Coin dispenser made with adjustable height structure
The present invention relates to a coin dispenser for use in vending machines for giving out change when the value of money inserted into the machine by a customer exceeds the price of the merchandise purchased. 
     The usual arrangement for dispensing coins is a vertical coin tube which contains a stack of coins of a single denomination. A channel extends horizontally beneath the lower end of the tube and has an upper wall with an aperture aligned with the coin tube and a lower wall with an aperture disposed over a change dispensing passageway. The aperture in the lower wall is offset from the vertical axis of the coin tube so that coins in the coin tube cannot fall directly through the aperture in the lower wall. A slide plate is disposed in the channel and serves to transfer coins from the bottom of the stack in the coin tube to the aperture in the lower wall. A slide plate is disposed in the channel and serves to transfer coins from the bottom of the stack in the coin tube to the aperture in the lower wall. The plate has circular apertures for receiving coins from the stack. The plate can be slid back and forth in the channel between a position in which the aperture in the plate is below the coin tube and there receives a coin from the tube and a position in which it is over the aperture in the lower wall from where the coin falls into the dispensing passageway. The height of the channel is between one and two coin thicknesses so that only one coin at a time can be dispensed. A machine which dispenses more than one denomination of coin as change will have such an arrangement for each denomination of coin. 
     For the dispenser described above to work reliably the dimensions of the dispenser must closely correspond to the diameter and thickness of the particular denomination of coin being dispensed. This means that the manufacturer of such dispensers for several countries offer a large number of different sizes of mechanism to suit the large variety of sizes of coins in use. 
     The aim of the present invention is to simplify the design of a coin dispenser so that different sets of coins can be catered for using a small range of parts. 
     According to the present invention a coin dispenser comprises a channel, an aperture in the upper wall of the channel, a coin tube extending down through the aperture in the upper wall of the channel the lower end of the tube projecting down below the level of the upper wall of the channel, an aperture in the lower wall of the channel offset from the axis of the tube, an apertured slide plate-mounted for reciprocating movement in the channel and means mounting the coin tube with its lower end a predetermined height above the lower wall of the channel. 
     By using the lower end of the coin tube to form the lowest point on the coin channel the individual slide plates and channels do not have to be made to suit the individual thickness of coins: it is possible to use one size of channel and slide plate to serve a large number of different sizes of coins. The slide plates and channels are used in combination with coin tubes selected from a range of different sizes of coin tubes and the mounting means are used to mount the selected coin tubes at the appropriate height for the particular thickness of coins being used. Thus for the manufacturer the number of different parts needed to meet the requirements of customers in different countries can be substantially reduced. Whilst the mounting means must be made to suit the particular denomination of coins being used, by making inexpensive mounting plates for each coin set, or by assembling the tubes in predetermined positions on a standard mounting plate, for example by using a different mounting jig for each coin set, and staking in position, the part which has the largest number of variants for the mounting plates is expensive to produce or assemble. 
    
    
     An embodiment of the invention will now be described, by way of example, with reference to the accompanying drawings, of which: 
     FIG. 1 shows an exploded perspective view of a coin dispenser according to the invention; 
     FIG. 2 shows a front view, partly in section, of the coin dispenser of FIG. 1; 
     FIG. 3 shows a horizontal section of the coin dispenser taken on the line III--III of FIG. 2; 
     FIG. 4 shows a vertical section of the coin dispenser taken on the line IV--IV of FIG. 2; and 
     FIG. 5 shows a plan view partly in section of the coin dispenser taken on the line V--V of FIG. 4. 
    
    
     The drawings show a coin dispenser 11 for dispensing three denominations of coins. The dispenser 11 includes three vertical coin tubes 12, 13 and 14 of moulded plastics, one for each denomination of coin. The coin tubes hold the coins in vertical stacks. 
     Beneath each of the coin tubes 12, 13 and 14 a respective channel 15, 16 and 17 extends horizontally. In the upper wall of each channel is an aperture 18, 19 and 20 through which the lower end of the coin tube 12, 13 and 14 extends. In the lower wall of each channel and out of alignment with the coin tube 12, 13 and 14 is an aperture 21, 22 and 23 leading to a coin dispensing passage (not shown). The coin dispensing passage leads to a receptacle which is accessible to a customer outside the machine in which the dispenser is housed so that the customer may collect the change dispensed. 
     A slide plate 24, 25 and 26 is disposed in each channel 15, 16 and 17. The plates each have an aperture 27, 28 and 29 for receiving coins from their associated tubes 12, 13 and 14. The slide plates 24, 25 and 26 are movable between positions in which the apertures in the plates are below their respective coin tubes and positions in which they are above their respective apertures in the lower walls of the channels by means of three solenoid actuators 30, 31 and 32. 
     The coin dispenser is made up from a base member 33 of moulded plastics material to which all other parts are secured. The base member comprises a horizontal plate 34 which forms the upper walls of the channels 15, 16, and 17 and contains the three apertures 18, 19 and 20. The base member also comprises a vertical plate 35 to the back of which are secured the solenoid actuators 30, 31 and 32 by means of screws 36. 
     As can be seen in FIG. 4 each solenoid actuator includes a bell crank lever 37 of moulded plastics material which is pivoted on a rod 38 which passes through lugs 39 carried by partition walls 40 moulded on the base member 33. The armature 41 of the solenoid actuator is pivotally connected to the bell crank lever 37. A leg 42 moulded or the lower end of the lever 37 sits in a slot 43 between two upstanding projections 44 at the rear of the slide plate 24, 25 or 26. A spring 45 is wound around the armature of the solenoid actuator and acts between the casing of the solenoid and a flange 46 on the armature to urge the armature into the extended position. In this position the bell-crank lever 37 is fully rotated in the anti-clockwise direction and the leg 42 holds the slide at the right hand end of its travel as shown in FIG. 4. Movement of the slide plates towards the rear is limited by abutment with the dispenser enclosure (not shown). When the solenoids are energised the armatures are retracted against the action of the springs 45, the bell crank levers 37 are rotated in the clockwise direction and the legs 42 engaging the slots 43 push the slide plates forward until the apertures 27, 28 and 29 in the plates are below the coin tubes 12, 13 and 14 respectively when the slide plates abut bosses 48 on the underside of the plate 34 or, alternatively, when projections 44 abut the horizontal plate 34. The solenoids are immediately de-energized and the slides return to the back of the channels under the action of the springs 45. 
     The lower walls of the channels 15, 16 and 17 are formed by a moulded plastics plate 49 which is secured to the underside of the plate 34 by screws 50. The bosses 47 and 48 serve as spacers to space the plate 49 from the plate 34. The plate 49 is spaced from the plate 34 by a distance at least as great as the thickness of the thickest coin which the dispenser may be required to dispense. The plate 49 contains the apertures, 21, 22 and 23. Two of the apertures are of the same diameter, one, 21, is larger but is partially covered on one side by a moulded web 51, the upper surface of which slopes down towards the chordal edge. The web 51 covers almost half of the area of the aperture 21. The diameter of the apertures 27, 28 and 29 in the slide plates match the diameters of the holes in the plate 49. 
     When the coins from the tube 12 are moved by the slide 24 to the aperture 21 they drop into the recessed upper part of the aperture and then slide down the inclined upper surface of the web 51 and through the open part of the aperture into the dispensing passageway. The web 51 serves to deflect coins dispensed through the aperture 21 into a defined coin-return area. Grooves 52 running from front to back are formed in the upper surface of the plate 49 and engaged by runners 53 on the underside edges of the slide plates 24, 25 and 26 to guide the plates for rectilinear sliding movement in the channels. 
     The coin tubes 12, 13 and 14 are mounted on a plastics mounting plate 54. Each tube has two pairs of pegs or studs 55 moulded on it which are received in corresponding pairs of holes 56 drilled in the plate. The tubes are of different diameter, but the horizontal and vertical spacing of the pegs is identical for every tube, such that any tube may be assembled into any one of the three locations in the mounting plate. 
     The peg holes in the mounting plate are slotted vertically to allow adjustment of the tube position so that the lower end of each tube is at the correct height above the lower wall of the channel when the dispenser is assembled. 
     The correct height is between one and two coin thicknesses so that coins are dispensed singly. 
     Once the coin tubes have been assembled on the plate and their positions adjusted, they are secured in place by collapsing the pegs as by ultrasonic melting to fill the slots completely and form mushroom-shaped heads. 
     Pegs or studs 61, 62 located in recessed pockets 63, 64 protrude beyond the planar surface of vertical plate 35 and are received in close-fitting holes 65, 66 drilled in mounting plate 54. Pegs 61, 62 and holes 65, 66 serve to position accurately the sub-assembly of plate 54 and the coin tubes with respect to vertical plate 35. 
     The sub-assembly of tubes and mounting plate is secured on the vertical plate 35 by two hooks 58 which are moulded integrally with the outer two partition walls 40. The lower ends of the tubes extend through into the apertures 18, 19, 20, and a packing ring 59 may be inserted between the lower ends of the smaller tubes and the aperture 18 to provide further stability. 
     We have found it possible to build dispensers for the coin sets of three different coins of the major currencies of the world from a single size of sub-assembly of base-member 33, bottom plate 49, slide plates 18, 19, 20, solenoid activators 30, 31, 32, tube mounting plate 54 and a range of up to six different sizes of coin tubes. 
     In this particular dispenser the tubes are selected from five having the following dimensions: 
     
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TUBE NO.     INTERNAL DIA.                                                
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1            29.5                                                         
2            24.5                                                         
3            21.5                                                         
4            19.5                                                         
5            17.5                                                         
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     The slides have the following dimensions: 
     
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SLIDE PLATE  APERTURE DIA. THICKNESS                                      
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24           29.85         1.15                                           
25           21.85         1.1                                            
26           24.85         1.1                                            
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     The bottom plate has the following aperture diameters: 
     
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BOTTOM PLATE    APERTURE DIA.                                             
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21              30.3                                                      
22              22.3                                                      
23              25.3                                                      
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     As examples of the tubes that may be used for different currencies of the following are given: 
     
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COUNTRY     SWITZERLAND                                                   
COINS       10c.         50c.   20c.                                      
TUBE SET    4            4      3                                         
HEIGHT (h)  2.1          1.95   2.43                                      
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COUNTRY    WEST GERMANY                                                   
COINS      10pf.        50pf.  1 DM                                       
TUBE SET   2            3      2                                          
HEIGHT (h) 2.3          2.18   2.38                                       
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COUNTRY     NORWAY                                                        
COINS       50φ      25φ                                          
                                1kr.                                      
TUBE SET    2            5      1                                         
HEIGHT (h)  2.33         2.0    2.46                                      
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     Where (h) is the height of the lower end of the tube above the lower wall of the channel on the assembled dispenser. 
     All dimensions are in millimeters.