GB2231033A - Delivery mechanisms - Google Patents

Abstract

A delivery mechanism for use in, for example, a coin-operated postage stamp vending machine, includes a feed wheel (19) over which a perforated strip of articles is passed, and a roller assembly (21, 22, 23, 24, 25) spring-loaded into engagement with the feed wheel (19) so that the strip is gripped between the wheel (19) and the rollers. The final roller (25) is tapered towards each end so as to effect bowing of the strip and thereby facilitate separation of the articles by tearing the perforations. <IMAGE>

Description

DELIVERY MECHANISMS FIELD OF THE INVENTION This invention relates to delivery mechanisms and is particularly concerned with the provision of an improved form of delivery mechanism for use in coin-operated postage stamp vending machines.

BACKGROUND TO THE INVENTION One of the primary requirements of a postage stamp delivery mechanism is that it should be capable of feeding the stamps from a roll forward through a distance corresponding to the length of one stamp and then securely holding all but the foremost stamp whilst this foremost stamp is separated from the remainder of the roll by tearing along the line of perforations between adjacent stamps.

The delivery mechanisms currently in use for this purpose have feed drums formed with rows of pins which engage with the perforations and the stamps are drawn by the feed drum over a series of guide spindles to issue through a slot in the housing containing the delivery mechanism.

The currently available delivery mechanisms have a number of disadvantages. One is that it is not always very easy to detach the foremost stamp by tearing along the line of perforations separating it from its adjacent stamp. Another is the it can be difficult to load the mechanism with a fresh roll of stamps because of the need to engage the pins of the feed drum in the perforations.

It is accordingly an object of the present invention to provide an improved form of delivery mechanism which not only avoids the above disadvantages but also affords cost and spacesaving benefits.

SUMMARY OF THE INVENTION According to the present invention there is provided a delivery mechanism for use in the feeding of articles in strip form with adjacent articles in the strip separated by perforations, said mechanism comprising a feed wheel over which the strip is passed, and a roller assembly including a plurality of rollers arranged to press the strip against the wheel whereby the strip is gripped between the wheel and the rollers, the final roller being shaped to effect bowing of the strip to facilitate tearing along the perforations.

Each of the rollers in the roller assembly, apart from the final roller, is preferably of cylindrical form and the feed wheel preferably has a cylindrical surface which is formed with a central circumferential groove or channel which cooperates with the shaped form of the final roller to afford said bowing of the strip.

A motorised drive system is preferably provided for driving the feed wheel and has a control system such that, at the end of each advancing movement of the strip, a line of perforations is located adjacent the final roller. The control system may include a detector for sensing the presence of a row of perforations and transmitting an appropriate control signal to the drive motor.

The final drive roller may be of doubly tapered form, i.e. it has a central portion of maximum diameter and tapers uniformly towards each end thereof, the maximum diameter portion of the final roller being disposed in register with the circumferential groove or channel of the feed wheel so as to press the central portion of the strip into the groove or channel and effect bowing of the strip in the vicinity of the perforations.

The roller assembly is preferably carried by a pivotally mounted frame spring-loaded into engagement with the upwardly presented portion of the feed wheel. A cleaning wheel having an adhesive or sticky surface layer is preferably provided, being spring-loaded against the downwardly presented portion of the feed wheel.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a longitudinal sectional view of a dispensing mechanism for a coin-operated stamp vending machine, Figure 2 is a front view of the mechanism shown in Figure 1, and Figure 3 is a detail view of the final roller forming part of said mechanism.

DESCRIPTION OF THE PREFERRED EMBODIMENT The delivery mechanism shown in the drawings is in the form of a module for mounting within a stamp vending machine.

There may be, for example four such modules within the machine, one for dispensing each of four different denominations of postage stamp. Within the machine there will also be the appropriate coin selection and evaluation mechanism which will be of generally known form.

The module includes a mounting plate 10 which is intended to be mounted immediately behind the front plate of the vending machine, the mounting plate 10 being formed with a slot 11 through which, in use, the stamps are delivered. Behind the mounting plate 10 there is a main body 12 the upper portion of which is afforded by a compartment 13 defined by two side walls 14 and 15. The space between the two side walls 14 and 15 is such that a roll of stamps 16 can be placed within the compartment 13 and will be supported quite securely merely by engagement with said side walls 14 and 15.

The roll of stamps 16 is placed within the compartment 13 in such manner that the free end of the strip of stamps on the roll extends forwardly from the bottom of the roll beneath a stamp sensor assembly 17. The sensor assembly 17 is connected to a control circuit carried by a printed circuit board located within a housing 18 disposed beneath the compartment 13. The sensor assembly 17 includes an infra red transmitter and receiver for sensing the presence of a row of perforations between adjacent stamps and for transmitting a control signal when a row of perforations is sensed.

After passing beneath the stamp sensor assembly, the forward end of the strip of stamps is passed over a stamp issue or feed wheel 19 the axis of rotation of which is disposed at substantially the same level as the stamp delivery slot 11. The feed wheel 19 is driven via suitable gearing by an electric motor 20 mounted alongside the main body 12 of the module. The electric motor 20 is actuated when the appropriate coinage has been inserted and the customer has operated a selection element corresponding to that particular value of stamp.

The period of time for which the electric motor is actuated to transmit drive to the feed wheel 19 is controlled by the control circuit so as to feed the strip of stamps forward by a distance equal to the height of one stamp as determined by the stamp sensor assembly. The control circuit also includes a timer such that, if the motor 20 drives the feed wheel 19 for a predetermined length of time and no signal is generated by the sensor assembly 17, the drive to the motor 20 is terminated and an "Empty" indicator is operated.

The feed wheel 19 has a smooth cylindrical form but is provided with a central circumferential channel or groove.

Bearing on the upper surface of the feed wheel 19 is a roller assembly comprising five rollers 21, 22, 23, 24 and 25 mounted on a frame 26. The rollers 21, 22, 23 and 24 are plain cylindrical rollers having a width substantially equal to that of the feed wheel 19. The frame 26 is pivotally mounted for movement about an axis coinciding with the axis of roller 24 and is spring-loaded towards the feed wheel 19. thus, as the strip of stamps is fed forwardly, the stamps are gripped effectively between the rollers 21, 22, 23 and 24 and the upwardly presented portion of the feed wheel 19.

Figure 3 shows the configuration of the foremost roller 25 and, as can be seen, the roller 25 is of twin-tapered form having a maximum diameter at its centre and tapering smoothly to either end thereof. The increased diameter central portion of the roller 25 registers with and just enters the central channel or groove in the feed wheel 19. The result of this is to cause bowing of the strip of stamps as they pass between the roller 25 and the feed wheel 19. When a dispensing operation is effected, the strip of stamps is fed forwardly until the line of perforations separating the foremost stamp from its neighbour is at or immediately adjacent to the line of contact with roller 25. This causes bowing of the line of perforations.

When, therefore, a customer has inserted the appropriate coinage into the machine and the strip of stamps has been fed forwardly so that one stamp projects outwardly of the slot 11, the customer can separate this foremost stamp from the remainder of the strip. The bowing of the portion of the strip contacted by the tapered roller 25 will ensure that, when the customer pulls on this foremost stamp, tearing of the line of perforations will commence at the central portion of the line and will require less force, by an appreciable extent, than would be the case for the rupturing of a non-bowed line of perforations. This reduction of the force required to effect rupturing of the line of perforations ensures that it is not possible to obtain dispensing of one stamp and then, by a continuously applied force, pull all of the roll of stamps out of the machine.

Beneath the feed wheel 19 and spring-loaded into contact with it, there is a cleaning wheel 27 which is provided with a surface layer of an adhesive tape or like sticky material. The feed wheel 19 is formed of a high-friction material and the cleaning wheel 27 is continuously biassed into contact with the surface of the feed wheel 19 to maintain this in a clean condition.

It is to be noted that the compact size of the module is such that four such modules can be fitted within the space occupied by two of the previous form of delivery mechanism.

Servicing is simplified in that , in the event of a fault, it is an extremely simple matter to remove and replace one of the modules. Loading of a fresh roll of stamps is also simplified in that there is no requirement for pins to be engaged with the perforations. The module can also be used for the dispensing of stamps of different lengths. When the stamp length is changed, all that is required is minor adjustment of the stamp sensor assembly 17.

Claims (9)

CLAIMS.

1. A delivery mechanism for use in the feeding of articles in strip form with adjacent articles in the strip separated by perforations, said mechanism comprising a feed wheel over which the strip is passed, and a roller assembly including a plurality of rollers arranged to press the strip against the wheel whereby the strip is gripped between the wheel and the rollers, the final roller being shaped to effect bowing of the strip to facilitate tearing along the perforations.

2. A delivery mechanism according to claim 1, in which each of the rollers in the roller assembly, apart from the final roller, is of cylindrical form and the feed wheel has a cylindrical surface which is formed with a central circumferential groove or channel which cooperates with the shaped form of the final roller to afford said bowing of the strip.

3. A delivery mechanism according to either of the preceding claims, in which a motorised drive system is provided for driving the feed wheel and has a control system such that, at the end of each advancing movement of the strip, a line of perforations is located adjacent the final roller.

4. A delivery mechanism according to claim 3, in which the control system includes a detector for sensing the presence of a row of perforations and transmitting an appropriate control signal to the drive motor.

5. A delivery mechanism according to claim 2, in which the final drive roller is of doubly tapered form, i.e. it has a central portion of maximum diameter and tapers uniformly towards each end thereof, the maximum diameter portion of the final roller being disposed in register with the circumferential groove or channel of the feed wheel so as to press the central portion of the strip into the groove or channel and effect bowing of the strip in the vicinity of the perforations.

6. A delivery mechanism according to any one of the preceding claims, in which the roller assembly is carried by a pivotally mounted frame spring-loaded into engagement with the upwardly presented portion of the feed wheel.

7. A delivery mechanism according to claim 6, in which a cleaning wheel having an adhesive or sticky surface layer is provided, being spring-loaded against the downwardly presented portion of the feed wheel.

8. A delivery mechanism for use in the feeding of a perforated strip, substantially as hereinbefore described with reference to and as shown in the accompanying drawings.

9. A coin-operated stamp dispensing machine which includes a delivery mechanism as claimed in any one of the preceding claims.