US3298213A - Tube cut-off mechanism - Google Patents

Description

5 Sheets-Sheet 1 Filed July 17, 1964 INVENTOR. FRANK .SZEL

ATTORNEYS Jan. 17, 1967 F. SZEL 3,298,213

TUBE CUT-OFF MECHANISM Filed July 17, 1964 3 Sheets-Sheet 2 8 I28 L '1 I2 000 I23 INVENTOR. BY FRANK SZEL Jan. 17, 1967 F. SZEL 3,298,213

TUBE CUT-OFF MECHANI SM Filed July 17, 1964 5 Sheets-Sheet 5 I L asa F" "4= i LJ u.

8 BY 9 FRANK .S'ZEL dMmg m" ATTORNEYS United States Patent "ice 3,298,213 TUBE CUT-GEE MECHANHSM Frank Szel, Cleveland, Ohio, assignor to The Yoder Company, Cleveland, Ohio, a corporation of Ohio Filed July 17, 1964, Ser. No. 383,482 18 Claims. (Cl. 72-186) This invention relates generally as indicated to a tube cut-off mechanism and more particularly to a cut-off mechanism for elongated travelling work which will produce end faces on cut-to-length sections which will not be deformed due to the severing action.

More particularly, this invention relates to certain improvements in the cut-off mechanism disclosed in the copending application of Charles J. Bognar, entitled, Method of Severing Tubes and Reforming Deformed Portion Caused by Severing Action, Serial No. 106,857, filed May 1, 1961, now Patent No. 3,145,462. In such application, there is disclosed a tube mechanism for elongated travelling work which includes a cooperating tube retarding device actively to urge the severed section against the cut-off blade after completionof the cut with means being provided on the blade to engage and remove any dimples or deformations in the tube produced by the severing action. While the cut-off mechanism disclosed in the aforementioned Bognar application adequately performs the desired tube reformation, a rather bulky, mas sive and somewhat cumbersome structure is required. It will be understood that the more massive the cut-off, the more force is required to accelerate the cut-01f to the speed of the travelling work. This generally requires special accelerator mechanisms to drive the dies with the work to obtain synchronous speeds during the cutting operation or if the work is of sufficient rigidity, the work itself may be employed to drive the dies with the work.

It is accordingly a principal object of the present invention to provide an improved cut-off mechanism for tubes and the like which will produce a more undistorted work end face.

A further principal object is the provision of a dedimpling punch type cut-off press of the type illustrated in the aforementioned Bognar application having substantially reduced mass and bulk.

Another object is the provision of an improved dedimpling cut-oft blade.

Still another object is the provision of an improved tube retarding device which will actively urge the severed end of the tube against the de'dimpling blade.

Yet another object is the provision of an improved dedimpling cut-off blade and tube retarding device which can readily be incorporated in conventional press type cut-offs to produce more accurate end faces in the work.

Still another object is the provision of an improved cut-off as set forth above wherein the reciprocation of the punching die is employed to operate the tube retarding device.

Other objects and advantages of the present invention will become apparent as the following description proceeds.

To the accomplishment of the foregoing and related ends, the invention, then, comprises the features hereinafter fully described and particularly pointed out in the claims, the following description and the annexed drawings setting forth in detail certain illustrative embodiments of the invention, these being indicative, however, of but a few of the various ways in which the principles of the invention may be employed.

In said annexed drawings:

FIG. 1 is a somewhat schematic fragmentary side elevation view of a flying shear or press-type cut-off in accordance with the present invention;

FIG. 2 is a perspective view of the exit end of the 3,298,213 Patented Jan. 17, 1967 1 the exit end thereof with the blade having entered the work;

FIG. 5 is a fragmentary vertical section taken substantially on the line 55 of FIG. 4 but showing the blade I in its elevated position;

base 1.

FIG. 6 is an elevationof a preferred form of cut-off lade as seen from the line 66 of FIG. 7;

FIG. 7 is a side elevation of the blade shown in FIG. 6 illustrating the blade de-dimpling action;

FIG. 8 is an elevation of another form of de-dimpling blade as seen from the line 88 of FIG. 9; and

FIG. 9 is a side elevation of the blade shown in FIG. 8.

Referring now to the annexed drawings and more particularly to FIG. 1, there is illustrated a cut-off press for tubes and like travelling work W in accordance with the present invention which comprises a base 1 having mounted thereon the cut-off mechanism illustrated gen erally at 2. The conventional cut-off press comprises a press head 3 which is mounted onposts 4, shown in phantom lines, at each corner thereof which are moved downwardly by the mechanism in the base l to drive the cut-off blade into the die mechanism illustrated generally at 5. The cut-off mechanism is supported for movement with the work by a pair of top slide r'ails ti and 7 and bottom slide rails 8 and 9 mounted on the The cut-off mechanism is thus mounted for horizontal sliding movement on the rails 6 through 9 in a direction parallel to the direction of movement of the work W and the severing action is obtained by vertically moving the press head 3.

The work W passes from the exit end of the mill 19 or tube straightener, passes through the die openings in the cut-off mechanism 2, and onto a run-out table 11 mounted on stand 12. A flag or trigger mechanism at the end of the run-out table, which may be adjusted therealong, may be employed to sense the end of the work to trigger the cutoff. The cut-off die is always held by die return springs 14 which may be anchored to the die 5 as indicated at 15 and to the exit end of the mill it) as indicated at 16. The return springs 14 hold the die against suitable stops and the cut-off blade or punch passing through the work may be employed to move the cut-oh along the rails with the work or a separate accelerator mechanism may be employed to drive the die with the Work. After the severing operation is complete and the punch blade is withdrawn, the springs 14 will return the press to its original position. Reference may be had to the aforementioned copending application as well as to US. Patent No. 2,630,177 for illustrations of exemplary cut-offs.

Referring now more particularly to FIGS. 2, 3, 4 and 5, and especially to FIG. 4, it will be seen that the press cut-oil of the present invention is comprised of top gibs l8 and 19 which cooperate with the top rails 6 and 7. Such gibs are mounted on top slide plate 29 and wear plates 21 and 22 are interposed between the slide plate and the rails 6 and 7, respectively. Secured to the underside of the top slide plate in are cam holders 23 and 24- and punch holder 25. Punch blade 26 is secured to the holder 25 by suitable fasteners indicated at 27. Secured to the cam holders 23 and 24- as well as to the top slide plate 20 are vertically extending earns 29 and 30. The press head thus comprises the two vertically extending cams 29 and 39 with the punch blade 26 extending transversely of the work path situated therebe tween. Since the rails 6 and 7 are mounted on the verti- 3 cally movable punch head, the entire upper assembly of the cut-off hereinabove described is mounted for vertical movement.

The cams 29 and 30 are mounted for vertical sliding movement in upstanding cam guides 32 and 33 which are mounted on the bottom die shoe 34 which is in turn mounted on bottom die slide plate 35. Gibs 36 and 37 hold the bottom slide plate 35 to the rails 8 and 9 for sliding movement therealong. The cam guides 32 and 33 have inwardly directed channel-shape guide surfaces 49 and 41 which closely confine and guide the cams 29 and 30 for vertical movement. Side guides 43 and 44 extend between the cam guides 32 and 33 and are secured thereto by suitable fasteners indicated at 45. Such side guides are also mounted on the bottom die shoe 34 and include windows 46 and 47 through which the workpiece W passes.

Mounted between the side guides 43 and 44 are die block holders 50 and 51, the configuration of which may perhaps more clearly be seen in FIG. 5. Each die block holder includes a base portion 52 mounted on the bottom die shoe 34 between the side guides 43 and 44. The base 52 of each die block holder is provided with a slot as indicated at 53 which is aligned with slot 54 in the shoe 34. The slots 53 and 54 accommodate the blade 26 for vertical movement. Each die block holder is mounted for short distance movement between the side guides 43 and 44 transversely of the path of the work W but such die block holders are retained by the side guides against any movement with the work except as the entire cut-off moves with the work.

Extending horizontally through the die holder 50 are pins 56 and 57, and pins 58 and 59 extend through the die holder 51. The pins 56 through 59 are identical in form and accordingly only one will be described in detail. With reference to FIG. 5, it will be seen that the end of the pin 59 projecting toward the entry side of the cut-off die is threaded and a nut 60 and washer 61 are mounted thereon with the washer bearing against cutting block 62. The pins 56 and 57 are provided also with nuts and washers, the latter bearing against the outer face of cutting block 63.

Each of the pins is provided with a shoulder 65 which is seated within the respective shoulder 66 in the die blocks 59 and 51. Thus in each die block a shouldered bore accommodates the pair of pins for passage therethrough. The opposite end of the pin 59 is provided with a head 67 and a washer 68 associated therewith serves as a seat for compression Spring 69, the opposite end of which is seated in recess 70 in clamp block 71. It will be appreciated that there are four compression springs 69', one for each of the guide pins 56 through 59. The compression springs on the pins 58 and 59 engage within circular recesses 70 in the clamp block 71 while the compression springs on the pins 56 and 57 engage within similar circular recesses on clamp block 72. (See FIG. 4.)

Referring now to FIG. 3, it will be seen that the cutting blocks 63 and 62 are provided with shoulders 73 and 74 respectively, bearing against cam blocks 75 and 76 which are secured to the upstanding portions of the die block holders t) and 51. Spacers 77 and 78 are situated between the cutting blocks 63 and 62 and cutting blocks 79 and 8%, respectively, spacing such cutting blocks to form a slot 81 accommodating the blade 26 .for vertical movement through the dies formed by the cutting blocks 62, 63, 79 and 80. As seen in FIG. 5, each of the spacers 77 and 78 are provided with apertures to accommodate the guide pins pass-ing therethrough. The cutting blocks are thus clamped by the nut 661 on the ends of the guide pins, the spacers therebetween against the entry face of the upstanding portion of the die block holders 5t and 51.

The clamping blocks 71 and 72 are, however, not clamped against the upstanding portions of the die block holder- s 50 and 51 except by the pressure of the springs 69. A slight clearance indicated at 83 in FIG. 5 between the clamping blocks and the side guide 44 permits the clamping blocks to move away from the die block holders against the pressure of the springs 69. The clamping blocks 71 and 72 include inner clamping sections 84 and 85, respectively, which are held to the clamping blocks by shoulder screws 86 and 87. The shoulder screws are threaded into the clamping blocks and compression springs 88 and 89 urge the clamping sections away from the clamping blocks to the extent permitted by the shoulder screws. A clearance indicated at 90 is provided to permit such relative movement between the clamping blocks and the clamping sections. The clamping sections are provided with arcuate tube engaging surfaces 91 and include semicircular axial extensions 92 and 93 as indicated in FIG. 3 which have flaring inner guide surfaces 94 and 95, respectively. Such axial extensions of the clamping sections fit between the upstanding port-ions of the die block holders 5i and 51 and such upstanding portions may be arcuately shaped to accommodate such axial extensions. The clamping blocks as well as the inner clamping sections are provided at the top and bottom with transverse slots indicated at 97 and 98 accommodating retainer bars or keys 99 and 1110 which may be secured to one of the clamping blocks to extend in a freely slidable manner through the slots in the inner clamping sections as well as the opposite clamping block. It will thus be seen that the die assembly includes the cutting blocks 62, 63, 79 and the die block holders 50 and 51; and the clamping blocks 71 and 72 with the clamping sections 84 and resiliently secured thereto; and cam blocks 75 and 76 secured to the npstanding portions of the die block holders 50 and 51. Movement of the tube clamping elements 63, 79, and 85 on the left-hand side of the tube as seen in FIG, 3 toward and away from the tube clamping elements 62, S0 and 84 on the right-hand side as seen in FIG. 3 is accomplished' by the cams 29 and 31 during the vertical move ment thereof. Compression springs 103 and 1104- ex tend between bores in the base sections of the die block holders 50 and 51 and serve resiliently to maintain the die assemblies on each side of the tube against the cams 29 and 30.

Referring now to FIGS. 4 and 5, it will be seen that each of the cams 29 and 30 includes an upper thicker portion 196 and a lower thinner portion 167 separated by inclined cam surfaces 108 and 1139. The cam surface 1119 engages the upper beveled edge 111 of the cam blocks 75 and 76 and the cam surface 108 engages the upper beveled edge 111 of the clamp blocks 71 and 72. Accordingly, as the cams 29 and 30 descend, the cam surfaces 108 and 109 will engage the cam blocks 75 and 76 which are secured to the die block holders 5th and 51, respectively, and move the same toward each other against the pressure of springs 103 and 104. Since the guide pins 56 through 59 support all of the other elements of the die assembly, it will be seen that the entire die assembly including both the cutting blocks as well as the tube clamping sections 84 and 85 will be caused to, move toward each other into a work gripping position. The engagement between the cam surfaces 108 and the inclined cam top edges of the clamp blocks 71 and 72 will facilitate the movement of the clamping sections to a work gripping position.

Referring now to FIGS. 3 and 5, each of the clamping blocks 71 and 72 is provided with a recess at the entry outside corner as indicated at 115 and 116 with the top edge of the recess extending normal to the direction of the work travel and facing the entry side of the die and beveled as indicated at 117 and 118, respectively.

Referring now especially to FIG. 5, it will be seen that each of the cams 29 and 30 is provided with a milled out portion 120 between the cam surfaces 108 and 109 accommodating a striker plate 121 held to the cam by fastener 122 and a pivotally mounted cam dog 123 immediately therebeneath. The cam dog includes a relatively large diameter pin portion 124 projecting through the cam and such pin may be held by lock ring 125 situated in recess 126 in the back of each cam. The end of each cam dog projecting in the direction of work travel is provided with a cam surface 128 which includes a lower relatively large radius cam surface 129 and an upper somewhat smaller radius roll surface 131]. The upper portion of the cam dog is provided with a recess containing a pin 131 to which is attached a tension spring 132, the opposite end of which is secured to pin 133 projecting from the inside wall of the cams 29 and 39. The spring 132 extends through an elongated slot 134 in the striker plate 121 and through extension 135 of the milled out portion 120. It can now be seen that the cam dog 123 will be held abutting the striker plate 121 as shown in FIG. by the tension spring 132. The cam dog is, however, free to rotate in a counterclockwise direction as seen in FIG. 5 against the pressure exerted by the spring 132. It is noted that the cam surface 129 of the dogs 123 is posi tioned slightly beneath the inclined cam surfaces 198 and 109 of the cams 29 and 30 so that as the latter descend, the cam surface 129 will engage the upper inclined surfaces 117 and 118 of the clamp blocks 71 and 72, respectively, moving the same a short distance in the direction of travel of the work W compressing the four springs 69. The cam dogs 123 will be firmly held in the position shown in FIG. 5 as the cams 29 and 30 descend because of the juxtaposition of the striker plates 121 and shortly after the cam surfaces 129 have moved the clamp blocks 71 and '72, the short distance illustrated in FIG. 3, away from the cutting blocks and thus the blade 26, the cam surfaces 108 and 109 will then move the cutting blocks and clamp sections toward each other to grip the tube with the clamped sections now slightly spaced from the rest of the die assembly in the direction of travel of the work. The cams 29 and 31) will then continue down to the lowermost position indicated in FIG. 4 and the blade 26 will sever the work. The cycle continues and the head now moves upwardly toward the position 1139 indicated in phantom lines in FIG. 4 and as the head starts upward, the cam dogs 123 will roll in a counterclockwise direction as viewed in FIG. 5 against the pressure of the tension springs 132 releasing the clamp blocks so that the severed section of tube gripped by the clamp sections 84 and 85 will be urged by the springs 69 back toward the blade 26.

As seen in FIGS. 3 and 5, guide bushings may be provided mounted on the exit side of the upstanding portions of the die block holders 5t) and 51 surrounding the uppermost pins 56 and 53 fitting within recesses on the entry side of the clamp blocks 72 and 71.

Referring now more particularly to FIGS. 6 and 7, the preferred embodiment of the blade 26 is provided with a projecting point 140 which has side cutting edges 141 which may be struck on a standard radius of approximately 2 /1 inches for a blade having an overall length of about 5% inches. Instead of the curvature continuing to the edges 142 of the blade, the cutting edges of the blade are interrupted by a thinner web portion 143 which has side edges that extend parallel to each other and to the direction of blade travel. The web 1 13 forms snag pockets 145 and 146 on the opposite faces of the blade 26. It is important that the sides 144 be parallel to each other so that the corners formed at the opposite ends thereof be coincident, one directly above the other. The top of each pocket has a rounded edge 147 which may be struck on a radius and from the same center as the bottom edge 148. The bottom edge 148 thus has a smaller radius than the top edge 147 and the sides 144 are parallel secants or chords of both circles. From the root of the web 143, arcuate cutting surfaces 151 and 151 extend to the side edges 142 of the blade. Such edges 159 and 151 may have the same radius as the edges 141 of the tip portion 149.

As seen in FIG. 7, the web portion 143 may be slightly more narrow at the upper end thereof providing sharp snagging edges or shoulders 152 at the bottom of the web and a slightly deeper recess at the top into which the upper dimpled portion of the trailing end of the severed section 153 and the leading end of the work W will be pressed by the various forces acting thereon. As an example, a blade with a total thickness of .150" may have a web portion 14-3 which is .110" thick at the bottom and .070" thick at the top. In this manner, the snagging shoulders 152 will be approximately .020" deep.

The dimple or depression D formed in the top of the workpiece W as well as the severed section 153 by the vertical downward movement of the blade 26 will then be caused to be removed upon the retraction or the vertical upward movement of the blade 26 after the severing operation. As the blade 26 moves upwardly in the direction of the arrow 154, the dimples D will slide or move into the recesses and 146 formed in the faces of the blade 26 due to the various forces acting on the blade and tubular workpieces as indicated by the arrows in FIG. 7. The compression springs 169 acting on a tube gripping sections 84 and 85 will cause the severed section 153 to be urged in the direction of the arrow 155 to insure that the dimple D on the trailing end thereof will be properly engaged with recess 145. Since the: work W is travelling in the direction of the arrow 156, the leading end of the unsevered workpiece vV will still bear against the blade with the substantial force and the die return springs 14 seen in FIG. 1 urging the cut-off to its retracted position will exert a force indicated by the arrow 157 holding the blade 26 and work W in proper Working engagement as the blade is retracted.

Referring now to FIGS. 8 and 9, there is illustrated a further embodiment of a cut-off blade that may be used with the present invention. The blade 160 comprises a more or less conventional blade body having the pointed punching tip 161 with curved cutting edges 162 and 163. Directly vertically above the point 161 which creates the dimple, a circular aperture 164 is provided in the blade and into such aperture there is pressed a hardened pin 165. The pin is provided with projections 166 and 167 which project equally from the faces 168 and 169, respectively, of the blade 161). Each of the projections includes a top shoulder 17%) which is horizontal and vertically extending sides 171. The outer surface of each projection includes a small fiat 172 at the top with a bottom inclined surface 173. The inclined surfaces 173 act as cams to cam the work past the projection as the blade descends and when the blade is retracted in a manner similar to that shown in FIG. 7, the top shoulders will engage the dimples formed by the blade and rework the same to provide more nearly circular end faces on the work.

Operation With the press head elevated as seen in FIG. 1, in phantorn lines in FIG. 4, and in FIG. 5, the workpiece W will pass through the separated die blocks onto the run-out table 11 to contact a length sensing device to actuate the cutoff. In this position, the ct1t-0ff will be held in its retracted position on the rails 6 through 9 against the stop 15 by the return springs 14. As the press starts its down stroke, the cams 29 and 3d guided in cam guides 32 and 33 start to enter the cavity between the cam blocks 75 and 7 6, that are mounted on the die holders 541 and 51, and the cam guides. Just before the cam surfaces 193 and 199 on each of the cams move the die block holders toward each other, cam dogs 123 engage the cam surfaces 118 and 117 on the clamp blocks 72 and 71, respectively, to move the tube gripping assembly form-ed by the blocks 71 and 72 and the respective clamp sections 34 and 85 forward away from the blade 26 a relatively short distance as shown in FIG. 3. This. distance may be approximately 4; of an inch depending upon the size of the 7 cut-off. The springs 69 always tend to keep the tube gripping assembly against the upstanding portions of the die block holders 54) and 51 which is the position indicated in FIG. 5.

As the cams 29 and 30 continue downwardly during the cutting stroke, the cutting blocks 62, 63, 79 and 80 will be caused to move together to grip the tube adjacent the cutting blade path. The blade then moves through the slot 81 to sever the tube as the press head moves down. As the cutting blocks grip the tube due to the vertical movement of the cams 29 and 3t), the clamping sections 84 and 85 of the tube gripping assembly will also be caused to move toward the tube firmly to grip the same. Since the guide pins 56 through 59 interconnect all of the components of the dies on each side of the tube path, movement of the cutting blocks toward each other will also cause the tube clamping sections 84 and 85 to move toward each other resiliently firmly gripping the tube therein. This inward motion of the tube clamping sections is also facilitated by the cam surfaces 108 on the cams engaging the inclined portions 111 of the clamping blocks 71 and 72. This inward mot-ion of the clamping sections is the second motion for the tube gripping assembly. The assembly first moves away from the blade to the position seen more clearly in FIG. 3 and then the clamping sections move toward each other gripping the tube in the now axially slightly spaced position.

At this point, while the gripper assembly has been axially located, the blade 26 has moved through the slot formed by the cutting blocks severing the tube and creating the dimple clearly illustrated in the end faces shown in FIG. 7. As the cams 29 and 30 reach the bottom of their stroke, the cam dogs 123 then overshoot the clamp blocks 71 and 72 so that the pressure of the springs 69 may now urge the gripping assembly and thus the severed section of tube back toward the blade. The tube gripper is then now cocked and gripping the severed section 153.

As the press starts its return stroke, the blade 26 is being withdrawn from the cutting blocks. The cam dogs 123 will engage the clamp blocks 71 and 72 and will roll in a counterclockwise direction as viewed in FIG. pivoting against the pressure of springs 132 so that on the upward stroke, they will be ineffective to move the gripping assembly axially against the pressure of springs 69. In this manner, the springs 69 will maintain pressure between the end face of the severed section 153 and the blade 26. The die return springs 14, seen in FIG. 1, will keep the blade pressing against the oncoming workpiece W. These spring pressures explained more fully in connection with FIG. 7 cause the severed and oncoming tubular workpieces to slip into the recesses 145 and i145 machined into the blade 26. As the blade continues to retract, the dimpled portions of the end faces are hooked by the blade and as a result, the dimples are wiped out or removed.

As the press approaches the top center, cams 29 and 3t pull away from the cam blocks 75 and 76, and the compression springs 103 and 1M between the die block holders 5th and 51 spread the holders away from each other. As this action is going on, the guide pins that carry the clamping blocks 71 and 72 move away from each other. This in turn unclamps the clamping sections 84 and 85 from the severed tube because the blocks 71 and 72 pull the sections 84 and 35 away from each other by means of the shoulder screws 86 and 87. Such shoulder screws couple the respective sections to the blocks and springs 88 and 89 provide a reaction member between the blocks and clamping sections.

It will, of course, be appreciated that clamping sections as well as cutting blocks having different work gripping configurations can readily be employed to accommodate work of different sizes through the cut-off. Also, it will be understood that the clamping action of the cutting blocks 62, 63, 79 and 8t is not such as to impair the effectiveness of the springs 69 and 14.

It can now be seen that there is provided a cut-off mechanism of a mom simplified nature which will effectively remove the dimple from the end faces of tubular work and the like. A tube gripping assembly is provided which is cocked in a direction away from the blade upon the vertical movement of the blade and then caused to grip the workpiece and resiliently urge the severed workpiece toward the blade upon return of the blade to its top center position.

Other modes of applying the principle of the invention may be employed, change being made as regards the details described, provided the features stated in any of the following claims or the equivalent of such be employed.

I, therefore, particularly point out and distinctly claim as my invention:

1. A tube cut-off comprising a movable blade having a de-dimpler thereon, a tube gripping asembly adapted to grip the severed section of tube and urge the severed end face thereof against said blade on its return stroke, and means responsive to the cutting stroke of said blade first to cock said assembly and the cause the same to grip such tube.

2. A tube cut-off as set forth in claim 1 wherein said assembly is mounted for movement axially of the tube, spring means urging said assembly toward the blade, said means to cock said assembly being operative to compress said spring means by moving said assembly away from the blade to a cocked position.

3. A tube cut-off as set forth in claim 2 including means to maintain said assembly in said cocked position throughout the cutting stroke.

4. A tube cut-oft as set forth in claim 3 wherein said blade is mounted on a vertically movable plate, vertically extending cams on said plate, a first cam surface on said cams operative to cock said assembly, and a second cam surface on said cams operative to cause said assembly to grip such tube.

5. A tube cut-off as set forth in claim 4 wherein said first cam surface is on a dog pivotally mounted on each said cam, and means to hold said dog in position to engage said assembly to cock the same on the cutting stroke of said blade and to release said assembly after said second cam surface has caused said assembly to grip such tube.

6. A tube cut-off as set forth in claim 1 including means responsive to the completion of the cut-off stroke to release said assembly to urge the severed section against the blade.

.7. A cut-off for elongated travelling work including a blade operative to sever a length from a continuous supply of such work while producing a dimple in the end wall of such severed length, spring means operative actively to urge such dimpled end of such severed length against said blade, de-dimpling means on said blade adapted to engage and remove such dimple on return movement of said blade, means operative to return said blade, and means responsive to the movement of said blade to preload said spring means for release at the completion of the cutting stroke.

8. A cut-off as set forth in claim 7 including a work gripping assembly on the exit side of the cut-off with said spring means acting thereon, and means responsive to the movement of the blade on the cutting stroke to move said assembly away from the blade to preload said spring means.

9. A cut-off as set forth in claim 8 including means responsive to the cutting stroke of the blade after said spring means have been preloaded to cause said assembly to grip such work.

it A cut-off as set forth in claim 9 including means responsive to the return stroke of said blade after the work has been dedimpled to release such work from said assembly.

11. A cut-01f as set forth in claim 7 wherein said dedimpling means comprises transverse recesses in said blade having straight and parallel side edges.

12. A cut-oil as set forth in claim 11 wherein said blade is pointed and said recesses extend completely across said blade behind said point.

13. A cut-off as set forth in claim 12 wherein said recesses have a-rcuate bottom shoulders.

14. A cut-off as set forth in claim 7 wherein said blade is pointed and said de-dimpling means comprises upstanding shoulders projecting from the faces of said blade and aligned with the point thereof.

15. A cut-off as set forth in claim 14 wherein said shoulders are provided on a hardened pin pressed into said blade and include inclined surfaces th-erebeneat-h.

16. A de-dirnpling cut-off blade comprising a projecting point having curved side edges, and transverse recesses in said blade on both faces thereof above said point and extending from edge to edge, the edges of said blade at said recesses being straight and parallel.

17. A de-dimpling cut-off blade comprising a projecting point, a hardened pin pressed into said blade above said point and having projecting shoulders thereon, and inclined surfaces on said pin beneath said shoulders.

18. A tube cut-off comprising a movable blade having a de-dimpler thereon, a tube gripping assembly adapted to grip the severed section of tube and urge the same against said blade, means responsive to the cutting stroke of said blade to cock said assembly and then cause the same to grip such tube, means responsive to the completion of the cut-off stroke to release said assembly to urge such severed section against the blade, and means responsive to the completion of the cut-off stroke to release the severed section from said assembly.

No references cited.

ANDREW R. JUHASZ, Primary Examiner.

LEONIDAS VLACHOS, Examiner.

Claims (1)

1. A TUBE CUT-OFF COMPRISING A MOVABLE BLADE HAVING A DE-DIMPLER THEREON, A TUBE GRIPPING ASEMBLY ADAPTED TO GRIP THE SEVERED SECTION OF TUBE AND URGE THE SEVERED END FACE THEREOF AGAINST SAID BLADE ON ITS RETURN STROKE, AND MEANS RESPONSIVE TO THE CUTTING STROKE OF SAID BLADE FIRST TO COCK SAID ASSEMBLY AND THE CAUSE THE SAME TO GRIP SUCH TUBE.

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