US3319445A - Pipe forming machine - Google Patents

Description

- May 16, 1967 J. E. STALKER PIPE FORMING MACHINE 3 Sheets-Sheet 1 Filed NOV. 15 1963 c/ames BY Fly. 5

May 16, 1967 J. E. STALKER PIPE FORMING MACHINE 3 Sheets-Sheet 2 INVENTOR.

Mffwwey y 1967 J. E. STALKER 3,319,445

PIPE FORMING MACHINE Filed Nov. 15, 1963 :5 sheets-sheet s Fly. 6

I NVEN TOR.

James 15 m/fie?" United States Patent 3,319,445 PIPE FORMING MACHINE James E. Stalker, Richardson, Tex., assignor to Home Metal Products Company, Plano, Tex., a corporation of Texas Filed Nov. 15, 1963, Ser. No. 323,965

6 Claims. (Cl. 7230) This invention relates to a pipe forming machine, and more specifically, to one having utility for forming sheet metal into stove vent pipes and the like.

Stove vent pipes are well-known in the art and have been used for many years. Most commonly, sections are joined together by telescoping a reduced end portion of one section onto the normal-sized end portion of an adjoining section. The reduction in size of an end portion of a section is usually accomplished by fluting or otherwise corrugating the end portion. Stop means below the reduced end portion of a section to firmly engage the normal-sized end of the adjoining section telescoping thereover are commonly provided by forming a rib joint below the corrugated end portion.

Various methods of corrugating the end portion of a joint, providing a stop rib below the corrugated section, and covering the sheet metal of the joint into the desired general cylindrical configuration have been used; however, such methods commonly require a series of time-consuming, separately performed operations and awkward and/ or complex machinery.

It is an object of the present invention to provide a machine for performing the corrugation and/or rib formations on the end of sheet metal and, concurrently therewith, bending said metal into the desired curvature. Moreover, it is an object to provide such a machine that is simple, etficient, and economical. It is a further object to provide such a machine that will perform the stated operations without deforming pre-formed edges on the sheet metal which are later interlocked to hold the curved sheet metal into the desired rigid cylindrical position.

In accordance with this invention, a system for rolling a pipe section from a sheet having lea-d and trailing edges preformed to interlock, one with the other, is provided which comprises an upper and a lower roller which have an annular rib and groove portion adjacent to one end for working a rib into a sheet; a forming roller on the back side of the upper and lower rollers for determining the curvature of the sheet forming roller, being spaced a different distance from the ends of the upper and the lower roller adjacent to the annular rib and groove portion than from the other end of said rollers; means for elevating and lowering one of the rollers to permit the sheet to be inserted between the rollers from the front; and a drive means operatively linked to the upper and lower rollers to drive the sheet past the forming roller.

An important feature includes adaption of the system for handling a sheet with preformed lead and trailing edges so that said preformed edges will not be deformed by said rollers during forming of the sheet.

A quite specific preferred embodiment of the instantinvention contemplates a system for rolling a sheet having opposite lead and trailing edges formed for interlocking, which comprises: a table having stop means thereon against which the trailing edge abuts; a pair of rollers positioned one above the other to define upper and lowerrollers, respectively, each of the rollers being generally tangent to the plane of the table at a distance from the stop means slightly less than the width of the sheet; means for elevating to an upper position and lowering to a forming position said upper roller to permit said sheet to be inserted between said rollers, the upper roller and the lower roller having an annular rib and groove portion adjacent to the one end for working a rib into the sheet and having "ice male and female fluted portions extending between the rib and groove portion of the end of the rollers for fluting the portion of the sheet beyond the rib; a forming roller on the side of the pair of rollers for determining the curvature of the sheet, which forming roller is spaced a dilferent distance from the fluted end of the pair of rollers than from the other end of the pair of rollers; a drive means; a chain belt linked to the first and second rollers and to the drive means; a resiliently positioned follower for engaging the chain link belt between the motor and the upper roller to permit the upper roller to be elevated and lowered while maintaining registration between the male and female fluted portions of the rollers; a timing rod mounted for translation adjacent the end of the table opposite the belt; a timing wheel mounted for movement with the upper roller to engage the timing rod when the upper roller is in its lower position; and control means at a predetermined point in the path of the timing rod for activating the elevating means for the upper roller a predetermined distance before the trailing edge of the sheet reaches the rollers.

For a more complete understanding of the present invention and for further objects and advantages thereof, reference may now be had to the following description taken in conjunction with the accompanying drawings in which:

FIGURE 1 is a rear perspective view of a preferred embodiment of the instant invention;

FIGURE 2 is a side view of the apparatus of FIG- URE 1;

FIGURE 3 is a top view of the apparatus of FIG- URE 1;

FIGURE 4 is a partial side view showing the apparatus of FIGURE 1 with the crown roller in forming position;

FIGURE 5 is a similar side view as FIGURE 4 except the crown roller is shown raised to its uppermost position;

FIGURE 6 illustrates a stove vent pipe, after assembly, which has been formed by use of the instant invention;

FIGURE '7 is a partial view of certain details of the machine of FIGURE 1, illustrating an adjustable sliding carriage in which the forming roller is journalized; I

FIGURE 8 is a simplified circuit diagram illustrating the electrical circuitry for the machine of FIGURE 1;

FIGURE 9 is a schematic of the structure of FIGURE 10 in which the crown roller is shown separated from the base rollerand a work sheet is shown supported there-be tween in position to be formed; and

- FIGURE 10 is a schematic view of a section taken along 10-10 of FIGURE 3, showing a work sheet being formed between the rollers.

Referring now to FIGURE 1, a machine is therein illustrated which is a preferred embodiment of the present invention. It is shown as viewed in perspective from the rear, FRONT being indicated by an arrow in connection with said figure. Accordingly, for purposes of locating parts and their relative location with respect to each other in this specification, it will be understood that reference to front refers to the machine of FIGURE 1 as viewed from FRONT. Moreover, reference to right or to left refers to those directions as would appear when the machine is viewed from FRONT. The designation rear" will be consistent with the foregoing.

A support means in indicated generally in FIGURE 1 by the reference numeral 11. It comprises horizontal rectangular support deck 13, depending vertical legs 15, 17, 19 and 21, and co-planar leg braces 23, 25, 27 and 29.

Right vertical standard 31 extends upwardly from the support deck 13 to which it is firmly anchored. It is shaped generally as a rectangular block. The right and left faces of the vertical standard 31 are in parallel vertical planes and are generally parallel to the edges of support deck 13. Vertical standard 33 is, like vertical standard 31, generally rectangular in configuration. It also has right and left parallel faces which are, in turn, parallel to the edges of support deck 13. It is therefore seen that the Vertical standards 31 and 33 are disposed with their opposite inner faces 32 and 34 in alignment.

Crown roller 35, base roller 37 and forming roller 39 are rotatably carried by the vertical standards 31 and 33. The longitudinal axes of all three of these rollers are generally parallel and are perpendicular to the inner faces 32 and 34 of the vertical standards. The crown roller 35' and the base roller 37 are generally cylindrical and are of substantially the'same diameter. Crown roller 35 is disposed above base roller 37, the pair of rollers 35 and 37 thus defining an upper and a lower roller, respectively. The forming roller 39 is positioned so that its longitudinal axis lies behind the longitudinal axis of the crown and base rollers. Forming roller 39 is tapered from left to right with its greatest diameter adjacent block 33 and its narrowest diameter adjacent block 31. Its upper surface even at its narrowest diameter lies at a higher elevation than the upper surface of the base roller 37.

A short'distance from the right end of crown roller 35, the flute-forming portion 41 is disposed on the surface of the roller. It comprises a plurality of alternate ridges and valleys running about the circumference of the roller. These ridges and valleys are parallel to the axis of the roller and are of the same length, with their left and right ends in alignment. An annular ridge 43 on crown roller 35 is disposed a short distance to the left of the left end of the flute-forming portion 41. It runs circumferentially outwardly with respect to the axis of the crown roller 35. Annular groove 44 in crown roller 35 lies just to the left of the annular ridge 43. Annular groove 44 extends circumferentially inward with respect to the axis of crown roller 35.

The base roller 37 has a flute-forming portion 45 with alternate ridges and valleys which mate with the valleys and ridges, respectively, of the crown roller 35 when the two rollers are pushed together as illustrated in FIGURE 1 and in FIGURE 10.

' An annular groove 47 extends circumferentially inward in the curved surface of the base roller 37 a short distance from the left end of the flute-forming portion 45. Annular groove 47 is in vertical alignment with annular ridge 43 of the crown roller 35. Annular ridge 49 extends circumferentially outward with respect to base roller 37. It is disposed immediately to tthe left of annular groove 47 and is so located'that it is in vertical alignment with the annular groove 44 on crown roller 35.

The surface configurations of the annular ridges and grooves just described and their relative orientation is such that they lie together in mating engagement when the crown roller is in contact with the surface of the base roller.

The configuration used in the machine of FIGURE 1 for the mating of flute-forming portions and the mating of annular ridges and grooves just described above can best be understood by reference to FIGURES l, 3, 9 and and by reference to the upper portion of the vent pipe illustrated in FIGURE 6. It should be understood, however, that various other configurations on the surfaces of the rollers 35 and 37 may be substituted and it is not intended that this invention be limited by the configurations just described.

A slot 51 extends vertically downward in the vertical face 32 of block 31. Crown bearing carriage block 53 rides in slot 51' with the sides of the carriage block in sliding engagement with the sides of the slot. Retainer strips 55 and 57 hold the crown bearing carriage within said slot. Thus, only vertical motion of the block is permitted. A cylindrical bearing surface 59 is formed within the movable carriage block 53, The journalized end of the crown roller 35 is carried within this bearing surface.

The end of the base roller 37 is journalized in a conventional recessed bearing surface formed in vertical standard 31.

An inclined rectangular slot 60 in face 32 of vertical standard 31 extends downwardly and rearwardly from a central portion of vertical standard 31. This rectangular slot is inclined with respect to the horizontal to a noncritical angle, being about 20 in the embodiment of FIGURE 1. Forming bearing block 61 is configured to slide within slot 60. Retainer strips 63 and 65, fixed to face 32 of vertical standard 31 by suitable means such as allen screws 66, overlie the edge of the slot to retain the forming bearing block 61 in slot 60 and confine said block to movement along the inclined longitudinal axis of the slot.

A cylindrical bearing surface is formed within forming bearing block 61 and it receives the journalized end of tapered forming roller 39. Adjustment screw 67 has its forward shank end 69 rotatably mounted within a bore running axially into bearing block 61. An annular groove 71 runs about the cylindrical surface of screw 67 adjacent shank end 69. A pin 75 extends from the outer surface of the forming bearing block 61 inwardly to ride within the annular depression 71 and confine screw 67 with respect to block 61 so that only rotation is permitted with respect thereto. Screw 67 passes through and threadedly engages retainer 77, which is held in fixed position with respect to vertical standard 31 by fasteners such as allen screws 79. Thus screw 67 may be manipulated by rotating it to cause it to move either inwardly or outwardly with respect to retainer 77. On such movement, block 61 is carried inward, or outward, as the case may be, to position the bearing block 61 in the desired location along slot 60.

The vertical support 33 supports the left end of the crown roller 35, the base roller 37 and the forming roller 39 in the same manner and by exactly the same parts and mechanisms .as have just beendescribed for the support provided on the right end of said rollers. The only difference is, as will later be explained in more detail, drive means are provided at the right end of the base and crown rollers but a timing wheel is provided at the left end of the crown roller.

The timing wheel 83 is a knurled, cylindrical member which is fixedly joined to the reduced cylindrical extension84 which runs axially outwardy from the left side of the journalized end of crown roller 35. An elongated opening 85 in vertical standard 33 permits the cylindrical extension 84 to pass through the block and, moveover, provides room permitting the crown roller 35 to be raised in the manner later explained herein. A timing rod 87 is carried on the left side of support deck 13, upon a plurality of rollers 89'and with its sides guided by spaced, parallel, vertical walls 91 and 93, which extend upward from support deck 13. The rollers 89 are journalized at either end within suitable bearing-defining apertures running through the support walls 91 and 93. As can be seen from reference to FIGURES l3, a cord 95 having a weight 97 supported from a free end is attached at the front end of timing rod 87 and runs downwardly over an end sheave 99, which is journalized at either end within bearing-forming supports within the support walls 91 and 93. For convenience, a second sheave (not illustrated, but its position discernible from the extending journalized end 101 of its shaft which is visible in the lower left-hand front portion of wall 93, as seen in FIG- URE l) is provided so that cord 95 may pass over sheave 99 and then downwardly and inwardly over the second sheave, thus locating the suspended end of cord 94 rearwardly from the extreme front portion of the apparatus of FIGURE 1. This displacement is merely a matter of convenience to move the free end of cord 95 out of the way of an operator or passerby.

The relative location and configuration of the timing rod 87 and its support means described above, is such that when crown rolled 35 is in its lower position, illustrated in FIGURE 1, the knurled surface of timing wheel 83 is in close frictional engagement with the surface of timing rod 87. It will thus be appreciated that rotation of the crown roller, with the attendant rotation of knurled timing wheel 83, will drive the metering rod along the rollers 89. Since the rotation of crown roller 35 is counterclockwise as viewed from the right side (the drive side) of the apparatus, it will be appreciated that the timing rod will be moved rearward by such action.

A microswitch 103 is mounted at the rear of the parallel support wall 93, along the outer side thereof. Its actuation arm 105 extends horizontally across and behind the open end portion defined between walls 91 and 93 so that it will be struck by the end of timing rod 87 when timing rod 87 is moved rearwardly a sufficient distance.

Now turning to the drive mechanism, attention is first directed to FIGURE 4. An opening 111 passes through vertical standard 31. This opening is located with respect to the standard so that a cylindrical extension 113 from the journalized right end of crown roller 35 is permitted to pass through said block 31. The opening 111 is configured to provide a vertical slot permitting said extending end to move upwardly and downwardly therein. The extending end 113 has keyed upon it, as by key 115, the crown roller drive gear 117.

The base roller 37 has an extending shaft portion 119 fixed to and running axially from its journalized right end. This portion passes through a suitable opening provided within vertical support block 31. On the outer side of the support block, i.e., the right side, base roller drive gear 121 is held in place on shaft 119 by means of key 123.

An idler gear 125 is supported by shaft 127, upon which it is held by key 129. This shaft is journalized and conventionally supported within vertical standard 31. It lies below base roller gear 121.

Motor 131 is supported by base 133, which is in turn mounted upon the rear, right upper portion of support deck 13. Motor 131 carries a sprocket 135 upon the end of its drive shaft. Sprocket 135 is aligned with gears 117, 121 and 125. Drive chain 137 is in engagement with the teeth of sprocket 135, crown roller drive gear 117, base roller drive gear 121 and idler gear 125. The teeth of these various gears are suitably engaged by drive links of drive chain 137, which consequently drives said gears.

Drive chain tension means are provided by a follower roller 141. This roller is rotatably mounted upon an extending shaft 143, which extends from the end of arm 145. Arm 145 is pivotally mounted by pin 147, which pin extends into the right vertical surface of vertical standard 31 near its upper righthand portions. A spring 149 has its lower end 151 supported by pin 152, which extends into the lower right-hand portions of the right vertical face of vertical standard 31. The other end of spring 149, i.e., generally its upper end, is connected to the lower portion of arm 145. Spring 149 is in tension so that it pulls roller 143 firmly downward against drive chain 137. This mechanism insures that the drive chain 137 is maintained in tight driving position whether the crown roller 35 is in the lower position, as shown in FIGURE 4, or the upper position, as shown in FIG- URE 5.

The work table 161 is mounted over the support deck 13 in front of the crown roller 35 and base roller 37. It is supported by vertical supports 163 and angular braces 165. Work table 161 is inclined downwardly to the front a non-critical angle, for example, to degrees. Its upper, rectangular fiat surface is disposed so that a thin sheet of metal to be worked by the rollers will be substantially tangent to the top of the base roller (and hence, the bottom of the crown roller, when the rollers are together) when the sheet metal rests upon the inclined table and extends over its rear portion adjacent the front of the rollers. The Work table has a feed guide 169 mounted upon its upper surface near the right edge of the table and extending perpendicular to the rollers. Feed guide 169 provides a means to insure that a rectangular sheet is fed straight into the rollers.

Initial positioning guides 171 are provided adjacent the front portion of the work table. They are small rectangular pieces having parallel aligned edges facing the crown and base rollers 35 and 37, respectively. Initial positioning guides 171 insure that the work is properly initially inserted a proper distance with respect to the rollers. As will later be more readily appreciated, the guides 171 lie in front of said rollers a somewhat shorter distance than the width of the sheet to be formed.

A conventional double-acting cylinder 181 is secured upon the upper portion of vertical support 31. Conventional piston rod 185 extends downwardly from the cylinder into the generally rectangular opening formed in the upper portion of vertical support block 31 and by its lower portion 187 threadedly engages crown bearing carriage block 53. Lock nut 189 is provided on the lower portion 187 of the piston rod to adjustably secure the piston rod with respect to crown bearing block 53.

Cylinder 191 is identical to cylinder 181. It rests upon the upper portion of left vertical standard 33. Analogous to cylinder 181, cylinder 191 has a downwardly extending piston rod connected to a crown bearing carrier block sliding within a vertical slot provided in vertical standard 33.

A horizontal shelf 201 is supported in between braces 25 and 29. Solenoid valve 203 is held in position on the upper central portion of shelf 201, as by bolts 205. This solenoid valve is a conventional 4-way valve type. The particular one illustrated is solenoid-operated with spring return means. It has air inlet nipple 207 extending into its valve body. Air supply line 209 is connected to 207. Conventional exhaust ports 211 and 212 are provided. Ts 213 and 215 extend upwardly from two air ports provided in the valve. The solenoid 217 adjoins the right side of the 4-way valve. A solenoid connection conduit 219 leads from solenoid 217 to the conduit boxes 221.

Upper cylinder air supply lines 223 and 225 join the upper portions of cylinders 181 and 191, respectively, with the air supply through T 213. Cylinder air supply lines 227 and 229 extend from their connection with either side of the T 215 to connect with the upper portions of the double-acting cylinders 181 and 191, respectively.

Hand actuated motor switch 231 is mounted on the right front of leg 15 in a convenient position. It is connected to the conduit box 221 by electrical cable 233. In turn, electrical cable 235 leads to the motor from conduit box 221.

Microswitch 103 is electrically connected through cable 237 to the conduit boxes 221. Y

A foot operated switch 241 lies on the floor in front of the support means 11 of FIGURE 1. This switch is closed when its treadle is depressed by the foot of an operator. Switch 241 is electrically connected by cable 243 to conduit box 221.

The wiring of the various electrical parts and arrangement of wires within conduit "box 221 can best be understood by reference to the simplified'circuitdiagram of FIGURE 8. Therein, power leads 251 and 252 (leads of power cable 245) have connected in parallel across them the motor 131 and the solenoid 217. Referring to the motor circuit, the motor switch 231, illustrated in open position, is closed to actuate the motor. Referring to the solenoid circuit, the foot switch 241, normally open, and the microswitch 103, normally closed, are in line With the solenoid 217. Thus, while the foot switch is depressed, the opening of microswitch 103 breaks the circuit to the solenoid. The significance of the operation of the solenoid circuit will be explained hereinafter in connection with an explanation of the operation of the machine.

Now turning to machine operation in general, the crown roller is raised above the base roller, thus permitting the sheet to be worked to be inserted with its leading edges extending a short distance rearward of the base and crown rollers. Thereafter, the crown roller is forced downward against the sheet to be worked to press it between the crown and base rollers and drive the sheet therebetween while the flute-forming portions and grooves and ridges on the rollers corrugate and form -a rib and adjacent depression in the sheet. The sheet is concurrently bent by the forming roller to the desired degree of curvature. A short distance prior to passage of the trailing edge of the sheet between the crown and base rollers, the rollers are effectively separated by the raising of the crown roller. This permits the Work to be removed without the damage which otherwise would occur to the lip on the trailing edge of the work sheet. Thereafter, the cycle described above may be repeated to form additional work sheets into the desired configuration.

Operation will now be explained in more detail. The solenoid valve 203 in its non-energized position conducts air from air line 209 to the underseide of the piston working within the double-acting cylinders 181 and 191 through lines 227 and 229, respectively. The top portion of the cylinders is vented through exhaust port 211 via lines 223 and 225. Accordingly, the piston is held in the up position by air pressure. Piston rod 187, as well as the like piston rod extending from cylinder 191, is thus maintained in the raised position as shown in FIG- URE 5. This positions crown bearing block 53, and the like block sliding vertically in vertical standard 33, in their highest elevation (see FIGURE In this position, crown roller 35 rests well above the upper surface of base roller 37 and work can easily 'be inserted therebetween (see the position of FIGURE 9). Note that the initial positioning guides 171 are located on inclined table 161 so that the work sheet 261 rests with its trailing edge abutting the guide 171 and its leading edge extending behind the point of ultimate tangency of the crown and base rollers. The locking lip on the leading edge of the work sheet is thus cleared for the crown roller to be lowered. Note the leading edge overlies the upper surface portions of the forming roller 39 when in the initial position.

After the work is positioned as just described and as illustrated in FIGURE 9, the treadle on the foot operated switch 241 is depressed to close the switch contacts. Since the microswitch 103 is normally closed, the solenoid circuit is consequently completed (see FIGURE 8) and the valve element within solenoid valve 203 retracted by the solenoid 217 to an energized position connecting the various air ports so that the upper portions of cyinders 181 and 191 are pressurized with air from air supply line 209 via lines 223 and 225. The lower portions of the cylinders 181 and 191 are vented to the atmosphere via lines 227 and 229. In this position, the pistons within cylinders 181 and 191 are forced to the down position (see piston rod 185 in FIGURE 4). The attached crown bearing blocks accordingly carry the crown roller 35 down. The crown roller 35 is thus moved downwardly against the work sheet 261. The flute-forming portions and ridges and grooves of the crown and base rollers force the Work to conform to the desired fluted and ribbed and grooved configuration as it is drawn between the rollers (see FIGURE 10). The work sheet passes from the crown and base rollers up over the forming roller 39 to bend the sheet to the desired degree of curvature. At all times during the operation the pressure in the upper portions of the cylinders 181 and 191 is maintained so that a substantial force is exerted upon the work sheet during forming.

Timing rod 87 is in its forwardmost position, where it is maintained by weighted cord 95, at the instant that the crown roller is lowered to form a work sheet. When the crown roller lowers, the knurled timing wheel 83 engages the timing rod 87 and frictionally drives it forward while the crown roller rotates. At the proper predetermined interval (determined by the appropriate length of timing rod 87, proper sizing of the knurled wheel 83, and/ or proper positioning of microswitch arm 105) the rear end of the timing rod 87 strikes the microswitch arm 105 and opens the microswitch. This opens the circuit to the solenoid and a spring return within the 4-way solenoid valve 203 forces the valve element of the solenoid to the disengaged position. In this position, air is again forced in under the pistons in cylinders 181 and 191 and exhausted above them. Thus crown roller is raised to its upper position. The foot operated switch 241 is released by the operator as the crown roller rises and the formed work sheet is removed.

Note that after the crown roller is raised on actuation of microswitch 103 and the foot operated switch returns to the open position, the pull cord retracts the timing rod 87 to pull it along its path over rollers 89 to its forwardmost position. It will thus be appreciated that the machine is then ready in all particulars for another cycle. Another work sheet can then be inserted, if desired, and the treadle of the foot operated switch depressed to drive the rollers together and again commence the cycle.

Throughout the operation of the machine, whether the crown roller is in the upper or lower position, the follower roller 141 bears down firmly against drive chain 137 to keep it taut in driving engagement with gears 117 and 121.

The relative location of the forming roller 39 is determinative of the curvature of the work passing through the machine. This curvature of the work passing through the machine. This curvature is adjustable by adjustment of the location of the forming roller 39 by suitable manipulation of the adjustable screw 67, as previously described herein.

The embodiment illustrated is suitable to work sheets of various thickness depending upon its scale and upon the force of the crown roller.

It should be noted that the tapering of the forming roller provides a substantially greater spacing between the right end af the rollers, where the fiuting and ridge forming operation is accomplished, and on the other end. This provides needed clearance so that the formed portions of the sheet being worked may properly clear the machine. In addition, .it is sometimes desirable to have a machined groove provided on the forming roller to assure clearance with rib forming structure on the crown and base rollers. Groove 262 in forming roller 39 (FIG- URE 1 and FIGURE 3) is an example of this experiency.

Various auxiliary devices are found useful in conjunction with the embodiment illustrated. For example, in FIGURE 1, a conventional counter 263 is provided to count the number of sheets worked by the machine. This is accomplished by contact of the front of the timing rod 87 with a small counter actuator arm, which causes the counter to register each time the metering rod strikes the arm.

Having described the invention in connection with certain specific embodiments thereof, it is to be understood that further modifications may now suggest themselves to those skilled in the art and it is intended to cover such modifications as fall within the scope of the appended claims.

What I claim is:

1. In a system for rolling a pipe section from a sheet having lead and trailing edges performed to interlock one with the other, the combination which comprises:

(a) an upper and a lower roller, said upper roller and said lower roller having an annular rib and groove portion adjacent to one end for working a rib into said sheet,

(b) a forming roller on the back side of the upper and lower rollers for determining the curvature of said 9 said sheet, said forming roller being spaced a diflerent distance from the ends of said rollers adjacent to said annular rib and groove portion than from the other end of said rollers,

() means for elevating and lowering one of said rollers to permit said sheet to be inserted between said rollers from the front, and

(d) a drive means operatively linked to said upper and lower rollers to drive said sheet past said forming roller.

2. In a system for rolling a pipe section from a sheet having lead and trailing edges preformed to interlock one with the other, the combination which comprises:

(a) a pair of drive rollers positioned one above the other to define a top and a bottom roller,

(b) means for elevating and lowering the top roller to permit said sheet to be inserted between said rollers, said top roller and said bottom roller having mating annular rib and groove portions adjacent to one end of said pair for working a rib into said sheet and having mating fluted portions extending between said rib and said end of said pair for corrugating the portion of said sheet beyond said rib, and

(c) a forming roller behind said pair of rollers for determining the curvature of said sheet, said forming roller being spaced farther from the fluted ends of said pair than from the other end thereof.

3. A system for rolling a sheet having opposite lead and trailing edges formed for interlocking, which comprises:

(a) a table having stop means thereon against which one of said edges abuts,

(b) a pair of rollers positioned one above the other to define an upper roller and a lower roller respectively, said rollers being generally tangent to the plane of said table at a distance from said stop means slightly less than the width of said sheet,

(c) means for elevating to an upper position and lower ing to a forming position said upper roller to permit said sheet to be inserted between said rollers, said upper roller and said lower roller having an annular rib and groove portion adjacent to one end for working a rib into said sheet and having male and female fluted portions extending between said rib and groove portion and said end of said rollers for fluting the portion of said sheet beyond said rib,

(d) a forming roller on the side of said pair of rollers for determining the curvature of said sheet, said forming roller being spaced a diiferent distance from the fluted ends of said rollers than from the other end of said rollers,

(e) a drive means, i

(f) a chain belt linked to said upper roller and said lower roller and to said drive means,

(g) a resiliently positioned follower for engaging said chain link belt between said drive means and the upper roller to permit said upper roller to be elevated and lowered while maintaining registration between said male and female fluted portions,

(h) a timing rod mounted for translation adjacent the end of said table opposite said belt,

(i) a timing wheel mounted for movement with said upper roller to engage said timing rod when said upper roller is in its lower position, and

(j) control means at a predetermined point in the path of said timing rod for activating said means for elevating said upper roller to an upper position a predetermined distance before the trailing edge of said sheet reaches said rollers.

4. A system for rolling a sheet having opposite lead and trailing edges, which comprises:

(a)'a pair of elongated rollers having mating male and female forming portions thereon adjacent one end and central roller portions,

(b) drive means for said rollers,

(c) an elongated forming roller behind said pair of rollers, said forming roller being positioned farther from said pair of rollers adjacent said one end than from said central roller portion,

(d) means for moving said rollers apart and together,

(e) first control means to actuate said means for moving said rollers together, and

(f) second control means responsive to a predetermined position of a sheet in between said rollers to actuate said means for moving said rollers apart. 5. A pipe forming machine for rolling and working pipe from a metal sheet having a lead and a trailing edge comprising:

(a) a crown roller having flute-forming portions and an annular rib adjacent one end, said roller being carried by vertically movable bearing means at either end thereof,

(b) a base roller lying below said crown roller and having flute-forming portions which are adapted to mate with the flute-forming portions on said crown roller and having an annular groove which is adapted to mate with said annular rib on said crown roller,

(c) a forming roller disposed behind said crown roller and base roller, said forming roller being spaced farther from said crown roller and base roller in the proximity of said flute-forming portions and said annular rib and said annular groove than for the balance of the length of said crown roller and base roller,

((1) means mounting said vertically movable bearing means for vertical movement,

(e) force application means for moving said vertically movable bearing means upward from a normal position in which said vertically movable bearing means rotatably hold said crown roller close to said base roller to a raised position in which said crown roller is separated from said base roller to permit the insertion of work between said crown roller and base roller,

(f) drive means for said crown roller and base roller,

and

(g) means for actuating said force application means (g) Means for actuating said force application means to raise said crown roller to the upper position at a predetermined distance before the trailing edge of a sheet being formed by said machine passes between said crown roller and base roller.

6. The pipe rolling machine of claim 5 in which said means for actuating said force application means comprises:

(a) a frictional wheel extending from said crown roller,

(b) a timing rod engaged by said frictional wheel when the crown roller is in the lower position, and

(c) an actuator located at a predetermined position in the path of said timing rod.

References Cited by the Examiner UNITED STATES PATENTS 49,045 7/ 1865 Valentine et a1 72-171 543,971 8/1895 Stoll 7230 947,291 1/ 1910 Berghausen 72--168 FOREIGN PATENTS 960,708 6/ 1964 Great Britain.

CHARLES W. LANHAM, Primary Examiner.

L. A. LARSON, Assistant Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,319,445 May 16, 1967 James E. Stalker It is certified that error appears in the above identified patent and that said Letters Patent are hereby corrected as shown below:

Column 3, line 49, for "tthe" read the column 4, line 48, for "outwardy" read outwardly line 64, before bearing" insert suitable column 5, line 3, for "rolled" read roller column 7, line 24, for "underseide" read H underside line 54, for "cyinders" read cylinders column 8, lines 33 and 34, strike out "This curvature of the work passing through the machine."; line 51, for "experiency" read expediency line 68, for "performed" read preformed line 75, strike out "said"; column 10, line 46,

strike out "(g) Means for actuating said force application means".

Signed and sealed this 22nd day of July 1969. (SEAL) Attest: Edward M. Fletcher, 11. JR.

Attesting Officer Commissioner of Patents

Claims (1)

1. IN A SYSTEM FOR ROLLING A PIPE SECTION FROM A SHEET HAVING LEAD AND TRAILING EDGES PERFORMED TO INTERLOCK ONE WITH THE OTHER, THE COMBINATION WHICH COMPRISES: (A) AN UPPER AND A LOWER ROLLER, SAID UPPER ROLLER AND SAID LOWER ROLLER HAVING AN ANNULAR RIB AND GROOVE PORTION ADJACENT TO ONE END FOR WORKING A RIB INTO SAID SHEET, (B) A FORMING ROLLER ON THE BACK SIDE OF THE UPPER AND LOWER ROLLERS FOR DETERMINING THE CURVATURE OF SAID SAID SHEET, SAID FORMING ROLLER BEING SPACED A DIFFERENT DISTANCE FROM THE ENDS OF SAID ROLLERS ADJACENT TO SAID ANNULAR RIB AND GROOVE PORTION THAN FROM THE OTHER END OF SAID ROLLERS, (C) MEANS FOR ELEVATING AND LOWERING ONE OF SAID ROLLERS TO PERMIT SAID SHEET TO BE INSERTED BETWEEN SAID ROLLERS FROM THE FRONT, AND (D) A DRIVE MEANS OPERATIVELY LINKED TO SAID UPPER AND LOWER ROLLERS TO DRIVE SAID SHEET PAST SAID FORMING ROLLER.

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