CN110815353B

CN110815353B - Edge cutting device for film layering

Info

Publication number: CN110815353B
Application number: CN201911208617.1A
Authority: CN
Inventors: 曹玉; 毛潞
Original assignee: Chongqing Ruiting Plastic Co Ltd
Current assignee: Chongqing Ruiting Plastic Co Ltd
Priority date: 2019-11-30
Filing date: 2019-11-30
Publication date: 2021-05-28
Anticipated expiration: 2039-11-30
Also published as: CN110815353A

Abstract

The invention belongs to the technical field of film trimming, and particularly discloses a trimming device for film layering, which comprises a workbench, wherein the workbench is sequentially provided with a deviation rectifying unit and a trimming unit along the conveying direction of a film, the deviation rectifying unit comprises two deviation rectifying frames, the two deviation rectifying frames are respectively positioned at two sides of the workbench, the two deviation rectifying frames are symmetrically arranged with each other, the two deviation rectifying frames are both connected with deviation rectifying blocks, the two deviation rectifying blocks are both in half I shape, the two deviation rectifying blocks are symmetrically arranged with each other, the deviation rectifying blocks are hollow, the upper side and the lower side of the deviation rectifying blocks are both provided with air outlets facing each other, the air inlet has still been seted up on the lateral wall of piece of rectifying, and the air inlet intercommunication lets in gaseous air feed unit to the piece of rectifying, and the unit of cutting edge includes two trimming framves, is connected with the cutting rod between two trimming framves, and the both ends of cutting rod all are connected with the cutter. The invention can correct the deviation of the film, so that the cut film has a regular shape.

Description

Edge cutting device for film layering

Technical Field

The invention belongs to the technical field of film edge cutting, and particularly discloses an edge cutting device for film layering.

Background

The existing plastic film blowing machine is composed of an extruder (the extruder heats and extrudes plastic to be in a molten state, the plastic is extruded by a die head and is blown into a film bubble by compressed air, the cross section of the film bubble is annular), a traction roller arranged above the die head and a coiling device, wherein a herringbone plate is also arranged below the traction roller, and the film bubble blown out of the extruder die head is extruded into two layers of flat films connected with each other before being coiled by the herringbone plate so as to be coiled (the film bubble is extruded into two layers of films after being extruded by the herringbone plate because the cross section of the film bubble is annular).

Before the film is reeled up in the later stage, the film of the platykurtic of two-layer interconnect needs to be conveyed to the edge cutting equipment to be cut edge and handled, cuts two-layer film interconnect's both sides to make separation between the two-layer film, form two-layer film, and then be convenient for the later stage to batch two-layer film respectively.

The film is in long distance processing transfer process, often because the operation of equipment is unstable, perhaps the material is because external environment changes, the phenomenon to one side skew appears, when the film of skew gets into cutting equipment and cuts, causes the film shape of cutting out irregularly easily, influences the rolling regularity of film and the quality of film to influence sale and normal use, still cause the area too big to the film cutting simultaneously easily, and lead to the waste of material.

Disclosure of Invention

The invention aims to provide an edge cutting device for film layering, which aims to correct the deviation of a film and enable the shape of the cut film to be regular.

In order to achieve the purpose, the basic scheme of the invention is as follows:

film layering is with side cut device, comprises a workbench, the workstation is equipped with the unit of rectifying and cuts edge the unit in proper order along the direction of transfer of film, the unit of rectifying includes two frames of rectifying, two the frame of rectifying be located the both sides of workstation respectively, two all be connected with the piece of rectifying on the frame of rectifying, two the piece of rectifying all be half I-shaped, and two the mutual symmetry setting of piece of rectifying, the inside cavity of piece of rectifying, the last side of piece of rectifying and downside all set up mutual just right gas outlet, the air inlet has still been seted up on the lateral wall of piece of rectifying, the air inlet intercommunication lets in gaseous air feed unit to the piece of rectifying, the unit of cutting edge includes two frames of cutting edge, two the frame of cutting edge between be connected with the hob, the both ends of hob all are connected with the cutter.

The working principle and the beneficial effects of the basic scheme are as follows:

through setting up the piece of rectifying of two half I-shapes among this technical scheme can carry on spacingly to the film both sides, rectify to the film, avoid the film the condition that the slope appears in transportation process to make the film can keep the state of rule after being cut, the later stage roll-up of being convenient for, thereby improve the quality and the regularity of the film after the later stage roll-up.

According to the technical scheme, the deviation rectifying unit and the edge cutting unit are sequentially arranged along the conveying direction of the film, so that the position of the film can be limited before the film is subjected to edge cutting, the film can keep a regular shape when entering the edge cutting unit, the position of the cutter is more accurate when the cutter is used for cutting the film, and the phenomenon that the cutter wastes film materials due to the fact that the area of the cutter for cutting the film is too large can be avoided.

In addition, the rectification blocks in the technical scheme are semi-I-shaped, the two sides of the film which are connected with each other respectively penetrate between the upper side surface and the lower side surface of the two rectification blocks, the side walls of the rectification blocks can limit the two sides of the film, the film is prevented from deflecting, and because the inside of the deviation rectifying block in the technical proposal is hollow, the air is blown into the inside of the deviation rectifying block through the external air supply unit, the air in the deviation rectifying block is respectively blown out from the upper side surface and the lower side surface of the deviation rectifying block, the air blown from the upper side surface of the deviation rectifying block and the lower side surface of the deviation rectifying block can make the upper side and the lower side of the film move towards the middle of the deviation rectifying block, so that the upper side and the lower side of the film are not contacted with the upper side surface and the lower side surface of the deviation rectifying block, therefore, the film can be prevented from being scraped with the side wall of the deviation rectifying block in the conveying process, so that the film is prevented from being scratched, and the quality of the film is improved.

Furthermore, two the frame of rectifying between fixedly connected with backup pad, the backup pad both ends all are connected with the connecting plate, the connecting plate all sets up with the backup pad is perpendicular, the one end that the backup pad was kept away from to the connecting plate is connected with the piece of rectifying.

So set up, the setting of backup pad and connecting plate is convenient for rectifying the connection and the installation of piece more.

Furthermore, the supporting plate is of a rectangular plate-shaped structure, the connecting plates are connected with the supporting plate in a sliding mode, and the two connecting plates slide along the length direction of the supporting plate.

So set up, can be according to the different width of film in the actual course of working, adjust the position of two pieces of rectifying to can make the side cut device application scope among this technical scheme wider.

Furthermore, the supporting plate is provided with a rectangular sliding groove along the length direction of the supporting plate, and one end, far away from the deviation rectifying block, of the connecting plate penetrates through the sliding groove and the sliding plate which is fixedly connected with the connecting plate.

The setting of slide among this technical scheme, the operating personnel of being convenient for is outside sliding connection board, and the spout plays the effect of direction to the slip of connecting plate.

Further, the both sides that backup pad upper end just was located the spout have all been seted up the adjustment tank, the adjustment tank all is parallel to each other with the spout, the equal fixedly connected with slider in slide bottom, the spout inserts in the adjustment tank and with adjustment tank sliding fit, all be equipped with in the adjustment tank and be used for restricting the gliding spacing unit of slide.

The adjusting groove has been seted up through the both sides at the spout among this technical scheme, can play direction and spacing effect to the slide to can also reduce the friction between slide and the backup pad, gliding situation can be avoided appearing again after adjusting the position to the setting of spacing unit in addition, thereby makes the slide keep fixed state, and then makes two piece of rectifying keep fixed, avoids appearing shifting.

Furthermore, the limiting unit comprises a screw and a nut, the screw is inserted into the adjusting groove, and the nut is in threaded fit with the screw.

The screw rod and the nut in the technical scheme are arranged, so that the sliding plate can be limited and fixed, the operation is simple, and the cost is low.

Furthermore, a pressing unit is arranged between the deviation rectifying unit and the trimming unit, the pressing unit comprises two pressing roller seats which are opposite to each other, an upper pressing roller and a lower pressing roller are connected between the two pressing roller seats in a rotating mode, and the upper pressing roller and the lower pressing roller are arranged in a vertical parallel mode.

The setting up of upper and lower compression roller in this technical scheme can make the cutter carry out the in-process that cuts to the film play a effect that compresses tightly and pull to the film, can offset the beat that the cutter produced when cutting the film to make the cutter carry out the in-process that cuts to the film more steady, the film of cutting out is more regular.

Further, two the mutual just right one side of side cut frame all seted up the slide opening, the slide opening is the rectangle through-hole structure, equal vertical sliding connection has the installation piece in the slide opening, the both ends of cutting rod respectively with two installation piece fixed connection, the equal fixedly connected with cylinder in side cut frame top, the output of cylinder all with installation piece fixed connection.

Among this technical scheme, the concertina movement of output through control cylinder makes the cutter can shift up or move down to adjust the distance between cutter and the film, and such setting is convenient for more change the cutter or the wearing and tearing situation of inspection cutter.

Furthermore, a plurality of supporting rollers are arranged below the cutting rod, the two ends of the supporting rollers are respectively in rotating connection with the two trimming frames, and the supporting rollers are arranged in parallel.

The setting of a plurality of backing rolls among this technical scheme can make the film in the in-process of cutting, plays the supporting role to the film, avoids the film soft to collapse and can not carry out effectual cutting by the cutter.

Further, the cutters are all disc-shaped, the cutters are all coaxially and fixedly connected with connecting cylinders, and the connecting cylinders are all in threaded connection with the cutting rods.

In this technical scheme, when the distance between two cutters need to be adjusted, can remove the position of cutter through rotating the connecting cylinder to make that the cutter can be accurate cut the film.

Drawings

FIG. 1 is a front perspective view of a first embodiment of a trimming device for film lamination according to the present invention;

FIG. 2 is a front view of a first embodiment of the edge slitting device for splitting a film according to the present invention;

FIG. 3 is an enlarged view of a portion of FIG. 1 at A;

FIG. 4 is a front perspective view of a second embodiment of the edge slitting device for splitting a film according to the present invention;

FIG. 5 is a partial enlarged view of the portion B in FIG. 4;

fig. 6 is a partially enlarged view at C in fig. 4.

Detailed Description

The following is further detailed by way of specific embodiments:

reference numerals in the drawings of the specification include: the automatic edge cutting machine comprises a workbench 1, a rack 2, a rotating seat 3, a first traction roller 4, a second traction roller 5, a third traction roller 6, a deviation rectifying frame 7, a supporting plate 8, a connecting plate 9, a deviation rectifying block 10, an upper side 101, a vertical surface 102, a lower side 103, an air inlet 11, an air outlet 12, an edge cutting frame 13, a sliding hole 14, an installation block 15, an air cylinder 16, a cutting rod 17, a cutter 18, a supporting roller 19, a supporting seat 20, a conveying frame 21, a conveying roller 22, a film 23, a compression roller seat 24, an upper compression roller 25, a lower compression roller 26, an adjusting groove 27, a sliding groove 28, a sliding plate 29, a screw 30, a nut 31 and a connecting cylinder.

Example one

The embodiment is basically as shown in the attached figures 1 and 2: film is side cut device for layering, including workstation 1, the left side of workstation 1 is equipped with frame 2, and frame 2 passes through bolt fixed connection with ground.

2 upper ends of frame are equipped with first carry over pinch rolls 4 and third carry over pinch rolls 6 from a left side to the right side in proper order, 2 lower extremes of frame are equipped with second carry over pinch rolls 5, second carry over pinch rolls 5 are located between first carry over pinch rolls 4 and the third carry over pinch rolls 6, be equipped with the both ends of first carry over pinch rolls 4 in this embodiment, the both ends of second carry over pinch rolls 5 and the both ends of third carry over pinch rolls 6 all are equipped with and rotate seat 3, it all with frame 2 welded fastening to rotate seat 3, the both ends of first carry over pinch rolls 4, the both ends of second carry over pinch rolls 5 and the both ends of third carry over pinch rolls 6 are connected rather than the roating seat 3 that is close to passing through the bearing rotation respectively, and first carry over pinch rolls 4, second carry over pinch rolls 5 and the mutual parallel arrangement.

Workstation 1 is equipped with the unit of rectifying and cuts edge the unit along the direction of transfer of film in proper order, and the unit of rectifying includes two frames 7 of rectifying, and two frames 7 of rectifying are located the front side and the rear side of workstation 1 respectively, and the frame 7 of rectifying all passes through bolt fixed connection with workstation 1, and two mutual symmetries of frame 7 of rectifying set up, and two frames 7 of rectifying all are the rectangular frame structure.

Welded fastening has the backup pad 8 that is the rectangular plate form between two frames 7 of rectifying, the equal perpendicular welded fastening in front portion and rear portion of backup pad 8 has connecting plate 9, the one end that backup pad 8 was kept away from to connecting plate 9 all is connected with the piece 10 of rectifying, two pieces 10 of rectifying all are half I-shaped, combine and show in fig. 3, two sides about rectifying 10 has, be side 101 and downside 103 on the side respectively, side 101 and downside 103 parallel arrangement each other go up, fixedly connected with perpendicular 102 between side 101 and the downside 103, the both ends of perpendicular 102 are fixed with the one end of side 101 and the one end of downside 103 on the side respectively, and perpendicular 102 and last side 101 and set up with downside 103 mutually perpendicular. In this embodiment, the upper side 101, the lower side 103 and the vertical surface 102 are integrally formed by injection molding.

The inside cavity of piece 10 of rectifying, and the gas outlet 12 that all sets up each other just to the setting is seted up at the bottom of the downside 103 of the piece 10 of rectifying and the bottom of the last side 101 of piece 10 of rectifying, set up on the perpendicular 102 of piece 10 of rectifying with the inside air inlet 11 that communicates of piece 10 of rectifying, air inlet 11 intercommunication is to the inside air feed unit who admits air of piece 10 of rectifying, and air feed unit can adopt the air-blower among the prior art.

Combine shown in fig. 1, the side cut unit includes two trimming frame 13, two trimming frame 13 are rectangle platelike structure, and two trimming frame 13 are located the front side and the rear side of workstation 1 respectively, and two trimming frame 13 symmetry each other sets up, two trimming frame 13 all passes through bolt fixed connection with workstation 1, slide opening 14 has all been seted up to two trimming frame 13 one side just right each other, slide opening 14 all is the rectangle through-hole structure, be connected with tangent bar 17 between two trimming frame 13, the equal fixedly connected with cutter 18 in both ends of tangent bar 17, cutter 18 is discoid, it is specific: the sliding holes 14 of the two trimming frames 13 are vertically and slidably connected with mounting blocks 15, two ends of a cutting rod 17 are fixedly welded with the mounting blocks 15 respectively, two cutters 18 are positioned at the front part and the rear part of the cutting rod 17 respectively, and the two cutters 18 are fixedly welded with the cutting rod 17 coaxially.

The top of the trimming frame 13 is fixedly connected with an air cylinder 16 through a bolt, and the output end of the air cylinder 16 is fixedly connected with the two mounting blocks 15 through bolts respectively. Three supporting rollers 19 are arranged below the cutting rod 17, the three supporting rollers 19 are arranged in parallel, the left side and the right side of the trimming frame 13 are respectively fixedly welded with a supporting seat 20, two of the supporting rollers 19 are respectively connected with the supporting seat 20 on the trimming frame 13 through bearings in a rotating mode, and the other supporting roller 19 is located between the two supporting rollers 19 and is connected with the two trimming frames 13 through bearings in a rotating mode.

Be equipped with two conveying frame 21 between side cut unit and the unit of rectifying, two conveying frame 21 are located the front side and the rear side of workstation 1 respectively, and two mutual symmetries of conveying frame 21 set up, two conveying frame 21 pass through bolt fixed connection with workstation 1, be connected with transfer roller 22 through the bearing rotation between two conveying frame 21, combine fig. 2 to show, the piece 10 of rectifying is less than the upside of third carry over pinch rolls 6, transfer roller 22 downside is less than the piece 10 of rectifying, and the upside of backing roll 19 and transfer roller 22's downside parallel and level, can make film 23 more smooth and easy at the in-process of pulling the conveying like this.

When the device is used, a film bubble is blown by an extruder, the film bubble is extruded into two layers of films 23 which are connected with each other, then the films sequentially pass through a first traction roller 4, a second traction roller 5 and a third traction roller 6 on a rack 2 for traction transmission, the films 23 passing through the third traction roller 6 sequentially pass between two deviation rectifying blocks 10, the front side and the rear side of each film 23 are respectively positioned between an upper side 101 and a lower side 103 of each deviation rectifying block 10, the deviation rectifying blocks 10 can avoid the deviation of the films 23 in the transmission process, so that the films 23 can be regularly and flatly transmitted to a trimming unit, the films 23 passing through the deviation rectifying blocks 10 pass through a transmission roller 22 and are positioned on three support rollers 19, in the process that the supporting rollers 23 move rightwards, two cutters 18 cut the front side and the rear side of the two layers of films 23, and the films 23 are prevented from being soft collapsed due to the supporting effect of the three support rollers 19 on, therefore, the cutting knife 18 can effectively cut the two sides of the film 23, so that the two layers of films 23 are layered to generate two layers of films 23, and the right ends of the two layers of films 23 are connected with a winding machine which is used for layering and winding the cut films 23.

In the process, the air blower is communicated with the air inlets 11 of the two deviation rectifying blocks 10, and is driven to fill air into the two deviation rectifying blocks 10, the air in the deviation rectifying blocks 10 is blown out from the upper side 101 and the lower side 103 of the deviation rectifying blocks 10 respectively, so that the upper side and the lower side of the film 23 are not in contact with the upper side 101 and the lower side 103 of the deviation rectifying blocks 10, and the deviation rectifying blocks 10 are prevented from scratching the surface of the film 23.

Through the flexible of control cylinder 16's output in this embodiment, installation piece 15 will drive and cut pole 17 and reciprocate, comes the distance between regulation cutter 18 and the film 23 in proper order, makes cutter 18 can carry out effectual cutting to film 23, in addition, when needs maintenance or change cutter 18, also can control cylinder 16's output upwards to retract, upwards lifts up cutter 18 to be convenient for operating personnel inspection and change.

Example two

As shown in fig. 4 and 5, the edge slitting device for film lamination differs from the first embodiment in that: in this embodiment, the connecting plate 9 is slidably connected to the supporting plate 8, and the connecting plate 9 slides along the length direction of the supporting plate 8. Specifically, the method comprises the following steps: the supporting plate 8 is provided with a rectangular sliding groove 28 along the length direction of the supporting plate, the sliding groove 28 is of a through groove structure, one end, away from the deviation correcting block 10, of the connecting plate 9 penetrates through the sliding groove 28, a sliding plate 29 of a rectangular plate-shaped structure is welded and fixed to one end, away from the deviation correcting block 10, of the connecting plate 9, the sliding plate 29 is perpendicular to the connecting plate 9, and the length of the sliding plate 29 is larger than the width of the sliding groove 28.

The upper end of backup pad 8 just is located the both sides of spout 28 and has all seted up adjustment tank 27, and adjustment tank 27 all is parallel to each other with spout 28.

Two sliding blocks (not shown in the figure) are welded and fixed to the bottom end of each sliding plate 29, the two sliding blocks on each sliding plate 29 are respectively inserted into the adjusting grooves 27 on the two sides of the sliding groove 28 and are in sliding fit with the adjusting grooves 27, limiting units used for limiting the sliding of the sliding plates 29 are arranged in the adjusting grooves 27, the limiting units in the embodiment are screw rods 30 and nuts 31, when the sliding plates 29 need to be limited, the screw rods 30 are inserted into the adjusting grooves 27, the nuts 31 are screwed into the screw rods 30, the nuts 31 are used for limiting and fixing the sliding plates 29, and the sliding plates 29 are prevented from sliding after being adjusted in position.

As shown in fig. 4, a compressing unit is further arranged between the deviation rectifying unit and the trimming unit, the compressing unit is located between the conveying roller 22 and the two trimming frames 13 in the embodiment, the compressing unit includes two mutually opposite compression roller seats 24, the two compression roller seats 24 are respectively located on the front side and the rear side of the workbench 1, an upper compression roller 25 and a lower compression roller 26 are rotatably connected between the two compression roller seats 24 through bearings, the upper compression roller 25 and the lower compression roller 26 are vertically arranged in parallel, the upper compression roller 25 is located right above the lower compression roller 26, and the upper compression roller 25 and the lower compression roller 26 are vertically arranged in parallel. In the process that the film is conveyed towards the trimming unit, the film needs to pass through the space between the upper pressing roller 25 and the lower pressing roller 26, so that the pressing force can be generated on the film by the upper pressing roller 25 and the lower pressing roller 26 when the film is cut by the cutter 18, and the jumping amplitude generated by the film when the film is cut by the cutter 18 is offset or compensated, so that the cutter 18 can stably cut the film, and the shape of the cut film is more regular.

Referring to fig. 6, the cutters 18 are coaxially welded and fixed with connecting cylinders 32, and the connecting cylinders 32 are in threaded connection with the cutting rods 17. With the arrangement, the position of the cutting knife 18 can be changed by rotating the connecting cylinder 32 according to the width of the film 23, so that the cutting knife 18 can be accurately aligned with the cutting position of the film 23, and the arrangement makes the application range of the edge cutting device in the embodiment wider.

The foregoing is merely an example of the present invention and common general knowledge of known specific structures and features of the embodiments is not described herein in any greater detail. It should be noted that, for those skilled in the art, without departing from the structure of the present invention, several changes and modifications can be made, which should also be regarded as the protection scope of the present invention, and these will not affect the effect of the implementation of the present invention and the practicability of the patent.

Claims

1. Film layering is with side cut device, including the workstation, its characterized in that, the workstation is equipped with the unit of rectifying and cuts edge the unit in proper order along the direction of delivery of film, the unit of rectifying includes two frames of rectifying, two the frame of rectifying be located the both sides of workstation respectively, two all be connected with the piece of rectifying on the frame of rectifying, two the piece of rectifying all is half I-shaped, and two the mutual symmetry setting of piece of rectifying, the inside cavity of piece of rectifying, the last side and the downside of the piece of rectifying all set up mutual just right gas outlet, the air inlet has still been seted up on the lateral wall of piece of rectifying, the air inlet intercommunication lets in gaseous air feed unit to the piece of rectifying, the unit of cutting edge include two frames of cutting edge, two the frame of cutting edge between be connected with the cutting rod, the both ends of cutting rod all are connected with the cutter.

2. The edge cutting device for film lamination according to claim 1, wherein a support plate is fixedly connected between the two deviation rectifying frames, connecting plates are connected to two ends of the support plate, the connecting plates are vertically arranged with the support plate, and one end of each connecting plate, which is far away from the support plate, is connected with a deviation rectifying block.

3. The edge slitting device for splitting films as set forth in claim 2, wherein the support plate has a rectangular plate-like configuration, the connecting plates are slidably connected to the support plate, and both of the connecting plates are slidably movable along the length of the support plate.

4. The edge cutting device for film lamination according to claim 3, wherein the support plate is provided with a rectangular sliding groove along the length direction thereof, and one end of the connecting plate, which is far away from the deviation rectifying block, penetrates through the sliding groove and is fixedly connected with a sliding plate.

5. The edge cutting device for film lamination according to claim 4, wherein the supporting plate is provided with adjusting grooves at the upper end thereof and at both sides of the sliding groove, the adjusting grooves are parallel to the sliding groove, the bottom end of the sliding plate is fixedly connected with a sliding block, the sliding groove is inserted into the adjusting groove and is in sliding fit with the adjusting groove, and the adjusting groove is provided with a limiting unit for limiting the sliding of the sliding plate.

6. The edge slitting device for splitting a film according to claim 5, wherein the stopper unit includes a screw inserted into the adjustment groove and a nut threadedly engaged with the screw.

7. The edge cutting device for film lamination according to claim 1, wherein a pressing unit is arranged between the deviation rectifying unit and the edge cutting unit, the pressing unit comprises two pressing roller seats which are arranged opposite to each other, an upper pressing roller and a lower pressing roller are rotatably connected between the two pressing roller seats, and the upper pressing roller and the lower pressing roller are arranged in parallel in a vertical direction.

8. The trimming device for thin film lamination according to claim 1, wherein the two trimming frames are provided with a slide hole on the opposite sides, the slide hole is of a rectangular through hole structure, the slide hole is vertically and slidably connected with a mounting block, the two ends of the cutting rod are respectively and fixedly connected with the two mounting blocks, the top ends of the trimming frames are fixedly connected with air cylinders, and the output ends of the air cylinders are fixedly connected with the mounting blocks.

9. The edge slitting device for splitting a film according to claim 1, wherein a plurality of support rollers are provided under the slitting bars, both ends of the plurality of support rollers are rotatably connected to the two edge slitting frames, respectively, and the plurality of support rollers are arranged in parallel with each other.

10. The edge slitting device for film lamination of claim 1, wherein the cutters are each in the shape of a disc, and the cutters are each coaxially and fixedly connected with a connecting cylinder, and the connecting cylinders are each in threaded connection with the cutting rod.