US2451635A - Apparatus for treating tubular bodies - Google Patents

Description

AIPAmvrUsv Fon TREATING TUBULAR BODIES Patented Oct. 19, 1948 OFFICE APPARATUS Fon TREA'rING 'rUBULAR BODIES Frank A. Schratt, Cincinnati, Ohio;

Application May 5, 1945, Serial No. 592,203

4 Claims.

The present invention relates to apparatus for treating cylindrical and tubular bodies and has for an object the provision of a simple and sturdy mechanism whereby the inside and outside surfaces of tubular bodies, or either of such surfaces may be uniformly treated to the action of fluid pressure nozzles for such purposes as sand blasting in order to clean, abrade, or etch the said surface o-r surfaces or for otherwise treating the same.

A further object of the invention is to provide apparatus that is simple and inexpensive to operate and entirely reliable Iand accurate in its operation.

A still further object of the invention is to provide apparatus of this character which automatically correlates combined rotation and longitudinal movement of the body thereby acted upon.

Another object o-f the invention is to provide a safe and simple apparatus for the removal of deposits from the surfaces of metal tubes after heat treatment thereof.

These and other objects are attained by the means described herein and exemplified in the accompanying drawings, in which;

Fig. l is a side elevational view showing apparatus embodying the invention, the wall of the dust chamber being cut away and shown in crosssection, and the pneumatic control mechanism being shown diagrammatically.

Fig. 2 is a top plan View of the apparatus of Fig.,1, the dust chamber being cut away and shown in cross-section and the pneumatic control being omitted.

Fig. 3 is a cross-sectional view taken on line 3-3 of Fig. 1, but showing a tube to be blasted in position on the carriage and also showing the nozzles adjusted for simultaneously sand blasting the inside and outside surfaces.

Fig. 4 is an end elevational view of the dust chamber of Figs. 1 3 showing the pneumatic control mounted thereon.

Fig. 5 is a longitudinal, cross-sectional view of a blast nozzle of the apparatus of the invention.

Fig. 6 is an end elevational view ofa uniformly adjustable nozzle-holding bracket forming ay detail of the invention.

Fig. '1 is a side elevational View of the device of Fig. 6.

Heretofore numerous diiculties have presented themselves in the treatment of the surfaces of cylindrical and tubular bodies, amongst these being the time required for mounting of such bodies for rotation about the axis thereof and the provision for the movement of a suitable tool in a relatively axial direction. As a specific example of a particularly difcult task the apparatus of the invention is herein exemplified in an arrangement for removing the very hard carbon deposits from lengths of previously heat treated vsteel tubing of comparatively small inside diameter. In general, the invention consists in providing a work holding truck I0 and a power truck Il both tractionally mounted on continuous straight tracks I2 and connected together for uniform travel in spaced relation by a tie rod I3 which is slightly longer than the tube or cylinder I4 to be operated upon. The trucks I0 and II are provided with grooved wheels I5 to insure rectilinear motion on the tracks I2. Substantially one-half the length of the tracks I2 is located within a dust chamber I6 of approved construction and arranged with vents I1 near the bottom thereof which are connected to a suitable air exhaust system I8. The end wall I9 of dust chamber I6 has a suitable packing gland 20 through which the tie rod I3 may pass without permitting the escape of dust or airborne material from chamber I6. The tie rod I3 is bolted or otherwise secured at its opposite ends to crossmembers 2| and 22 of trucks I0 and II respectively. Rigidly mounted intermediate tracks I2, exteriorly of and adjacent the end wall I9 is an air cylinder 23 which has its axis in a common vertical plane with the tie rod I3. Within cylinder 23 is a piston 24 to which is connected a piston rod 25 whichextends beneath and beyond the truck II. The piston rod 25 has on its extreme louter end an upturned, U-shaped member 26 which is rigidly connected in substantial alignment with the tie rod I3 by bolting or otherwise fastening it to a cross member 21 of truck I I. As

`the piston 24 reciprocates in the cylinder 23, the

truck II moves from the position shown in Fig. 1 to a position over the cylinder 23during which time the tie rod I3 pushes the truck or work carriage I0 away from the wall I9 to approximately the opposite end of chamber I6.

Mounted on truck II is an electric motor 28 which drives a variable speed reducer mechanism 29 of any suitable design from which operates a second speed reducer 3l). A shaft 3| is thus rotatable at a predetermined selected speed. The shaft 3| has a coupling 32 thereon which connects with coupling 33 on a shaft 34. Shaft 34 passes through end wall I3 of chamber I6 and is surrounded by another dust tight packing gland 20. Interiorly of chamber I3, shaft 34 is connected to the end of a short projecting shaft Y35 of a roller 36 by means of a coupling indicated generally at 31. Roller 36 is mounted for axial rotation on the work carriage IB and a freely rotating companion roller 38 is journaled in spaced parallelism thereto upon carriage Ill. The tube or work piece I4 to be abraded, cleaned or otherwise treated is supported on and disposed between power roller 36 and free roller 38 and has tangential contact therewith throughout the length thereof.

From the foregoing it will be apparent that with a tube or cylinder I4 resting on the rollers, power rotation of roller 36 from motor 28 will re- Vsult in a rotation of the work I4 about its own longitudinal axis while recipreeation of truck II will move the work carriage I0 along the tracks I2 to eiect longitudinal recprocation of the work in the direction of its longitudinal axis. The arrangement in Figs. 1, 2 and 3 provides for the simultaneous treatment, i. e. sand blasting of the inside and outside surfaces of a tubular body. For blasting the inside surface of the tube, a straight, rigid pipe 39 with a blast nozzle 40 on the end thereof is clamped adjacent its opposite end in a collar 4I on an adjustable bracket 42 which is in turn rigidly and adjustably mounted on a truss 43, the base 44 of which is desirably bolted or otherwise secured to tracks I2. The bracket (see Fig. 6) may have elongated bolting slots 45 therein to provide a desired degree of elevational adjustment of the pipe 39, A sand blast hose 46 is adapted to be connected at its one end to any suitable source of abrasive and pressure air (not shown) while the opposite end enters chamber I6 and is connected to the end of pipe 39 which projects through collar 4I. By the hereinbefore described arrangement it is possible to remove deposits or material from the inside surface of a tube such as I4, the inside diameter of which is notgreatly in excess of the diameter of the nozzle on the pipe. A very accurate degree of deposit or material removal is attained by adjusting the rotational speed of shaft 34 and the rate of longitudinal travel of the piston 24 in cylinder 23. The rotary speed adjustment is effected by shifting the manual lever 4l of the conventional Variable speed reducer 29. The adjustment of the longitudinal travel of work carriage I0 is effected by regulating the speed of piston travel, particularly during the cutting or blasting movement of the tube I4.

It is desirable for expediting the work to `arrange for rapid return or withdrawal of the tube from over the nozzle 40' to permit the finished work to be removed and replaced with another piece in a minimum of time after the blasting operation is complete. This requires that the movement of piston 24 from the piston shown at the right-hand end of cylinder 23 to the opposite end of the cylinder be made slow and that the return movement shall be quite rapid but without undue impact. This is conveniently arranged for by utilizing an adjustable pneumatic control as shown-for example in United States Patent Nos. 840,876 and 840, 877 and indicated .diagrammatically at 48. According to the present arrangement of said prior patented control the cylinder 23 is secured horizontally and its piston rod 25 Y reciprocates in parallelism with tracks I2, An air pressure supply line 49 connects with a Valve 50 operable by lever 5I to connect supply line 49 with the pipe 52 which leads to the left-hand end of cylinder 23, while pipe 53, leading to the righthand .end of the cylinder is closed off from the pressure supply pipe 49 but is vented to the atmosphere. As shown in Fig. 1 the lever 5I is set in reverse position and the truck II has just completed its movement to the right-hand limit. The pipes 52 and 53 serve alternately as supply and exhaust pipes in the pneumatic control of the reciprocating movement. Pipe 52 has a pair of Oneway by-pass valves 54 and 55 controlling the flow of pressure and exhaust air in opposite directions therethrough. Pipe 52 has a similar set of adjustable Oneway, by-pass valves 56 and 51.

When the apparatus is to be operated, a tube such as I4 is placed on rollers 36 and 38 Wl'ilGh serve to automatically center the work between them. The bracket 42 is now adjusted vertically and laterally until the nozzle 4I) will be received by the hollow interior of the tube when the tube `is reciprocated. It is preferred that the nozzle be disposed eccentrically of the tube as shown, for example, in Fig. 3. During the adjustment of the apparatus lever 5I is left in a vertical or neutra position wherein pressure from pipe 49 `is completely closed off from both of the pipes 52 and 53. Operation is begun by energizing motor 28 which serves to drive roller 36 in a clockwise direction as viewed in Fig. 3 whereupon the tube i4 is caused to rotate in a `counterclockwise direction and this in turn causes the supporting freely rotatable roller 38 to turn inthe same direction as the power roller 36. The sand blast apparatus (not shown) is now turned on to supply an abrasive blast through hose 46 and nozzle 40 and the lever 5I is moved to the forward position as shown in dotted lines in Fig. 1 whereupon power truck II and work Icarriage I0 are slowly moved toward the left while the work is rotated on its axis as it is moved. 'Ihe blast from the nozzle 40 thus traces a very close pitched spiral of sand 'blast upon the inside of tube I4 generally comparable to an interior, material removing cut of a tool in a lathe. The `adjustable valves 55 an-d 55 are regulated so that the incom-v ing pressure air through pipe 53 entering behind the piston and the exhaust air passing from the .front of the piston through pipe 52 to the atmosphere, may travel at substantially uniform slow rate. When the truck II has reached the limit of movement and the tube `I4 has passed completely over the nozzle 40, piston 24 has expended its slow power stroke and an adjustable Vstop 58 on the tie rod is ready to engage the wall I9. The lever 5I is now thrown manually or otherwise to the position shown in full lines in Fig. 1 whereupon the pressure air, as regulated by adjusting valve 54, passes at a 'higher rate through pipe 52 and is exhausted at a comparable rate from the opposite end of the cylinder through pipe 53 and the regulator valve 5l. This operation rapidly moves carriage II) to the position shown in Fig. l and withdraws the tube from over nozzle 4U. At this instant lever 5I is moved to an intermediate or neutral position to shut oi the longitudinal movement of the carriage by the piston.

The removal of stubborn and hard deposits from the interior of relatively small tubes has been a very diilicult task when convention boring apparatus has been used. The present apparatus is thus highly advantageous for this type of operation since there is no difflcultly used tool in danger of becoming rapidly dull and frequently broken. The blast abrasive and the material removed is forced through the tube and allowed to fall from the trailing end thereof.

It is frequently desired to remove carbon deposits or the like from both outside and inside surfaces of a tube, and this is accomplished sil multaneously by utilizing the nozzle 40 as afore- .described and providing a bracket 42 as shown in Fig. 6 on the side wall of chamber I 6 and securing a sand blast pipe 58 with a blast nozzlel yfrom nozzle 40 will not meet or play upon the bodies of the nozzles when no work intervenes in the paths of the abrasive blasts.

Any suitable means may be provided for automatically shutting off the power to motor 23 when power truck ll reaches the end of its return travel against stops 6|. For example, an electric limit switch 62 may be connected into the power cable circuit 63 and mounted on one of the stops 6| for actuation by the return movement of truck Il.

The apparatus as previously indicated may be utilized for a variety of operations e. g. for etching or sand blasting the interior surface of a tube of` metal, glass or other material. By adjusting the return of longitudinal feed to a greater or lesser speed and also by adjusting the rotational speed it is possible to effect a greater or lesser degree of material or deposit removal; or if desired, to produce a distinct etched spiral on either inside or outside surfaces of the tube. ting off the longitudinal feed and utilizing the rotational drive, band-like areas may be sand blasted to the exclusion of adjacent parts. By deenergizing motor 28 and utilizing the pneumatic reciprocating mechanism only, a straight longitudinal sand blast strip may be produced upon the inside or outside surface of a tube. In any event, the apparatus when properly adjusted can be relied upon to perform uniformly identical operations upon a series of similar tubes or cylinders. l.

Access to the chamber i 6 may be through a suitable door such as 64 placed at any convenient location in the chamber.

In order to baille and deflect the velocity sand blast, spray or other medium which is discharged from nozzle oran equivalent element, a sheet metal deector such as 65 is suitably secured to the work carriage I 0.

While the apparatus and method has been herein described in connection with sand blasting .f

as a specific operation, it is to be understood that other surface treatment operations may be performed on tubular or cylindrical bodies by utilizing any other type of spray, brush or applicator instrumentality in lieu of the sand blast. It will also be understood that one or more nozzles, sprays, applicators, or the like, of the same or different character may be grouped and mounted with relation to nozzles 40 and 59 or their equivalents so as to effect one type of surface treatment operation on the surface of the tube in advance of another and thus complete several operations on a given surface of a tube or cylinder in a single cycle of movement thereof.

What is claimed is:

1. Apparatus of the class described comprising supporting track members, a power truck supported on said track members, a work carriage supported on said track members, a tie rod connecting said truck and carriage and retaining them in predetermined spaced relation, rotary power means carried by the power truck, a pair of spaced apart rollers journaled on the carriage and arranged for constant parallel relation with each other and with said tracks, a power shaft connected at its opposite ends to the power means and one of said rollers, means for reciprocating the said truck and carriage at predetermined rates of speed along said track members, a first sand blast pipe, means for supporting said pipe in adjusted positions with relation to the ends of the rollers and parallel thereto, a second sand blast pipe and means for supporting said second sand blast pipe with its discharge in predeter- By shutmined relation to the corresponding end of the iirst mentioned sand blast pipe.

2. Apparatus of the class described comprising a pair of parallel track elements, a dust chamber surrounding a portion of said tracks at one end, a work carriage tractionally supported on said tracks within the dust chamber, a power truck tractionally supported on said tracks exteri-orly of 'the chamber, a tie rod passing slidably through th-e w-all of the dust chamber and rigidly connecting said work carriage and said truck in spa-.ced relation, variable speed power means mounted on the truck, a pair of rollers mounted in spaced side by side relation upon the work carriage in parallelism with the tracks, a drive shaft passing through the wall Iof the dust -chamber and rotatably connecting one 4of said rollers with said power means, means disposed exteriorly `of the chamber for reciprocating said truck and carriage in unison along said :track members, and means including a sand blast nozzle and :an adjustable support therefor for xedly holding said nozzle in predetermined relation to the truck for operating on a body supported on said rollers on said work carriage.

3. In combination a pair of parallel track members, a power truck tractionally supported thereon, a pneumatic -cylinder rigidly mounted between the tracks and having a piston reciprocable in 'the cylinder, an extended piston rod on said piston and connected to said truck, Va tractionally supported work carri-age connec-ted in spa-ced relation to said truck for moving in unison therewith under the action of the piston in the cylinder, a pair of n-oncontacting work support rollers on said carri-age; means for driving one of said rollers at a selected speed and means for xedly mounting a surface treatment instrumentality in predetermined relation .with respect to the path of travel of a body supported yon said rollers.

4. In combination a pair of parallel track members, a power truck tractionally supported thereon, a Ipneumatic ycylinder rigidly mounted between the tracks and having a piston reciprocable in the cylinder, an extended piston rod on said piston and connected to said truck, a tractonally supported work carriage on said track, transund-er the action of the piston in the cylinder,

tube supporting rollers on said carriage, power means on said power truck, a rotatable connection from said power means on said truck extending in dust tight relation through said barrier and connecting with one of the tube supporting rollers, yand means for xedly mounting a surface treatment instrumentality with respect to the path of travel of a tube supported on said rollers. K

FRANK A. SCI-TRATT.

REFERENCES CITED The following references are of record in the Number Number

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