CA1058132A - Scrap chopper - Google Patents
Scrap chopperInfo
- Publication number
- CA1058132A CA1058132A CA219,525A CA219525A CA1058132A CA 1058132 A CA1058132 A CA 1058132A CA 219525 A CA219525 A CA 219525A CA 1058132 A CA1058132 A CA 1058132A
- Authority
- CA
- Canada
- Prior art keywords
- chopper
- gear
- rolls
- roll
- blades
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23D—PLANING; SLOTTING; SHEARING; BROACHING; SAWING; FILING; SCRAPING; LIKE OPERATIONS FOR WORKING METAL BY REMOVING MATERIAL, NOT OTHERWISE PROVIDED FOR
- B23D25/00—Machines or arrangements for shearing stock while the latter is travelling otherwise than in the direction of the cut
- B23D25/12—Shearing machines with blades on coacting rotating drums
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23D—PLANING; SLOTTING; SHEARING; BROACHING; SAWING; FILING; SCRAPING; LIKE OPERATIONS FOR WORKING METAL BY REMOVING MATERIAL, NOT OTHERWISE PROVIDED FOR
- B23D25/00—Machines or arrangements for shearing stock while the latter is travelling otherwise than in the direction of the cut
- B23D25/14—Machines or arrangements for shearing stock while the latter is travelling otherwise than in the direction of the cut without regard to the exact dimensions of the resulting material, e.g. for cutting-up scrap
Abstract
ABSTRACT OF THE DISCLOSURE
A rotary chopper having upper and lower chopper rolls, in which the rolls run in contact with one another, with the chopper blades being formed flush with the surface of the rolls, the surface of the rolls between the chopper blades being formed of a relatively hard stiff resilient material, of such a nature, that at least adjacent to the location of the chopper blades themselves, it may be deflected inwardly to accomodate the over-lap of the chopper blades, and then will spring outwardly again so as to constitute the smooth cylindrical surface of the roll.
In this way, the scrap edge portion of the strip is permanently gripped between the nip of the rolls at all times, and at the same time the fan-like action of the blades is eliminated, since they are flush with the surface of the rolls.
A rotary chopper having upper and lower chopper rolls, in which the rolls run in contact with one another, with the chopper blades being formed flush with the surface of the rolls, the surface of the rolls between the chopper blades being formed of a relatively hard stiff resilient material, of such a nature, that at least adjacent to the location of the chopper blades themselves, it may be deflected inwardly to accomodate the over-lap of the chopper blades, and then will spring outwardly again so as to constitute the smooth cylindrical surface of the roll.
In this way, the scrap edge portion of the strip is permanently gripped between the nip of the rolls at all times, and at the same time the fan-like action of the blades is eliminated, since they are flush with the surface of the rolls.
Description
i()S~
The invention relates to apparatus for chopping scrap sheet metal strips. In particular, it relates to the chopping of sheet metal strips of narrow gauge which are easily bent or crumpled, and are difficult to feed to the chopper,although the invention is not exclusively restricted to such narrow gauge ~trips.
BACKGROUND OF THE INVENTION ~-_ . .
In the preparation of strip sheet metal for subsequent use, the edges of the rolled sheet metal strips are often dis-carded as scrap. For example, when thin sheet metal is being '~
slit into separate strips for use in making for example beveragecans or the like, the edges of the strip will often be wrinkled and jagged and will be unsuitable for prcduction. Accordingly, as they leave the slitter or trimmer, the two edge strips are passed through rotary choppers whîch simply chop the strips up into short lengths of typically six to twelve inches which are then collected in a waste receptacle and returned to the mill a~ scrap.
In the past, such rotary choppers have consisted of a drum member provided, typically with two or three radially extend-ing blade3. Two such drums one above and one beneath the stripwere provided, and the blades on the two drums were arranged to overlap so as to provide a shearing action on the strips. Such prior art choppers have been,generally speaking,adequate for use with the thicker gauges of strip sheet metal. However, they are found to be unsuitable for various reasons, for use with thinner gauges of sheet metal such as are now coming into wider usage for example in the manufacture of beverage cans. One of the problems of such prior art rotary choppers is the fact that no satisfactory method had been developed for continuously feeding the scrap edge ~trip to the chopper blades. Thu~ when u~ng a thinner more flex-- 05~3~;3"'Z ~
ible strip, it was possible for the scrap edge portion to become deflected so that it did not in fact reach the chopper blades, but became bent and crumpled up. This would then require shutting down the line while the crumpled portion was removed, and then re-starting it again.
In addition,as the speed of the entire line was increased, the rotation of the upper and lower drums, with their blades ex-tending outwardly from the drum surface, acted somewhat like a fan and created air currents which tended to deflect the scrap edge portions of the strip causing them to flutter or shake, so that Y
they frequently became deflected from between the upper and lower drums, again causing a misfeed and involving shutting down the line b while the crumpled or deflected scrap edge portion was cleared up.
BRIEF SUMMARY OF THE INVENTION
The invention therefore seeks to overcome the foregoing disadvantages by the provision of a rotary chopper having upper and lower chopper rolls,in which the rolls run in contact with one another, with the chop~er blades being formed flush with the surface of the rolls, the surface of the rolls between the chopper blades being formed of a relatively hard stiff resilient material, of such a nature, that at least adjacent to the location of the chopper blades themselves, it may be deflected inwardly to accomodate the overlap of the chopper blades, and then will spring outwardly again so as to constitute the smooth cylindrical surface of the roll. In this way, the scrap edge portion of the strip is permanently gripped between the nip of the rolls at all time, and at the same time the fan-like action of the blades is eliminated, since they are flush with the surface of the rolls.
More particularly, it is an objective of the invention to provide a scrap chopper having the foregoing advantage~ in which .
The invention relates to apparatus for chopping scrap sheet metal strips. In particular, it relates to the chopping of sheet metal strips of narrow gauge which are easily bent or crumpled, and are difficult to feed to the chopper,although the invention is not exclusively restricted to such narrow gauge ~trips.
BACKGROUND OF THE INVENTION ~-_ . .
In the preparation of strip sheet metal for subsequent use, the edges of the rolled sheet metal strips are often dis-carded as scrap. For example, when thin sheet metal is being '~
slit into separate strips for use in making for example beveragecans or the like, the edges of the strip will often be wrinkled and jagged and will be unsuitable for prcduction. Accordingly, as they leave the slitter or trimmer, the two edge strips are passed through rotary choppers whîch simply chop the strips up into short lengths of typically six to twelve inches which are then collected in a waste receptacle and returned to the mill a~ scrap.
In the past, such rotary choppers have consisted of a drum member provided, typically with two or three radially extend-ing blade3. Two such drums one above and one beneath the stripwere provided, and the blades on the two drums were arranged to overlap so as to provide a shearing action on the strips. Such prior art choppers have been,generally speaking,adequate for use with the thicker gauges of strip sheet metal. However, they are found to be unsuitable for various reasons, for use with thinner gauges of sheet metal such as are now coming into wider usage for example in the manufacture of beverage cans. One of the problems of such prior art rotary choppers is the fact that no satisfactory method had been developed for continuously feeding the scrap edge ~trip to the chopper blades. Thu~ when u~ng a thinner more flex-- 05~3~;3"'Z ~
ible strip, it was possible for the scrap edge portion to become deflected so that it did not in fact reach the chopper blades, but became bent and crumpled up. This would then require shutting down the line while the crumpled portion was removed, and then re-starting it again.
In addition,as the speed of the entire line was increased, the rotation of the upper and lower drums, with their blades ex-tending outwardly from the drum surface, acted somewhat like a fan and created air currents which tended to deflect the scrap edge portions of the strip causing them to flutter or shake, so that Y
they frequently became deflected from between the upper and lower drums, again causing a misfeed and involving shutting down the line b while the crumpled or deflected scrap edge portion was cleared up.
BRIEF SUMMARY OF THE INVENTION
The invention therefore seeks to overcome the foregoing disadvantages by the provision of a rotary chopper having upper and lower chopper rolls,in which the rolls run in contact with one another, with the chop~er blades being formed flush with the surface of the rolls, the surface of the rolls between the chopper blades being formed of a relatively hard stiff resilient material, of such a nature, that at least adjacent to the location of the chopper blades themselves, it may be deflected inwardly to accomodate the overlap of the chopper blades, and then will spring outwardly again so as to constitute the smooth cylindrical surface of the roll. In this way, the scrap edge portion of the strip is permanently gripped between the nip of the rolls at all time, and at the same time the fan-like action of the blades is eliminated, since they are flush with the surface of the rolls.
More particularly, it is an objective of the invention to provide a scrap chopper having the foregoing advantage~ in which .
- 2 - ~ `
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segments of the rolls may be removed so as to adjust and position f the blades.
More particularly, it is an objective of the invention to provide a scrap chopper having the foregoing advantages in which the cutting blades are formed of steel bars having an essentially rectangular cross section,and including releasable attachment means for attaching and adjusting them in the rolls in at least two and preferably four different positions so as to make use of at least two and preferably four edges of the bar one after the other.
It is a further and related objec~ive of the invention to provide a scrap chopper having the foregoing advantages which is additionally provided with anti-backlash gearing, including ~-adjustment means for taking up any backlash in the gearing system, so as to enable precise adjustment of the meshing of the cutting blades to be achieved.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understand-ing of the invention, its operating advantages and specific objects attained by its use, reference should be had to the accompanying drawings and descriptive matter in which there are illustrated and described preferred embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a perspective illustration showing a scrap [
chopper according to the invention; ~
` Figure 2 is an exploded perspective illustration showing ~;
the construction of one of the rolls of the scrap chopper of Figure 1:
Figure 3 is a greatly enlarged end elevation of the scrap chopper rolls par~ially cut away;
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Figure 4 is an enlarged sectional side elevation along the line 4-4 of Figure 1, and, Figure 5 is a cut away perspective illustration of a portion of the anti-backlash gearing system.
DESCRIPTION OF A SPECIFIC EMBODIMENT
Referring now to Figure 1, it will be seen that the scrap chopper according to the invention is shown generally as 10 t consisting of a housing 12, and upper and lower chopper rolls 14 and 16 driven through a single drive shaft 18 extending out of the rear of housing 12. The scrap edge portion of the steel strip is shown as S, passing between the upper and lower rolls 14 and 16.
It will of course be appreciated that the remaining portion of the strip metal is not shown, for the sake of simplicity. m e strip S as shown is merely the scrap edge portion as trimmed off at a cutter or slitter, forming part of the complete sheet metal working line (not shown).
It will of course be appreciated that the scrap edge portion S is moving in the direction of the arrow A at a contin-uous adjustable steady speed, which may typically be up to six thousand feet per minute. As will be seen from Figure 1, the strip S is unsupported and once it is chopped up by the chopper 10, it ~;~ is then n~ longer subject to any continuous traction pulling it through the sheet metal working line.
According to the present invention, the problem of con-trolling the strip S may be overcome by the use of chopper rolls 14 and 16 in which the blades are located more or less flush with the cylindrical frictional surface of the roll and the other in-ventive features as claimed herein. This type of construction is shown in Figures 2 and 3. According to thi~ particular example of the invention, a chopper roll 14 or 16 may be made up with a cyl-105&~ 2 indrical surface in the following manner. A central solid core 20 is formed of steel, having an essentially generally triangular shape in cross section and a central bore 22. At each corner of the triangular shape of the core 20, a blade receiving groove 24 is formed, preferably having one side 26 lower than the other side 28. The surface of the core adjacent the high side 28 of the f groove 24 is formed into an arc having a predetermined radius con-centric with the center of the bore 22.
. . i The core 20 defines three flat generally rectangular lD shaped surfaces 32, preferably provided with registering means such as dowel pins 34 or any other suitable means. In order to form a completely cylindrical roll surface, three arcuate segments 36 of any suitable material are provided, having bores therein for re-ceiving the dowel pins 34, and having further bores 3~ for receiving attachment bolts 38. ~olts 38 fit within the threaded recesses 40 - in the core 20. Around the exterior of the arcuate segments 36 - there is provided a hard resilient tread portion 42 adhesively bonded to the arcuate surface of the segments 36, and having holes 44 extending therethrough in registration with the bores 37. Pre-ferably,the tread portions 42 are made of hard resilient frictional material such as polyurethane plastic material or the like such that it will make a good frictional grip with the strip metal S, and at the same time be sufficiently resilient to be deformed under pressure.
A tread strip 46 of similar material is also adhesively bonded to the arcuate surface 30 so as to give the entire roll a smooth regular cylindrical surface of the same material.
~; In order to shear the strip S, three blades 48 are pro-vided located in the grooves 24 as shown. The blades 48 are rec-tangular ~teel bars having four corners or edges 50, and provided with bores 52 extending therethrough which are preferably counter-sunk from both sides 80 that fastening screws 54 may be pa~od ~, . . .
iO58~3Z
through the bores 52 in either direction, ~o that the blades 48 may be used either way round. The screws 54 pass through bore 52 ana through the longer siae wall 26 of the groove 24. The side walls 26 may be provided with threaded recesses for reception of the bolts 54, or alternatively, a portion of the core may be cut away to provide a recess as at 56 to permit the use of a thread- ~
ed nut 58. In order to locate the blades 48 in the correct position ~' and to support it during use, shims 60 may be provided both between the blade and the high side 28 of the groove 24, and also between the blade and the bottom of the groove 24 as shown. The blades will be so adjusted that the outer corner~ or edges can be located relative to the cylindrical surface of the tread 46.
Referring now to Figures 4 and 5, it will be seen that the lower roll 16 is mounted on the drive shaft 18, and the upper roll 14 is mounted on a driven shaft 62. The drive shaft 18 is seen to extend completely through the housing 12 from one end to the other, and the driven shaft 62 is located within the housing and exten~s beyond the housing only to the left hand side thereof 60 that it may carry the other roll 14.
Both drive shaft 18 and driven shaft 62 are carried in suitable roller bearings 64, or any other suitable bearing means which are adequate for the purpose.
Mounted on drive shaft 18 is a helical drive gear 66 and mounted on driven shaft 62 is an anti-backlash gear indicated generally as 68, which is shown in more detail in Figure 5. The anti-backlash gear 68 will be seen to comprise a fixed gear portion ~, 70 having a sleeve 72 extending therefrom, and keyed to the shaft 62 by means for example a key 74. The fixed gear 70 will be seen to be formed with helical teeth, and is somewhat less than half the width of the gear 66. It is however of the same diameter and will lOS~
have the same number of teeth so that both shafts 18 and 62 rotate in the same speeds in opposite directions.
A movable gear portion 76 is slidably located on the sleeve 7~, and is adjustably fastened to the fixed gear 70 by means of the bolts 78 extending through the gear 70 and fastening in suit- !
able threaded recesses in the gear 76.
The gear 76 is formed with an annular recess 80, and a spring 82 is located within the annular recess 80, and extends be- ¦
tween the gear 76 and the gear 70, normally urging them apart from one another. The gear 76 is also formed with helical teeth and is of the same diameter and has the same number of teeth as the gear 70. The gear 76 is of slightly less than one half the width of the gear 66. In this way, when the chopper 10 is being installed, any backlash in the gears may be taken up by simply tightening up the bolts 78 thereby drawing the gear 76 towards the gear 70 and closing up the gap.
Once the backlash in the gear system is eliminated, then the positions of the blades 48 may be adjusted on the upper and lower rolls 14 so that they make a shear like engagement as 20 shown in Figure 3. Preferably, there will be substantially no clearance between the adjacent corners 50 of the blades 48 on the upper and lower rolls 14 and 16, and the adjacent corners 50 will in fact overlap one another so that there is a shearing action ap- ¦
plied to the strip S as it passes between them.
The portions of the tread 46 adjacent to the blades 48 will be c~mpressed by such overlapping engagement of the blades 48, and will then spring back again as the upper and lower rolls 14 and 16 continue to rotate. It will be notcd however that while such compression is taking place, the continuous portion of the strip S
ie. that portion which has not yet passed between the upper and .. ' 1.
105~
lower rolls 14 is still subject to the gripping action of the por-tions of the tread 46 which are in contact therewith on both sides thereof, and are subject to the frictional action of the portions of the tread 46 which apply continuous traction to the portion of the strip S and thereby prevent it from becoming deflected away from the nip of the upper and lower rolls 14. f At the same time, since the adjacent corners S0 of the blades 48 are more or less flush with or very close to the surface of the tread 46, there is virtually no fan-like effect created by 10the blades 48 and therefore the tendency for the blades and rolls to set up disturbing air currents is greatly reduced.
In this way, the chopper rolls can be operated at greatly increased rotational speed, and can accomodate thinner sheet metal strips with a far greater degree of reliability than in the past.
When the corners 50 of the blades 48 become dull, all that is required is for the segments 36 to be removed, and the bolts 54 of the blades 48 are removed and the blades 48 are simply r rotated around to locate another corner S0 in the operative posi- t tion. '~
Any tendency for clearance to develop between the upper and lower blades 48 can be eliminated by inserting or removing shims between the blades 48 and the back wall 28, and by adjusting the anti-backlash gearin~ unit.
It will of course be appreciated that various changes - can be made without departing from the scope of the invention.
For example, the invention has been described specifically in relation to the use of three blades 48, this being a convenient number to arrange around a cylindrical rotor as shown, for the particular type of operation. ~owever, it would of course be equally possible ~o provide merely a single blade or two blades .
lOS813Z
or four blades, depending upon the size of the rotors, the speed of operation, and the nature of the material to be chopped up. Furthermore the invention has been described specifically in relation to the chopping of thin strip sheet metal. It will however be equally applicablë to the chopping of other strip materials for example paper, sheet plastic and the like.
Having described what is believed to be the best mode by which the invention may be performed, it will be seen that the inven~ion may be paricularly defined as follows:
A rotary chopper for strip sheet material, for chopping a strip thereof into shorter lengths, said chopper comprising, -~ upper and lower roll members of generally cylindrical shape, b~, ~ mounting means for supporting said upper and lower rolls in contact with one~another, and drive means for driving the same in unison, in opposite directions, at least one pair of upper and lower chopper blade means mounted in said upper and lower rolls respectively, and having cutting edges located in the periphery of said rolls whereby said cutting edges overlap one another on each complete revolution of said rolls and provide a shearing action, and, resilient tread means arranged around the remainder of each said roll, said tread means on one said roll being adapted to be deflected by pressure of said blade means of the other said roll during rotation to permit said overlapping shearing action of said blade means, and said tread means being mutually deflected by one another during the remainder of said rotation to provide a gripping action ; on a strip passing therebetween.
The foregoing is a description of a preferred embodiment of the invention which is given here by way of example only. The invention is not to be taken as limited to any of the specific features as described but comprehends all such ~ariations thereof as come within the scope of the appended claims.
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segments of the rolls may be removed so as to adjust and position f the blades.
More particularly, it is an objective of the invention to provide a scrap chopper having the foregoing advantages in which the cutting blades are formed of steel bars having an essentially rectangular cross section,and including releasable attachment means for attaching and adjusting them in the rolls in at least two and preferably four different positions so as to make use of at least two and preferably four edges of the bar one after the other.
It is a further and related objec~ive of the invention to provide a scrap chopper having the foregoing advantages which is additionally provided with anti-backlash gearing, including ~-adjustment means for taking up any backlash in the gearing system, so as to enable precise adjustment of the meshing of the cutting blades to be achieved.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understand-ing of the invention, its operating advantages and specific objects attained by its use, reference should be had to the accompanying drawings and descriptive matter in which there are illustrated and described preferred embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a perspective illustration showing a scrap [
chopper according to the invention; ~
` Figure 2 is an exploded perspective illustration showing ~;
the construction of one of the rolls of the scrap chopper of Figure 1:
Figure 3 is a greatly enlarged end elevation of the scrap chopper rolls par~ially cut away;
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Figure 4 is an enlarged sectional side elevation along the line 4-4 of Figure 1, and, Figure 5 is a cut away perspective illustration of a portion of the anti-backlash gearing system.
DESCRIPTION OF A SPECIFIC EMBODIMENT
Referring now to Figure 1, it will be seen that the scrap chopper according to the invention is shown generally as 10 t consisting of a housing 12, and upper and lower chopper rolls 14 and 16 driven through a single drive shaft 18 extending out of the rear of housing 12. The scrap edge portion of the steel strip is shown as S, passing between the upper and lower rolls 14 and 16.
It will of course be appreciated that the remaining portion of the strip metal is not shown, for the sake of simplicity. m e strip S as shown is merely the scrap edge portion as trimmed off at a cutter or slitter, forming part of the complete sheet metal working line (not shown).
It will of course be appreciated that the scrap edge portion S is moving in the direction of the arrow A at a contin-uous adjustable steady speed, which may typically be up to six thousand feet per minute. As will be seen from Figure 1, the strip S is unsupported and once it is chopped up by the chopper 10, it ~;~ is then n~ longer subject to any continuous traction pulling it through the sheet metal working line.
According to the present invention, the problem of con-trolling the strip S may be overcome by the use of chopper rolls 14 and 16 in which the blades are located more or less flush with the cylindrical frictional surface of the roll and the other in-ventive features as claimed herein. This type of construction is shown in Figures 2 and 3. According to thi~ particular example of the invention, a chopper roll 14 or 16 may be made up with a cyl-105&~ 2 indrical surface in the following manner. A central solid core 20 is formed of steel, having an essentially generally triangular shape in cross section and a central bore 22. At each corner of the triangular shape of the core 20, a blade receiving groove 24 is formed, preferably having one side 26 lower than the other side 28. The surface of the core adjacent the high side 28 of the f groove 24 is formed into an arc having a predetermined radius con-centric with the center of the bore 22.
. . i The core 20 defines three flat generally rectangular lD shaped surfaces 32, preferably provided with registering means such as dowel pins 34 or any other suitable means. In order to form a completely cylindrical roll surface, three arcuate segments 36 of any suitable material are provided, having bores therein for re-ceiving the dowel pins 34, and having further bores 3~ for receiving attachment bolts 38. ~olts 38 fit within the threaded recesses 40 - in the core 20. Around the exterior of the arcuate segments 36 - there is provided a hard resilient tread portion 42 adhesively bonded to the arcuate surface of the segments 36, and having holes 44 extending therethrough in registration with the bores 37. Pre-ferably,the tread portions 42 are made of hard resilient frictional material such as polyurethane plastic material or the like such that it will make a good frictional grip with the strip metal S, and at the same time be sufficiently resilient to be deformed under pressure.
A tread strip 46 of similar material is also adhesively bonded to the arcuate surface 30 so as to give the entire roll a smooth regular cylindrical surface of the same material.
~; In order to shear the strip S, three blades 48 are pro-vided located in the grooves 24 as shown. The blades 48 are rec-tangular ~teel bars having four corners or edges 50, and provided with bores 52 extending therethrough which are preferably counter-sunk from both sides 80 that fastening screws 54 may be pa~od ~, . . .
iO58~3Z
through the bores 52 in either direction, ~o that the blades 48 may be used either way round. The screws 54 pass through bore 52 ana through the longer siae wall 26 of the groove 24. The side walls 26 may be provided with threaded recesses for reception of the bolts 54, or alternatively, a portion of the core may be cut away to provide a recess as at 56 to permit the use of a thread- ~
ed nut 58. In order to locate the blades 48 in the correct position ~' and to support it during use, shims 60 may be provided both between the blade and the high side 28 of the groove 24, and also between the blade and the bottom of the groove 24 as shown. The blades will be so adjusted that the outer corner~ or edges can be located relative to the cylindrical surface of the tread 46.
Referring now to Figures 4 and 5, it will be seen that the lower roll 16 is mounted on the drive shaft 18, and the upper roll 14 is mounted on a driven shaft 62. The drive shaft 18 is seen to extend completely through the housing 12 from one end to the other, and the driven shaft 62 is located within the housing and exten~s beyond the housing only to the left hand side thereof 60 that it may carry the other roll 14.
Both drive shaft 18 and driven shaft 62 are carried in suitable roller bearings 64, or any other suitable bearing means which are adequate for the purpose.
Mounted on drive shaft 18 is a helical drive gear 66 and mounted on driven shaft 62 is an anti-backlash gear indicated generally as 68, which is shown in more detail in Figure 5. The anti-backlash gear 68 will be seen to comprise a fixed gear portion ~, 70 having a sleeve 72 extending therefrom, and keyed to the shaft 62 by means for example a key 74. The fixed gear 70 will be seen to be formed with helical teeth, and is somewhat less than half the width of the gear 66. It is however of the same diameter and will lOS~
have the same number of teeth so that both shafts 18 and 62 rotate in the same speeds in opposite directions.
A movable gear portion 76 is slidably located on the sleeve 7~, and is adjustably fastened to the fixed gear 70 by means of the bolts 78 extending through the gear 70 and fastening in suit- !
able threaded recesses in the gear 76.
The gear 76 is formed with an annular recess 80, and a spring 82 is located within the annular recess 80, and extends be- ¦
tween the gear 76 and the gear 70, normally urging them apart from one another. The gear 76 is also formed with helical teeth and is of the same diameter and has the same number of teeth as the gear 70. The gear 76 is of slightly less than one half the width of the gear 66. In this way, when the chopper 10 is being installed, any backlash in the gears may be taken up by simply tightening up the bolts 78 thereby drawing the gear 76 towards the gear 70 and closing up the gap.
Once the backlash in the gear system is eliminated, then the positions of the blades 48 may be adjusted on the upper and lower rolls 14 so that they make a shear like engagement as 20 shown in Figure 3. Preferably, there will be substantially no clearance between the adjacent corners 50 of the blades 48 on the upper and lower rolls 14 and 16, and the adjacent corners 50 will in fact overlap one another so that there is a shearing action ap- ¦
plied to the strip S as it passes between them.
The portions of the tread 46 adjacent to the blades 48 will be c~mpressed by such overlapping engagement of the blades 48, and will then spring back again as the upper and lower rolls 14 and 16 continue to rotate. It will be notcd however that while such compression is taking place, the continuous portion of the strip S
ie. that portion which has not yet passed between the upper and .. ' 1.
105~
lower rolls 14 is still subject to the gripping action of the por-tions of the tread 46 which are in contact therewith on both sides thereof, and are subject to the frictional action of the portions of the tread 46 which apply continuous traction to the portion of the strip S and thereby prevent it from becoming deflected away from the nip of the upper and lower rolls 14. f At the same time, since the adjacent corners S0 of the blades 48 are more or less flush with or very close to the surface of the tread 46, there is virtually no fan-like effect created by 10the blades 48 and therefore the tendency for the blades and rolls to set up disturbing air currents is greatly reduced.
In this way, the chopper rolls can be operated at greatly increased rotational speed, and can accomodate thinner sheet metal strips with a far greater degree of reliability than in the past.
When the corners 50 of the blades 48 become dull, all that is required is for the segments 36 to be removed, and the bolts 54 of the blades 48 are removed and the blades 48 are simply r rotated around to locate another corner S0 in the operative posi- t tion. '~
Any tendency for clearance to develop between the upper and lower blades 48 can be eliminated by inserting or removing shims between the blades 48 and the back wall 28, and by adjusting the anti-backlash gearin~ unit.
It will of course be appreciated that various changes - can be made without departing from the scope of the invention.
For example, the invention has been described specifically in relation to the use of three blades 48, this being a convenient number to arrange around a cylindrical rotor as shown, for the particular type of operation. ~owever, it would of course be equally possible ~o provide merely a single blade or two blades .
lOS813Z
or four blades, depending upon the size of the rotors, the speed of operation, and the nature of the material to be chopped up. Furthermore the invention has been described specifically in relation to the chopping of thin strip sheet metal. It will however be equally applicablë to the chopping of other strip materials for example paper, sheet plastic and the like.
Having described what is believed to be the best mode by which the invention may be performed, it will be seen that the inven~ion may be paricularly defined as follows:
A rotary chopper for strip sheet material, for chopping a strip thereof into shorter lengths, said chopper comprising, -~ upper and lower roll members of generally cylindrical shape, b~, ~ mounting means for supporting said upper and lower rolls in contact with one~another, and drive means for driving the same in unison, in opposite directions, at least one pair of upper and lower chopper blade means mounted in said upper and lower rolls respectively, and having cutting edges located in the periphery of said rolls whereby said cutting edges overlap one another on each complete revolution of said rolls and provide a shearing action, and, resilient tread means arranged around the remainder of each said roll, said tread means on one said roll being adapted to be deflected by pressure of said blade means of the other said roll during rotation to permit said overlapping shearing action of said blade means, and said tread means being mutually deflected by one another during the remainder of said rotation to provide a gripping action ; on a strip passing therebetween.
The foregoing is a description of a preferred embodiment of the invention which is given here by way of example only. The invention is not to be taken as limited to any of the specific features as described but comprehends all such ~ariations thereof as come within the scope of the appended claims.
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Claims (7)
- Claim 1. A rotary chopper for strip sheet material, for chopping a strip thereof into shorter lengths, said chopper comprising;
upper and lower roll members of generally cylindrical shape;
mounting means for supporting said upper and lower rolls in contact with one another, and drive means for driving the same in unison, in opposite directions;
at least one pair of upper and lower chopper blade means mounted in said upper and lower rolls respectively, and having cutting edges located in the periphery of said rolls whereby said cutting edges overlap one another on each complete revolution of said rolls and provide a shearing action, and, resilient tread means arranged around the remainder of each said roll, said tread means on one said roll being adapted to be deflected by pressure of said blade means of the other said roll during rotation to permit said overlapping shearing action of said blade means, and said tread means being mutually deflected by one another during the remainder of said rotation to provide a gripping action on a strip passing therebetween. - Claim 2. A rotary chopper as claimed in Claim 1 including adjust-able fastening means for fastening said chopper blade means in position is said rollers, said fastening means permitting adjust-ment of the position of said blade means relative to the periphery of said roll whereby to adjust the overlap of said blade means with the other said blade means of said pair.
- Claim 3. A rotary chopper as claimed in Claim 1 including at least two cutting edges on each said chopper blade means, and releasable fastening means for fastening the same in position in said roll, said fastening means being releasable to permit changing from one said cutting edge to another of said blade means.
- Claim 4. A rotary chopper as claimed in Claim 1 including gear drive means linking said upper and lower roll members for driving in opposite directions in unison as aforesaid, and adjustment means in said gear drive means for taking up back-lash in said gear drive means.
- Claim 5. A rotary chopper as claimed in Claim 1 wherein each said roll member comprises a generally triangular shaped core portion, blade mounting means formed at three equally spaced points around said core portion, and having fastening screw means for fastening said chopper blades in position therein, and three generally arcuate shaped segment portions releasably attachable on said core, said resilient tread means being attached around the arcuate portion of each said segment, whereby to define a generally cylindrical per-iphery for said rollers.
- Claim 6. A rotary chopper as claimed in Claim 5 including further portions of said resilient tread means attached directly on portions of said core.
- Claim 7. A rotary chopper as claimed in Claim 4 wherein said gear means comprise a drive gear, and a driven gear, and wherein said driven gear comprises two gear portions namely a fixed gear disc having gear teeth around the periphery thereof, the periphery there-of having a width somewhat less than one-half the width of said drive gear, and a movable gear disc, having a toothed periphery having a width somewhat less than one-half the width of said drive gear, said movable gear disc being movable towards and away from said fixed gear disc, spring means urging said movable gear disc away from said fixed gear disc, and adjustable means for adjustably drawing said movable gear disc towards said fixed gear disc against said spring.
Priority Applications (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA219,525A CA1058132A (en) | 1975-02-06 | 1975-02-06 | Scrap chopper |
| AU10795/76A AU490971B2 (en) | 1976-02-04 | Scrap chopper | |
| GB431576A GB1530004A (en) | 1975-02-06 | 1976-02-04 | Apparatus for chopping strip sheet material |
| JP1212976A JPS51103388A (en) | 1975-02-06 | 1976-02-06 | SUKURATSU PUCHOTSUPA |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA219,525A CA1058132A (en) | 1975-02-06 | 1975-02-06 | Scrap chopper |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1058132A true CA1058132A (en) | 1979-07-10 |
Family
ID=4102226
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA219,525A Expired CA1058132A (en) | 1975-02-06 | 1975-02-06 | Scrap chopper |
Country Status (3)
| Country | Link |
|---|---|
| JP (1) | JPS51103388A (en) |
| CA (1) | CA1058132A (en) |
| GB (1) | GB1530004A (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4655739A (en) * | 1984-04-12 | 1987-04-07 | Robert H. Pratt | Gauze folding machine |
| IT1281448B1 (en) * | 1995-11-09 | 1998-02-18 | Danieli Off Mecc | CUTTING GROUP FOR LAMINATES |
| CN102398070A (en) * | 2011-11-27 | 2012-04-04 | 襄阳博亚精工机器有限公司 | Cropping scissor shaft system |
| CN111924626A (en) * | 2020-08-11 | 2020-11-13 | 周晓杰 | One-way packing box and cutting device |
-
1975
- 1975-02-06 CA CA219,525A patent/CA1058132A/en not_active Expired
-
1976
- 1976-02-04 GB GB431576A patent/GB1530004A/en not_active Expired
- 1976-02-06 JP JP1212976A patent/JPS51103388A/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| AU1079576A (en) | 1977-08-11 |
| JPS51103388A (en) | 1976-09-11 |
| GB1530004A (en) | 1978-10-25 |
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