WO1995022128A1

WO1995022128A1 - Drive assemblies

Info

Publication number: WO1995022128A1
Application number: PCT/GB1995/000317
Authority: WO
Inventors: Anthony Michael Jeffs
Original assignee: Starpoint Electrics Limited
Priority date: 1994-02-14
Filing date: 1995-02-13
Publication date: 1995-08-17
Also published as: GB9402773D0; JPH09508828A; GB2301473A; DE19581599B4; GB9616101D0; GB2301473B; DE19581599T1

Abstract

A drive assembly (100) comprises: a strip (112) arranged in a continuous loop and associated with at least one row of driving members (162) spaced longitudinally along the loop; at least one support (116) around which the strip (112) is wrapped with the or at least one of the supports (116) being associated with at least one series of circumferentially spaced driving members (164) for location sequentially with adjacent ones of the driving members (162) associated with the strip (112); and an electric multi-phase stepper motor for driving said or said at least one of the supports (116) and thus moving the strip (112); the arrangement being such that the number of steps of the motor needed to move the strip (112) a distance equal to the distance between adjacent ones of the driving members (162, 164) when divided by the number of phases of the motor is an integral number.

Description

Drive Assemblies

The present invention relates to drive assemblies and is especially, but not exclusively, concerned with drive assemblies for use with gaming machines, sometimes referred to as fruit machines or amusement machines.

It is well known for gaming machines to include a number of adjacent reels marked around their circumferential surfaces with symbols such as fruit. In operation, the reels are caused to spin about a common axis by pulling on a handle or pressing a button. When the reels come to a standstill, the positions of the symbols on the different reels in relation to one or more predetermined lines decide whether or not a player has won.

Each of the reels is typically formed from a strip presenting the symbols and a drum-like support carrying the strip.

Recently, it has been proposed that the drum-like support be replaced by a plurality of parallel and rotatable supports around which the strip is wrapped.

The present invention is particularly advantageous in that it can enable the strip to be applied to the drum-like or rotatable support(s) in any position i.e. without reference to the position of the symbols relatively to the support(s) .

According to the present invention, a drive assembly comprises: a strip arranged in a continuous loop and associated with at least one row of driving members spaced longitudinally along the loop; at least one support around which the strip is wrapped with the or at least one of the supports being associated with at least one series of circumferentially spaced driving members for location sequentially with adjacent ones of the driving members associated with the strip; and an electric multi-phase stepper motor for driving said or said at least one of the supports and thus moving the strip; the arrangement being such that the number of steps of the motor needed to move the strip a distance equal to the distance between adjacent ones of the driving members when divided by the number of phases of the motor is an integral number.

Preferably, said integral number is one. The motor may be a four-phase motor with one of its phases being synchronised to driving software in electronic circuitry.

Preferably, the strip is provided with at least one row of longitudinally spaced apertures and there are a plurality of rotatable supports of which at least one is provided with at least one series of circumferentially spaced studs. The driving members are thus in the form of studs and apertures. However, the driving members could take other forms and could be formed separately from the strip and/or the support(s). The driving members associated with the strip, for example, may be a row of teeth formed in a band to which an edge of the strip is secured. There may be two of the bands each of which is associated with a respective one of the edges of the strip. Preferably, there are three of the rotatable supports, none of which has a diameter exceeding 39mm.

The strip may be formed of a translucent plastics material permitting back illumination of symbols of conventional size presented thereby, but the strip could be of an opaque material such as white card.

A tab may be provided as part of an optical device for providing information to the electronic circuitry.

Preferably, a pair of parallel and non-rotatable supports are provided to which the rotatable supports are rotatably secured.

The non-rotatable supports may be formed as plates of generally triangular outline with the rotatable supports extending therebetween and being located at or near the corners thereof, but plates of other shapes would be possible.

In use of the preferred drive assembly, the electrical stepper motor rotates only one of the rotatable supports, which thus positively moves the strip wrapped therearound whilst the other rotatable supports merely idle, in order to bring symbols presented by the strip into successive view through one or more windows in a gaming machine. A particularly preferred drive assembly according to the present invention will now be described by way of example only with reference to the accompanying drawing which is a schematic perspective view of the drive assembly. The drive assembly 100 includes: a strip 112 arranged in a continuous loop; a plurality of parallel and rotatable supports 116 around which the strip 112 is wrapped; and a pair of parallel and non-rotatable supports 130 to which the rotatable supports 116 are rotatably secured. The strip 112 may be a translucent plastics strip of generally conventional construction having symbols 160 printed or otherwise formed thereon. A row of apertures 162 may be formed near an edge of the strip 112 such that the apertures 162 are spaced apart along the length of the strip. A second row of similar apertures may be formed near the other edge of the strip.

For convenience, each of the rotatable supports 116 may be integrally moulded of a plastics material to the same shape, even though only one of the supports 116 is here to be driven.

A conventional toothed timing belt 122 may connect an electric multi-phase stepper motor to a toothed disc 124 carried centrally of a driven shaft 126, which is in turn to drive the strip 112 wrapped therearound whilst the other rotatable supports 116 merely idle. More particularly, the ends of each of the rotatable supports 116 are formed with respective discs 128. If the strip 112 is to have one row of the apertures 162, only one of the two driven discs 128 on the driven shaft 126 needs to be formed with a series of circumferentially spaced studs 164. If the strip has two rows of the apertures 162, both of the two driven discs are formed with a respective series of the studs 164. Alternatively, as appropriate, other ones or even all of the discs 128 may be provided with corresponding series of circumferentially spaced studs 164. It will be appreciated that, in use, the studs 164 sequentially engage with the apertures 162 to locate the strip correctly as the strip is driven.

The non-rotatable supports 130 may be of a rigid metal construction capable of being secured to a pair of end brackets 166 which are themselves capable of being secured through holes 167 to the body of a gaming machine.

Each of the non-rotatable supports 130 may be a plate of identical shape to the other, for convenience, even though not all of the mountings and other features are then utilised. Thus, each of the plates 130 may have an elongate cutout 168 and a pair of slotted offset tongues 170. However, a plastics lamp housing may be a snap fit with just one of the cutouts 168 and the stepper motor may be adjustably secured to just one pair of the tongues 170. Preferably, the lamp housing is fixed to one of the plates 130, whereas the stepper motor is fixed to the other of the plates 130. Similarly, each of the plates 130 may have a hole 172 to which an optic unit 174 can be secured, although only one of holes 172 is utilised.

The lamp housing may incorporate a plurality of individual lamp sections, the stepper motor may be associated with a pair of sprung loaded belt tensioners 179 (only one shown) for tensioning the belt 122, and the optic unit 174 may have a pair of arms 180 between which can pass an optic tab stuck or otherwise fixed to the inner surface of the strip 112. The driven shaft 126 is mounted at opposed bearings 182 whereas the other two rotatable supports 116 are sprung mounted in bearings 184 - the springs keep the correct tension in the strip 112, but can be compressed to disengage the studs 164 from the apertures 162 and thus facilitate fitting/removal of the strip 112. Finally, three struts 186 extend between opposed pairs of holes 188 to provide rigidity and the correct spacing between the plates 130.

The numerical features of the illustrated particular embodiment will now be described.

The strip is 600mm long, one full revolution of the strip requires 160 steps of the motor (due to the ratio between the motor and a drive roller) , one full revolution of the motor requires 48 steps, the strip has 40 apertures along its length, the motor has 4 phases and there are 8 studs circumferentially arranged about each rotatable support (one of which is the drive roller) .

It will be demonstrated that the number of steps of the motor needed to move the strip a distance equal to the distance between adjacent ones of the studs when divided by the number of phases of the motor is an integral number.

One pitch between adjacent studs = 360/8 = 45" Ratio of motor to drive roller = 2:3

1 step of motor = 360/48 = 7 "

Steps per stud pitch = 45 x 2. = 4 steps

7.5 3

1 pitch between studs = 600/160 x 4 = 15mm Circumference of drive roller = 8 x 15 = 120mm Diameter of drive roller = 38.2mm

Steps per stud pitch / Number of phases of motor = 4/4 = 1

With the motor energised, it is rotated about its central axis to position the strip drive roller to a datum position with a stud lined to a reference point. The strip (with an optic tab located at a predetermined position) can now be loaded onto the drive/idler rollers.

When the motor is fully stepped round, every 4 steps brings one drive stud back to the datum position and at the appropriate 4th step the position tab will be central in a sensor optic to give the strip .master position.

Thus it is irrelevant at which drive roller position the strip is loaded. For equal steps per symbol operation

No. of symbols x No. of whole steps/symbol = 160 steps i.e. 16 symbols = 10 steps/symbol 20 symbols = 8 steps/symbol 10 symbols = 16 steps/symbol The above particular embodiment enables the strip to be applied in any position when a particular one of the four motor phases is to be utilised. A four-phase stepper motor has four groups of coils surrounding the rotor. When any group of coils is energised, the rotor or shaft of the stepper motor rotates by one step. The groups of coils are energised successively. Since four steps are required to drive a stud back to the datum position, the driving software may be synchronised with the energising of just one group of coils, namely with one phase, as a stud will always be at the datum position upon energising of this group of coils.

Clearly, in other embodiments the studs and apertures may be replaced by other driving members.

Claims

1. A drive assembly comprising: a strip arranged in a continuous loop and associated with at least one row of driving members spaced longitudinally along the loop; at least one support around which the strip is wrapped with the or at least one of the supports being associated with at least one series of circumferentially spaced driving members for location sequentially with adjacent ones of the driving members associated with the strip; and an electric multi-phase stepper motor for driving said or said at least one of the supports and thus moving the strip; the arrangement being such that the number of steps of the motor needed to move the strip a distance equal to the distance between adjacent ones of the driving members when divided by the number of phases of the motor is an integral number.

2. A drive assembly according to claim 1, in which said integral number is one.

3. A drive assembly according to claim 1 or claim 2, in which the motor is a four-phase motor with one of its phases being synchronised to driving software in electronic circuitry.

4. A drive assembly according to any preceding claim, in which the strip is provided with at least one row of longitudinally spaced apertures and there are a plurality of rotatable supports of which at least one is provided with at least one series of circumferentially spaced studs.

5. A drive assembly according to any preceding claim, in which the strip is 600mm long, one full revolution of the strip requires 160 steps of the motor, one full revolution of the motor requires 48 steps, the strip has 40 apertures along its length, the motor has 4 phases and there are 8 studs circumferentially arranged about each rotatable support.