Title of Invention

CUTTING MECHANISM HAVING A CONCEALED RETURNING UNIT

Abstract

A cutting mechanism for a forming machine includes a support (1) having amounting hole (113), a cutting holder (2) mounted on the support (1) and extending through the mounting hole (113), a drive unit (5) for moving the cutter holder (2) forward, and a returning unit (3) for urging the cutting holder (2) to move rearward. The cutter holder (2) includes a front end provided with a cutting seat (21) and a rear end provided with a mounting part (22), and is movable rearward and forward. The returning unit (3) is concealed and disposed between the support (1) and the mounting part (22).

Full Text

This invention relates to a cutting mechanism, more particularly to a cutting mechanism of a forming machine such as a forging machine. Reference is hereby incorporated to the applicant's co-pending Indian application 175/KOL/2005 relating to the invention entitled " CUTTING MECHANISM HAVING ADJUSTABLE CUTTER HOLDER". Forging machines usually have a cutting mechanism to cut a continuous strip or rod into pieces which are used as blanks. The cut blanks are held by a clamping unit in subsequent steps to perform different forging operations. Figures 1 and 2 show a cutting mechanism 9 mounted on a machine frame 90 which has a feed channel 901 disposed thereon. The cutting mechanism 9 includes a fixed seat 91 fixed to the machine frame 90, a cutter holder 93 movable in a cutting direction 92 and mounted on the fixed seat 91, a blade seat 94 disposed at a front end of the cutter holder 93, a cutter blade 95 mounted on the blade seat 94 and having a feed receiving slot 951, a fixed plate 96 disposed at the back of the cutter holder 93, a cam plate 97, and a returning unit 98 projecting from the fixed plate 96. The cam plate 97 is driven by a power-operated drive mechanism (not shown) to move to-and-fro along working directions 99. The cam plate 97 of the conventional cutting mechanism 9 includes a cam face 971 confronting a roller 931 of the cutter holder 93. The cam face 971 has a starting point 972 and a pushing point 973 having a height difference with the starting point 972. The returning unit 98 includes two guide rods 981 parallel to the cutting direction 92 and CUTTING MECHANISM HAVING A CONCEALED RETURNING UNIT This invention relates to a cutting mechanism, more particularly to a cutting mechanism of a forming machine such as a forging machine. Forging machines usually have a cutting mechanism to cut a continuous strip or rod into pieces which are used as blanks . The cut blanks are held by a clamping unit in subsequent steps to perform different forging operations. Figures 1 and 2 show a cutting mechanism 9 mounted on a machine frame 90 which has a feed channel 901 disposed thereon. The cutting mechanism 9 includes a fixed seat 91 fixed to the machine frame 90, a cutter holder 93 movable in a cutting direction 92 and mounted on the fixed seat 91, a blade seat 94 disposed at a front end of the cutter holder 93, a cutter blade 95 mounted on the blade seat 94 and having a feed receiving slot 951, a fixed plate 96 disposed at the back of the cutter holder 93, a cam plate 97, and a returning unit 98 projecting from the fixed plate 96. The cam plate 97 is driven by a power-operated drive mechanism (not shown) to move to-and-fro along working directions 99. The cam plate 97 of the conventional cutting mechanism 9 includes a cam face 971 confronting a roller 931 of the cutter holder 93. The cam face 971 has a starting point 972 and a pushing point 973 having a height difference with the starting point 972.the returning unit 98 includes two guide rods 981 parallel to the cutting direction 92 and connected fixedly to the cutter holder 93, and two springs 982 sleeved respectively onto the guide rods 981. When the cutting mechanism 9 is in an inoperative position, the starting point 972 of the cam plate 97 is in alignment with the roller 931, and the cutter holder 93 is urged by the springs 982 to move rearward, i.e. rightward as shown in Figs. 1 and 2. In this state, the feed slot 951 of the cutter blade 95 is aligned with the feed channel 901. When the cutting mechanism 9 is changed to a cutting position as shown in Figure 1, the cam plate 97 is moved in the working directions 99 so that the pushing point 973 thereof is aligned with the roller 931. In this state, the springs 982 are compressed, and the cutter holder 93 is moved forward against the biasing force of the springs 982 so that the feed is cut off. As the cam plate 97 reciprocates, the starting point 972 of the cam plate 97 is aligned once again with the roller 931 so that the springs 982 expand and the cutting mechanism returns to the non-cutting inoperative position. In the above cutting mechanism 9, since the springs 982 projects rearward from the fixed plate 96, they are exposed from a support of the forming machine on which the cutting mechanism 9 i.s installed. The exposed configuration increases the volume or size of the cutting mechanism 9. Therefore, a large space is needed for the installation of the cutting mechanism 9. The object of the present invention is to provide a forming machine with an improved cutting mechanism which has a concealed returning unit, thereby reducing the volume of the cutting mechanism and facilitating the installation thereof. According to this invention, a cutting mechanism for a forming machine is characterized by: a support having a mounting hole; a cutter holder mounted on the support and extending through the mounting hole, the cutter holder including a front end provided with a cutter seat and a rear end provided with a mounting part, the cutter holder being movable rearward and forward; a drive unit for moving the cutter holder forward; and a returning unit disposed between the support and the mounting part for urging the cutter holder to move rearward. Other features and advantages of the present invention will become apparent in the following detailed description of the preferred embodiment of the invention, with reference to the accompanying drawings, in which: Fig. 1 is a plan view of the prior art; Fig. 2 is an elevation view of the prior art of Fig. 1; Fig. 3 is a plan view of a preferred embodiment of the cutting mechanism according to the present invention; Fig. 4 is a sectional view taken along line V-V of Figure 3; Fig. 5 is a partially sectioned view of a cutter holder seat in the preferred embodiment; Fig. 6 is an exploded view showing components of the preferred embodiment; Fig. 7 is another exploded view showing the cutter holder seat and a cutter holder of the preferred embodiment; and Fig. 8 is the same view as Figure 3 but with the cutter holder being moved forward. Referring to Figures 3, 4 and 5, there is shown a preferred embodiment of a cutting mechanism according to the present invention which may be used to cut off an elongated material such as a continuous rod (not shown). The embodiment includes a support 1, a cutter holder 2, a returning unit 3, a cutter 4 disposed at the front end of the cutter holder 2, and a drive unit 5 capable of reciprocating leftward and rightward along directions shown by arrows 20. The support 1 includes a support wall 11, a cutter holder seat 12, four wedge blocks 13 for adjusting the cutter holder seat 12 along upward, downward, leftward and rightward directions, and a channel member 14 adjustably mounted at the rear side of the cutter holder seat 12. The support wall 11 has a front face 111, an opposite rear face 112, a mounting hole 113 extending through the front and rear faces 111 and 112, a feed channel 114 extending in a direction perpendicular to the mounting hole 113 to guide a feed rod, and an abutment face 115 formed within a recessed surface of the rear face 112 and parallel to the rear face 112. The cutter holder seat 12 is adjustably mounted on the support wall 11 and is inserted into the mounting hole 113. The cutter holder seat 12 includes a sleeve wall 121 defining a sleeve hole 122, a front collar 123 projecting radially from the sleeve wall 121, and a rear coupling block 124 formed at a rear end of the sleeve wall 121. The sleeve wall 121 has a front small diameter portion 125, a rear large diameter portion 126, a shoulder 127 formed between the small and large diameter portions 125, 126, and a plurality of first slots 128 formed in the shoulder 127 in an angularly spaced apart relationship. Each first slot 128 has a first abutment part 129 parallel to the abutment face 115. In the present invention, the wedge blocks 13 are disposed at the periphery of the front collar 123 to fix or adjust the position of the cutter holder seat 12 along the upward, downward, leftward and rightward directions. The channel member 14 is disposed at the back of the cutter holder seat 12. Since the invention in this application is directed to the returning unit 3 "of the cutter holder 2, the adjustment of the cutter holder 2 through the channel member 14 which is disclosed in a co-pending application, will not be detailed hereinafter. Referring to Figures 3, 6 and 7, the cutter holder 2 is mounted movably inside the sleeve hole 122 of the cutter holder seat 12 and is able to reciprocate forward and rearward in directions shown by arrows 20. The cutter holder 2 includes a front end provided with a cutter seat 21 which is inserted into the sleeve hole 122 in the small diameter portion 125 of the cutter holder seat 12, a rear end provided with a mounting part 22 of an enlarged cross-section which is inserted into the large diameter portion 126 of the cutter holder seat 12, a roller 23, and two saddles 24 for retaining the roller 23 in a rotatable position at the rear end of the mounting part 22. The cutter seat 21 has a front end 211. The mounting part 22 is larger in diameter than the cutter seat 21 and has a plurality of angularly spaced-apart second slots 222 formed in a face 221 which is opposite to the shoulder 127 of the cutter holder seat 12. The second slots 222 are aligned respectively with the first slots 128 and each have a second abutment part 223 opposite to the first abutment part 129 of the corresponding first slot 128. The returning unit 3 functions to resiliently push the cutter holder 2 rearward, and includes a plurality of spring members 31 each having a front portion extending into a corresponding one of the first slots 128 and a rear portion extending into a corresponding one of the second slots 222. Each spring member 31 has two opposite ends respectively abutting against the corresponding first and second abutment parts 129, 223. The cutter 4 for cutting the feed rod includes a blade seat 41 mounted at the front end 211 of the cutter seat 21, and a cutter blade 42 fixed to the blade seat 41 and having a feed slot 421. The feed slot 421 can be aligned or disaligned with the feed channel 114 by moving the blade seat 41. Since the construction of the cutter 4 does not form any part of the present invention, it is not detailed herein. The drive unit 5 is driven by a drive mechanism (not shown) and is movable leftward and rightward along directions shown by arrows 50. The drive unit 5 includes a cam plate 51 which projects towards the cutter holder 2. The cam plate 51 includes a cam face 511 to abut with the roller 23 of the cutter holder 2. The cam face 511 has a pushing projection 513 and a non-pushing part 512 which is spaced apart from the pushing projection 513. When the cutting mechanism according to the present invention is its inoperative position as shown in Figures 3 and 4, the returning unit 3 pushes the cutter holder 2 rearward (rightward in Figures 3 and 4) so that the cutter holder 2 abuts against the cam face 511 of the cam plate 51. In particular, the roller 23 of the cutter holder 2 contacts the non-pushing part 512 of the cam plate 51. In this state, the feed slot 421 of the cutter blade 42 is aligned with the feed channel 114. Referring to Figures 3 and 8, when the cutting mechanism is changed to an operative position shown in Figure 8 from the non-operative position shown in Figure 3, the pushing projection 513 of the cam plate 51 gradually moves in a direction toward the roller 23. Since there is a distance between the non-pushing part 512 and the pushing projection 513, when the pushing projection 513 reaches the roller 23, the cutter holder 2 is moved forward against the spring force of the returning unit 3 so that the feed slot 421 of the cutter blade 42 is out of alignment with the feed channel 114. The feed rod is therefore cut off. In this state, the returning unit 3 is compressed and stores energy. When the cam plate 51 is driven such that the non-pushing part 512 moves gradually to the roller 23, the cutter holder 2 is pushed rearward by the returning unit 3 so that the cutting mechanism is changed from the operative position (Figure 8) to the inoperative position (Fig.3) . While the returning unit 3 includes a plurality of spring members 31 provided in the respective first and second slots ]28 and 222 in this preferred embodiment, it may be altered by replacing the spring members 31 with a single coil spring. In this case, the shoulder 127 of the cutter holder seat 12 and the face 221 of the cutter holder 2 may be respectively provided with first and second annular grooves to receive the single coil spring. Alternatively, the single coil spring may be retained by abutting two opposite ends thereof against the shoulder 127 of the cutter holder seat 12 and the face 221 of the mounting part 22. As mentioned above, the returning unit 3 is concealed within the support wall 11 and the cutter holder seat 2. As such, the size of the cutting mechanism is decreased, and the space required to install the cutting mechanism is reduced. WE CLAIM 1. An improved cutting device for a forming machine adaptable to cut-off an elongated material, comprising: a support (1) having a mounting hole (113), a cutter holder (2) mounted on said support (1) and extending through said mounting hole (113), said cutter holder (2) comprising a front end provided with a cutter seat (21) and a rear end provided with a mounting part (22), said cutter holder (2) being movable rearward and forward, a drive unit (5) for moving said cutter holder (2) being movable rearward and forward, a drive unit (5) for moving said cutter holder (2) forward; characterized by comprising: a concealed returning unit (3) disposed between said support (1) and said mounting part (22) for urging said cutter holder (2) to move rearward. 2. The improved cutting device as claimed in claim 1, wherein said support (1) comprises a support wall (11) formed with said mounting hole (113), and a cutter holder (2) being disposed within said cutter holder seat (12). 3. The improved cutting device as claimed in claim 3, wherein said cutter holder seat (12) comprises a sleeve wall (121) defining a sleeve hole (122) to receive said cutter holder (2), said returning unit (3) having at least one spring member (31) disposed within said sleeve wall (121) to urge said mounting part (22). 4. The improved cutting device as claimed in claim 3, wherein said sleeve wall 121 comprises a small cross-section portion (125) disposed around said cutter seat (21), a large cross-section portion (126) disposed around said mounting part (22), and a shoulder (127) formed between said small cross-section (125) and large cross-section portion (126), said shoulder (127) being formed forwardly of said mounting part (22), and wherein, said spring member (31) having two opposite ends being retained respectively on said shoulder (127) and said mounting part (22). 5. The improved cutting device as claimed in claim 4, wherein said shoulder (127) has at least one first slot (128) to receive a front portion of said spring member (31), said mounting part (22) comprising a face (221) opposite to said shoulder (127), and at least one second slot (222) formed in said face (221) to receive a rear portion of said spring member (31). 6. The improved cutting device as claimed in claim 5, wherein said first and second slots (128, 222) are aligned respectively in a front-to-rear direction. 7. The improved cutting device as claimed in claim 6, wherein said returning unit (3) comprises a plurality of said spring members (31), a plurality of said first slots (128) being angularly spaced apart in said shoulder (127) to receive respectively said spring members (31), and a plurality of said second slots (222) are annually spaced apart in said mounting part (22) to receive respectively said spring members (31). Dated this 17th day of March 2005 A cutting mechanism for a forming machine includes a support (1) having amounting hole (113), a cutting holder (2) mounted on the support (1) and extending through the mounting hole (113), a drive unit (5) for moving the cutter holder (2) forward, and a returning unit (3) for urging the cutting holder (2) to move rearward. The cutter holder (2) includes a front end provided with a cutting seat (21) and a rear end provided with a mounting part (22), and is movable rearward and forward. The returning unit (3) is concealed and disposed between the support (1) and the mounting part (22).

Documents:

00176-kol-2005 abstract.pdf

00176-kol-2005 claims.pdf

00176-kol-2005 correspondence-1.1.pdf

00176-kol-2005 correspondence-1.2.pdf

00176-kol-2005 correspondence-1.3.pdf

00176-kol-2005 correspondence.pdf

00176-kol-2005 description(complete).pdf

00176-kol-2005 drawings.pdf

00176-kol-2005 form-1-1.1.pdf

00176-kol-2005 form-1.pdf

00176-kol-2005 form-18.pdf

00176-kol-2005 form-2.pdf

00176-kol-2005 form-3.pdf

00176-kol-2005 p.a.pdf

176-KOL-2005-(13-01-2012)-FORM-27.pdf

176-KOL-2005-AMENDED CLAIMS.pdf

176-KOL-2005-AMENDED PAGES OF SPECIFICATION.pdf

176-KOL-2005-CLAIMS 1.1.pdf

176-KOL-2005-CLAIMS 1.3.pdf

176-KOL-2005-CORRESPONDENCE-1.4.pdf

176-kol-2005-correspondence1.5.pdf

176-kol-2005-examination report.pdf

176-kol-2005-form 18.pdf

176-kol-2005-form 26.pdf

176-KOL-2005-FORM 27.pdf

176-kol-2005-form 3.pdf

176-kol-2005-form 5.pdf

176-kol-2005-granted-abstract.pdf

176-kol-2005-granted-claims.pdf

176-kol-2005-granted-description (complete).pdf

176-kol-2005-granted-drawings.pdf

176-kol-2005-granted-form 1.pdf

176-kol-2005-granted-form 2.pdf

176-kol-2005-granted-specification.pdf

176-kol-2005-reply to examination report.pdf