Abstract:
A machine for continuously making gaskets and similar flat products. Sheet gasket material is fed from a roll and through tooling that successively: cuts the outline, separates the center scrap, then separates the gaskets from the remaining sheet stock waste. The cutting tool rotates. The center scrap and the gaskets may be removed by rotating tooling or by vacuum and air pressure, respectively. Design and fabrication of such a machine, especially the cutting roller, is made possible by state of the art CAD software.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     The applicants claim the benefit of their prior provisional Application, Ser. No. 60/119,307, filed Feb. 8, 1999. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates to the field of gaskets and more particularly to the field of machines for making gaskets. 
     Gaskets are used to make pressure tight joints between stationary parts. Gaskets are made of thin deformable material, usually in the form of a ring. Typically, gaskets are made on punch presses. Dies are made, and fastened to the moveable jaw of the press. Then one or more layers of sheet stock are fed between the jaw and the bed of the machine. At each stroke of the press, gaskets are cut. After cutting, useable gaskets must be removed from the waste which consists of the center scrap and other left over material. In the batch process, one or more lengths of material at a time are fed into a press containing cutting dies. Then the gaskets must be separated from the scrap. 
     Since gasket making is a labor intensive, batch process, people have designed machines which will automatically produce gaskets and similar products. U.S. Pat. No. 2,692,020 discloses a portable die cutting and work feeding apparatus in which multiple layers of cloth with cardboard and a movable belt underneath and cutting dies on top, are laid out on a table. A portable platen press is moved to one end of the table. The assembly of cloth, etc. is moved under the platen and the press activated. Then the cut cloth is moved out from under the platen. 
     U.S. Pat. No. 3,701,275 discloses a machine for making spacer-expanders for piston oil rings. The machine comprises a punch press having a plurality of stations through which strip stock is fed progressively at accurately predetermined increments. The stations perform such operations as blanking, piercing bending, etc. 
     U.S. Pat. No. 3,801,406 discloses a method of making gaskets by producing a continuous strip of sheet stock, punching to form blanks, and vulcanizing under pressure. 
     U.S. Pat. No. 5,019,314 discloses a process for die cutting a sheet of thermoplastic material imprinted with data of limited spacial displacement in which the data is sequentially die cut in alternating rows and lines in a plurality of die cutting stations until all data has been cut with a residual attachment to the sheet. 
     U.S. Pat. No. 5,346,664 discloses an apparatus for forming a continuous ribbon of connected dish-shaped sequins. The apparatus includes a supply reel, a take-up reel, a punch and die set and a motor system to incrementally move material from the supply reel, through the punch and die set and onto the take-up reel. 
     U.S. Pat. No. 5,437,828 discloses a method of making photographic film spools involving continuously forming and punching out flanges and assembling them onto spool cores. 
     The disadvantages of these machines are that punching of the sheet must still be done flat in the equivalent of a punch press, the process must be carried out incrementally and not continuously, and such machines have many moving parts and are expensive to build and maintain. To truly streamline the process of making gaskets, and thus make gaskets more cheaply, a fully continuous process is needed. Development of a machine which can fabricate gaskets and similar parts truly continuously represents a great improvement in the field of machine design and satisfies a long felt need of the gasket maker and user. 
     SUMMARY OF THE INVENTION 
     The present invention is a machine for continuously making gaskets and similar flat products. Sheet gasket material is fed from a roll and through tooling that successively: rotatively cuts the outline, separates the center scrap, then separates the gaskets from the remaining sheet stock waste. Design and fabrication of such a machine, especially the cutting roller, is made possible by state of the art CAD software. The advantage of this machine is that it produces gaskets continuously rather than by the standard batch process thus making fabrication cheaper. Removal of the center scrap may be accomplished by rotating tooling or vacuum. Removal of the gaskets may be accomplished by rotating tooling or forced air. 
     An appreciation of the other aims and objectives of the present invention and an understanding of it may be achieved by referring to the accompanying drawings and description of a preferred embodiment. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a side elevation view of this invention. For the sake of clarity much of the supporting structure is not illustrated. 
     FIG. 2 is a top view of this invention. For the sake of clarity much of the supporting structure is not illustrated. 
     FIG. 3 is a top view of the cutting roller. 
     FIG. 4 is a cross section along the lines  4 — 4  of FIG.  3 . 
     FIG. 5 is a cross section along the lines  5 — 5  of FIG.  3 . 
     FIG. 6 is an enlarged view of area  6  on FIG.  1  and FIG.  20 . 
     FIG. 7 is a top view of the center hole punching roller. 
     FIG. 8 is a cross section along the lines  8 — 8  of FIG.  7 . 
     FIG. 9 is a cross section along the lines  9 — 9  of FIG.  7 . 
     FIG. 10 is a cross section along the lines  10 — 10  of FIG.  7 . 
     FIG. 11 is an enlarged view of area  11  on FIG.  1 . 
     FIG. 12 is a top view of the gasket punching roller. 
     FIG. 13 is a cross section along the lines  13 — 13  of FIG.  12 . 
     FIG. 14 is a cross section along the lines  14 — 14  of FIG.  12 . 
     FIG. 15 is a cross section along the lines  15 — 15  of FIG.  12 . 
     FIG. 16 is an enlarged view of area  16  on FIG.  1 . 
     FIG. 17 is a top view of gasket material as it is being successively cut and punched by this invention. 
     FIG. 18 is a side elevation view of an embodiment of this invention which includes a center scrap collecting bin and a part collecting carrousel. 
     FIG. 19 is a top view of the part collecting carrousel shown in FIG.  18 . 
     FIG. 20 is a side elevation view of an alternate embodiment of this invention. For the sake of clarity much of the supporting structure is not illustrated. 
     FIG. 21 is a top view of the alternate embodiment of this invention illustrated in FIG.  20 . For the sake of clarity much of the supporting structure is not illustrated. 
     FIG. 22 is an enlarged view of area  23  on FIG.  20 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIGS. 1 and 2 represent side and top views of this invention  10 . The machine  10  has a feed bed  14 . The feed bed  14  is preferably made out of 4130 steel, normalized and precision ground with a hard chrome finish. At one end  18  of the bed  14  is located a holder  20  for a roll  22  of gasket material  24 . Rolls  22  of gasket material  24  are commercially available. Preferably, the axle  25 , holding this roll  22  is in line with the feed bed  14 . Next to the material feed roller  22  is a cutting roller  26 . This roller  26  is mounted over the feed bed  14 . Preferably this  26  roller is made out of 6061-T6 aluminum. On the circumference  30  of this roller  26  are mounted cutters  34 , which are radially compensated. This means that the cutters  34  are designed so that they will cut out flat articles of true dimension even though the cutters  34  themselves are curved to fit on the circumference  30  of the roller  26 . Preferably, the cutters  34  are made of D-2 tool steel hardened to R c 58-60. The cutters  34  cut out the outlines of the gaskets, which will be produced on the machine  10 . As will be further described below, the outline includes the periphery of the gasket and the center hole. The outline may also include the mounting holes. Alternatively, mounting holes may be cut in a subsequent operation. 
     A receiving roller  38  is mounted under and in vertical alignment with the cutting roller  26 . Preferably, the receiving roller  38  is made out of D-2 tool steel hardened to R c 58-60 with a thermally diffused vanadium carbide surface. The receiving roller  38  can be re-ground and replaced, thus saving wear and tear on the bed  14  from continuous action of the cutters  34 . 
     Next to the cutting roller  26  is a center scrap removing roller  42 , which is mounted over the feed bed  14 . Preferably this roller  42  is made of 6061-T6 aluminum. On the circumference  46  of the center scrap removing roller  42  are mounted cylindrical punches  50 . Preferably the punches  50  are made of 101 Nylon®. The cross sections of the punches  50  are the same shape as the center opening and, if cut, the mounting holes of the gasket. The roller  42  and punches  50  are fed with compressed air to assist in removal of the center scrap from the gasket material  24 . The air supply is described in more detail below. Under the feed bed  14 , in alignment with the vertical cylindrical punch  50 , is located a center scrap receiver  54 . The receiver  54  can be a container of cross section slightly larger than the center scrap. Consequently, as the center scrap removing roller  42  rotates, the punches  50  punch out the centers and, if cut, the mounting hole scraps from the gaskets. The center and mounting hole scraps are then collected in the receiver  54 . When the receiver  54  is full, it is replaced with an empty one. 
     Next to the center scrap removing roller  42  is a gasket removing roller  58 , which is mounted over the feed bed  14 . Preferably this roller  58  is made of 6061-T6 aluminum. On the circumference  62  of the part removing roller  58  are mounted annular punches  66 . Preferably, these punches  66  are made of 101 Nylon®. The cross sections of these punches  66  are the same shape as the gaskets. The punch  66  and roller  58  combination is designed so that as the roller  58  rotates, the end of the punch  66  moves to just below the back of material  24 . The roller  58  and punches  66  are fed with compressed air to assist in removal of the gaskets from the gasket material  24 . The air supply is described in more detail below. Under the feed bed  14 , in alignment with the vertical annular punch  66 , a part receiver  70  is located. This receiver  70  is again a container of cross section slightly larger in all dimensions that the size of the gasket. Consequently, as the gasket removing roller  58  rotates, the punches  66  punch out the gaskets and the gaskets are collected in this receiver  70 . When this receiver  70  is full, it is also replaced with an empty one. The remaining material  24 , which has not been punched out and collected, rolls off the end of the feed bed  14  and is collected by any convenient means. Typically this means would be a cutter  74  and bin (not illustrated). 
     The machine  10  is driven by any convenient power source connected to the rollers  26 , 38 ,  42 ,  58  by any convenient means. For example, the machine  10  could be powered by a single phase  120 v motor connected to the rollers  26 ,  38 ,  42 ,  58  by timing belts. The machine  10  may be designed and built with other rollers, for example a stock straightening roller  78 , at various locations in order to maintain tension and keep the gasket material  24  flat as it passes through the machine  10 . Exact locations, adjustment, etc. of such rollers will be apparent to those most familiar with the art to which this invention pertains. 
     Recently available CAD tooling has made design and manufacture of radially compensated tooling possible. Briefly, the procedure is to design the cutter  34  flat on a computer using one of many available CAD programs and then instruct the computer to curve the base of the cutter  34  to match the surface  30  of the roller  26 . The software then takes care of translating the design so that dimensions and angular relationships are properly maintained. In this way, after the cutter  34  is produced and used, it will cut articles of true dimension even though curved. 
     FIGS. 3,  4  and  5  provide further details about the design and construction of the cutting roller  26 . Each gasket cutter  34  consists of an inner cutter  82 , which is the shape of the center hole, and an outer cutter  86 , which is the shape of the outer perimeter of the gasket. As illustrated on FIG. 3, two or more different gasket designs could be cut at one time. In this case, for most efficient use of material, the gasket cutters should be staggered. Although not illustrated, it will be obvious to those who are most familiar with the art to which this invention pertains, that mounting holes can be cut in a similar manner. 
     FIG. 6 is an enlarged view of the cutting roller  26  in operation. There is an opening  90  of the appropriate size in the feed bed  14  vertically below the cutting roller  26 . The cutters  34  meet the receiving roller  38  tangentially through this opening  90 . The space between the receiving roller  38  and the cutting roller  26  is adjusted so that the gasket material  24  is gripped with the proper tension and so that the cutters  34  will cut completely through the gasket material  24 . As the material  24  is fed under the cutters  34 , the outer perimeter and center hole of the gasket are cut out. Staggering of the cutters  34 , helps feed the material  24  smoothly between the rollers  26 ,  38 . 
     FIGS. 7,  8  and  9  provide more details about the design and construction of the center hole punching roller  42 . Each punch  50  is the shape of the center hole of the gasket. If the cutting roller  26  is designed to cut two or more gaskets with staggered cutters  34 , the punches  50  will be of different shapes and similarly staggered. Also, if mounting holes are cut at the cutting roller  26 , punches for punching out the mounting holes (not illustrated) will also be provided on this roller  42 . 
     FIGS. 8,  9  and  10  provide details of the air assist system. One channel  94  is provided through the axle  98  of the roller  42 . A second channel  102  runs radially through the roller  42  and to the end  106  of each punch  50 . The axle channel  94  has one or two exit holes  110 , depending on how many rows of punches  50  there are, pointing vertically downwards. The holes  110  line up with each radial channel  102  once each revolution. Compressed air is fed into the entrance  114  to the axial channel  94 . In this way, as the roller  42  rotates, compressed air is only fed to the active punch  50 , i.e. the punch  50  that is vertical and presently punching out the center hole scrap. 
     FIG. 11 is an enlarged view of the center hole punching roller  42  in operation. There is an opening  118  of the appropriate size in the feed bed  14  vertically below the roller  42 . The roller  42  is adjusted so that the end  106  of the vertical punch  50  just passes through the material  24  through this opening  118 . As the material  24  is fed under the roller  42 , the center hole scrap  122  is pushed out by the combined action of the punch  50  and air pressure. Staggering of the punches  50 , helps feed the material  24  smoothly under the roller  42 . 
     FIGS. 12,  13  and  14  provide more details about the design and construction of the gasket punching roller  58 . Each punch  66  is the shape of the gasket. If the cutting roller  26  is designed to cut two or more gaskets with staggered cutters  34 , the punches  66  will be of different shapes and similarly staggered. 
     FIGS. 13,  14  and  15  provide details of the air assist system. One channel  126  is provided through the axle  130  of the roller  58 . A second channel  134  runs radially through the roller  58  and to the end  136  of each punch  66 . The axle channel  126  has one or two exit holes  138 , depending on how many rows of punches  66  there are, pointing vertically downwards. The holes  138  line up with each radial channel  134  once each revolution. Compressed air is fed into the entrance  114  to the axial channel  94 . In this way, as the roller  58  rotates, compressed air is only fed to the active punch  66 , i.e. the punch  66  that is vertical and presently punching out the gasket. 
     FIG. 16 is an enlarged view of the gasket punching roller  58  in operation. There is an opening  146  of the appropriate size in the feed bed  14  vertically below the roller  58 . The roller  58  is adjusted so that the vertical punch  66  just passes through the material  24  through this opening  146 . As the material  24  is fed under the roller  58 , the gasket  150  is punched out by the combined action of the punch  66  and air pressure. Staggering of the punches  66 , helps feed the material  24  smoothly under the roller  58 . 
     FIG. 17 is a top view of gasket material  24  as it is being successively cut and punched by this invention  10 . To use this machine, referring again to FIG. 1, the following steps are followed. A roll  22  of gasket material  24  is mounted onto the holder  20 . The material  24  feeds through the machine  10  along the feed bed  14 . As the material  24  passes between the cutting roller  26  and the receiving roller  38  , the pattern  154  of the gasket  150  and its center hole  124  is cut. This is illustrated at area A on FIG.  17 . As the material  24  passes between the center scrap removing roller  42  and the center scrap receiver  54 , the center hole scrap  122  is punched out. This is illustrated at area B on FIG.  17 . As the material  24  passes between the gasket removing roller  58  and the gasket receiver  70 , the finally formed gasket  150  is punched out. This is illustrated at area C on FIG.  17 . Consequently, when the machine  10  is actuated, all the rollers  22 ,  26 ,  42 ,  58  turn and the machine  10  continuously: cuts a gasket outline  154  into the material  24 , punches out the center scrap  122  into a receiver  54 , punches out the gaskets  150  into a receiver  70  and collects the left over material  158 . The left over material  158  is illustrated at area C on FIG.  17 . The gaskets  150  and scrap  122 ,  158  are separately collected. The gaskets  150  are used in specific engineered applications, and the scrap  122 ,  158  is discarded or returned to be re-ground and used in the manufacture of further gasket material  24 . 
     FIG. 18 is a side elevation view of an embodiment of this invention  10  which includes a center scrap collecting bin  162  and a part collecting carrousel  166 . FIG. 19 is a top view of the part collecting carrousel  166  shown in FIG.  18 . The bin  162  can be of any convenient size and shape. The collected center scrap  122  can be compressed before it is discarded or remanufactured. 
     The carrousel  166  has a series of rods  170  of diameter smaller than the center hole  124  of the completed gasket  150 . One of the rods  170  is positioned directly under the gasket receiver  70 . Then as the gaskets  150  fall out of the machine  10  they are collected on the rod  170 . As each rod  170  “fills up” with gaskets  150 , a second rod  170  is rotated under the receiver  70  by any convenient mechanism (not illustrated). The rods  170  are removable and function as convenient means for collecting, storing and transporting the gaskets  150 . 
     FIGS. 20 and 21 are side and top views of an alternate embodiment  200  of this invention. For the sake of clarity much of the supporting structure is not illustrated. The alternate embodiment  200  is essentially the same as the primary embodiment  10  described above and works in a similar manner. The differences are: 1) the center hole punching roller  42  is replaced by a vacuum system  204  and 2) the gasket punch  66  is replaced by a forced air system  208 . A vacuum hose or tube  212  connects the vacuum system  204  with the second holes  220  through the feed bed  14 . Note that the second holes  220  are teardrop shaped to facilitate removal of the center hole scrap  122 . The forced air system  208  ends with tubes  216  directed approximately to the centers of the third holes  146  through the feed bed  14 . As the material  24  is fed over the feed bed  14 , the center hole scrap  122  is sucked down into the vacuum system  204  for later removal and disposal and the gasket  150  is blown down by the forced air into the gasket receiver  70 . 
     FIG. 22 is an enlarged view of area  23  on FIG.  20 . There is an opening  146  of the appropriate size in the feed bed  14 . A tube  216  directs compressed air  224  downwards approximately through the center of the opening  146 . As the material  24  is fed under the tube  216 , the gasket  150  is pushed out by air pressure. 
     The following reference numerals are used on FIGS. 1 through 22. 
       10  Continuous gasket making machine 
       14  Feedbed 
       18  End of feed bed 
       20  Holder for roll of gasket material 
       22  Roll of gasket material 
       24  Gasket material 
       25  Axle of roll of gasket material 
       26  Cutting roller 
       30  Circumference of cutting roller 
       34  Cutter 
       38  Receiving roller 
       42  Center hole punching roller 
       46  Circumference of center hole punching roller 
       50  Center hole punch 
       54  Receiver for center hole scrap 
       58  Gasket punching roller 
       62  Circumference of gasket punching roller 
       66  Gasket punch 
       70  Gasket receiver 
       74  Left over material cutter 
       78  Material straightening roller 
       82  Inner cutter 
       86  Outer cutter 
       90  First opening through feed bed 
       94  Channel through axle of center hole punching roller 
       98  Axle of center hole punching roller 
       102  Radial channel through center hole punching roller and center hole punch 
       106  End of center hole punch 
       110  Vertical communication hole between axial and radial channels in center hole punching roller 
       114  Entrance to axial channel in center hole punching roller 
       118  Second opening through feed bed 
       122  Center hole scrap 
       124  Center hole of gasket 
       126  Channel through axle of gasket punching roller 
       130  Axle of gasket punching roller 
       134  Radial channel through gasket punching roller and gasket punch 
       136  End of gasket punch 
       138  Vertical communication hole between axial and radial channels in gasket punching roller 
       142  Entrance to axial channel in gasket punching roller 
       146  Third opening through feed bed 
       150  Gasket 
       154  Gasket outline 
       158  Left over material scrap 
       162  Center scrap collection bin 
       166  Gasket collecting carrousel 
       170  Rod 
       200  Alternate embodiment of continuous gasket making machine 
       204  Vacuum system 
       208  Forced air system 
       212  Vacuum hose or tube 
       216  Forced air directing tube 
       220  Teardrop shaped second opening through feedbed 
       224  Direction of air flow 
     The continuous gasket making machine has been described with reference to several embodiments 10,  200 . Other modifications and enhancements can be made without the spirit and scope of the claims that follow.