US3679049A

US3679049A - Rotary can separator

Info

Publication number: US3679049A
Application number: US145774A
Authority: US
Inventors: George E Kilner
Original assignee: Filper Corp
Current assignee: NORTHERN HOLDING CORP; JPMorgan Chase Bank NA
Priority date: 1971-05-21
Filing date: 1971-05-21
Publication date: 1972-07-25
Anticipated expiration: 1989-07-25

Abstract

A rotary can separator for separating pairs of telescopically combined cans, each pair having a smaller can nested within a large can with the closed end of one extending across the open end of the other comprising a pair of rotatable, opposed, spaced, vertically diverging discs mounted on the same drive shaft, a motor for rotating the discs, a can feeding track which feeds the cans between the discs, a set of stationary magnets backing each disc of sufficient strength to attract and hold the closed ends of the cans against the respective discs and a pair of can withdrawing tracks which receive the separated cans and transport them from between the discs.

Description

United States Patent Kilner [54] ROTARY CAN SEPARATOR [72] inventor: George E. Kilner, Alameda, Calif.

[73] Assignee: Filper Corporation, San Ramon, Calif.

[22] Filed: May 21, 1971 [2]] Appl. No.: 145,774

[52] US. Cl. ..209/7l, 209/74, 198/31 AA, 198/41 [51 Int. Cl. ..B07c 5/36 [58] FieldofSearch ..209/73,74,7l,72; l98/4l,

[56] References Cited UNITED STATES PATENTS 3,596,761 8/1971 Campbell ..209/74 Primary Examiner-Allen N. Knowles Attorney-Boyken, Mohler, Foster & Schwab [57] ABSTRACT A rotary can separator for separating pairs of telescopically combined cans, each pair having a smaller can nested within a large can with the closed end of one extending across the open end of the other comprising a pair of rotatable, opposed, spaced, vertically diverging discs mounted on the same drive shaft, a motor for rotating the discs, a can feeding track which feeds the cans between the discs, :1 set of stationary magnets backing each disc of sufficient strength to attract and hold the closed ends of the cans against the respective discs and a pair of can withdrawing tracks which receive the separated cans and transport them from between the discs.

13 Claims, 8 Drawing Figures Patented July 25, 1972 3,679,049

4 Sheets-Sheet 1 I INVENTOR.

1550K665 MAN/5K FI'E- -2- 5%,MM6M

A TTOKNEV5 ATTOK/VE V5 4 Sheets-Sheet 8 Patented July 25, 1972 F IG- (550/865 5. K/LNEK BO MWKLMHM I0 PIE:- 5

Patented July 25, 1972 3,679,049

4 Sheets-Sheet 5 INVENTOR.

. BY GEORGE E. K/LA/Ek w fvz' ROTARY CAN SEPARATOR BACKGROUND OF INVENTION In the canning industry it is customary to maintain large supplies of empty cans of various sizes. In order to economize on storage space and keep dust and other material from entering the cans while they are stored, cans of different sizes are telescopically combined in pairs, each pair having a smaller can inside a large can preferably with the closed end of one extending across the open end of the other, and palletized.

Before they are filled in the canning process such telescopically combined cans must be separated. In the past the cans have been separated with devices with endless, opposed, spaced, moving belts that engage the closed ends of the cans of the cylindrical side wall of the large can and move the pair along a linear, diverging path such that the small can drops from within the larger and is held against the bottom belt. Such devices, while fairly fast and efficient, have been limited in speed because the endless belts must move on their tracks without substantial slippage. Also, since the belts are normally flexible they tend to stretch and require periodic replacement or adjustment. If such maintenance is not done diligently the device willjam frequently.

DESCRIPTION OF INVENTION The novel apparatus and method of this invention efficiently and rapidly separates telescopically combined cans by means of a pair of rotating, opposed, diverging discs which are backed by magnetic fields which hold one of the cans of the pair against one disc and the other against the other disc. As the discs rotate the cans are moved along separate, arcuate, diverging paths and are thus separated. This unique device will separate cans substantially faster than the previously available can separators and does not involve parts, such as flexible moving belts, which require frequent adjustment or replacement.

In addition to the pair of discs and means for forming the magnetic fields the separator includes means for feeding the combined cans between the discs, means for withdrawing the separated cans from between the discs and power means to rotate the discs. As described hereinafter, in the preferred embodiment of this apparatus the magnetic fields are formed by sets of stationary magnets positioned closely adjacent the nonopposing sides of the discs from the point at which the can pairs are fed between the discs to the point at which the separated pairs are withdrawn therefrom.

Accordingly, one of the objects of the invention is to provide an improved apparatus and method for separating tele scopically combined cans at a high rate of speed without injury to the cans.

Another object is to provide an apparatus and method for separating telescopically combined cans more efficiently and at greater speeds than heretofore realized.

An added object is to provide an apparatus for separating cans which is easy to operate and maintain and is constructed so that the cans are clearly visible to an operator at all times and are readily accessible to such operator.

Other objects and advantages of this invention will be readily apparent from the drawings and the following description of the can separator illustrated thereby.

DESCRIPTION OF DRAWINGS FIG. 1 is a side elevational view of the can separator.

FIG. 2 is a diagrammatic side view showing the relative positions of the cans as they are handled by the separator of FIG. 1.

FIG. 3 is a plan sectional view of the separator of FIG. 1 taken along line 33 of FIG. 1.

FIG. 4 is an enlarged, fragmentary, plan sectional view of the can feed, inlet or receiving portion of the separator of FIG. 1 taken along line 44 of FIG. 1.

FIG. 5 is an enlarged, fragmentary plan sectional view of the can withdrawal or discharge portion of the separator of FIG. I taken along line 55 of FIG. I.

FIG. 6 is an enlarged, fragmentary side sectional view of the separator of FIG. 1 taken along line 6-6 of FIG. 3.

FIG. 7 is a fragmentary, perspective, exploded view of the rotatable upper disc of the separator of FIG. I, and the magnetic backing plate associated with it taken along line 6-6 of FIG. 3.

FIG. 8 is a side sectional view through the assembled structure of FIG. 7.

In the drawings (as illustrated in FIG. 2 by the arrows), the cans move from right to left as they are handled by the separator. The separator could, of course, be constructed to move the cans counterclockwise.

DESCRIPTION OF SEPARATOR The can separator comprises a generally rectangular, stationary frame, generally designated 1, comprising four spaced, parallel, vertically elongated frame members 2 at the corners of the rectangle; a pair of spaced, parallel, horizontally elongated upper frame members 3 extending between the upper ends of the front and rear frame members 2, respectively; and a pair of lower, horizontally elongated, parallel spaced, frame members 4 extending between the lower ends of the front and rear vertical frame members 2, respectively. Frame 1 also includes a pair of parallel, spaced, upper cross members 5 extending between the frame members 3 and a pair of lower, parallel, spaced cross members 6 extending between frame members 4. The cross member 6 on the right hand side of FIG. 3 is higher than the cross member 6 on the left hand side of FIG. 3.

Supported within frame 4 are a pair of generally horizontally opposed, vertically diverging discs, generally designated 8, 9, between which the

cylindrical cans

10, 11 are fed, held, separated and withdrawn in that order. The upper disc 8 is supported within frame I such that it is essentially horizontal; whereas the lower disc 9 is supported such that it is downwardly inclined from right to left as viewed in FIG. 1. Thus, discs 8, 9 diverge vertically from the can receiving point at the right hand side of the separator to the can discharge point at the left hand side thereof.

As illustrated in FIG. 1 the pairs of cans 10, II are fed between the discs 8, 9 with the large can 10 closed end up and the smaller can 11 nested inside the large one with its closed end down. As discussed in detail hereinafter, when the can pairs are fed in such position the large cans 10 will be held against the bottom surface of disc 8 and the smaller cans II will be held against the top surface of disc 9. It is entirely possible to feed the can pairs with the large can closed side down and the smaller cans closed side up. In that instance disc 8 would receive the smaller can and disc 9 would receive the large cans. It is also possible to feed the can pairs open end to open end and closed end to closed end.

Upper disc 8 and lower disc 9 are constructed essentially identically. Referring to FIGS. 6 and 7 each disc consists of a horizontally elongated, fiat ring 12 bolted to a spoked wheel, generally designated 13. The rings 12 are made of a strong, non-ferromagnetic material such as plastic, fiberglass or the like. Wheel 13 includes a flat, horizontally elongated rim 14, spokes 15 and hub 16. Ring 12 is bolted to one of the horizontal sides of rim l4 and radial spokes 15 are rigidly attached to its opposite horizontal side. The spokes extend radially from cylindrical hub 16 which has a central bore 17 in it.

Each disc is mounted on shaft 18 which passes axially through the bores 17 of the wheel hubs 16 of each disc. Shaft 18 consists of a lower segment 19 to which lower disc 9 is keyed spoked-side downward and an upper segment 20 to which disc 8 is keyed spoked-side upward. The shaft segments 19, 20 are joined by universal joint 25 at a point intermediate the hub of the lower wheel and the hub of the upper wheel. The function of universal joint 25 is, of course, to permit lower disc 9 to be inclined relative to upper disc 8 while each are driven by shaft 18 at the same speed. Lower segment 19 is journaled in

bearings

26, 27. Bearing 27 is mounted on the underside of horizontal plate 28. Upper segment 20 is journaled in bearings 29, with an end section 31 extending significantly outwardly of the top of bearing 30. A driven sprocket 32 is afiixed to end section 31. Sprocket 32 is connected by an open belt or chain 33 to the driving sprocket (not shown) of motor 34. Bearing 30 and motor 34 are both mounted on the top of flat plate 37 which is attached horizontally across the tops of frame members 5.

As shown in FIG. 6 discs 8, 9, are each backed by a stationary, magnetic backing plate, generally designated 38, 39, respectively. These plates create the magnetic fields which hold the cans against the discs. Backing plate 39 is positioned directly below the flat ring 12 of disc 9 in spaced, opposed, parallel relationship thereto and backing plate 38 lies directly above the corresponding flat ring of disc 8 in spaced, opposed parallel relationship thereto. Backing

plates

38, 39 are also constructed essentially identically. As shown in FIGS. 6, 7 and 8 each includes a set of spaced magnets 40 mounted on the top side of a three-layered flat ring generally designated 41. The magnets 40 extend around layered ring 41 from approximately the can receiving point to approximately the can withdrawal point, which is approximately 180 of the ring and are spaced thereon to maintain a field of substantially constant strength along that portion of the ring. The top layer 42 of the ring 41 is a thin sheet of a high strength, non-ferromagnetic material. The intermediate layer consists of two flat, concentric, spaced

ferromagnetic bars

44, 45 which act as the north and south poles of the backing plate. The third layer 46 is a sheet of a wear resistant material having a low coefficient of friction, such as teflon.

Backing plate 39 is supported by four

stanchions

48, 49, and 51, all made from a non-ferromagnetic material. Stanchions 48 and 49 are positioned approximately below the can receiving point and the can discharge point, respectively and extend downwardly from the first layer of the layered ring 41 of backing plate 39 to a flat beam 52 which is rigidly attached across the tops of cross frame members 6. Web braces 53, 54 extend outwardly from the vertical sides of frame members 6 and are attached to the underside of beam 52 to provide further support for beam 52.

Stanchions

50, 51 extend from the first layer of the sheet 41 of backing plate 39 to the tops of cross members 6.

The upper backing plate 38 is similarly supported from

stanchions

55, 56, 57 and 58. As illustrated in FIG. 1,

stanchions

55, 56 extend vertically between backing plate 38 and flat beam 59 and

stanchions

57, 58 are interposed between backing plate 38 and upper cross frame members 5. Bearing 26 is mounted on the top side of beam 52 and bearing 29 is mounted on the underside of beam 59.

DESCRIPTION OF SEPARATOR OPERATION From storage the pairs of telescopically combined cans may be fed between discs 8, 9 from a conventional can handling track 60. Track 60 comprises parallel sets of bars or rods which form a rectangular shaped cage of sufficient size to accommodate the can pairs. The movement of the cans on track 60 may be gravitational or the track may include mechanical means such as moving belts or rollers which cause the cans to move in a desired direction. As illustrated in FIGS. 3, 4 and 7, track 60 enters between discs 8 and 9 almost normally to the axis of disc 8 and then bends in the direction of rotation thereof such that the open exit of the track faces in the direction or rotation and is annular to said axis.

The discs 8, 9 are driven at the same rotational speed by variable speed motor 34. The speed of rotation is correlated with the rate at which the can pairs are fed from track 60 between discs 8, 9.

The exit of track 60 lies just beyond the first magnet in the set extending around the arc of ring 41 of each backing plate but within the magnetic field of same. As the can pair moves off the bottom support rods of track 60 the pair accelerates slightly due to the pull exerted by the first magnet. This slight acceleration helps to horizontally space the cans between the discs 8, 9. At this point the spacing between the discs is just slightly greater than the height of the large can 10. As the cans move into the field of the upper and lower sets of magnets 40 the upper field attracts and holds the bottom of large can 10 on the bottom surface of the ring 12 of upper disc 8 and the lower field attracts and holds the bottom of smaller can 11 against the upper surface of the ring 12 of lower disc 9.

The strengths of the fields should be such as to exert sufficient attractive force to hold the cans firmly against the above mentioned surfaces but permit a disc to rotate substantially freely. Ideally, the discs and backing plates are always very slightly spaced apart from each other and do not contact as the discs rotate. However, in practice it is difficult to maintain close tolerances between the discs and backing plate and it has been found advantageous to interpose a wear pad such as layer 46 between the magnetic surface and the rotating disc. The wear pad, being made of a low friction, wear resistant material, accommodates whatever sliding contact is made between the disc and the backing plate with a minimum of drag.

FIG. 2 diagrammatically illustrates the paths and relative positions of the cans as they rotate firmly held against the discs. As shown in FIG. 2, the large cans l0 follow a horizontal path with no substantial vertical movement. In contrast, since disc 9 diverges downwardly from the can receiving point, the path of the smaller cans 11 diverges downwardly from the path of the large cans. As the spacing between discs 8 and 9 increases the cans begin to separate. The angle at which the discs diverge should be such that the cans separate cleanly without any substantial contact between the inner side wall of the large can and the outer wall and lip of the smaller can. The maximum divergence angle will depend on the diameters of the cans. As the cans continue to rotate clockwise they continue to separate until they are completely separated. At this point, the spacing between the discs is approximately the sum of the height of the smaller can and the height of the large can. Actually, because of the angle of divergence the spacing will be slightly more than this sum. In order to minimize the chances of jamming due to irregularly shaped cans, it is advantageous to withdraw the cans at a point where they are significantly clear of each other and the spacing between the discs is significantly greater than the above mentioned sum.

When the cans are thus separated they are respectively discharged into a smaller can discharge track 61 and a large can discharge track 62.

Tracks

61 and 62 are constructed similarly to track 60 and also comprise sets of parallel bars in the form of a rectangular cage. The entrance to large can track 62 is positioned directly below upper disc 8 in the path of the large cans. Correspondingly, the smaller can discharge track 61 is positioned just above lower disc 9 with its entrance in the path of the smaller cans 11. As illustrated in FIG. 5, as the cans enter the

tracks

61, 62 they engage the inside (rearward) vertical, parallel rods of the tracks and are thus swept of the discs. The last magnets in each row or set of magnets 40 are stationed just in front of the entrances to

tracks

61, 62. Thus as the cans are discharged into these tracks they leave the magnetic fields and are free to move on these tracks from between the discs and away from the separator.

Modifications of the separator described in the drawings and description above which do not materially change the mode of operation of the separator will be readily apparent to those skilled in the can handling and mechanical arts. It is intended that such modifications be included within the scope of the invention as hereinafter claimed.

Iclaim:

1. A can separator for separating empty cans of two different sizes open at one of their ends and closed at their opposite ends and telescopically combined in pairs, each pair having a smaller can inside a larger can comprising:

a. a pair of spaced, generally horizontally opposed, vertically diverging, rotatable discs; 1

b. means for feeding the combined pairs of cans in a generally upright position between said discs at a point where the spacing between said discs is approximately the height of the larger can and diverges therefrom in the direction of rotation to at least approximately the sum of the height of said larger can and the height of said smaller can;

c. means for forming a magnetic field about each of said discs whereby an end of one of the cans of said pair is magnetically held against the lower surface of the upper disc of said pair of discs and an end of the other can of said pair is magnetically held against the upper surface of the lower disc of said pair of discs; and

d. means for rotating said discs at substantially the same speed thereby moving said cans in diverging paths causing them to be separated;

e. means for withdrawing the separated cans from between the discs.

2. The can separator of claim 1 wherein said means for forming a magnetic field about each of said discs includes:

f. a first set of stationary magnets positioned in parallel,spaced,closely adjacent relationship to the top surface of the upper disc; and

g. a second set of stationary magnets positioned in parallel,

spaced, closely adjacent relationship to the bottom surface of the lower disc.

3. The can separator of claim 2 wherein:

h. each set of magnets extends along the respective arcs of said discs from approximately the point at which the can pairs are fed between the discs to approximately the point at which the separated cans are discharged from between the discs.

4. The can separator of claim 2 wherein:

h. the portions of said discs against which the cans are held and the sets of magnets are adjacent to are made of a nonmagnetic material.

5. The can separator of claim 2 including:

h. a first thin layer of wear resistant, low friction material interposed between said top surface of said upper disc and said first set ofmagnets; and

- i; a second thin layer of wear resistant, low friction material interposed between said bottom of the lower disc and said second set of magnets.

6. The can separator of claim 3 wherein the means for feeding the pairs of cans between the discs includes:

i. a rod track the exit of which faces generally in the direction of rotation and is slightly rearward of the first magnets in said sets of magnets.

7. The can separator of claim 3 wherein the means for withdrawing the separated cans from between the discs includes:

i. a pair of rod tracks the entrances of which are interposed in the respective paths of the separated cans and are slightly rearward of the last magnets in said sets of magnets.

8. The can separator of claim I wherein each of said discs includes:

f. a wheel; and

g. a flat horizontally extending ring attached to the periphery of said wheel and against which the cans are held.

9. The can separator of claim 8 wherein said means for rotating the disc includes:

h. a shaft which extends axially through the hubs of the wheels of each disc and upon which each of said discs are mounted, said shaft having a universal joint positioned between said discs to permit said divergence; and

i. a motor operably connected to one end of said shaft to rotate said shaft.

10. A can separator for separating empty cans of two different sizes open at one of their ends and closed at their opposite ends and telescopically combined in pairs, each pair having a smaller can inside a larger can with the closed end of one extending across the open end of the other comprising:

a. a pair of spaced, generally horizontally opposed, vertically diverging,rotatable discs, each disc including a wheel and a flat,horizontally extending non-magnetic ring attached to the periphery of the wheel;

b. a shaft which extends axially through the hubs of the wheels of each disc and upon which said discs are mounted, said shaft having a universal joint positioned between said discs to permit said divergence;

c. a motor operably connected to one end of the shaft to rotate said shaft, thereby causing said discs to rotate at substantially the same speed;

d. a track for feeding the can pairs between the flat rings of the discs, the exit of which faces generally in the direction of rotation and is positioned at a point between said rings where the spacing therebetween is approximately the height of the large can and diverges therefrom in the direction of rotation to at least approximately the sum of the height of the large can and the height of the smaller can;

e. a first set of stationary magnets positioned in parallel, closely spaced relationship to the top surface of the flat ring of the upper disc, said first set of magnets extending along that portion of the circumference of said ring of the upper disc between approximately the point at which the cans are fed between the rings to the point where the spacing therebetween is approximately said sum;

f. a first layer of wear resistent, low friction material interposed between said first set of magnets and the top surface of the flat ring of the upper disc;

g. a second set of stationary magnets positioned in parallel, closely spaced relationship to the bottom surface of the flat ring of the lower disc, said second set of magnets extending along that portion of the circumference of said flat ring of the lower disc between approximately the point at which the cans are fed between the rings to the point where the spacing therebetween is approximately said sum;

h. a second layer of wear resistant, low friction material interposed between said second set of magnets and the bottom surface of the flat ring of the lower disc; and

i. a pair of tracks for receiving the respective separated cans, the entrances to which are positioned at approximately said point where the spacing between the rings is approximately said sum.

11. Method for separating empty cans of two different sizes open at one of their ends and closed at their opposite ends and telescopically combined in pairs, each pair having a smaller can inside a larger can, comprising:

a. rotating a first surface in an endless path;

b. rotating a second surface in an endless path which is spaced, generally horizontally opposed and vertically diverging from the path of said first surface, the speeds of rotation of said first surface and said second surface being substantially equal;

c. feeding said combined can pairs in a generally upright position between said surfaces;

d. forming a first magnetic field about said first surface whereby an end of one of said cans is attracted to and held against said first surface and simultaneously forming a second magnetic field about said second surface whereby an end of the other can is attracted to and held against said second surface, thereby causing said cans to follow the path of the surface to which they are respectively held and be separated; and

e. withdrawing the separated cans from between said surfaces.

12. The method of claim 11 wherein:

f. each of said paths are circular.

13. The method of claim 11 wherein:

f. each of said paths are circular;

g. the can pairs are fed between said surfaces at a point where the spacing therebetween is approximately the height of the large can and continuously diverges therefrom to the point at which the separated cans are withdrawn; and h. each of said magnetic fields are formed only about the portions of said surfaces which extend from the point at which the cans pairs are fed therebetween to the point at which the separated cans are withdrawn.

Claims

1. A can separator for separating empty cans of two different sizes open at one of their ends and closed at their opposite ends and telescopically combined in pairs, each pair having a smaller can inside a larger can comprising: a. a pair of spaced, generally horizontally opposed, vertically diverging, rotatable discs; b. means for feeding the combined pairs of cans in a generally upright position between said discs at a point where the spacing between said discs is approximately the height of the larger can and diverges therefrom in the direction of rotation to at least approximately the sum of the height of said larger can and the height of said smaller can; c. means for forming a magnetic field about each of said discs whereby an end of one of the cans of said pair is magnetically held against the lower surface of the upper disc of said pair of discs and an end of the other can of said pair is magnetically held against the upper surface of the lower disc of said pair of discs; and d. means for rotating said discs at substantially the same speed thereby moving said cans in diverging paths causing them to be separated; e. means for withdrawing the separated cans from between the discs.

2. The can separator of claim 1 wherein said means for forming a magnetic field about each of said discs includes: f. a first set of stationary magnets positioned in parallel, spaced,closely adjacent relationship to the top surface of the upper disc; and g. a second set of stationary magnets positioned in parallel, spaced, closely adjacent relationship to the bottom surface of the lower disc.

3. The can separator of claim 2 wherein: h. each set of magnets extends along the respective arcs of said discs from approximately the point at which the can pairs are fed between the discs to approximately the point at which the separated cans are discharged from between the discs.

4. The can separator of claim 2 wherein: h. the portions of said discs against which the cans are held and the sets of magnets are adjacent to are made of a non-magnetic material.

5. The can separator of claim 2 including: h. a first thin layer of wear resistant, low friction material interposed between said top surface of said upper disc and said first set of magnets; and i. a second thin layer of wear resistant, low friction material interposed between said bottom of the lower disc and said second set of magnets.

6. The can separator of claim 3 wherein the means for feeding the pairs of cans between the discs includes: i. a rod track the exit of which faces generally in the direction of rotation and is slightly rearward of the first magnets in said sets of magnets.

7. The can separator of claim 3 wherein the means for withdrawing the separated cans from between the discs includes: i. a pair of rod tracks the entrances of which arE interposed in the respective paths of the separated cans and are slightly rearward of the last magnets in said sets of magnets.

8. The can separator of claim 1 wherein each of said discs includes: f. a wheel; and g. a flat horizontally extending ring attached to the periphery of said wheel and against which the cans are held.

9. The can separator of claim 8 wherein said means for rotating the disc includes: h. a shaft which extends axially through the hubs of the wheels of each disc and upon which each of said discs are mounted, said shaft having a universal joint positioned between said discs to permit said divergence; and i. a motor operably connected to one end of said shaft to rotate said shaft.

10. A can separator for separating empty cans of two different sizes open at one of their ends and closed at their opposite ends and telescopically combined in pairs, each pair having a smaller can inside a larger can with the closed end of one extending across the open end of the other comprising: a. a pair of spaced, generally horizontally opposed, vertically diverging,rotatable discs, each disc including a wheel and a flat,horizontally extending non-magnetic ring attached to the periphery of the wheel; b. a shaft which extends axially through the hubs of the wheels of each disc and upon which said discs are mounted, said shaft having a universal joint positioned between said discs to permit said divergence; c. a motor operably connected to one end of the shaft to rotate said shaft, thereby causing said discs to rotate at substantially the same speed; d. a track for feeding the can pairs between the flat rings of the discs, the exit of which faces generally in the direction of rotation and is positioned at a point between said rings where the spacing therebetween is approximately the height of the large can and diverges therefrom in the direction of rotation to at least approximately the sum of the height of the large can and the height of the smaller can; e. a first set of stationary magnets positioned in parallel, closely spaced relationship to the top surface of the flat ring of the upper disc, said first set of magnets extending along that portion of the circumference of said ring of the upper disc between approximately the point at which the cans are fed between the rings to the point where the spacing therebetween is approximately said sum; f. a first layer of wear resistent, low friction material interposed between said first set of magnets and the top surface of the flat ring of the upper disc; g. a second set of stationary magnets positioned in parallel, closely spaced relationship to the bottom surface of the flat ring of the lower disc, said second set of magnets extending along that portion of the circumference of said flat ring of the lower disc between approximately the point at which the cans are fed between the rings to the point where the spacing therebetween is approximately said sum; h. a second layer of wear resistant, low friction material interposed between said second set of magnets and the bottom surface of the flat ring of the lower disc; and i. a pair of tracks for receiving the respective separated cans, the entrances to which are positioned at approximately said point where the spacing between the rings is approximately said sum.

11. Method for separating empty cans of two different sizes open at one of their ends and closed at their opposite ends and telescopically combined in pairs, each pair having a smaller can inside a larger can, comprising: a. rotating a first surface in an endless path; b. rotating a second surface in an endless path which is spaced, generally horizontally opposed and vertically diverging from the path of said first surface, the speeds of rotation of said first surface and said second surface being substantially equal; c. feeding said combined can pairs in a generally upright position between said surfaces; d. forming a first magnetic Field about said first surface whereby an end of one of said cans is attracted to and held against said first surface and simultaneously forming a second magnetic field about said second surface whereby an end of the other can is attracted to and held against said second surface, thereby causing said cans to follow the path of the surface to which they are respectively held and be separated; and e. withdrawing the separated cans from between said surfaces.

12. The method of claim 11 wherein: f. each of said paths are circular.

13. The method of claim 11 wherein: f. each of said paths are circular; g. the can pairs are fed between said surfaces at a point where the spacing therebetween is approximately the height of the large can and continuously diverges therefrom to the point at which the separated cans are withdrawn; and h. each of said magnetic fields are formed only about the portions of said surfaces which extend from the point at which the cans pairs are fed therebetween to the point at which the separated cans are withdrawn.