US2926372A - Sewer cleaning machine - Google Patents

Description

March l, 1960 J. v. o'BRu-:N

SEWER CLEANING MACHINE 2 Sheets-Sheet l Filed Feb. 2l, 1957 jugs/Z257!" @yen (fn, l Vm mi, *In WMA/ym z 5 l Tdk/y0 March l, 1960 J. v. BRIEN 2,926,372

SEWER CLEANING MACHINE Filed Feb. 2l, 1957 2 Sheets-Sheet 2 SEWER CLEANING MACHINE John V. Brien, Park Ridge, lli., assigner to H. D. Conkey 8L Company, Mendota, lili., a corporation of Illinois I Application February 21, 1957, Serial No. 641,536

v' 6 Claims. (Cl. 154104.25)

in which a flexible cable or coil is inserted into the con- I duit to be cleaned or cleared of obstructions, the flexible shaft or coil being power rotated to transmit the torque necessaryto etfect the cleaning operation.

Many sewer cleaning machines of the above type have heretofore been devised but they are all open to one or more objections. vThus some machines of the prior art require, for their operation, operators having special skill or training. y Other machines are of such construction that there is considerable likelihood of danger to the operator because of the action of the exible shaft or coil when subjected to excessive and improperly controlled torque. .g

Again, in certain machines there is nothing to indicate to an ordinary operator when the flexible shaft or coil is being overloaded with the result that abnormal kinkage or breakage of the flexible shaft or coil occurs.

VSome prior art machines are so designed thatl it is pos- 4sible to use only one size flexible shaft or coil with that specific machine, thus limiting the use of the machine to only certain cleaning operations, or if adapted to use with more than one size exible shaft or coil there is no way in which the change can be made quickly easily.

The general object of my invention is to provide a sewer cleaning machine which will overcome most of the objections above noted.

More specifically it is an object of my invention to provide a` sewer cleaning machine which depends to a lesser extent on the skill of the operator, thus making it adaptable for efcient use by ordinary workmen. .Another object ofi'ny' invention is to provide a sewer cleaning machine which will enable the operator to operate the machine more nearly at maximum eiciency for a greater part of the time without danger of kinking or breaking the flexible shaft or coil.

Again, it is an objectof my invention to-provide a sewer cleaning machine which, inV the event the operator fails to observe and act upon the indication which the machine, because of its constructional characteristics, gives upon reaching a condition likely to cause kinkage or breakage of the flexible shaft, functions automatically to limit or remove the applied torque, thus preventing damage to the flexible shaft.

Another object of thev invention is to provide a sewer cleaning machine of such construction that a different ize iiexible shaft can be quickly' and easily substituted forthe one being used when *conditionsl require andato provide for the transmission of torque of the order that particular exible vshaft is capable of safely transmitting. vStill further o-bjects'of the invention are to prvidea ZZhZ Patented Mar. l, 35@

companying drawings which illustrate a preferred embodiment wherein:

Fig. 1 is a perspective view of a sewer cleaning machine embodying the preferred form of the invention, as viewed 4from the driving motor end thereof, when the drum is tilted to a position for an overhead operation.

Fig. 2 is a perspective view of the flexible shaft-packed drum of the machine, as viewed from the tool operating end thereof.

Fig. 3 is an elevation of the machine viewed in the direction of the arrows 3 3 of Fig. 4, but on a scale reduced therefrom and with the axis of the drum disposed in a horizontal plane, as is the drum axis in Fig. 4.

Fig. 4 is a longitudinal vertical sectional view througi the machine as taken on the line 44 and on a scale enlarged over that of Fig. 6.

Fig. 5 is a detail transverse vertical sectional view through a part of the machine as taken on the line 5-5 and on a scale enlarged over that of Fig. 4.

Fig. 6 is a top plan view of the machine on the scale of Fig. 3.

Fig. 7 is a, vertical longitudinal sectional view through the friction clutch assembly embodied in the machine as taken on the line 7-7 and on a scale enlarged over that of Fig. 5.

Pig. 8 is a detail elevational view of the front or exible shaft pay out end of the machine as viewed in the direction of the arrows 8-8 and on a scale enlarged over'that of Fig. 4.

Fig. 9 is a view in front end elevation of the inner drum of the machine on substantially the Scale of Fig. 4; and

Fig. l() is a view in side elevation of the power takeoff gear and its clutch assembly unit of the gear reducing mechanism of the machine, which is adapted for detachable driving engagement with a mating element of the friction clutch assembly of Fig. 7.

Referring now in detail to that embodiment of the invention illustrated in the accompanying drawings, the improved machine comprises a base which, as a whole, bears the reference B. The base B as shown is made of metal plate formed to a U-shape, comprising a horizontal bottom portion Ztl andV two upstandin-g portions 2i- 2.1. The base is provided with rubber buttons or feet 22 which serve to protect the floor surface on which the machine rests, serve to assist in preventing creepage of the machine when in operation, and also proside portions 23, 24 a-rear cross-connecting portion 25 sewer cleaning machine of simple construction and in will bemor'e readilyV understood byreference to the' acj.

and a front cross-connecting portion 26 (best shown as a whole in Fig. 6r).

The cradle C is mounted for swingingV movement in the base B by means of the trunnions 27-27 which are carried by the upstanding portions 2l- 211. In order that the cradle C and the flexible shaft vdrum which, as explained later is carried thereby, may be held in various placed positions when swung on the trunnions 227-27, the cradle-like frame C is provided on side 24 thereof with a stud member 2S which projects through the arcuate slot 29 in the adjacent opstanding portion Zi or" the base member B. The outer end of the stud member 28 is threaded to receive the internally threaded, hand-manipulatable knob 30. By turning the knob in one direction, the cradle and portion 21 of the base are drawn tightly together so that swinging movement of the cradle-like frame C is prevented. By turning the knob in the opposite direction the parts are loosened enough so that swinging movement of the cradle is permitted.

Positioned within the cradle C is a structure D comprising an outer drum DO and an inner drum DI which are independently rotatable. While the structure D as a whole is specifically different, it operates upon the basic principles disclosed in my prior Patent 2,730,740 insofar as the action of the inner and outer drums per se is concerned. Hence, it is not thought necessary here to explain in detail the advantages thereof insofar as the inner-outer drum construction per se is concerned.

The outer drum DO includes an outer cylindrical portion 40, a central radially extending portion 41, and intermediate portions 42, 43 and 44 which unite the central portion 41 with the cylindrical portion 40. It will be observed that portion 41 is disposed in a plane forward of the plane of portion 44, thus providing a recess R which serves to accommodate a number of the operating parts, as will be later explained.

The inner drum DI includes a slightly conical annular portion 45 which is disposed within the cylindrical portion 40 of the outer drum DO and closer to the axis of rotation of the drum structure than the portion 40 of the outer drum. The innermost part of the portion 4S surrounds the portions 41, 42 and 43 of the outer drum but is spaced therefrom to permit independent rotation of the outer and inner drums. The front end of the inner drum DI terminates in a central radially extending portion 46 disposed in a plane forward of the plane of the front wall 47 of the outer drum, the portion 46 being joined to the portion 45 by a conical portion 48.

On the inner side of portion 46 of the inner drum there is positioned a bearing plate 50, and on the outer side a generally conical hollow member S1. Parts 50 and 51 are `secured together and to the portion 46 of the inner drum by tap bolts 52.

A flexible shaft distributor S opens at one end through the portion 45 of the inner drum and at the other end terminates short of the forward end of member 51 adjacent the rear end of a steel sleeve 56 which fits tightly in the forward end of member 51. Positioned on the sleeve 56 is a bronze collar 57, held against movement longitudinally of the sleeve by snap rings 58 and 59. The forward end assembly just described is held down against the underlying central supporting portion 61 of the cradle C by means of a latch plate 60 pivoted for swinging movement between full and dotted line positions (best shown in Figs. 6 and 8). When in locking position the latch plate 60 can be drawn tight by means of thumb screw 62.

Motor and reduction gear structure An electric motor 70 having special characteristics, later described, is positioned on shelf-like portion 25S of the cross portion 25 of cradle C, being held lirmly in position thereon by means of tap bolts 71, best shown in Fig. 4. Also mounted on and fixed to a lower portion 2SL of the cross portion 25 is a reduction gear structure 72. Motor and reduction gear are thus firmly held in position on the cradle C, the armature shaft of the motor, not shown, being operatively connected to drive a pinion gear of the reduction gear, not shown, which in turn meshes with the gear 73 of the unit assembly 74 (best shown in Fig. l0), which as a whole is mounted for rotation in the casing of the gear reduction mechanism (see Fig. 4). The unit 74 comprises a centrally disposed collar 75, thus providing a central opening 76, to receive the rear end portion 80 of the longitudinally disposed shaft S1 presently to be described.

The clutch assembly and associated parts Mounted upon opposite sides of the central radial portion 41 of the external drum DO are members 82 and 83, the former being in the shape of a at ring and the latter having a hollow hub portion 84 to receive a bearing sleeve 85.

Longitudinally disposed shaft 81 extends through the sleeve 85, its forward end 81F being accommodated within the hub portion 87 of the bearing plate 50, and its rear end which is of reduced size, being, as before explained, received `in the central opening 76 of the unit assembly 74 in the gear reducing mechanism 72.

Mounted on the shaft 81 is a clutch assembly unit, which, as a whole, bears the numeral 90 and which is best shown in Figs. 4 and 7. Centrally the unit comprises a bearing sleeve 91 with a radial ange portion 92 at its forward end. Spaced from the flange 92 is a plate member 93 preferably made of noncorrosive metal, such as stainless steel, so that its operating characteristics are not seriously affected by moisture.

On opposite sides of plate 93 are discs 94, 95 of friction material bounded in turn by metal pressure plates 96 and 97 respectively. Interposed between the flanges 92 of sleeve 91 and pressure plate 96 is a small metal disc 98 (see Fig. 7).

In order that the clutch may be adjusted to transmit torque of desired magnitude there is provided a sleeve 100, having a threaded outer periphery 101 on which is operatively mounted a nut 102. Interposed between the nut 102 and the adjacent pressure plate 97 is a spring washer 103. By screwing the nut toward pressure plate 97 the capacity of the clutch to transmit torque is increased and by backing the nut away the capacity of the clutch to transmit torque is reduced. in order to lock the nut 102 in any desired position there is provided a set screw 104.

In order that the clutch can drive the drum structure the central plate 93 of the clutch is provided with a pair of diametrically spaced openings 105 which slidably accommodate the outer ends 106 of the bolts 107 which clamp the members 82 and 83 to the central portion 41 of the outer drum (see Fig. 4).

The driving connection between the clutch assembly 90 and the reduction gear assembly unit 74 (Fig. 10) is provided by the lugs 74L of unit 74 which extend into recesses 100K in member 100.

The various parts on shaft 81 are held against movement longitudinally of the shaft by snap lock rings 110, 111 and 112 which intert with grooves in the shaft properly positioned to receive them.

Miscellaneous 0111er parts It will be understood that the drum D is designed to hold a considerable length of exiblc shaft or coil 113. As by way of example and not by way of limitation 50 to 75 feet is typically used, most of which, when the machine is not in operation, being stored in a known manner in the annular space AS between the inner and outer drums, one end of the flexible shaft being secured to the outer drum, as indicated at 114 in Fig. 4. The free end of the flexible shaft passes through the distributor 55, emerging through the sleeve 56 so that the axis of the ilexible shaft at that point is substantially coincident with the axis of rotation of the drum structure. As is also well known, rotation of the drum causes rotation of the flexible shaft. The outer end of the flexible shaft is usually provided with a cutting tool, one form of which is illustrated at 115 and which is designed to engage and remove the obstruction in the sewer line or other conduit to be cleaned or cleared.

An electric switch 116 is provided to start and stop the motor and a reverse switch (not shown) is preferably provided so thatthe motor and drum rotation and hence the exible shaft can be reversed to prevent the cutting tool from being hung up in the sewer line obstruction.

Special operational features There are several special advantageous operational features which are not obvious from the description thus far given and indeed without which some of the objects of the invention are unattainable.

1 In order for most eflicient operationit is desirable that the r.p.m. of the liexible" shaft be relatively high when' it is being' fed into the sewer line or conduit toward the obstruction point and before -being subject to loads of the order met with when the cutting tool engages the obstruction to be removed. Thereason for this is Ythat when rotating at relatively high speed the tool at the working end of the flexible shaft more readily passes through elbows. Ts and other angularly disposed joints in the conduit. v

Such relatively high speed is also advantageous when l the cutting tool initially engages the obstruction to be removed since its inertia aids in cutting penetration. While it is desirable, in order to do the most Work in the shortest time, that the rotation of the flexible shaft be main-l tained' at substantially its maximum speed, it should not be maintained to such an extent as will cause kinkage or breakage of the exible shaft. It is, therefore, desirable that the characteristics of the motor driving the drum, and hence the nexible shaft, shall be such that when subjected to increasing load the speed thereof will be automatically and rapidly reduced to a substantial extent noticeable audibly and/or visibly noticeable, evento an unskilled operator, because of the reduction in the r.p.m. of the storage drum. In this way the operator is warned that excessive torque is developing in the flexible shaft and that it is advisable to retract the flexible shaft temporarily from the obstruction to prevent kinkage or breakage.

It is also desirable that means be provided so that if the operator fails to observe and/ or act when the danger signals which the substantialy lower speed of the motor noticeably reflects and which, if continued, is likely to result in kinkage or breakage of the exible shaft, that slippage in the drive between motor and drum will automatically result. However, if the machine is to continue to operate at the highest safe speed, which is necessaryv if maximum work is to be done, slippage should not occur until it is actually necessaryv to relieve the flexible The motor clutch and flexible'shaft characteristics I find that by using an electric motor `the character'- istics of which are such that as the load is increased from one of small value the speed reduces'rapidly and substan-l tially, advantageous coaction with other" parts of the machine is possible. Thus, such a motor operates at relatively high speed prior to engagement of the tool carrying end of the flexible shaft with thc obstruction to be removed. When, however, the tool end engages the obstruction, the increased load reacts on the motor to reduce the motor speed quicklyandsto a' large extent if the obstruction is one which it is difficult to remove'.

The rapid reduction in speed lis noticeable in the change in the whine of the motor froma higher pitch to a lower pitch. The reduction inv speed of the drum may" also be readily observed. -Thereduction ofthe rotational 6 clutch so that it will transmit'torque of an order. sub,-V s'tantially lower than the maximum torqne"` which the exible cable is capable of withstanding without danger of kinkage or breakage and still have the machine fune-v tion effectively and eflicient'ly. The end result of the co-v operative functioning ofthe elements and the built-in safety lprovided thereby' is that an operator without havf. ing special skill is'able to operate the machine under more advantageous conditions for obstruction removal at a higher safe rate and for a greater part` of the operating period without danger of causing kinkage or breakage of the liexible cable.

In practice I have found that a motor' of the following order when used with a reduction gear of 50 to 1 gives excellent results: l

Rating 1/12 H.P.; duty cycle continuous; rpm. outpt shaft 8000; volts 115; frequency D.C, -60 PH1; amps 1.4; type series universal; ventilation int. fan; armature diameter 1.8125; length 1%; poles 2; bearings ball. ,y

I also find that such a motor while rated at 8000l r.p.r`n. and which with a 50 to 1 reduction, if operating speed of' the motor thus tends to Akeep pace with thel reduction in the rotational speed of the flexible shaft should it be progressively subjected to greater resistance to rotation as bycontact with an obstruction which itf The action just described alsoy isdifficult to remove.

therefore tends to maintain the clutch as an elfective driving unit for a greater period of time before slippage results than would be the case were the motorconstruc-f tion such as to tend to maintainv its rotational speed as the load increases. It is possihle therefore to set the at 8000 r.p.m., would rotate the flexible shaft at r.p.m., usually rotates the exible shaft at a substantially higher r.p.m. whilst driving the drum prior to insertion of the flexible shaft into the conduit. Indeed,.the r.p.in. rotation of the 'flexible shaft may evenv be of thel order of 240 r.p.rn. at that time which, of course, reflects an initial r.p.r`n. motor speed well in excess of 8000 r.p`.m. shown by the manufacturer for rating purposes. As before explained, this initial higher r.p.rn. is particularly advantageous for sewer cleaning operations. Such a motor is generally termed an A.C.D.C. series wound type' v 'Gther motors having similar characteristics, such for' example as a series wound D.C. motr, may be sed, but the A.C.D.C, is preferable'because of its adapta# bility for use with Veither A.C. or 'lD.C. current. A `motor ofthe type specifically above'mentionedfis also particularly advantageous because when the speed decreases rapidly as the load increases from one of low value, the torque increases at a lesser percentage rate. This characteristic is helpful in enabling the use of a slip clutch which will slip when subjected to torque of a value substantially below the torque which the flexible shaft with which it is used is able to withstand without kinkage' or breakage.

Clutch characteristics i As by way of illustration I have found that by provid;4 v ing a friction clutch which is adapted to transmit a load liverable torque the' clutch lcan be set to deliver four foot pounds of torque;

Drum removal feature As before explained,one of the objects of the inven-I' tion is to provide means whereby'the operator can quickly, easily, safely, and iny a-'clean manner operate thev machine with flexible shafts of different diameters as may be best ladapted for theparticular sewer or conduit"I yto be cleaned.

Y This desired result is` accomplished by providing-al plurality of drums each having therein a length of flexibleshaft of desired diameter. Assume that the drumv shown in Fig. 1 contains a length of flexible shaft of one diameter andthe drum of Fig. 2 flexible shaft having a different diameter and that itis desirable to vuse flexible shaft mandava" ofthe diameter carried in the storage drum of Fig. 2.

'To remove the drum from the cradle loosen thumb screw 62 and swing latch plate 60 to dotted line position (Fig. 6). Then lift part 51 upwardly a slight distance, at which time the whole drum structure, including the friction clutch assembly, can be pulled away from the reduction gear, the reduced end portion 80 of shaft 81 sliding out of the socket 76 of assembly 74. The drum assembly of Fig. 2, which is preferably also provided with a clutch assembly properly related to the cable contained in the storage drum, is then placed in the cradle C. This is accomplished by inserting the reduced end portion of a shaft corresponding to shaft 81 in the socket 76 of assembly 74, lowering the front end of part corresponding to 51 into position in the cradle supporting portion 56, swinging latch plate from dotted-line position of Fig. 6 to full-line position and tightening thumb screw 62. This change can be made in a fraction of a minute.

It will be understood that the flexible shafts having operated in sewer lines are usually anything but clean. However, the fiexible shaft is stored in the drum when not in use, thus preventing the soiling of lioors, walls and adjacent objects.

Of course, if desired, the same clutch could be used with several drum assemblies being removed from one assembly and placed on the other at the time of interchange of drums in the cradle of the machine. However, this would take additional time, and would require, for best results, the readjustment of the clutch to adapt it to the particular cable. Usually there would not be available in the field facilities to test the foot pounds of torque the clutch is adapted to handle, although it is possible to provide indicating means on the `clutch so that if the nut 102 were at one point it would be suitable for use say with a 15732 cable and when at another suitable for use with a one-half inch cable.

But by providing a clutch with each drum assembly and which is properly related to the specific flexible shaft carried by the drum, the time saved is well worth the cost of the extra clutch.

I claim:

l. A sewer cleaning machine comprising in combination an annular drum for the storage of convolutions of fiexible coil interiorly of the drurn and adapted to cause rotation of the flexible coil when the drum is rotated, means mounting the drum for rotation on its axis, means for guiding the iiexible coil between the convolutions thereof interiorly of the drum and a position exteriorly of the drum and substantially coincident with the axis of rotation of the drum, said drum having a substantially imperforate wall substantially closing the rear side of the drum and being formed to provide a central forwardly extending recess, an electric motor having a normal operating speed substantially higher than that desired in the drum, speed reducing means connected to the motor, means connecting the speed reducing means and the drum, said last mentioned connecting means being positioned in the said drum recess and being operative to effect slippage in the drive when the connection is subjected to torque of a value which is substantially below the maximum torque which the iiexible coil is able to withstand, during operation, without kinkage or breakage, as when the end which is exteriorly of the drum engages an obstruction preventing free rotation of the coil and the drum is rotated in a direction to reduce the diameter of the flexible coil, said motor being one having characteristics such that as the load thereon is increased from one of low value the speed decreases rapidly.

' 2. vThe combination set forth in claim 1 in which the means for causing slippage is a friction clutch.

3. A drum structure for use in a sewer cleaning ma chine and adapted to be power driven when mounted for rotation on its axis, said drum structure comprising an inner drum and an outer drum, the latter having an annular portion spaced outwardly of the inner drum thereby providing space therebetween for convolutions of a fiexible sewer cleaning coil, said drum structure including a central shaft on which both said drums are mounted for rotation and for rotation one relative to the other, said drum structure also including means for guiding the exible coil between the convolutions interiorly of the drum and a position externally thereof substantially on the drum structure axis, said outer drurn having an imperforate wall with a central portion extending forwardly within the inner drum to provide a recess, said shaft having a portion extending rearwardly of the outer drum mounted thereon for the accommodation of a friction clutch within said recess.

4. A drum structure for use in a sewer cleaning machine and adapted to be power driven when mounted for rotation on its axis, said drum structure comprising an inner drum and an outer drum, the latter having an annular portion spaced outwardly of the inner drum thereby providing space therebetween for convolutions of a flexible sewer cleaning coil, said drum structure including a central shaft on which both said drums are mounted for rotation and for rotation one relative to the other, said drum structure also including means for guiding the fiexible coil between the convolutions interiorly of the drum and a position externally thereof substantially on the drum structure axis, said outer drum having an imperforate wall with a central portion extending forwardly within the inner drum to provide a recess, said shaft having a portion extending rearwardly of the outer drum mounted thereon, and a friction clutch mounted upon said rearwardly extending shaft portion so as to be disposed within said recess.

5. A sewer cleaning machine comprising, in combination, a frame, a flexible coil, an annular member having vsurfaces shaped to define an interior annular space for reception and storage of convolutions of said coil, means defining an exit from the front of said annular space, said exit being substantially coaxial with said annular space and adapted to pass said coil into or out of such space, said annular member also having surfaces shaped to define an exterior recess surrounded by said annular space and disposed rearwardly of said exit, a drive coupling fixed in said recess, said coupling having input and output members and means for causing them to slip relatively when more than a predetermined torque is applied to the coupling, means drivingly connecting said output member to said annular member, means for removably supporting said annular member in said frame with freedom to rotate about its axis relative to the frame, power means carried by said frame, and means for disengageably coupling said power means to said input member when said annular member is supported in said frame.

6. For use in a sewer cleaning machine having a frame and rotative power means thereon, a storage unit for a flexible coil comprising, in combination, an annular member having surfaces shaped to define an interior annular space for reception and storage of convolutions of said coil, means defining an exit from the front of said annular space, said exit being substantially coaxial with said annular space and adapted to pass said coil into or out of such space, said annular member also having surfaces shaped to define an exterior recess surrounded by said annular space and disposed rearwardly of said exit, a drive coupling fixed in said recess, said coupling having input and output members and means for causing them to slip relatively when more than a predetermined torque is applied to the coupling, means drivingly connecting said output member to said annular member, means for removably supporting said annular member in said frame with freedom for rotation relative References Cited in the le of this patent UNITED STATES PATENTS 5 Remmen Oct. 19, 1909 10 Gassen Mar. 16, 1937 Sanger July 25, 1939 Emery Mar. 31, 1942 OLeary Aug. 11, 1942 Long May 4, 1943 OBrien Jan. 17, 1956

Images