GUILLOTINE KNIFE ASSEMBLY

BACKGROUND TO THE INVENTION

Guillotine knife, specifically guillotine knife for paper trimming, gets worn with repeated usage and has to be either regrind or replaced. Guillotine knife is normally mounted and clamped onto the moving guillotine arm of the guillotine press. Regrinding the worn edge of the guillotine knife implied dismantling said knife from the guillotine arm, sending the knife out for regrinding and remounting and clamping the regrind knife back onto the guillotine arm. There is an incurred downtime in this procedure. Alternatively a spare knife can be held in stock this cutting down the downtime significantly. However this incurs additional costs i.e. the extra costs of the additional knife. Additionally dismantling and refitting of the knife, either new or regrind, is tedious and time consuming as the knife can be quite heavy. Additionally for the regrind knife, it position on the holder has to be readjusted as the regrind knife dimension has been altered after the regrinding process. This is time consuming and need to be conducted by skillful personnel. For this reason it is easier to use a new knife every time as adjustment in its position is not required but this approach can be very costly.

SUMMARY OF THE INVENTION

A knife insert and a holder for holding said knife insert with said knife insert and said holder forming a guillotine knife assembly of the present invention and with said guillotine knife assembly designed for mounting onto a guillotine press. The holder further comprises a main body, an insert clamp, a fastening means to couple said insert clamp onto said main body after the knife insert is correctly positioned interleaved between said main body and said insert clamp and a clamping means to prevent said knife insert extracted from said holder. Additionally the main body and the insert clamp are substantially equal in length longitudinally as compared to the knife insert. The guillotine knife assembly is to substitute a conventional guillotine knife for trimming of paper with said guillotine knife assembly mounted on to a guillotine press in a similar manner as said conventional guillotine knife.

The knife insert is an indexable type and of a longitudinal strip having opposing cutting edges and with said strip bent substantially symmetrically midway along it longitudinal length forming two sections, the inner section and the outer section, with said two sections inclined at an obtuse angle to one another. The main body is a longitudinal strip comprises substantially parallel opposing longitudinal edges, a plane upper face and opposing stepped lower faces namely the lower inner face, the clamp seating and the lower outer face in that order with the planes of the stepped lower faces substantially parallel to said upper face and with step lower faces are connected by stepped edges. The upper face and the lower outer face are connected by a sloping edge. On the main body is a plurality of spaced apart countersunk through holes and at least a tapped grease inlet hole and at least a tapped grease outlet hole. On the reverse side of the main body and concentric to the grease inlet hole and the grease outlet hole is a circular groove each where an 'O' ring locates. Along the inner region of the clamp seating is a grease flow slot and a chord seal slot encircling said grease flow slot and with a chord seal locating in said chord seal slot.

The insert clamp comprises a longitudinal strip of a defined thickness having a top face and an opposing bottom face with the planes of both said faces substantially parallel to one another and with said top face and said bottom face connected at the outer edge by a sloping surface termed the insert seating and at the inner edge by a step inner edge. In the assembled guillotine knife the step inner edge abuts the step edge between the lower inner face and the clamp seating of the main body. On the top face of the insert clamp are a plurality of tapped holes equal in number to the countersunk through holes on the main body, at least one grease inlet hole and at least one grease outlet hole. The grease inlet hole substantially overlaps the tapped grease inlet hole of the main body with fluid admitted from said tapped grease inlet hole able to flow into said grease inlet hole. Likewise the grease outlet hole substantially overlaps the tapped grease outlet hole of the main body with fluid being able to flow out from said grease outlet hole into said tapped grease outlet hole. Also along the top face are a plurality of grease flow holes connected to and in communication with grease flow slot on the main body in an assembled guillotine knife assembly and an equal number of pressure washer seatings. The pressure washer seatings each

comprises two concentric circular sections, a top section and a lower section with said top section of a greater diameter than said bottom section and with a pressure washer of thickness equal to or less then the height of said top section located in a level position at said top section. A plurality of grease tunnels, equal in number as the pressure washer seatings, are situated transversely within the insert clamp with one such grease tunnel connects the grease inlet hole, a pressure washer seating and a grease flow hole while another such grease tunnel connects the grease outlet hole, a pressure washer seating and a grease flow hole. Fluid admitted into the grease tunnel from the grease inlet hole gets transmitted to the pressure washer seating at one end and to the grease flow hole at the other end where said fluid exits into the grease flow slot of the main body and get transmitted to the other grease tunnels. The fluid exits from the system through the grease outlet hole that is connected to the grease tunnel. The other grease tunnels each connects a pressure washer seating and a grease flow hole with fluid admitted into a grease tunnel from said grease flow hole at one end gets conveyed to said pressure washer seating at the other end. In an operational guillotine knife assembly fluid pressure within the system is maintained at a predetermined value. At each pressure washer seating pressure transmitted by the fluid lifts the pressure washer and presses it against the knife insert clamping said knife insert against lower outer face of the main body. In the guillotine knife assembly the knife insert is interleaved between the main body and the insert clamp with said knife insert located towards the outer edge of said guillotine knife assembly and supported by the insert seating of said insert clamp. A fastening means couples the insert clamp onto the main body after the knife insert is correctly positioned with said fastening means comprises cap screws with the heads of said cap screws located in the countersunk sections of the countersunk through holes in said main body and the threads on the shanks of said cap screws engaged to the threads of corresponding tapped holes in said insert clamp. A cutting edge of the knife insert is exposed to form the operational cutting edge of the guillotine knife assembly while the other cutting edge remains unused and lies adjacent to a recess of said main body.

A clamping means is provided to prevent the knife insert from being extracted from the holder of the guillotine knife assembly with said clamping means in the form

of a plurality of pressure washers, residing in corresponding pressure washer seatings of the insert clamp, pressing the knife insert against the lower outlet face of the main body when the pressurized fluid is being admitted into the grease tunnels and with the pressure of said fluid maintained at a predetermined level. Frictional forces at the contact between the knife insert and the lower outer face of the main body prevent said knife insert from being extracted from the holder of the guillotine knife assembly.

These and other features, advantages and objectives of the present invention will be further understood and appreciated by those skilled in the art by the following specification, appended drawings and claims.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 shows the guillotine knife assembly of the present invention.

Fig. 2 shows the main body of the guillotine knife assembly.

Fig. 2A shows the reverse face of the main body, as shown in Fig. 2, of the guillotine knife assembly.

Fig. 3 shows the insert clamp of the guillotine knife assembly.

Fig. 4 shows the knife insert of the guillotine knife assembly.

Fig. 5 shows the section view 'A - A' of Fig. 1 of the guillotine knife assembly. Fig. 6 shows the section view 'B - B' of Fig. 1 of the guillotine knife assembly.

Fig. 7 shows the section view 'C - C of Fig. 1 of the guillotine knife assembly.

Fig. 8 shows the section view 'D - D' of Fig. 1 of the guillotine knife assembly.

Fig 9A shows details of enclosure 'A' as shown in Fig. 2A.

Fig. 9B shows details of enclosure 'B' as shown in Fig. 2 A.

Fig. 9C shows details of a pressure washer seating of the insert clamp and the related washer.

DETAIL DESCRIPTION OF THE INVENTION

A knife insert (3) and a holder for holding said knife insert (3) with said knife insert (3) and said holder forming a guillotine knife assembly (10) of the present invention with said guillotine knife assembly (10) designed for mounting onto a guillotine press. The holder further comprises a main body (1), an insert clamp (2), a fastening means to couple said insert clamp (2) onto said main body (1) after the knife insert (3) is cooperatively and correctly positioned interleaved between said main body (1) and said insert clamp (2) and a clamping means to prevent said knife insert (3) extracted from said holder. Additionally the main body (1) and the insert clamp (2) are substantially equal in length longitudinally as compared to the knife insert (3).

The guillotine knife assembly (10) is to substitute a conventional guillotine knife for trimming of paper with said guillotine knife assembly (10) mounted on to a guillotine press in a similar manner as said conventional guillotine knife. It should be noted that for the sake of clarity all the components and parts of the guillotine knife assembly (10) may not be shown and marked in the drawings. Additionally the terms as used in this description refer to the items as orientated in the drawings and they may be in any various orientations when in use and as such the orientations as illustrated in the drawings are not necessary for operability.

The knife insert (3), as shown in Fig. 4, forming part of the guillotine knife assembly (10) is an indexable type and comprises a longitudinal strip with opposing cutting edges and with said strip bent substantially symmetrically midway along it longitudinal length. Two sections are thus formed, the inner section (56) and the outer section (57) with said two sections (56, 57) inclined at an obtuse angle to one another. The inner section (56) further comprises an inner top surface (52) and an inner bottom surface (54) connected by an inner face (58) while the outer section (57) comprises an outer top surface (53) and an outer bottom surface (55) connected by an outer face (59) as shown in Fig. 4. Additionally two cutting edges, the first cutting edge (50) and the second cutting edge (51) are present, with the first cutting edge (50) along the full length of the longitudinal edge of the outer section (57) and the second cutting edge (51) along the full length of the longitudinal edge of the inner section (56) and with said cutting edges (50, 51) substantially parallel to one another.

The main body (1) of the guillotine knife assembly (10) is a longitudinal strip comprises substantially parallel opposing longitudinal edges, a plane upper face (11) and opposing stepped lower faces namely the lower inner face (12), the clamp seating (13) and the lower outer face (14) in that order, as shown in Fig. 2 and Fig. 2A and with the planes of the stepped lower faces (12, 13, 14) substantially parallel to said upper face (11). The step lower faces (12, 13, 14) are connected by stepped edges (16, 17) that extend along said step lower faces (12, 13, 14) with said stepped edges (16, 17) substantially parallel to the opposing longitudinal edges of the main body (1). The upper face (11) and the lower outer face (14) are connected by a sloping edge (15). Alone the length of the main body (1) is a plurality of spaced apart countersunk through holes (18) and in the preferred embodiment, as shown in Fig. 2, said countersunk through holes (18) are positioned in adjacent pairs transversely and along a pair of imaginary parallel lines longitudinally. Also on the main body (1) are at least a tapped grease inlet hole (19) and at least a tapped grease outlet hole (20) and in the embodiment, as shown in Fig. 2, said grease inlet hole (19) and said tapped grease outlet hole (20) each locate within separate clusters of countersunk through holes (18). On the reverse side of the main body (1), as shown in Fig. 2A, and concentric to the exit of the grease inlet hole (19) and the exit of the grease outlet hole (20) is a circular groove (23) each configured to accommodate an 'O' ring (7) and as shown for said grease inlet hole (19) in Fig. 9B. In the assembled guillotine knife assembly (10) an 'O' ring (7) resides in each of the circular grooves (23). Also on the reverse side of the main body (1) and along the inner region of the clamp seating (13) is a grease flow slot (21) that extends longitudinally along a substantial length of said main body (1) but stop short of the transverse end edges as shown in Fig. 2 A. Encircling the grease flow slot (21) is a chord seal slot (22), as shown in Fig 2 A and in detail in Fig. 9A, that is configured to accommodate a chord seal (62) that is used to prevent seepage of fluid from the grease flow slot (16) into the joint face between the main body (1) and the insert clamp (2) in an operational guillotine knife assembly (10). In the assembled guillotine knife assembly (10) a chord seal (62) resides in the chord seal slot (22). On the lower outer face (14) of the main body (1) is a recess (24) located adjacent to the unused cutting edge of the knife insert (3) in an assembled guillotine knife assembly (10) as shown in Fig. 5 to Fig. 8. The recess (24) provides a

clearance for the unused cutting edge of the knife insert (3) to prevent any possible damage to said unused cutting edge.

The insert clamp (2), as shown in Fig. 3, comprises a longitudinal strip of a defined thickness having a top face (37) and an opposing bottom face (38) with the planes of both said faces (37, 38) substantially parallel to one another. In additional the top face (37) and the bottom face (38) are connected at the outer edge by a sloping surface termed the insert seating (30) and at the inner edge by a step inner edge (39). The step inner edge (39) is configured to abut the step edge (16) between the lower inner face (12) and the clamp seating (13) of the main body (1) in the assembled guillotine knife (10). In the embodiment as shown in Fig. 1 the thickness of the insert clamp (2) is substantially similar to the height of the step edge (16) of the main body (1) such that when said insert clamp (2) is correctly mounted to said main body (1) the bottom face (38) of said insert clamp (2) and the lower inner face (12) of said main body (1) are on substantially similar plane. On the top face (37) of the insert clamp (2) are a plurality of tapped holes (32) that equal in number to the countersunk through holes (18) on the main body, at least one grease inlet hole (34) and at least one grease outlet hole (35). The positions of the axes of the tapped holes (32) on the insert clamp (2) are substantially coincidental to the corresponding axes of the matching countersunk through holes (18) on the main body (1) and when said insert clamp (2), said main body (1) and the knife insert (3) are correctly positioned with respect to one another they can be secured together by suitable fasteners (4) and with the countersunk heads of said fasteners (4) residing within the countersunk through holes (18) of said main body (1) while the threaded shanks of said fasteners (4) engaged to the threads of said tapped holes (32) of said insert clamp. The grease inlet hole (34) on the insert clamp (2) substantially overlaps and in communication with the tapped grease inlet hole (19) of the main body (1) in the guillotine knife assembly (10) with fluid admitted from said tapped grease inlet hole (19) on said main body (1) able to flow into said grease inlet hole (34) of said insert clamp (2). Likewise the grease outlet hole (35) on the insert clamp (2) substantially overlaps and in communication with the tapped grease outlet hole (20) of the main body (1) in the guillotine knife assembly (10) with fluid being able to flow

out from the grease outlet hole (35) of said insert clamp (2) into the grease outlet hole (20) on said main body (1).

Also along the top face (37) are a plurality of grease flow holes (33) connected to and in communication with grease flow slot (21) on the clamp seating (13) of the main body (1) in an assembled guillotine knife assembly (10) and an equal number of pressure washer seatings (31) as shown in Fig. 3. The pressure washer seatings (31) are located proxy to the insert seating (30) with each said pressure washer seating (31) comprises two concentric circular sections, a top section (31a) and a lower section (31b) with said top section (31a) of a greater diameter than said bottom section (31b) and with said top section (31a) configured to accommodate a pressure washer (5) in a level position as indicated in Fig. 6 and Fig. 9C. Additionally the thickness of the pressure washer (5) used is equal to or less then the height of the top section (31a) of the pressure washer seating (31).

Situated transversely within the insert clamp (2) is a plurality of grease tunnels (36) equal in number as the pressure washer seatings (31). One such grease tunnel (36) connects the grease inlet hole (34), a pressure washer seating (31) and a grease flow hole (33) as shown in Fig 7. Another such grease tunnel (36) connects the grease outlet hole (35), a pressure washer seating (31) and a grease flow hole (33) as shown in Fig. 6. Fluid admitted into the grease tunnel (36) from the grease inlet hole (34) get transmitted to the pressure washer seating (31 ) at one end and to the grease flow hole (33) at the other end where said fluid exits into the grease flow slot (21) of the main body (1) and get transmitted to the other grease tunnels (36). At the transverse plane, as shown in Fig. 6, wherein the grease outlet hole (35) is present part of the fluid exits from the system through said grease outlet hole (35). The other grease tunnels (36) each connects a pressure washer seating (31) and a grease flow hole (33) as shown in Fig. 8 with fluid admitted into a grease tunnel (36) from said grease flow hole (33) at one end gets conveyed to said pressure washer seating (31) at the other end. In an operational guillotine knife assembly (10) fluid pressure within the system is maintained at a predetermined value. At each pressure washer seating (31) pressure transmitted by the fluid lifts the pressure washer (5) and presses said pressure washer (5) against the knife insert (3) clamping said knife insert (3) against lower outer face (14) of the main body (1).

The arrangement of the main components to form the guillotine knife assembly (10) of the present invention is shown in Fig. 1. In this arrangement the knife insert (3) is interleaved between the main body (1) and the insert clamp (2) with said knife insert (3) located towards the outer edge of the guillotine knife assembly (10). A fastening means is present to couple the insert clamp (2) onto the main body (1) after the knife insert (3) is correctly positioned. The fastening means comprises cap screws (4) with heads of said cap screws (4) located in the countersunk sections of the countersunk through holes (18) in the main body (1) and the threads on the shanks of said cap screws (4) engaged to the threads of the corresponding tapped holes (32) in the insert clamp (2). The axes of the countersunk through holes (18) in the main body (1) are substantially coincidental with the matching corresponding axes of the tapped holes (32) in the insert clamp (2) when said main body (1) and said insert clamp (2) are correctly position with respect to one another. The knife insert (3) locates between the main body (1) and the insert clamp (2) with a cutting edge, the first cutting edge (50) in this example, exposed to form the operational cutting edge of the guillotine knife assembly (10) as shown in Fig. 5 to Fig. 8. The second cutting edge (51) remains unused and lies adjacent to the recess (24) of the main body (1).

The outer bottom surface (55) of the knife insert (3) abuts and rests on the insert seating (30) of the insert clamp (2). When the guillotine knife assembly (10) is mounted on the guillotine press and when said guillotine press is operational the insert seating (30) provides a support to react the cutting force on the cutting edge (50) of the knife insert (3).

A clamping means is provided to prevent the knife insert (3) from being extracted from the holder of the guillotine knife assembly (10). The clamping means takes the form of a plurality of pressure washers (5), residing in corresponding pressure washer seatings (31) of the insert clamp (2), pressing the knife insert (3) against the lower outlet face (14) of the main body (1) when the pressurized fluid is being admitted into the grease tunnels (36) and with the pressure of said fluid maintained at a predetermined level. Frictional forces at the contact between the knife insert (3) and the lower outer face (14) of the main body prevent said knife insert (3) from being extracted from the holder of the guillotine knife assembly (10).

The foregoing description is considered as illustration of the principles of the invention. Furthermore, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.