This invention relates to apparatus for treating bulk produced pellets for airguns.

Airgunning is a sport that is growing in popul¬ arity around the world. There are more than two million shooters in -Britain and many more in the United States, Canada, Europe and Australia. For the first time air¬ gunning was included in the Olympics in 1934 _*

There are a large number of manufacturers that sell air-rifles, air-pistols, pellets and associated air- gunning equipment. For example, in the UK, airgun pellets are supplied by British, German, American, Spanish and Japanese manufacturers. British air rifles and pellets are manufactured to calibres of 0.177 inch and 0.22 inch while German ones are manufactured to calibres of 4 _* 5 mm and 5-5 mm. Although these calibres are similar, they are not identical. Of the scores of British pellets per¬ haps only one is specifically made to suit German rifles and no German pellets are manufactured to suit British air rifles. Airgun ammunition is made of lead, copper, zinc or plastic coated metal alloys; lead pellets being the most popular and the most abundantly available by far. Lead pellets can be broadly classified into three groups according to the groups of people they cater for. 'Match' grade pellets are used by 'competition' or paper target marksmen. This is the most popular aspect

of airgunning. Hundreds of clubs are devoted to Match shooting and all international competitions are in this category.

'Hunter' grade pellets are used by pest controll- ers and by people who hunt live quarry.

'Plinker' grade pellets are used by marksmen who shoot for 'fun' at metal targets or at tin cans.

There are scores of pellet types and shapes spread across the above classifications. Only two, or perhaps three of these types, intended for 'Match' use, are packaged with the pellets separated. Even these pellets however, are not individually airtight sealed. The vast majority of pellets are supplied in bulk in 'tins' of 500, 25 or 200. These pellets are free to press against each other and by the time a 'tin' reaches the consumer, most, if not all the pellets in the 'tin' have suffered deformation due to handling and transportation.

There is considerable variation in the weights of pellets in any 'tin'. This variation in weight is detrimental to consistently accurate marksmanship.

It is difficult for a user to purchase a small number of pellets; he must buy the whole 'tin'. Once opened, the 'tin' seal is broken and the lead pellets begin to oxidize. This results in hardening of the lead and inaccuracies in shooting.

As mentioned above, there are scores of lead pellet types. However, although each type differs from the next by distinctly different shapes, they all have the following in common; a solid 'head' or forward- section and a hollow 'skirt' or rear section.

An object of the invention is to enable better accuracy to be achieved from bulk produced pellets.

This invention includes apparatus "for treating bulk produced pellets for airguns, comprising means for auto- matically sorting a batch of such pellets having weights

over a given range into a plurality of batches each com¬ prising pellets with weights over a respective predeter¬ mined range within said given range.

The apparatus may further comprise means for re- storing or modifying the shape of each pellet to a de¬ sired shape, in which the apparatus preferably comprises means for feeding the pellets sequentially, one at a time, to said sorting means and second means for feeding said pellets sequentially, one at a time, from said sorting means to said restoring or modifying means, one of said first and second feeding means being arranged to orientate the pellets so that they are axially aligned and face the same direction.

The apparatus may further comprise means for indi- vidually packaging the pellets.

When the apparatus includes both the means for re¬ storing or modifying the shape of each pellet to a de¬ sired shape and the means for individually packaging the pellets it preferably also includes means for automatic- ally feeding the sorted and restored or modified pellets to the packaging means.

The invention also includes a method of treating bulk produced pellets for airguns, comprising sorting a batch of such pellets having weights over a given range into a plurality of batches each comprising pellets with weights over a respective predetermined range within said given range, and individually packaging said sorted pellets.

Preferably prior to said packaging step, the shape of said pellets is restored or modified to a desired shape.

The pellets may be packaged into packets each of which comprises a plurality of recessed compartments which are sealed in an airtight manner. The invention also includes a method of treating

bulk produced pellets for airguns, comprising sorting a batch of such pellets having weights over a given range, into a plurality of batches each comprising pellets with weights over a respective predetermined range within said given range, and restoring or modifying the shape of said pellets, to a desired shape.

In order that the invention may be well understood, the presently preferred embodiment thereof, which is given by way of example only, will now be described, with reference to the accompanying drawings, in which:

Fig. 1 shows the general arrangement and sequence of operations of the apparatus;

Fig. 2 is a plan view of the automatic pellet dispenser; Fig. 3 is a view on line T-T in Fig. 2;

Fig. 4 is a sectional view through the pelle unidirectionalizer;

Fig. 5 is another sectional view through the pellet unidirectionalizer along line U-U; Fi _* o is a detail of the electrical circuitry shown in Fig. 5;

Fig. 7 is a plan view of the Equal-Weight grouping mechanism;

Fig. δ is a view on line V-V in Fig. 7; Fig« 9 is a view on line W-W in Fig. 7;

Fig. 10 is a detail of the electrical circuitry shown in Fig. 7;

Fig. 11 is a plan view on the Feed Trolley mechanism;

Fig. 12 is a view along line X-X in Fig. 11 showing the cam-actuated press mechanism and the Feed Trolley;

Fig. 13 is a sectional view through the pellet packing mechanism;

Fig. 14 is a view along line Y-Y in Fig. IS and

Fig. 15 is a plan view along line Z-Z in Fig. 13 showing a pellet packet.

Reference is first made to Figure 1 which shows schematically the general arrangement of the apparatus, which is best described with reference to the sequence of _. operations it performs. In this sequence, a batch of 5 pellets of one type which are either bulk produced or, following bulk production, are bulk supplied, and having weights over a given range are laid out on a flat vi¬ brating table A to cause them all to lie on their sides. Badly damaged pellets are removed and the remainder fed

1.0 down a sloping chute B which tapers into a half-round tube C. The pellets are now all axially aligned and are stored in a spirally wound storage tube D. From this storage tube the pelle-ts are led into an automatic pellet dispenser E which feeds randomly oriented pellets one at

15 a time, into a pellet unidirectionalizer F. Here the pellets are all realigned to face in the same direction.

From here the batch of pellets pass into a sorting, or equal-weight grouping mechanism G where they are automatically divided or sorted, into a plurality of 0 batches, or groups, each of which comprises pellets with weights over a respective predetermined range within the given range of weights of the original batch. Each group of pellets is stored in a respective spirally wound storage tube H. When a sufficient number of pellets of 5 a particular weight range has been stored in a tube H they are led into a second automatic pellet dispenser I which feeds the pellets unidirectionally one by one, into a feed trolley J along an axial plane A4- The feed trolley conveys the pellet to an axial plane A2. 0 In this position the pellet, usually deformed, is pressed back into its original shape by a rotating press L. The reshaped pellet is released into a pellet filling mechanism M. From here the filled packets of pellets pass on to covering rollers N where the packets are air- 5 tight sealed with foil, PVC tape or similar covering.

The feed trolley J and the press L are actuated by cams at axes A3 and A2 respectively. A sprocket and chain drive 0 maintains these cams and further cams on the maching in phase with one another. An electric motor drives the chain.

A 5:1 gear ratio drive P and a 5:1 gear ratio drive Q service the pellet filling mechanism M.

Referring now to Figures 2 and 3 which show in more detail the automatic pellet dispensers E and I. In these dispensers, a cam-actuated tapered-edge mechanism la,lb,lc by moving to and fro through bearings 2,3 causes bars 5a, 5b; 5c, 5d; 5e,5 "to slide back and forth between guide wheels 6. A spring system 7 ensures that the bars remain in contact with the tapered-edges at all times. Nibs Sa,8b; δc.Sd; δe,δf are attached to the bars 5a,5b; 5c, 5d; 5e,5 respectively and move together with the bars. These nibs are interchangeable and are unique to the type of pellet being serviced.

Top and bottom plates 10,11 hold the guide wheels 6 and the spring mechanism 7 in position. A block 9 holds the pellets in position at the bottom of tube 13 when the nibs δ ^' a,δb; 8c,Sd; δe,Sf are in their 'open' positions. The whole pellet dispenser mechanism is supported by member 4- At the start of the cycle the nibs δe.Sf are in the 'closed' position, sealing off the bottom of tube 13 while nibs 8a,δb; δc,Sd are in the 'open' position. Pellets from the storage tube D in Fig. 1 enter the tube 13 and stack up vertically. The second stage of the cycle closes nibs δa,Sb around the pellet 12a and thus now supports the column of pellets in tube 13- The third stage of the cycle causes the nibs 8c, δd to lock the pellet 12b into its correct drop alignment. The fourth stage of the cycle 'opens' the nibs δe,8f. The fifth stage Opens' nibs δc,8d which causes the pellet 12b to fall out of the tube 13. The sixth stage 'closes' nibs

8e,δf. The seventh stage 'opens' nibs 8a, 8b; 8c, d to start the next cycle.

The automatic pellet dispenser E in Fig. 1 is used for dispensing randomly stacked pellets, i.e. pellets which can face either up or down. In this dis¬ penser the nibs 8c, 8d are not used and may be omitted.

The automatic pellet dispenser I in Fig. 1 is used for unidirectionally stacked pellets, i.e. pellets which all face downwards. Nibs δc,δd as described above are used in dispenser I.

Referring now to Figures 4 _? 5 and 6, there is shown in more detail the pellet unidirectionalizer F. This is a device that accepts pellets that face either forwards or backwards and causes them to emerge all facing in the same direction. In the device, a hinged valve 14a is positioned above a tube 15a such that the top surface of the valve lines up with the tube opening when the valve is rotated into position 14b. Valve 14a is support¬ ed by a bar lόa through a roller lδ. When the bar rotates at its hinge 17a into position lόb the valve is pushed into position 14b. Springs 19a, 19 ensure that the valve and bar return to their original positions, after rotation.

A second bar lόc is positioned above the valve 14a and holds a saddle 20 over the valve. When the bar ro¬ tates at hinge 17b into position lόd the saddle is situated over the opening to the tube 15b. The spring 19c returns the bar to its original position, after rotation. Tubes 15a, 15b merge into a single tube 15c prior to exiting a supporting material block 21. An electrical contact point 24b is positioned central to the pellet position. It makes contact with the point 25b when it is depressed. A time delay relay 26 is connected to the circuit and leads to solenoids 28a, 28b and a power source

27- ,The circuit is arranged such that when points 24b, 25b make contact, the solenoid 2δa is activated and re¬ mains activated till the circuit is broken by the time delay relay 26. When the points 24b, 25b do not make contact the solenoid 2δb is activated when the switch 24a is closed.

A pellet dispensed from tube 13 (see Fig. 3) of the pellet dispenser E runs along a chute 22 and enters the saddle 20 assuming the position 23- If on entering the saddle the pellet is facing forwards, the pellet head strikes the contact point 24b which triggers the solenoid 28b into action as described above. The bar l6c is pulled forward by the solenoid. This causes the bar to rotate into position lόd and the saddle 20 to push the pellet 23 into the tube 15b. This action is kept 'open' by the time delay relay to allow sufficient time for the pellet to clear the saddle. The pellet thus emerges from tube 15c facing forwards.

If on entering the saddle 20 the pellet is facing backwards, the pellet skirt, being hollow, avoids contact with the point 24b. When the switch 24a is closed, it triggers the solenoid 28a into action. The bar lόa is pulled forward by the solenoid. This causes the bar to rotate into position 16b thus causing the valve to ro- tate into position 14b. The pellet 23 slides down the valve and enters the tube 15a. The action is kept 'open' by the time delay relay to allow sufficient time for the pellet to clear the valve. This pellet also thus emerges from the tube 15c facing forwards. The pellets 23a, 23b shown in Fig. 6 are the two most common shapes of the various types available.

Referring now to Figures 7,8 and 9, the 'equal- weight ' grouping mechanism G will now be described in more detail. In this mechanism, a system of balance beams 30a, 30b, 30c, 30d rest on fulcrums 31 which are fit¬ ted into V-shaped grooves to prevent them from spinning around. The balance beams are prevented from rotating

- -- . -. - .=-_ ^* y _ by contact points 42,43 on one side and by cam-actuated rods 32 on the other. The system is arranged such that the first beam 30a is positioned higher than and in be¬ tween the next pair 30b; only one beam of the pair is shown; each lower beam 30b is positioned higher than and in between the next pair 30c, 30d.

Predetermined loads 50b, 50c, 50d, 50e are placed on the right hand sides of the beams. These loads are de¬ signed such that the balance beams remain horizontal when a pellet of less than or of equal weight is placed on the opposite end of the beam. If the pellet at the opposite end is heavier than the load on a beam, the balance beams will tip over. These loads are determined by the actual weight range of a particular type of pellet and by the amount of tolerance acceptable in the equal-weight groups. A numerical example of loads is given hereinafter.

A system of tubes 39a, 40a,40b,41a,41b,41c,41d is arranged to lead from each side of a balance beam down to the centre of a lower balance beam.

Systems of hinged bars 35 _? 36,37 are located above the left hand ends of the balance beams. These bars are able to rotate about the 'fixed' hinges 49 and about, the 'free' hinges 48. Each vertical bar has a saddle 51 fixed to its bottom end, just clear of the balance beam. When the vertical bars are rotated one way the saddles are positioned over the tube openings on the left hand sides of the balance beams, and when rotated the other way, the saddles are positioned over the tube openings on the right hand sides of the balance beams. For example, along line W-W in Fig. 9 the saddles 51 all lie either over the tubes 41a,41c or over the tubes 41b, 41d.

Solenoids 45a,45b are positioned in close proximity to the top members of the hinged bars system

- 40

37« Similar pairs of solenoids are similarly positioned at the hinged bar systems 35 _. 36.

The cam-actuated rods 3 move up and down through bearings 33 - In its topmost position each rod makes contact with the left hand side underside of a balance beam 34- On its way down the rod loses contact at 34 _* Further down, the rod makes contact with and 'closes' an electrical switch 47• This switch is 'opened' when the rod begins to move upwards again. Each lateral rod system - across a section such as line W-W in Fig.7 - is controlled by a cam placed directly under it . Thus all the rods across any one section move up and down together. The cams under the rod systems are In phase with each other and with the cam controlling the pellet dispenser E in Fig. 1 by all being linked by a single chain drive. Dispensed pellets pass through the pellet unidirectionalizer F in Fig. 1 and follow one another along the equal-weight system such that only one saddle across a line such as W-W in Fig. 7 has a pellet in it during any one cycle of the cams.

Figure 10 shows the electrical detail at the contact points 42,43- The circuit is arranged such that when the points 42,43 are in contact, a normally-open- relay 44 only allows the solenoid 45a to become activ- ated by the power source 46 when the switch 47 is closed by the rods 32. If the contact points 42,43 are not in contact when the circuit is closed, the normally-open- relay only allows the solenoid 45b to become activated. In use, a pellet 50a emerging from the pellet unidirectionalizer in Fig. 4 slides along the chute 38 and enters the saddle 51 over the balance beam 30a. As the cam-actuated rod 32 begins to descend the beam support at 34 is removed and a balance is struck between the pellet 50a and the load 50b. If the weight of pellet 50a is equal to or less than the load 50b the two points 42,43 remain in contact. When the switch 47 is 'closed' by the rod 32 the solenoid 45a will be activated.

_ 4 i _

The hinged system 35 will be attracted to the solenoid and will cause the saddle 51 ~o push the pellet 50a into the tube 39a. The contact at switch 47 is spring loaded and contact is maintained for a sufficient length of time to allow the pellet to clear the saddle before the saddle returns to its original position.

If the pellet 50a is heavier than the load 50b the balance beam 30a will tip to the lefthand side and break the contact between points 42,43« Now when the switch 47 is closed, the solenoid 45b will be activated causing the pellet 50a to be pushed into tube 39b.

A pellet entering tube 39a will slide down the tube and come to rest in the saddle 51 over balance beam 30b. During the next cam cycle, and in a manner des- cribed above, the pellet will be pushed into tube 4 a or into tube 40b depending on whether it is lighter than or equal to, or heavier than the load 50c. Similarly - from the balance beam 30c for example - the pellet will be pushed into either tube 41a or 41 depending on whether it is lighter than or equal to, or heavier than the load 50d.

As a numerical example : If 50b = 10 grains

50c = 9.8 _. grains 50d = 9-7 grains

50e = 9-9 grains pellets emerging from tube would all weigh

" 41a " less than 9-7 grains

" 41b " between 9.7-9.δ grains " 41c " " 0.8- ^Q .9 grains

" 41d " 9.9-10 grains

Similar weight groupings (all over 10 grains) would be produced on the other side of the centreline.

Referring now to Figure 11, the feed trolley will now be described in more detail. The feed trolley

comprises a frame 56 carried on guide wheels 53 which run to and fro along a guide track 54 _. its movements controlled by a cam at the axial plane A3«

A tapered edge mechanism 60 is actuated by a cam 58 through a roller 71• Its forwards and backwards movement through the bearings 6la,6lb causes the bars 62a,62b to slide back and forth between the guide wheels 63. A spring system within the bars and the spring 69 ensure that all parts of the mechanism always remain in contact. Nibs 64a,64b are attached to the bars and move together with them. These nibs are interchangeable and are unique to the type of pellet being serviced. Top and bottom plates 55 hold the guide wheels and bar spring system in position. A further tapered-edge mechanism 66 is situated directly above the tapered-edge mechanism 60. It is actuated by a cam 57 through a roller 70 and guided in bearings 67a,67b. The movement of nibs 64c, 64d is controlled by the tapered-edge mechanism 66 in a similar manner to that described above. Pellet holding blocks 65 unique to the head shape of the pellet being serviced are carried by a bottom plate 55 and are capable of being pulled down by solenoids placed directly under them.

All the above mechanisms, including the cams 57 ₅ 58 are mounted on the frame 56 and move along with it. Referring now to Figure 12, the press L is shown in more detail. The press has a cross-beam 106 which connects two vertical rods 103a through bearings 104. Attached to the bottom ends of these vertical rods are press heads 103b which are unique to the shape of the pellet skirt . Also attached to the cross-beam 106 are small electric motors 68 which rotate the vertical rods 103a and the press heads 103b through a belt and pulley system 78. A cam 108 at the axial plane A2 moves the cross-

- I - beam with all its attachments up and down through a roller 107 ₅ a spring 105 keeping it in contact with the roller.

Operation of the trolley J and the press L will now be described with reference to Figures 11 and 13• Firstly, however it will be appreciated that by having several sets of nibs and control systems any number of pellets can be serviced simultaneously on this machine. Only two sets however, have b.een shown on the drawings and the operation of only one set is described below.

At stage 1 of the chain drive system 0 in Fig. 1, the pellet holding block 65 on the feed trolley (Fig.11) is in the axial plane A4• The nibs 64a, 64b, 64c,64d are 'open'. A pellet, drops into the holding block from the pellet dispenser I in Fig. 1.

At stage 2 the nibs 64a,64b 'close' and secure the pellet firmly in the holding block.

As stage 3 , the holding block 65 is pulled free of the pellet by the solenoid under it. At stage 4, the feed trolley moves the pellet to the axial plane A2.

At stage 5, the cam-actuated press pushes the press head 103b into the skirt of the pellet. This down¬ ward action coupled with the spin of the press head re- shapes the pellet skirt to its true shape.

At stage 6, while the press heas if just free of the pellet skirt the nibs 64c, 64d close around the outer surface of the pellet skirt.

At stage 7 _? the nibs 64a, 64b and the press head withdraw.

At stage 8, the nibs 64c, 64d open and the pellet drops into the pellet filling mechanism M in Fig. 1.

At stage 9 , the Feed Trolley returns to the axial plane A4• At stage 10, the pellet holding block 65 springs back to its upper position.

The machine has now completed one cycle and is in position to receive the next pellet.

The pellet packing mechanism M will now be des¬ cribed with reference to Figures 13 to 15. This mechanism comprises vertical tubes 8l positioned at the axial plane A5 and directly under the centreline of the press L. The tubes 8l lead into curved tubes 85a,85b which travel to the longitudinal centreline of the pack¬ ing mechanism. The curved tube ends are supported on plates 101a, 101b hinged at 86a, 86b and lead into openings 100a, 100b etc in a block 100. The plates 101a, 101b pass through slots in the rod 91 and bear against rollers 96a, 96b which are attached to the rod 91. Springs 97a, 97b hold the plates against the rollers at all times. The rod 91 moves through bearings 90a, 90b and is actuated by a cam 94 at the axial plane A7 through contact with a roller 93. A spring 95 keeps the roller in contact with the cam. An adjustable screw 9 allows adjustments in the rod length. The cam 94 rotates in the ratio of 1 to 10 rotations of the axle at axial plane Al.

A rack 88 and single-toothed pinion 89 support a pellet packet 87 _? of for example P.V.C. such that the pockets in the packet line up with the bottom of the openings 100a, 100b etc in block 100. The pinion is driven through bevelled gears 99 off the axle at axial plane Aό and rotates in the ratio of 1 to 5 rotations of the ^" axle at axial plane Al.

For every 10 cycles of the chain drive system 0 in Fig. 1 the cam 94 completes one cycle. For the first 5 cycles of the chain system 0 the cam 94 pushes the tubes 101a, 101b over each of the 5 openings 100a, 200b, 100c, lOOd, lOOe, in turn; for the second 5 cycles the tubes 101a, 101b are positioned over the openings one by one in reverse order. The system is phased such that the tubes are over the openings in turn prior to the release of

- A S - pellets from the recovery trolley.

For every 5 cycles of the chain drive system 0 in Fig. 1, the single toothed pinion 89 completes one cycle. At each revolution the pinion moves the rack and the pellet packet from the vertical axis Aδ to the vertical axis A9 in Fig. 15« Thus when a row of pockets in the pellet packet 87 has been filled by the tubes 101a, 101b the packet is moved forward to line the next row up for filling. In this manner, as the tubes 101a, 101b swing back and forth laterally and the packet moves forward intermittently, all the pockets in the packet are systematically filled with pellets.

Thereafter the pellet packet is closed by an overlying sheet of film secured thereto.

It is to be understood that one or all of the mechanically operated tapered edge mechanisms described above can be replaced by electrically operated solenoids where desirable. It is also to be understood that the present in¬ vention includes independently of other features the features of the pellet dispensers, the pellet unidirect¬ ionalizer, the equal-weight grouping mechanism, the shuttle trolley, the press, the packaging mechanism and the pellet containers described herein.

It will be appreciated that use of the above des¬ cribed embodiment of the invention gives rise to the following advantages:

1. Perfectly shaped lead pellets can be made available across all types of pellets and to all cate¬ gories of marksmen.

2. Batches of pellets with a smaller weight range can be made available for consistent and more accurate shooting. 3- Smaller packages of pellets can be made avail¬ able to those unable to afford large quantities.

4. Individual pellets can be safe from damage in

the easy to carry, light, pocket sized packets.

5« One or more pellets can be removed from the pack without exposing the rest to the atmosphere.

It will also be understood that the embodiment can be used (i) to treat bulk produced pellets already packaged by the manufacturer in bulk, for example in 'tins' by anyone obtaining such bulk supplied pellets or (ii) to treat bulk produced pellets before any bulk packaging thereof. Furthermore, it will be appreciated that the press can be used not only to restore the shape of a damaged bulk supplied pellet to its desired true shape, but also to modify the shape of a pellet to a desired shape to enable pellets manufactured to a metric calibre size to be modified to an Imperial calibre size and vice versa