175665A

GB2175665A - Disengageable coupling between drive motor and wheel of a powered trolley for an overhead rail conveyor

Info

Publication number: GB2175665A
Application number: GB08611953A
Authority: GB
Inventors: Nicola Catena
Original assignee: Fata European Group SpA
Current assignee: Fata European Group SpA
Priority date: 1985-05-23
Filing date: 1986-05-16
Publication date: 1986-12-03
Also published as: GB8611953D0; DE3617239A1; ES8703187A1; ES555021A0; IT8521924V0; FR2587424A1

Abstract

A disengageable coupling between a drive shaft and a driven shaft, in particular for powered trolleys for overhead transportation of loads on a monorail, comprises, in combination: two axial shafts (14, 15), the former keyed to the output shaft of a motor (10) and the latter keyed to the drive wheel (11) of the trolley, a rail mounted cam contacting a sensor roller (32) to rotate a shaft (30) moving a rod (16) axially to disengage a clutch (13). The clutch (13) comprises balls (23) diametrical bores (21) of a head end portion (21) of the drive shaft (14), engageable with notches (24) in a socket portion (25) integral with the driven shaft (15). <IMAGE>

Description

SPECIFICATION Disengageable coupling between a drive shaft and a driven shaft This invention relates to a disengageable coupling between a drive shaft and a driven shaft, in particular for powered trolleys for overhead transportation of loads on a monorail.

As is well known to persons skilled in the art, powered trolleys for overhead transportation on a monorail are required to be able to move idly along predetermined sections of the monorail. It is consequently necessary for the output shaft of a motor to be connected to the shaft of a drive wheel by means of an automatically engageable and disengageable coupling. The overall object of the present invention is to provide a coupling which fulfills the aforesaid requirements, is relatively straightforward and economical to manufacture and is at the same time highly dependable in operation.

Another object of the invention is to provide a coupling of the kind described constructed in such a way as to be readily mountable between a drive shaft and a driven shaft, with no need for arduous operations, in particular on a trolley of the kind described above.

To achieve these objects, the present invention proposes a disengageable coupling between a drive shaft and a driven shaft, in particular for powered trolleys for the overhead transportation of loads on a monorail, which comprises, in combination two co-axial shafts, the former keyed to the output shaft of a motor and the latter keyed to the drive wheel of the trolley, provision being made between the opposed ends of the said two shafts for reciprocally disengageable connecting means with which externally actuated control means co-operate.

The structural and function characteristics of the invention, and its advantages over the known art, will become more apparent from the following description, by reference to the accompanying diagrammatic drawings, in which: Figure 1 is a longitudinal section of a coupling according to the invention applied between the motor and bearing wheel of a powered trolley adapted for overhead transportation of loads on a monorail; Figure 2 is a plan view illustrating part of the coupling of Fig. 1, namely a control device; Figure 3 is a view on the arrow F3 in Fig.

2; Figure 4 is a view on the arrow F4 in Fig.

2; Figure 5 is a section on the line V-V in Fig.

1; and Figure 6 is a section on the line VI-VI in Fig. 1.

In the drawings there is shown substantially the motor 10 of a trolley (not shown) and the drive wheel 11 which runs on a monorail 12.

The motor 10 and the wheel 11 are operationally interconnected through the intermediary of the coupling 13 constructed according to the invention.

The coupling 13 consists structurally of the two co-axial shafts 14, 15. The first shaft 14 is keyed to the output shaft of the motor 10, and the second shaft is keyed to the wheel 11.

The shaft 14 is hollow and is traversed by a rod 16 which is displaceable against the pressure of a spring 17.

Both ends of the rod 16 project from the shaft 14 and terminate respectively in a ferrule 18 and a cylindrical portion 19, which is connected to the rod 16 by a truncated cone portion 20.

The portions 19, 20 traverse a diametrical bore 21 in a head 22 which forms the end portion of the shaft 14.

The bore 21 houses a set of spherical rollers 23. The internal rollers 23 co-operate with the portions 19, 20 of the rod 16, and the external rollers co-operate with matching notches 24 in a socket 25 integral with the pin 15.

A cam 26 co-operates with the ferrule 18 through the intermediary of a lever 27 pivoted at 28 to a box-shaped structure 29 integral with the motor casing 10.

The cam 26 is attached to a shaft 30 rotating on the casing 29.

One end of the shaft 30 projects from the casing 29 and carries a radial arm 31 terminating in a cam-sensor roller 32.

The mode of operation of the coupling according to the invention as above described with reference to the drawings is briefly as follows: In the position shown in Fig. 1, the coupling is engaged, i.e. the shafts 14, 15 are rigidly interconnected and the motor 10 transmits motion to the wheel 11.

In this position, the spring 1 7 maintains the rod 16 with its end 19, 20 in the withdrawn position shown in Fig. 1 by solid lines, in which position the spherical rollers 23 are thrust radially outwards into engagement with the notches 24 of the socket 25.

The motor 10 consequently transmits motion to the wheel 11 by means of the kinematic chain consisting of the shaft 14, the spherical rollers 23, the socket 25 and the shaft 15.

When it is required to disengage the coupling so as to allow the wheel 11 to idle, the cam (not shown) provided on the monorail acts on the sensor roller 32, causing it to move the arm 31 to the position indicated by the dot and dash lines in Figs. 4 and 5.

This change in position of the radial arm 31 causes a rotation of the shaft 30 and thus of the cam 26, which takes up the position indi cated by the dot and dash lines in Fig. 5, in this way causing a rotation of the intermediary lever 27 which acts on the ferrule 18, causing the rod 16 to displace in the direction of the arrow F in Fig. 1.

The portions 19, 20 will therefore be taken inside the seating 33 of the socket 25 (in the position indicated by the hatching) with resulting discontinuation of the radial thrust outwards onto the spherical rollers 23, which leave the seatings 24 and in this way break the operational connection described above between the shafts 14, 15.

When the action of the cam on the sensor roller 32 has ceased, the spring 17 will automatically return the system to the original coupling engaged position, with consequent transmission of motion by the motor 10 to the wheel 11.

The advantages of a coupling according to the present invention can be summarised as follows: very great straightforwardness in construction, which is thus economical; a high degree of dependability over a period of time; and the possibility of application to trolleys already in service by means of a fast and simple operation not calling for any costly modification of the system.

The cam-operated or other type of control system can thus be added at a later stage, if desired.

It should be noted that the cam-operated control system acting on the ferrule 18 has been described and illustrated herein only by way of non-limiting example. Because of the fact that the spring 17 is not a powered spring, the displacement of the rod 16 can be manually controlled if need be.

In this regard it is to be noted that the said control system can be mounted with ample scope for spatial orientation in that the actuating member is required to act on one point only-that is to say the ferrule 18.

Moreover, the coupling according to the invention could also be positioned within the wheel 11, and would if thus positioned reduce the bulk dimension of the whole.

Also noteworthy is the fact that, compared for example to couplings with frontal teeth, the joint according to the invention has the advantage of minimising the angular clearance between the two shafts, at the same time permitting reciprocal engagement and disengagement even when they are moving at low relative velocity.

Lastly, the joint according to the invention permits of a small radial and angular disalignment between the two shafts sufficient to permit the coupling of the geared motor to the support structure without the need for high-precision processing.

Claims

1. A disengageable coupling between a drive shaft and a driven shaft, in particular for powered trolleys for overhead transportation of loads on a monorail, characterised in that it comprises, in combination: two axially aligned shafts, one keyed to the output shaft of a motor and the other keyed to the drive wheel of the trolley, provision being made between the opposed ends of the said two shafts for reciprocally disengageable connecting means with which externally actuated control means co-operate.

2. A coupling as claimed in claim 1, characterised in that the said connecting means comprise a set of spherical rollers housed within a diametrical bore in a head which forms the end-portion of the shaft keyed to the output shaft, the internal spherical rollers co-operating with the said control means and the external rollers co-operating with matching notches in a socket integral with the shaft.

3. A coupling claimed in claim 2, characterised in that said control means comprise a rod which is displaceable within the shaft against the pressure of a spring, the said rod terminating at one end in an external ferrule and at the opposite end in shaped portions acting on the internal spherical rollers.

4. A coupling claimed in claim 3, characterised in that a control device acts on the said external ferrule.

5. A coupling as claimed in claim 4, characterised in that the said control device comprises a cam mechanism.

6. A disengageable coupling between a drive shaft and a driven shaft substantially as hereinbefore described with reference to, and as shown in, the accompanying drawings.