US 3668964 A
Description (OCR text may contain errors)
United States Patent Lomas [4 June 13, 1972  CHOPPER BODY 3,340,757 9/1967 Rudszinat ..83/674 X 3,424,043 1/1969 Martin ..83/65 9 X Eric Ellis Lomfls, Wallasey, England 2,829,694 4/1958 Jarvis ..83/674 x I 73] Fibreglass 'l Ravenhead FOREIGN PATENTS OR APPLICATIONS Helens, Lancashire, England 4,90 19 6 B g 1968 8 2/ 0 Great ritam 83/346 [2 1 1 Primary Examiner-Andrew R. .luhasz Assistant Examiner-Leon Gilden Attorney-Birch, Swindler, McKie & Beckett Foreign Application Priority Data Aug. 22, 1967 Great Britain ..38,653/67  ABSTRACT Apparatus for chopping sized glass fiber filaments comprising  U.S. Cl ..83/347, 83/674, 83/698 two co-operating parallel rollers between which the filaments  Int. Cl. .JB23d 25/12, 823d /00 are passed one roller having a series of spaced blades project-  Field of Search ..s3 343, 346, 347, 659, 665, ng m its surface; g p being provided in h r ller between 83/674, 698, 561 successive blades to reduce the area of this roller in contact with the filaments at any given time. . References Cited sclaims, 9 w g Figures UNITED STATES PATENTS 2,829,689 4/1 958 Jarvis ;.s3/ 34 x 22 32a 17! 15 23 325, 4e 54 V 78 P P P g 52 PATENTEUJUH 1 3 I972 SHEET 3 BF 3 F/GB.
CHOPPER BODY This invention relates to the chopping of continuous filaments into short lengths and has particular application to the chopping of continuous glass fiber strands.
It is known to chop continuous filaments into short lengths bypassing the filaments between two parallel rollers one of which has a series of cutters projecting from the periphery thereof and the other of which is covered with a resilient material. The cutters, particularly those used for severing filaments such as glass strands, comprise very thin blades and the known roller bodies for supporting these very thin blades comprises a solid roller body with thin radial slots into which the cutter blades are inserted as a forced fit". The depth of the slots is such that only a very small amount of the cutter blade projects from the periphery of the cutter roller so that maximum support is afforded to the cutter blades. The roller coated with the resilient material is a backing roller and the two rollers are loaded towards one another and rotated with uniform peripheral speeds so that the continuous filaments are gripped therebetween, passed through the nip with a linear speed equal to the peripheral speed of the rollers, and severed by a cutter blade only when the cutter blade is forced into the backing roller.
This type .of chopper has a very limited life, particularly when chopping coated filaments, such as glass fiber strands which are coated with a size, because the rollers tend to pick up size from glass strands passing therebetween and become coated with the size. The rolling pressure between the two rollers and the action of the blades working" the surface of the backing roller create heat which is easily dissipated from the surface of the resilient roller but is retained in the relatively solid, usually metallic, body of the cutter roller and as the temperature of the cutter roller increases size deposited thereon is solidified. The'solidified deposit of size increases the rolling pressure between the rollers and thus increases the temperature of the chopper body so that the build up of further size deposits on the roller is facilitated.
The build up of size deposit on the cutter roller greatly reduces the operating life of the cutter and in practice frequent replacement of the cutter rollers is necessary.
SUMMARY OF THE INVENTION The object of the present invention is to provide a chopper body construction which is not readily susceptible to failure by solidification of deposits thereon and which thereby affords a longer effective life than known chopper constructions. I According to the present invention apparatus for chopping continuous filaments comprises a rotatable chopper body carrying a plurality of chopper blades whose cutting edges are arranged to describe a cylinder of revolution, a rotatable backing roller mounted so that there is interference between the periphery of the Additionally and said cylinder of revolution sufficient to enable said blades to chop filaments against the roller, feeding means to feed continuous filaments between the chopper body and the backing roller, and drive means to rotate said chopper body so that successive blades respectively make successive chops, wherein said chopper body comprises support means arranged to support said blades in circumferentially spaced relationship and to provide a gap between successive blades such that contact between at least part of the periphery of the backing roller and the chopper body is avoided between of said gap.
The present invention thus envisages a chopper body having gaps between successive cutter blades so that the area of the chopper body contacting the filaments, and thereby susceptible to contamination by the coating on the filaments, is reduced and the mass of the chopper body is reduced. Additionally the surface area of the chopper body exposed to atmosphere can be increased and the construction can permit air to be entrained in the gaps so that the chopper body is efsuccessive chops by reason 2 fectively cooled and solidification of the size contacting the roller parts is reduced.
The gaps between the chopper blades may comprise grooves or slots cut into the curved surface of asolid chopper body or the chopper body may comprise a fabricated structure.
Thus, said support means may comprise at least two support elements spaced apart along the axis of rotation of the chopper body, and there may be provided a further support element arranged to support each chopper blade at a'posi'tion substantially central of the blade. Conveniently said support elements are mounted on a common shaft.
The chopper body may include end plates, and retaining means associated with saidend plates and said chopperblades adapted to prevent radial movement of said blades relative to the chopper body.
When the chopper blade is thin, or unsupported over lengths which permit flexing thereof, each chopper blademay be mounted against at least one support plate, and may be sandwiched between a pair of support plates.
The term filament" when used in the present invention includes any single filament or strand, roving ribbon or rope made up of a number of fibers DESCRIPTION OF THE DRAWINGS The present invention will now be described further by way of example with reference to the accompanying drawings in which:
FIG. 1 shows a vertical section through a filament chopping arrangement on the line II, II of FIG. 2,
FIG. 2 shows a center line section through the chopper arrangement on the line III, III of FIG. 1,
FIG. 3 is an end view of a cutter assembly support member,
FIG. 4 shows an end view of an end flange,
FIG. 5 shows a section on the line IV, IV of FIG. 4,
FIG. 6 shows an exploded view of a cutter assembly,
FIG. 7 is an end view of a cutter assembly,
FIG. 8 is a vertical section through a modified form of chopper body, and
FIG. 9 is an end view of the body shown in FIG. 8.
DESCRIPTION OF THE PREFERRED EMBODIMENT In the apparatus illustrated in FIG. 1 for chopping continuous glass strands the strands pass between driven rollers l l 12 which direct said strands between a backingroller 13 and a chopper body 14.
The chopper body 14 comprises a hollow tubular shaft 15, with reduced ends 1 6, 17 upon which a first support member 18, having a boss 19, is secured by a pin 20. The support member 18 has eight radial slots 2] equally spaced about its periphery and the slots 21 are of equal depth so that the roots thereof lie on a common circle concentric with the axis of shaft 15. A second support member 22, identical with support member 18 and having a boss 23 and radial slots 24, is secured on shaft 15 by a pin 25 so as to lie in spaced parallel relationship with support member 18 and with its slots 24 aligned with the slots 21 in support member 18 in planes passing through the axis of shaft 15.
Cutter assemblies 30 are inserted into the aligned slots 21, 24 so as to lie parallel to the axis of shaft 15 and each cutter assembly comprises a support plate 31, having a base 32, a cutter blade 33, and a backing plate 34. The base 32 of support plate 31 extends outwardly from one face of plate 31 to form a seat for the lower edge of the blade 33 and the lower edge of the backing plate 34. The plate 31, blade 33 and plate 34 have the same length, which length is equal to the distance between the outside plane faces of support members 18 and 22 when said members are secured on shaft 15 but the base 32 extends outwardly beyond the ends of plate 31 to form location lugs 32a for the assemblies 30.
part of a support element used in When a cutter assembly 30 is inserted into aligned slots 21 and 24, said assembly being a relatively tight fit in said slots 21, 24, the slots 21, 24 contain the assembly against displacement normal to the plane of the blade 33 and thus each blade 33 is supported along the whole of its lower edge and over the major part of its plane faces. To retain the blade 33 and plate 34 against relative displacement in the plane of the blade 33 two pegs 35, 36 are passed through holes 37, 38 respectively in plate 31, holes 39, 40 respectively in blade 33, and holes 41, 42 respectively in plate 34.
With all the cutter assemblies 30 located in their respective slots 21, 24 in the support members 18, 22 the lugs 32a of the base 32 project outwardly from the support members 18, 22 and an end flange 43, having an annular recess 44, is secured onto support member 18 by screws 45 with the lugs 32a projecting from member 18 engaged in the recess 44. An end flange 46 with an annular recess 47 is, in like manner, secured on support member 22 by screws 48 with the lugs 32a projecting from support member 22 located in the annular recess 46. It will thus be seen that the end flanges 43 and 46 restrain the cutter assemblies 30 against radial displacement.
The backing roller 13 comprises a solid core 50 with a resilient sleeve 51 secured thereon and said core 50 has reduced ends 50a and 50b. The reduced ends 50a and 50b are supported in bearings presented by plates P forming part of the machine frame and plates P also present bearings for the reduced ends 16 and 17 of the shaft 15.
The apparatus is driven by a gear wheel 52, rotated by a drive means (not shown) which meshes with a gear wheel 53 secured on reduced end 5012 of core 50 and gear wheel 53 in turn meshes with a gear wheel 54 secured on reduced end 17 and by this means backing roller 13 and chopper body 14 are rotated in opposite directions. The backing roller 13 is mounted relative to the chopper body so that there is interference between the periphery of the backing roller and the cylinder of revolution described by the cutting edges of the chopper blades 33.
The diameter of roller 13 is greater than the effective diameter of chopper body 14 i.e. that diameter swept by the outermost faces of the cutter assemblies, so that the blades 33 engage different parts of roller 13 to avoid excessive wear in limited regions of roller 13 and the gear wheels 52 and 53 are so selected that the peripheral speed of roller 13 is equal to the peripheral speed at the effective diameter of chopper body 14.
In operation gear wheel 52 transmits drive through gear wheel 53 and gear wheel 54 to rotate backing roller 13 and chopper body 14 and driven rollers 11, 12 pass the endless strands to be chopped into the nip between roller 13 and body 14. The filaments are driven at uniform speed and the peripheral speed of the effective diameter of roller 13 and body 14 are equal to the linear speed of the strands. As the chopper body 14 rotates the strands are caught between the cutter assemblies of body 14 and the backing roller 13; there is pressure contact between the cutter assemblies and the backing roller 13 and the projecting cutter edge of blades 33 sever the strands.
It will be seen that the space between the support members 18 and 22 provides a gap between cutter assemblies such that contact between part of the periphery of the backing roller 13 and the chopper body is avoided between successive chops by reason of this gap.
The cutter assemblies are largely exposed to the surrounding atmosphere and have the form of paddles which stir the surrounding atmosphere so that the chopper assemblies remain relatively cool, and as the parts of the chopper body which normally contact the endless filaments are the cutting edge of the blade 13 and the outermost surfaces of the plates 31 and 34, and as these surfaces are cooled, the solidification of cutting deposits on the chopper body 14 is reduced.
The chopper body shown in FIG. 8 comprises a shaft 60 on which end support elements 61 and 62 are mounted at positions spaced along the shaft. The elements 61 and 62, which are identical, are generally disc-like in form but with projecting bosses 63 and 64 respectively having diametrical holes in which pins 65 and 66 are fitted to secure the support elements to the shaft 60, the latter having corresponding holes through which the pins pass. Associated with the support elements 61 and 62 are respective adaptor discs 67 and 68 of the same outside diameter as the support elements and with a central hole such that the discs 67 and 68 fit over the bosses 63 and 64. The adaptor discs 67 and 68 are secured to the support elements 61 and 62 by screws passing through arcuate slots in the discs and threaded into holes in the support elements, the screws, holes and slots not being shown in the drawing.
Mounted on the shaft 60 in a position substantially midway between the end support elements 61 and 62 is a central support element 69, which is generally disc like in form but with a projecting boss 70. A pin 71 is fitted in a diametrical hole in the boss and passes through a corresponding hole in the shaft 60 to secure the support element to the shaft. Associated with the central support element 69 is an adaptor disc 72, like the discs 67 and 68, having a central hole such that it fits over the boss 70. The disc 72 is secured to the element 69 by means of screws through arcuate slots in the disc and threaded into holes in the support element. The outside diameter of the disc 72 and central support element 69 is the same as that of the end support elements 61 and 62 and adaptor discs 67 and 68.
The support elements 61, 62, and 69 and the adaptor discs 67, 68 and 72 have equi-spaced radially extending slots 73 in their peripheries (see FIG. 9). These slots are essentially similar to the slots 21, 24 previously described but are provided in greater number, and are somewhat narrower for a reason which will become apparent. The support elements and adaptor discs are so oriented that the peripheral slots 73 therein are aligned in a direction parallel to the shaft 60, i.e. a series of sets of aligned slots is provided, each set comprising one slot in each of the support elements and adaptor discs. A cutter or chopper blade 74 is fitted in each set of aligned slots with the blades linear cutting edge facing outwardly and projecting from the slots. The positioning of the support elements and adaptor discs along the shaft 60 is such that each blade 74 is supported adjacent its ends by the end support elements 61 and 62 and their associated adaptor discs 67 and 68, and substantially centrally along its length by the central support element 69 and its associated adaptor 72. In this manner a series of chopper blades 74 are carried in circumferentially spaced relationship round the chopper body, the spaces between the central support and the end supports providing gaps between successive blades.
The slots 73 are narrower than the slots 21, 24 previously described because the slots 73 accommodate only a chopper blade 74, whereas the slots 21, 24 accommodate a chopper blade 33 together with support plates 31, 34 between which the blade is sandwiched.
Each of the blades 74 used in the embodiment shown in FIG. 8 is provided with end slots or recesses 75 and 76. Disclike end plates or caps 77 and 78 are provided with ring projections 79 and 80, which fit in the recesses 75 and 76 respectively, and thereby hold the blades against movement radially outwards. The end plates or caps 77 and 78 have central holes such that they fit over bosses 81 and 82 respectively provided on the end support elements 61 and 62, the end plates being secured to the end support elements by mans of screws 83 and 84. The end-most part of the periphery of the end support elements 61 and 62 is of reduced diameter to permit inward projection of the rings 79 and on the end plates.
The operation of the chopper body shown in fig. 8 is essentially the same as previously described, the shaft 60 being rotated and the blades 74 successively chopping filaments against a rotatable backing roller.
In the drive arrangement previously described, the chopper body and the backing roller are positively driven in opposite directions by means of appropriate gears. lf preferred, the chopper body alone may be directly driven by the drive means, and the backing roller may be mounted for free rotation and may be rotated by frictional contact with the rotating chopper body.
What we claim is:
1. Apparatus for chopping continuous filaments comprising a rotatable chopper body having a pair of disc-shaped blade support members along the axis of rotation thereof, each of said support members having radially extending blade receiving slots in circumferentially spaced relationship, said slots of one of said support members being aligned with said slots on the other of said support members in planes passing through the axis of rotation,
a plurality of chopper blades mounted in said slots and supported at their ends by said slots such that the cutting edges of said blades protrude from said slots to describe a cylinder of rotation of the diameter greater than the diameter of said support members,
blade support plate means associated with each of said chopper blades and coextensive therewith, said blade support plate means comprising a base member against which the base of said blade is seated and a backing member against which a side of said blade is seated, said backing member including means engaging said blade and locking said blade against relative movement with respect to said support plate means, said blade and said support plate means being received in said slots,
a pair of end plates on said chopper body for locking said blades against radial and axial movement, said end plates engaging said blade support plate means,
a rotatable backing element having a resilient surface mounted on a parallel axis adjacent said chopper body and spaced from said chopper body such that there is interference between the periphery of said cylinder of rotation described by said cutting edges and said backing roller sufficient to enable said blade to chop filaments against said backing roller while direct contact between said chopper body and said backing roller is avoided,
means for feeding continuous filaments between said chopper body and said backing roller, and
means rotating said chopper body.
2. Apparatus as set forth in claim 1 wherein each of said blades is sandwiched between a pair of backing members.
3. Apparatus as set forth in claim 1 wherein each of said blades includes at least one opening therethrough and wherein said means engaging said blades includes projections on said backing plates for engaging said openings to lock said blade against movement relative to said support plate means.