US2715235A

US2715235A - Pipe cleaning machine adjustable for pipe size as to tool speed, angle, and pressure

Info

Publication number: US2715235A
Application number: US90253A
Authority: US
Inventors: Robert A J Dawson
Original assignee: Individual
Current assignee: Individual
Priority date: 1949-04-28
Filing date: 1949-04-28
Publication date: 1955-08-16
Anticipated expiration: 1972-08-16

Description

Aug. 16, 1955 R. A. J. DAWSON 2,715,235

PIPE CLEANING MACHINE ADJUSTABLE FOR PIPE SIZE AS TO TOOL SPEED, ANGLE, AND PRESSURE Filed April 28, 1949 5 Sheets-Sheet l r :1 In v m o I N I In 1' 1 v Q I 55 m m c: a i 0 k2 n a N Lb m m S :9, g m

I I H I .Q I I I I N 3 I I I I O I t n I i INVENTOR:

ROBERT A. J DAWSON 8Y7? a a.

ATTORNEY Aug. 16, 1955 R. A. J. DAWSON 2,715,235

PIPE CLEANING MACHINE ADJUSTABLE FOR PIPE SIZE AS TO TOOL SPEED, ANGLE, AND PRESSURE Filed April 28, 1949 5 Sheets-Sheet 2 INVENTOR:

ROBERT A. J. DAWSON ATTORNEY 16, 1955 R. A. J. DAWSON PIPE CLEANING MACHINE ADJUSTABLE FOR PIPE SIZE AS TO TOOL SPEED, ANGLE, AND PRESSURE Filed April 28, 1949 5 Sheets-Sheet 3 INVENTOR:

ROBERT A..J. DAWSON ATTORNEY Aug. 16, 1955 PIPE CLEANING MA i\ 57 so 64 63 59 R. A. J. DAWSON CHINE ADJUSTABLE FOR PIPE SIZE AS TO TOOL SPEED, ANGLE, AND PRESSURE Filed April 28, 1949 IOI 5 Sheets-Sheet 4 FIG. 4

IN VEN TOR.

ROBERT A J DAWSON ATTORNEY Aug. 16, 1955 R. A. J. DAWSON 2,715,235

PIPE CLEANING MACHINE ADJUSTABLE FOR PIPE SIZE AS TO TOOL SPEED, ANGLE, AND PRESSURE Filed April 28, 1949 5 Sheets-Sheet s INVENTOR.

ROBERT A. J. DAWSON ATTORNEY PIPE CLEANING MACIEJE ADJUSTABLE FOR PIPE SIZE AS TO T001. SPEED, ANGLE, AND PRESSURE Robert A. J. Dawson, Houston, Tex.

Application April 28, 1949, Serial No. 90,253

16 Claims. (Cl. 15-1(l4.04)

This invention pertains to pipe cleaning machines of 1 the general type shown, for example, in United States Patent 1,611,920, granted December 28, 1926, to Frank Kinzbach. More particularly, the invention pertains to a tool carriage assembly for this type of machine. Some of the advantages of the invention can best be set forth by comparison with known machines of this type, the structure and operation of which will first be described briefly, followed by a statement of the difiiculties encountered therewith.

In pipe cleaning machines of the aforementioned type as represented by machines currently in use, the tool carriage assembly comprises an annular support ring adapted to be placed around the pipe to be cleaned. The ring is rotatably mounted in a suitable bearing annulus and includes an annular drive sprocket connected to a drive motor. A number of rods are supported in holes in the ring and disposed with their axes parallel to the pipe and equally spaced around it. These rods support a plurality of rocker arms, each of which carries a cleaning tool at one end. A spring means for urging or biasing the tool toward the pipe is disposed between the other end of each rocker arm and some part of the adjacent rocker arm.

The spring biasing means also serves to take up for wear of the tool and in addition can be adjusted to care for minor variations in pipe diameter. It cannot be used to adjust for substantial changes in pipe diameter, however, because the angle between the cleaning tools and the pipe would be changed so much that the tools would not function properly. For substantial'adjustments' it is necessary to change the position of the rods in the support ring.

Rod adjustment is usually provided for by making the support ring with a plurality of sets of'holes, each set at a different radial distance from the ring axis. Since the support ring must fit over the largest size pipe with sufficient clearance to pass around bends in the pipe, the minimum inside diameter of the ring is fixed relative to the diameter of the largest pipe to be cleaned therewith. This places a limit on the minimum radial spacing of the rods and hence on the smallest size pipe that can be cleaned with a given support ring. To adapt to smaller sizes of pipe it has been the practice to bolt annular adapter plates to the support ring, the plates having sets of holes for holding the rods.

When it is desired to change the rod positions, it is necessary that all of the rods together with the rocker arms and tools mounted thereon be entirely removed from one set of holes and replaced in another. This is a long and tedious task. Some relief from this difliculty in changing rod positions has been afforded by the use of slotted plates fastened to the support ring. The rods are held in the slots and can be adjusted in position without removal. However, the possible range of adjustment in such slots is limited, as will appear hereinafter.

Because of the interconnection of each rocker arm with the adjacent rocker arms through the spring biasing means,

each rocker arm and the adjacent spring may be C011? sidered to be a chord of the rod circle of the support ring This chord length is nearly fixed so that there is a definite relation between the number of rods used and their radial. distance from the axis of the support ring. An adjustment of the radial position of the rods to care for a major change in pipe diameter, say of the order of a 70 per cent reduction, must be accomplished by a change in the number of rods used. More rods are required for large diameter pipes and fewer rods for smaller pipes in order that the spacing between adjacent rods be maintained within. the permissible range for proper functioning of the rocker arms and their biasing means. A diiferent number of equally spaced rods requires a different configuration. of the support ring holes so that these holes cannot all be placed in radial alignment. This limits the range of adjustment in slots to the range in which no change. in. number of rods is required.

Another difiiculty with the present day tool carriages that is also caused by the spring biasing means lies inthe fact that adjustment of the spring tension on one rocker arm affects that on the adjacent arm because the adjacent arm serves also as a support for the spring biasing means; of the first arm. Therefore, any adjustment of the pressure of one tool on the pipe to be cleaned changes the pressure of all the other tools in the same set, a set meaning all tools in the same plane perpendicular to the pipe axis. Adjusting tool pressure is thus reduced to a never ending process of trial and error. This time consuming process of interrelated tool adjustment is appropriately termed crabbing down. Furthermore, if one tool should break or become inactive while the machine is in operation, it changes the pressures on all the other tools in the set so that they too are rendered wholly or in part inoperative. When it is desired to free the tools from the pipe, a long reverse crabbing up process is required.

Other troubles caused by the springs interconnecting the tools are the inability to remove and replace a single tool. particularly a tool near the support ring, without disturbing all or most of the other tools; necessity for special crabbing wrenches to adjust inaccessible fastening bolts and adjusting nuts; and clogging up of the tool carriage with paper, felt, dirt and other debris removed by the cleaning tools.

An important factor in a pipe cleaning machine of the type herein considered is its center of gravity. The drive motor for the machine is necessarily disposed above, the pipe to be cleaned in order to clear obstructions. It is desirable to mount the motor as low as possible.

The limiting factor is the clearance between the crank case pan of the motor and the outer periphery of the path of the tool carriage assembly. Here again difliculty is encountered because of the spring biasing means, the yokes of which extend beyond the outer edge of the support ring. Furthermore, the radially protruding yokes are subject to high centrifugal forces which limits the speed of rotation and increases the vibration. Also,

in case of breakage of the springs they are free to flyby the space needed for the supports therefor, including the rods and spring biasing means. In machines as presently constructed it is the'spring biasing means that takes.

up most of the space.

A further problem pertaining to the tool carriage as The number of tools that can be used in any one plane around the pipe is limited' sembly of such machines involves the drive means therefor. It has been mentioned hereinbefore that to adapt the tool carriage ring to small diameter pipes it has been the practice to bolt adapter plates to the ring. While this serves the purpose of providing support for the rods, such that the rocker arms and tools can be placed at the correct angle for proper functioning of the tools, it causes a reduction in the linear speed of the cleaning tools relative to the periphery of the pipe for any given speed of the drive motor. This inherent defect has not been given any attention prior to this invention, since it was not previously recognized that there is a definite tool speed corresponding to maximum efliciency of pipe cleaning. With this fact in mind, however, the magnitude of the defect is readily shown. A single pipe cleaning machine may be used to clean pipe varying in size all the way from fourteen inches in diameter down to three-quarters of an inch. For a given angular speed of the tool carriage and taking the linear tool speed on the fourteen-inch pipe as 100 per cent speed, the linear tool speed on the three-quarter-inch pipe will be less than 6 per cent.

With the foregoing difiiculties, limitations, and defects of the prior art apparatus in mind, it may be said that the general object of this invention is to improve such equipment so as to overcome these troubles. Some of the more specific objects of the invention are as follows:

First, it is an object of this invention to provide a tool carriage assembly which can be easily and quickly adjusted to pipes of all different sizes, both as to tool angle and linear tool speed.

Second, it is an object of the invention to provide a tool carriage assembly in which all the individual tool pressures can be easily, quickly, and independently adjusted.

Third, it is an object of the invention to provide a tool carriage assembly in which each individual tool can be removed and replaced with a minimum of effort.

Fourth, it is an object of the invention to provide a tool carriage assembly in which failure of one tool during operation will not require stopping of the machine and will not cause danger to the operator from flying parts.

A further object of the invention is to provide a tool carriage assembly which will allow the center of gravity of the machine to be as low as possible.

Another object of the invention is to provide a tool carriage assembly adapted to carry a maximum number of tools.

Still another object of the invention is to provide a tool carriage assembly for a pipe cleaning machine that will be strong and durable, eflicient and reliable in operation, and inexpensive to construct, operate, maintain, and repalr.

Briefly, the invention comprises a tool carriage assembly including a plurality of separate support rings, each having the same outside diameter, so as to fit in the same bearing annulus, but each having a different inner diameter adapted for a different range of pipe sizes. Each ring also has a different size drive sprocket appropriate to the particular range of pipe size so as to give proper linear tool speed. Each ring has a set of slots therein in which are adjustably mounted a set of rods. Rocker arms are pivotally mounted on each rod. There are torsion springs around the rods, each fixed at one end to the associated rocker arm and at its other end to a ratchet. Each torsion spring provides a means for biasing or pressing against the pipe the rocker arm and tool held thereon that is completely independent of the biasing means for the other tools. Since the springs are disposed around the rods they will not fly off even if they break. The ratchet provides an independent and easily operated means for adjusting the tool pressure. The independent spring biasing means permit the rods to be adjusted radially in the slotted support ring over the full range of pipe sizes within the range of the particular support range without changing the number of rods and hence without having to remove and replace them. The tool angle can at all times be maintained at the value corresponding to most efficient tool operation. When it is necessary to replace a tool, only the tools on the one rod outside of the one tool need be disturbed. There is a free space between each rod and the adjacent rod through which paper, felt, and other debris can be thrown out free of the machine. When adjustment is required for a major change of pipe size, it is made by substituting a different support ring which automatically changes the drive gear ratio so as to maintain efiicient linear tool speed.

Other objects and advantages of the invention will become apparent from the following detailed description of a preferred embodiment thereof, in which:

Figure l is a side elevation, partly schematic, showing a pipe cleaning machine of the type hereinabove referred to, the tool carriage being undressed, that is, without any tools or rocker arms or spring biasing means mounted on the rods in the support ring.

Figure 2 is a front elevation of the bearing annulus and a support ring adapted for the smaller pipe sizes, for example, in the range A to 8" O. D., showing the slots in the ring for adjustably supporting the rods.

Figure 3 is a perspective view of a support ring adapted for larger sizes of pipe in the range 6" to 14" O. D.

Figure 4 is a diametrical section through a portion of the tool carriage along the axis of one of the rods and showing the support ring, the rods, rocker arms, torsion springs, ratchets, and tools mounted thereon, and the end ring for stabilizing the rods.

Figure 5 is a sectional view of a tool carriage taken along the line 5-5 of Figure 4 showing the independent disposition of the rods, rocker arms, and tools around a pipe to be cleaned.

Referring to Figure 1, there is shown the general outline of a pipe cleaning machine comprising a supporting frame 11 having four legs depending therefrom such as those shown at 12 and 13 within which are pivotally mounted crawler wheels such as those shown at 14 and 15. Disposed on top of the supporting frame 11 is a suitable source of motive power such as a gasoline engine indicated generally on the drawing at 16.

Referring now to both Figures 1 and 2, depending from the supporting frame 11 is a bearing annulus indicated generally at 17. The upper portion of the bearing annulus comprises two plates 18 and 19 fastened to the underside of the supporting frame 11 and held apart in fixed spaced relation by spacing rods not shown. The lower half of the bearing annulus comprises a similar pair of plates 20 and 21, also held together by spacing rods not shown. The upper and lower portions of the bearing annulus are hinged together at one side at 22 and releasably fastened together at the other side by means of bolts as shown at 23. The bearing annulus carries a plurality of rollers such as those shown at 24, 25, and 26. The rollers are rotatably mounted on shafts such as those shown at 27, 28, and 29, extending between the plates thereof. Each roller is provided with a pair of annular flanges such as those shown at 30 and 31 on roller 26.

. Reference will now be made to Figure 3, as well as Figures 1 and 2. Since the support ring of Figure 3 differs from that of Figures 1 and 2 only as to dimensions, like parts have been given like reference numbers. Within the bearing annulus there is provided a support ringindicated generally on the drawing by the reference character 32. The support ring is made up of an upper pair of semi-circular plates 33 and a lower pair of semicircular plates 34. The inner edges of the plates forming the support ring are welded to two semi-circular hoop-shaped

plates

35 and 36. The upper and lower portions of the ring are pivotally connected together at one side and releasably fastened together at the other bysuitable means as indicatedat 37 and-38 (not shown in Figure 1).

Each of the plates forming the support ring is provided with an exterior annular flange such as that indicated at 39 on plate 33. These flanges extend outside the flanges and 31 on the rollers of the bearing annulus, thereby holding the support ring in correct axial alignment with the bearing annulus. In between the flanges 39 the outer edges of the plates forming the support ring provide tracks which ride on the flanges 3G and 31 of the rollers in the bearing annulus.

Held between the opposite plates of the support ring by spacers such as those shown at 40 and 41 are two semi-circular

sprocket wheel segments

42 and 43. The diameter of the sprocket wheel is smaller than that of the roller track. A drive chain 44 passes over the two halves of the sprocket wheel in the support ring and over a drive sprocket at- 45 driven by the motor 16.

The supporting ring is provided with a plurality of axially extending rods such as those shown at 46 upon which tools may be'mounted. The rods are held in

slots

47, 48, 49, 5t 51, and 52 in the support ring.

Before the machine is placed in operation the support ring is fastened to the bearing annulus by a suitable means as shown at 53. Then the two halves of the hearing annulus and the support ring are disconnected at one side and allowed to pivot about the hinges connecting them together at the other side. After the bearing annulus and support ring have been opened, the machine may be placed in position upon a pipe such as that indicated in dashed lines on the drawing at 54 with the crawler wheels resting on the top surface of the pipe. tions of the bearing annulus and support ring may then be connected together, the fastening 53 removed, chain 44 trained over sprockets 42-43 and 45, and the machine is ready for operation; The motor 16 acting through the drive sprocket 45, drive chain 44, and the sprocket wheel formed by

segments

42 and 43 in the support ring will cause the support ring to be rotated about the pipe while riding on the rollers of the bearing annulus, The motor may also be connected to the crawler wheels to advance the whole machine along the pipe.

Referring now to Figures 4 and 5 there is shown themanner of mounting the rods 46 on the support ring 32 1 Each rod comprises a cylinand the tools on the rods. drical shaft 57 having reduced threaded

portions

58 and 59 at its opposite ends. Between the threaded end 59 and the cylindrical center portion 57 there is a hexagonalnut portion 6 3 integral with the rod and of slightly greater minimum radius than portion57 so as to provide a shoulder stop for tool supports mounted on the shaft 57. The nut also serves as a wrench engaging member. 59 is passed through slot 51 in the support ring and heldin place by nut 62 and lock washers 63 and 64-.

Disposed along the shaft 57 are a plurality of similar tool supporting rocker arms such as that shown at 7%,-

bolted thereto at 78. For supporting and holding, other:

types of cleaning tools than knives, a slightly modified construction may be used, for example as shown thetongue' 79' and holder 81 for mounting brush 81.

To one side of each holder there is disposed a helical spring such as that shown at 89 coiled around shaft 57. One end. of the spring is held in a hole 90 in. the sleeve 71. The other end of the spring is held in a hole 91 in a ring 92 which is also rotatably and slidablyv mounted on shaft 57. The face of the end of the ring The sec-- The end 92 away'from the spring is provided with ratchet teeth;

93 which are in engagement with teeth 94 of a similar ring 95. Ring 95 is fixed on shaft 57 by means of a pin- 96 passing through holes in the ring and shaft. A cotter pin 97 holds the pin 96 in place.

Rings

93 and 95 may be made identical, each provided with six radial holes such as those shown at 98 which serve to receive the P111 96 of the fixed ring and into which a rod such as. that shown at 99 may be inserted for turning the rotatable ring.

The springs 89 act as torsion springs. When the ma-- chine is in place around a pipe 54 the tools can be pressed against the pipe by winding up the springs with the ratchets. This is done simply by putting the rod 99 into each rotatable ratchet ring and turning it with respect to the fixed ratchet ring in the proper direction.

ratchet faces of the rings in engagement so as to prevent the spring from unwinding. If too much spring pressure is produced it can be reduced by backing off the ratchet ring. This is done by holding the movable ratchet against turning by means of rod 99 While unpinning the fixed:

ratchet and then turning both through a half revolution or more in the opposite direction and repinning the fixed ratchet. If this reduces the spring bias too much it can be increased by turning the movable ratchet again. In the usual case, however, the operator will know exactly how many notches of the ratchet must be passed in winding up each spring to the desired amount.

The inside diameter of the unstressed springs must be larger than the outside diameter of the rods so that when the springs are wound up, either initially to produce tool pressure or while in operation due to catching of the.

tools, the springs will not bind on the rods. The coils of each spring must be separated slightly so that when placedin compression they will not bind on each other. spacing must not be too great, however, or the spring will tend to compress further axially on being wound up, first causing the ratchet to slip and finally allowing the ends of the spring to pop loose.

In order to stabilize the rods 4-6, their ends opposite to those held in the support ring 32 are held in an end ring 100. This ring is split diametrically in a manner similar to ring 32 so that it can be placed around the pipe without having to go over one end thereof. The halves are connected together in any suitable manner.

The end ring is provided with slots such as that shown at 101 corresponding. in number and radial extent to the.

slots 4752 in the support ring. The end 55 of rod 46 is held in'slot 101 by means of nut 192 and lock

washers

103 and 104 disposed respectively outside and inside the end ring.

Once the tools have been adjusted, if it is necessary temporarily to free them from the pipe the nuts on the ends of the rods can be loosened and the whole subassembly of rod and tools allowed to spin away from the pipe under the spring pressure. The lock washers which have teeth engaging the support ring and end ring keep the rods from slipping in the slots. When it is desired to put the tools back in operating position the whole group on the rod can be simultaneously turned with the rod to its original position and the nuts retightened, thus eliminating the need of any further adjustment. These rods and tool groups can also be treated as subassembly units in the original dressing of the tool carriage ring and in repair, replacement, and change of tools.

From the foregoing description of a preferred embodiment of the invention exemplifying one Way in which it can be carried out, it will be clear how the objects of the invention are attained. When it is desired to adjust the tool carriage assembly to a difierent size pipe the nuts on the ends of the rods are loosened and the rodsv moved in the slots of the support and stabilizing rings until in the desired position and the nuts are against tightened. In this way the tools are adjusted to the proper Eachspring is also in slight compression so that it keeps the The angle for the particular size of pipe. Within the limits of the particular support ring the linear tool speed can also be correctly adjusted by changing the speed of the drive motor. In case of a major change of pipe size a different support ring is substituted which not only permits proper tool angle adjustment, but also provides a change of gear ratio in the drive means to make possible correct linear tool speed adjustment. In addition to making correct tool speed adjustment possible and making correct tool angle adjustment easier, the invention also makes possible independent adjustment of tool pressures as is brought out most clearly by inspection of Figure which shows each tool to be entirely separate in any given plane perpendicular to the pipe axis. Figure 5 also shows that no part of the tool carriage assembly extends beyond the support ring so that the entire machine may have a low center of gravity.

While a preferred embodiment of the invention has been illustrated and described it is obvious that many modifications thereof can be made by one skilled in the art without departing from the spirit of the invention, and it is intended to protect by Letters Patent all forms of the invention falling within the scope of the following claims.

I claim:

1. A pipe cleaning machine including a pipe riding support, an annular bearing mounted thereon, and a tool carriage assembly, said assembly comprising an annular support ring rotatably mounted in said bearing and having a plurality of slots therein, a tool support rod for each slot adjustably mounted therein as to radial distance from the pipe to be cleaned, a tool holder rotatably mounted on each rod, and a torsion spring disposed about each rod anchored at one end and connected at the other end to the tool holder for urging it in a direction tending to move the active part of a tool held therein toward the pipe to be cleaned.

2. A tool carriage assembly for a pipe cleaning ma chine comprising a tool carriage ring, a tool support rod carried by the tool carriage ring and extending axially therefrom and held against rotation about its own axis with respect to said ring, a plurality of tool holders rotatably mounted on said rod for rotation in a plane per pendicular to the rod axis, and means to bias said tool holders toward the ring axis including a plurality of torsion springs disposed around said rod, each spring being operatively connected at one point to one of the tool holders and at another point to the rod, the con nection between each spring and the rod comprising a pair of ratchet faced discs, one of said discs being connected to the spring and the other having a plurality of spaced apertures therein, and a pin through one of said apertures adjustably securing the disc to the rod in desired position of angular adjustment relative to the rod axis.

3. A tool carriage assembly for a pipe cleaning ma chine comprising a tool carriage ring, said ring having a plurality of slots, the length of each slot extending from nearer the ring axis to farther therefrom, a plurality of tool support rods, means to mount said rods in the slots of the ring, said means being adjustable as to angular position of the rods about their own axes and as to radial distance of the rods from the ring axis, a too] holder rotatably mounted on each rod a torsion spring disposed around each rod operatively connected at one part to the rod and at another part to the tool holder for biasing the tool holding part of the tool holder radi ally inward toward the ring axis.

4. A pipe cleaning machine including a support, an annular bearing mounted thereon, a ring rotatably mounted in said bearing, said ring having a plurality of circum' ferentially spaced apertures therein, a plurality of rods, releasable means to fixedly mount each of said rods in one of said apertures, said releasable means preventing rotation of said rods about their own axes relative to said ring but being adjustable as to angular position of the rods about their own axes relative to said rings, a plurality of tool holders, means rotatably mounting each of said holders on one of said rods, a helical spring around each of said rods anchored at one end to the tool holder, a pair of ratchet faced rings disposed on each of said rods with said faces in juxtaposition, one of said rings being connected to the other end of the spring on the same rod, the other of said rings having a plurality of intersecting diametral holes extending entirely therethrough, a hole extending entirely through each of said rods perpendicular to the axis of the rod, and a quickly releasable pin extending through one of said diametral holes in each of said other rings and said hole in the rod to adjustably position said other ring in the desired angular position about said rods, each of said springs being in compression between said one ring and the tool holder to which it is anchored to hold said pairs of rings in engagement, the teeth of each of said pairs of ratchet faced rings being disposed at an angle to prevent uncoiling of the spring connected thereto.

5. A tool carriage assembly for a pipe cleaning machine comprising a tool carriage ring having a plurality of circumferentially spaced slots therein, said slots each extending over a range between positions nearer and farther from the axis of the ring, a tool support rod disposed in each slot of the tool carriage ring and extending axially therefrom, adjustable means to hold each rod in its slot at the desired radial distance from the axis of the ring Within said range of the slot and to hold the rod against rotation about its own axis with respect to said ring, a plurality of tool holders rotatably mounted on each of said rods for rotation in a plane perpendicular to the rod axis, and means to bias said tool holders toward the ring axis including a plurality of torsion springs disposed around each of said rods, each spring being operatively connected at one point to one of the too] holders on the rod about which it is disposed and at another point to the rod on which it is disposed.

6. A tool carriage assembly for a pipe cleaning machine comprising a tool carriage ring having a plurality of circumferentially spaced slots therein, said slots each being so disposed as to at least have a radial component, a tool support rod carried by the tool carriage ring in each slot and extending axially therefrom, means to secure each rod in a desired position in the respective slot and hold it against rotation about its own axis with respect to said ring, a plurality of tool holders rotatably mounted on each of said rods for rotation in a plane perpendicular to the rod axis, and means to bias said tool holders toward the ring axis including a plurality of torsion springs disposed around each of said rods, each of said springs being operatively connected at one point to one of the tool holders and at another point to the respective rod, each of the last said connections including a pair of ratchet faced rings disposed with their ratchet faces in juxtaposition one of said rings being anchored to one point of the spring and the other of said rings being secured to the rod by adjustable means to dispose the ring in any one of a plurality of angular positions relative to the rod.

7. A pipe cleaning machine including a support, an annular bearing mounted thereon, a ring rotatably mounted in said bearing, said ring having a plurality of circumferentially spaced slots therein, said slots each extending over a range between positions nearer and farther from the axis of the ring, a tool support rod disposed in each slot of the tool carriage ring and extending axially therefrom, releasable means to hold said rod in its slot at any desired radial distance from the axis of the ring within said range of the slot and to hold the rod against rotation about its own axis with respect to said ring, a plurality of tool holders rotatably mounted on each of said rods for rotation in a plane perpendicular to the rod axis, a plurality of torsion springs disposed around each rod with each spring operatively connected at one part to the rod and at another part to one of the tool holders thereon, and separate means for adjusting the torsion of each helical spring.

8. A pipe cleaning machine including a'support, an-annular bearing mounted thereon, a tool carriage ring rotatably mounted in said bearing, a plurality of tool support rods carried by said tool carriage ring and extending axially therefrom and each held against rotation about its own axis with respect to said ring, a plurality of tool holders rotatably mounted on each of said rods for rota tion in planes perpendicular to the rod axes, and means to bias each of said tool holders toward the ring axis including a plurality of torsion springs disposed around each rod, means operatively connecting each spring at one point to one of the tool holders on the rod and at another point to the rod, each of said bias means including a ratchet serially connected with the torsion spring whereby the bias of each tool holder may be adjusted.

9. A pipe cleaning machine including a support, an annular bearing carried by the support, a tool carriage ring rotatably mounted in said bearing, said tool carriage ring having a plurality of circumferentially spaced slots, each slot having at least a radial component, an end stabilizing ring having a plurality of circumferentially spaced slots, the last said slots each having at least a radial component, a plurality of rods each disposed with one end in a slot of each ring, releasable means for securing the ends of the rods in said slots the desired radial distance from the axis of the ring, at least one rotatably mounted tool holder on each rod, means on each rod to bias each of said tool holders toward the axis of the ring, each of said means including a helical spring disposed around the rod and a ratchet disposed around the rod and serially connected to the spring, one end of each of the last said means being operatively connected to the rod and the other to the tool holder.

10. A pipe cleaning machine including a support, an annular bearing mounted thereon, a tool carriage ring rotatably mounted in said bearing, a plurality of tool support rods carried by said tool carriage ring and extending axially therefrom and each held against rotation about its own axis with respect to said ring, a plurality of tool holders rotatably mounted on each of said rods for rotation in planes perpendicular to the ring axis, and separate means to bias each of said tool holders toward the ring axis including a plurality of torsion coil springs disposed around each rod with the coils of each spring coaxial with the rod, means operatively connecting each spring at one point to one of the tool holders on the rod and at another point to the rod.

11. A pipe cleaning machine including a support, an annular bearing mounted thereon, a tool carriage ring rotatably mounted in said bearing, a plurality of tool support rods carried by said tool carriage ring and extending axially therefrom and each held against rotation about its own axis with respect to said ring, a plurality of tool holders rotatably mounted on each of said rods for rotation in planes perpendicular to the ring axis, and separate means to bias each of said tool holders toward the ring axis including a plurality of torsion coil springs disposed around each rod with the coils of each spring coaxial with the rod, means operatively connecting each spring at one point to one of the tool holders on the rod and at another point to the rod, each of said bias means including a means for adjusting the azimuthal position around the rod axis of the part of each spring connected to the rod.

12. A pipe cleaning machine including a support, an annular bearing mounted thereon, a tool carriage ring rotatably mounted in said bearing, a plurality of tool support rods carried by said tool carriage ring and extending axially therefrom, means to hold each rod against rotation about its own axis with respect to said ring, the last said means being adjustable to hold each rod in any desired azimuthal position with respect to its own axis,

a plurality of tool holders rotatably mounted on each of said rods for rotation in planes perpendicular to the ring axis, separate means to bias each of said tool holders toward the-ring axis including a plurality of torsion coil springs disposed around each rod with the coils of each spring coaxial with the rod,'means operatively connecting each spring at one point to one of the tool holders on the rod and at another point to the rod, each of said bias means including a means for adjusting the azimuthal position around the rod axis of the part of each spring connected to the rod.

13. A pipe cleaning machine including a support, an annular bearing mounted thereon, a tool carriage ring rotatably mounted in said bearing and wholly supported thereby, a plurality of tool support rods carried by said tool-carriage ring and extending therefrom parallel to the ring axis and each held against rotation about its own axis with respect to said ring, a plurality of tool holders rotatably mounted on each of said rods for rotation in planes perpendicular to the ring axis, and means to bias each of said tool holders toward the ring axis including a plurality of helical torsion springs disposed around each rod with the helix axis of each spring coaxial with the rod, means operatively connecting each spring at one point to one of the tool holders on the rod and at another point to the rod, each of said bias means including a ratchet serially connected with the torsion spring whereby the bias of each tool holder may be separately adjusted, said rods and said bias means lying wholly within the outer periphcry of said tool carriage ring.

14. A pipe cleaning machine including a support, an annular bearing mounted thereon, a tool carriage ring rotatably mounted in said bearing and wholly supported thereby, an end stabilizing ring coaxial with and axially spaced from said tool carriage ring, each of said rings having a plurality of circumferentially spaced slots therein, said slots each extending over a range between positions nearer and farther from the axis of the rings, a plurality of tool support rods each disposed with its opposite ends in registering portions of slots in said tool carriage ring and said end stabilizing ring respectively, adjustable means to hold each rod in the slots in the rings at each end thereof at the desired radial distance from the axis of the rings within said range of the slots and to hold the rod against rotation about its own axis with respect to said rings, a plurality of tool holders rotatably mounted on each of said rods for rotation in a plane perpendicular to the rod axis, and means to bias said tool holders toward the ring axis including a plurality of torsion springs disposed around each of said rods, each spring being operatively connected at one point to one of the tool holders on the rod about which it is disposed and at another point to the rod on which it is disposed.

15. A pipe cleaning machine including a support, an annular bearing mounted thereon, a tool carriage ring rotatably mounted in said bearing, an end stabilizing ring coaxial with said tool carriage ring and axially spaced therefrom, each of said rings having a plurality of slots, the length of each slot extending from nearer the ring axis to farther therefrom, a plurality of tool support rods, means to mount said rods with their opposite ends in the slots of said rings, said means being adjustable as to angular position of the rods about their own axes and as to radial distance of the rods from the ring axis, a plurality of tool holders rotatably mounted on each rod, a plurality of torsion springs disposed around each rod, each spring being operatively connected at one part to the rod and at another part to one of the tool holders for biasing the tool holding part of the tool holder radially inward toward the ring axis.

16. A pipe cleaning machine including a support, in annular bearing mounted thereon, a tool carriage ring rotatably mounted in said bearing, an end stabilizing ring coaxial with said tool carriage ring and axially spaced therefrom, each of said rings having a plurality of slots, the length of each slot extending from nearer the ring axis to farther therefrom, a plurality of tool support rods, means to mount said rods with their opposite ends in the slots of said rings, said means being adjustable as to angular position of the rods about their own axes and as to radial distance of the rods from the ring axis, a plu- 5 rality of tool holders rotatably mounted on each rod, a plurality of helical springs wound around each rod and connected at one end to a tool holder, and a plurality of adjustable ratchets on each rod, each ratchet being fixed at one end to the rod and at the other end to the other 10 end of one of said springs.

References Cited in the file of this patent UNITED STATES PATENTS 864,932 Staples Sept. 3, 1907 15 12 Mikshel Feb. 7, 1922 Haase July 10, 1928 Fisher Aug. 29, 1933 Lynch May 19, 1936 Boax et a1 Aug. 4, 1936 Gordon June 16, 1942 Heldenbrand Dec. 15, 1942 Cummings et al. Feb. 17, 1948 Perrault et al. May 31, 1949 FOREIGN PATENTS France Feb. 10, 1917