Abstract:
A weld sample cutter has a rotating saw blade and a vice. The vice has jaws which will retain a cylindrical work piece so that it can be cut either longitudinally or transversely by the blade. The vice is movable along a slide plate so that the work piece held in the vice can be moved toward or away from the saw blade.

Description:
The present invention relates to machines used to cut metal tubes, and in particular to a machine to cut a sample of tubing both longitudinally and transversely for the purposes of opening the sample into a flat strip so that the inner surface of the weld is visible and the quality of a weld can be inspected. 
     BACKGROUND OF THE INVENTION 
     The semi-conductor industry undertakes the precision manufacture of small parts, and the machinery required to make those parts uses purified pressurized liquids which pass through long lengths of tubing. The tubing used in such machines is very expensive because it has electropolished inner surfaces to prevent contamination of the purified liquids flowing therein. The lengths of tubing are formed by welding sections of tubing end to end. Such tubing typically has a diameter ranging from ⅛ inch to 1 inch or more and the welds that join the lengths must be perfectly formed such that the tube, including the welds, will not contaminate the liquid passing therethrough. Also, the welding process consumes materials which could contaminate the liquid passing through the tube, and if the weld is not perfectly formed, traces of unconsumed welding material may remain on the inner surface of the tube. 
     To test the quality of a weld, a welding machine is first used to weld the ends of two short pieces of tubing together, after which a length of the sample, including the weld, is cut lengthwise, and the sample is rolled opened and laid flat so that the inner surface thereof can be inspected. The quality of a weld can be determined by visually inspecting the color and texture of the weld surface. 
     To maintain the required quality of the weld made by a welding machine a sample weld is inspected by independent inspectors at regular intervals. Some specifications require that samples be inspected at the beginning and at the end of each day while other specifications require that an inspection be made as frequently as every tenth weld. The inspectors mark each sample they inspect and retain the samples as evidence that the inspections were properly conducted. 
     Prior to the present invention, to prepare a weld sample for inspection, a length of tubing including a sample weld was manually moved against a rotating blade to first make a longitudinal cut in the length of the sample, after which a second transverse cut was also manually made. Ideally, the second cut would not be made through the entire cross section of the tubing, leaving a small section of the tubing wall to retain the cross-cut sample to the remaining tubing length. After the sample has been cut, pliers or other tools were used to spread the sample flat so that it could be visually inspected. 
     SUMMARY OF THE INVENTION 
     Briefly, the present invention is embodied in a machine having a rotating cutting blade and a vise for gripping a cylindrical work piece and retaining a work piece while it is being cut by the blade. The vise has first and second gripping portions which interact to grip around a cylindrical work piece and retain it for making a cut either longitudinally or transversely to the length thereof. The vise is slidably movable toward and away from the rotating blade and a work piece retained therein is cut as the vise is moved toward the blade. 
    
    
     GENERAL DESCRIPTION OF THE DRAWINGS 
     A better and more complete understanding of the present invention will be had from a reading of the following detailed description taken in conjunction with the accompanying drawings wherein: 
     FIG. 1 is an isometric view of the machine in accordance with the present invention with a piece of tubing fitted transversely into the jaws of the vise thereof; 
     FIG. 2 is a side elevational view of the machine shown in FIG. 1 with portions of the interior thereof shown in phantom lines; 
     FIG. 3 is a left side elevational view of the housing for the machine shown in FIG. 1; 
     FIG. 4 is a right side elevational view of the housing shown in FIG. 3 with interior portions shown in phantom lines; 
     FIG. 5 is a cross sectional view of the housing shown in FIG. 3 taken through line  5 — 5  thereof with the saw blade and a fragment of the motor attached thereto; 
     FIG. 6 is a front elevational view of the vise for the machine shown in FIG. 1; 
     FIG. 7 is a cross-sectional view of the machine shown in FIG. 1 taken through line  7 — 7  of the vise as shown in FIG. 6; 
     FIG. 8 is a side elevational view of the slide block for the machine shown in FIG. 1 with a through hole shown in broken lines; 
     FIG. 9 is a top elevational view of the slide block shown in FIG. 8; 
     FIG. 10 is a cross-sectional view through line  10 — 10  of FIG. 9 of the slide block shown in FIG. 8; 
     FIG. 11 is a bottom view of the slide block shown in FIG. 8; 
     FIG. 12 is a front elevational view of the slide block shown in FIG. 8 with undercuts forming a guide channel shown in broken lines; 
     FIG. 13 is a front elevational view of the vise slide for the machine in FIG. 1; 
     FIG. 14 is a right side elevational view of the vise slide shown in FIG. 13; 
     FIG. 15 is a top view of the vise slide shown in FIG. 13; 
     FIG. 16 is a bottom view of the vise slide shown in FIG. 13; 
     FIG. 17 is a rear elevational view of the vise slide shown in FIG. 13; 
     FIG. 18 is a top view of a cam for the machine shown in FIG. 1; 
     FIG. 19 is a side elevational view of the cam shown in FIG. 18 with the interior portions thereof shown in phantom lines of the cam shown in FIG. 18; 
     FIG. 20 is a side elevational view of a tool for use in conjunction with the machine as shown in FIG. 1; 
     FIG. 21 is a perspective view of a piece of tubing which has been cut to expose the weld using the machine shown in FIG.  1  and the tool shown in FIG.  20 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to FIGS. 1 and 2, a machine  10  for cutting a weld sample for a piece of tubing  12  has a housing  14  mounted on a pedestal  16  and is driven by a motor  18  controlled by a switch  19 . The machine  10  has a first knob  20  for adjusting the vise  22  as further described herein and a second knob  24  for moving the vise  22  vertically along a slide surface  25  on the housing  14  to thereby force the piece of tubing  12  in the vise thereof into a rotating saw blade  26 . Metal chips cut by the blade  26  are removed through a vacuum hose  28  to a collection site remote from the machine  10 . 
     The housing  14  has a threaded bore  30  for receiving the threads of a stud on the pedestal  16  to retain the housing  14  with respect to the pedestal. For the purpose of this description, the elements of the machine  10  will be described with respect to their orientation as shown in FIGS. 1 and 2. 
     Referring to FIGS. 1-7, fitted against one side of the upper end of the housing  14  is a housing cap  34  and within a cavity  35  formed between the body of the housing  14  and the cap  34  are a plurality of gears  36 ,  37 ,  38  which transfer rotational power from the motor  18  to the saw blade  26 . A guard  40  extends around a portion of the outer circumference of the saw blade  26  leaving exposed only a portion of the teeth thereof against which the tubular work piece  12  retained in the vise on the slide surface  25  can be moved. An arcuate wiper  39  made of pliable material such as felt or the like, is mounted around the inner edges of the guard and has sufficient thickness to press against the teeth of the blade  26  as it rotates. The arcuate wiper  39  will dislodge particles of metal clogged within the teeth of the blade  26  as it cuts through a work piece  12 . 
     It is desirable that the saw blade  26  have small teeth. If the teeth of the blade  26  are too large, the teeth will bind around a small diameter work piece such as ⅛ inch diameter work piece and the binding will cause the mutilation of the work piece. On the other hand, it has been found that small particles of metal will become retained within smaller sized teeth and the retained particles of metal will prevent the saw blade from cutting efficiently. Inefficient cutting causes the blade to overheat and wear out after only a few cuts. The wiper  39  in the guard  40  removes small particles of metal which would otherwise remain between the teeth of the saw blade  26  and thereby maintains the efficiency of the blade  26  as it cuts a work piece  12 . With the wiper  39 , the blade can be made with a thickness of 30 thousandths of an inch and the blade is usable for 200 to 300 cuts. 
     As best shown in FIGS. 2,  5 , and  7  the housing  14  further has a transverse hole  42  extending through the body thereof which serves as the vacuum port and on the rearward side of the housing  14  is a nipple  44  through which the transverse hole  42  extends and around which the vacuum hose  28  is fitted for drawing cuttings from the blade  26  away from the work site. 
     Although a wiper  39  discussed above is used to remove particles from the teeth of the blade  26 , any other method whereby particles would be dislodged from the teeth could be employed. For example, the vacuum port  42  could be positioned to draw particles from between the teeth of the blade  26 , or a pressurized air line could direct through the port across the teeth. 
     Referring to FIGS.  2  and  6 - 12 , the housing  14  has an inclined slide surface  25  against which is positioned a slide plate  46 . The slide plate  46  has a width which is wider than the width of the slide surface  25 , and the vise  22  includes a slide block  48  having opposing hook shaped guides  50 ,  52  sized to fit around the edges of the slide plate  46  to slidably retain the slide block  48  to the slide plate  46 . As seen in FIG. 7, extending longitudinally along the center of the slide plate  46  is an elongate rack  54  having teeth which are engaged by a pinion  56  fixed on a shaft  58  extending through holes  57 ,  59  in the block  48  and to the second knob  24 . Rotation of the knob  24  will rotate the pinion  56  and move the slide block  48  and, therefore, the vise  22  along the slide plate  46 . As best seen in FIGS. 7 and 10, the slide block  48  has an elongate cavity  61  therein to receive the rack  54  and an adjoining nearly cubically shaped cavity  63  to receive the pinion  56 . 
     Referring to FIGS.  2  and  6 - 17 , the slide block  48  has a second pair of opposing hook shaped guides  60 ,  62  which define a second track parallel to the track defined by guides  60 ,  62  and between the guides  60 ,  62  is fitted an elongate vise slide  64 . The vise slide  64  has a generally rectangularly shaped slide portion  66  sized to slidably fit between the guides  60 ,  62  and at the upper end of the slide portion  66  is a tooth  68  with a slot  70  therein sized to receive the saw blade  26 . The slide portion  66  of the vise slide  64  further has a transverse, generally oval shaped hole  72  having outer dimensions sized to receive the largest diameter of a work piece  12  for which the machine  10  is adapted to cut when the work piece is retained in the vise  22  as shown in FIG.  6 . 
     The vise slide  64  moves perpendicular to the axis of the blade  26  such that movement of the slide block  48  upward along the slide plate  46  will move the two sides of the slotted tooth around the blade  26 , thereby allowing the blade to cut a work piece held in the vise. The rotation of the second knob  24  will, therefore, move a work piece held in the vise  22  against the blade  26 . 
     As best shown in FIGS. 9 and 10, extending parallel to the slide plate  46  along the upper surface of the slide block  48  is a V-shaped groove  76  and perpendicular to V-shaped groove  76  is a second V-shaped groove  78 . The distal end of the slotted tooth  68  of the vise slide  64  is sized and positioned to move toward and away from the intersecting grooves  76 ,  78  upon movement of the slide portion  66  downward or upward within the slide block  48 . 
     Referring to FIGS. 2,  6  and  7 , first knob  20  is fixedly mounted on a shaft  80  which is rotatably fitted through a mounting plate  87  retained by bolts  82 ,  83  to the slide block  48  and the shaft  80  is retained within the mounting plate  87  by a clip  84 . The distal end of the shaft  80  is threaded and is threadedly received in a threaded hole  85  (shown in FIGS. 13,  14  and  17 ) in the bottom surface of the slide portion  66  of the vise slide  64 . 
     Rotation of the first knob  20 , therefore, will cause the shaft  80  to be threaded into or out of the hole  85  of the vise slide  64  thereby moving the slotted tooth  68  upwardly or downwardly with respect to the slide block  48 . A work piece  12  can be retained in the vise  22  with the axis thereof parallel to the slide plate  48 , as shown in FIGS. 1 and 2, by inserting it under the tooth  68  and in groove  76 . Alternately, a work piece  12  can insert in the vise  22  with the axis thereof perpendicular to the slide plate  46 , as shown in FIG. 6, by inserting it through the oval hole  72 , along groove  78  and under tooth  68 . Rotation of the knob  20  will tighten or loosen the grip of the vise  22  around a work piece which is to be retained in either orientation. 
     Referring to FIGS. 2,  6 ,  15 ,  18  and  19 , the upward movement of the slide block  48  along the slide plate  46  is limited by a contact of an upper surface of a cam  88  against a pin  90  on the housing  14 . As best shown in FIGS. 18 and 19, the cam  88  has a spiral ramp upper surface having a bottom position  89  and top position  91 , and is fixedly mounted on a shaft  93  and secured to the opposite end of shaft  93  is a control knob  97 . The shaft  93  is rotatable within an elongate hole  95  in the slide block  48  such that rotation of the shaft  93  will rotate the cam  88 . When the cam  88  is oriented for the bottom position  89  to contact the pin  90  when the slide block is moved upward, the blade  26  will cut entirely through a work piece  12  retained in the vise  22 . When the cam  88  is oriented for the top position  91  to contact the pin  90  when the slide block  48  is moved upward, the saw blade  26  will cut through the greater portion of the wall of the largest size work piece to be accepted by the machine, but leave uncut a small portion  99  as shown in FIG.  21 . 
     As shown in FIG. 2, indicia numbers  92  around the outer surface of the knob  97  can be aligned by a marking line  94  on the housing to thereby adjustably limit the maximum upward movement of the slide block  48  with respect to the slide plate  46 . 
     Referring to FIGS. 20 the, machine  10  is used in conjunction with a tool  96  having first and second arms  98 ,  100 , respectively, which are retained to each other about a centrally located pivot pin  102 . The working ends of each of the arms  98 ,  100  have separator plates  104 ,  106 , respectively, attached thereto the inner surfaces of which abut each other when the handle ends of the arms  98 ,  100  are in spaced from each other, as shown. A spring  108  between the arms  98 ,  100  retains the separator plate  104 ,  106  in abutting relationship to each other when the tool is in its standby condition. When the handle ends of the arms  98 ,  100  are squeezed toward each other, the spring  108  is compressed and the separator plates  104 ,  106  are moved apart from one another. 
     Referring to FIGS. 21, the tool  96  is used to open the cut ends  110 ,  112  of a work piece by inserting the plates  104 ,  106  between the ends  110 ,  112  after the work piece has been longitudinally cut by the blade  26  of the machine  10 . Once the plates  104 ,  106  are between the ends  110 ,  112 , the handles of the tool are squeezed causing the plates  104 ,  106  to separate the ends  110 ,  112  of the sample to the orientation shown in FIG.  21 . 
     OPERATION 
     To inspect a test sample of a weld, a short length of tubing  12 , perhaps six inches in length, is cut with the weld  114  spaced approximately ½ inch from one face  116  thereof. The second knob  24  of the machine  10  is rotated to move the slide block  48  to the bottom of the slide plate  46  and the first knob  20  is rotated to raise the slotted tooth  68  of the vise. The work piece  12  is then fitted into the vise  22  as shown in FIG.  1  and retained therein by turning the first knob  20  until the work piece is tightly retained. Next, the knob  97  is rotated until the indicia numbers  92  thereon align with the markings  94  of the housing for the diameter of the work piece being cut to limit the upward movement of the slide block  48 . The saw blade  26  will not cut all the way through the tubing  12 , but will allow the pieces to be retained together by a small portion  99  as shown in FIG.  21 . The switch  19  is then thrown to activate the motor  18  and rotate the saw blade  26 . Then, the second knob  24  is then rotated to move the vise  22  upward along the slide plate  46  and force the sample tubing  12  against the saw blade  26  to make the transverse cut which forms face  116  shown in FIG.  21 . 
     After the transverse cut has been completed, the second knob  24  is rotated in the opposite direction to lower the vise  22  away from the blade  26 . The first knob  20  is turned to loosen the work piece  12  from the vise, and the work piece  12  is fitted through the transverse hole  72  in a slide portion  66  and between the tooth  68  and the V-shaped groove  78  and the vise  22  is again tightened as shown in FIG.  6 . The first knob  20  is again turned to tighten the end of the work piece in the vise and the second knob  24  is again rotated to moved the work piece against the rotating saw blade  26  and make a longitudinal cut defining ends  110 ,  112 . 
     Next, the work piece is then removed from the machine  10  and the separator plates  104 ,  106  of the tool  96  are fitted between the ends  110 ,  112  of the work piece and the handles compressed together to butterfly the ends of the work piece to the orientation shown in FIG.  21 . The inner surface of the weld  114  can then be seen. 
     While the present invention has been described with respect to a single embodiment, it will be appreciated that many variations and modifications may be made without departing from the true spirit and scope of the invention. Therefore, it is intended by the appended claims to cover all such variations and modifications which come within the spirit and scope of the invention.