US3819880A

US3819880A - Power connecting apparatus for movable members

Info

Publication number: US3819880A
Application number: US00384465A
Authority: US
Inventors: P Johnston
Original assignee: Diamond Power Specialty Corp
Current assignee: Babcock and Wilcox Co
Priority date: 1973-08-01
Filing date: 1973-08-01
Publication date: 1974-06-25
Anticipated expiration: 1991-06-25
Also published as: JPS5037902A; SE401063B; SE7402893L; DE2412188A1; BE812261A; FR2239786B1; DE2412188C3; NL7403388A; GB1457813A; IN140555B; AU6642074A; NL155138B; BR7404433A; FR2239786A1; SU651734A3; JPS5144245B2; IT1011079B; DE2412188B2; CA1004652A

Abstract

A helically coiled flexible electrical conductor extensible and retractable axially to provide electrical connection to a movable element is slidably supported by a rod which extends through it, one end of the coil being fixed and the other end movable. A tube slidably fitted on the rod extends from the movable end through convolutions of the coil and is movable with the movable end of the coil. A knob carried by the rear end of the tube controls the escape of convolutions from the tube during forward movement.

Description

United States Patent [191 Johnston POWER CONNECTING APPARATUS FOR MOVABLE MEMBERS Paul R. Johnston, Lancaster, Ohio Diamond Power Specialty Corporation, Lancaster, Ohio Filed: Aug. 1, 1973 Appl. No.: 384,465

Inventor:

Assignee:

US. Cl. 191/12 R, 15/317, l37/355.l6 Int. Cl. H02g 11/00, A471 5/12 Field of Search 191/12 R; 15/317;

References Cited UNITED STATES PATENTS Knott 191/12R Wilson 191/12RX June 25, 1974 Nelson et a1 15/317 Nelson 191/12 R X Primary Examiner-Robert S. Ward, Jr. Attorney, Agent, or Firm-Harness, Dickey & Pierce [5 7] ABSTRACT A helically coiled flexible electrical conductor extensible and retractable axially to provide electrical connection to a movable element is slidably supported by a rod which extends through it, one end of the coil being fixed and the other end movable. A tube slidably fitted on the rod extends from the movable end through convolutions of the coil and is movable with the movable end of the coil. A knob carried by the rear end of the tube controls the escape of convolutions from the tube during forward movement.

6 Claims, 9 Drawing Figures PAtEmEmms rem I A POWER CONNECTING APPARATUS FOR MOVABLE MEMBERS BACKGROUND OF THE INVENTION The present invention relates to conductors for providing a power conductive connection between relatively movable elements and has been developed in connection with work directed to overcoming problems which arise where a power connection must be provided to a movable motor such as is employed in long traveling soot blowers wherein the motor and a supporting carriage travel with a lance tube, the carriage', motor and lance tube being typically supported on tracks carried by a horizontal beam structure, the carriage being arranged to travel along the beam for distances which may be as great as 50 or 60 feet. The motor may be either electric or air powered. Various power feeding means of extensible and retractable character have been employed. In boiler environments where soot blowers are utilized, several factors tend to shorten the life of the equipment. Such factors include heat, vibration, corrosion and the presence of abrasive flyash in the atmosphere; Some form of continuous cable is desirable to supply electric power, but the factors mentioned, and the fact that a compact design is usually required due to space limitations, has rendered the life of electric cables employed in this service less than satisfactory in many cases where long travels are involved.

Copending U.S. pat. application of David A. Rausch and this applicant, Ser. No. 340,116, filed Mar. 12, 1973, discloses one solution to this problem which has been found commercially practical and which is successfully employed where the distance traveled by the movable end of the coil is as great as 25 feet. At greater distances, however, difficulty has been encountered due to the fact that the frictional drag on the convolutions farthest from the fixed end causes these convolutions to contract to such a degree as to bind on the rod. The present invention aims to improve upon the construction disclosed in the aforementioned application with respect to the length of travel which can be achieved without undue stress upon or binding of the convolutions on the rod. Another object is to provide such a construction which retains the compact features of said prior application and which can be accommodated within an elongated construction of limited cross section, such as the beam of a soot blower.

Other objects and advantages will become apparent upon consideration of the present disclosure in its entirety.

BRIEF DESCRIPTION OF THE FIGURES OF THE DRAWING FIG. 1 is a fragmentary cross section of a portion of a known type of soot blower, illustrative of apparatus with which this invention is adapted to be usefully employed;

FIG. 2 is a longitudinal vertical elevational sectional view on a larger scale of the control asembly of power connection means constructed in accordance with the present invention, with an electric cable shown in section thereon;

FIG. 3 is a top plan view of the control assembly;

FIG. 4 is a cross section taken substantially on the line IVIV of FIG. 2 and looking in the direction of the arrows;

FIG. 5 is a perspective view of a control assembly and cable installed on a soot blower carriage, the beam and other portions of the soot blower being omitted and broken away;

FIG. 6 is a diagrammatic side elevational view of a coiled cord power supply assembly constructed in accordance with the aforementioned application Ser. No. 340,1 l6, illustrating the binding efiect which occurs if such a system is employed at travels exceeding the practical operating range thereof;

FIG. 7 is a diagrammatic view similar to FIG. 6 illustrating the action which occurs during extension of the coil of apparatus constructed in accordance with the present invention;

FIG. 8 is a rear end view of the soot blower with the rear wall, and some other parts unrelated to the present invention, omitted; and

FIG. 9 is a view similar to FIG. 2 showing a modified control assembly.

The drawings are not made to a uniform scale.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION The soot blower fragmentarily shown in the drawing and generally designated 10 is presumed to be of the well-known IK long retracting type, comprising a main supporting beam in the general form of an inverted U-channel and which incorporates a carriage generally designated 22 rollably supported in the beam in a well known manner (and which is not illustrated). Carriage 22 incorporates a motor 28 attached to and traveling with and as a part of the carriage assembly and which drives the carriage assembly and the lance tube 25 (fragmentarily illustrated axially and rotatively. A soot blower of the indicated variety is fully disclosed in US. Pat. No. 3,439,376.

The motor 28 derives its power from a suitable source of electricity which is deliverable through conventional means (not shown) to the vicinity of the rear end wall 30 of the soot blower, where it is electrically connected to the fixedly secured end portion 31 of the helically coiled flexible conductor 32. The end portion 31 is shown as secured to the beam near the wall 30 by a clip-like bracket 33. The coiled conductor 32 is suspended upon a rod 35 formed of steel having a lowfriction covering such as nylon sheath. The rod is fastened at its rear end to the wall 30 and its forward end to a bracket 38 near the front or wallbox end of the blower assembly.

Although a soot blower powered by an electric motor is illustrated and described in connection with the invention, it will be recognized that the invention might be used in other environments, and that the flexible conductor might be a tube for a fluid, rather than an electrical conductor. (Of course the word rod is intended to encompass any suitable internal support of restricted cross section.)

Actuating means for the movable free end of the coil comprises an arm 40 pivotally connected to the carriage assembly by a transverse pivot pin 42 extending through and carried by a bracket 44 attached to the carriage assembly. The arm 40 is thus swingable in a vertical plane but travels longitudinally with the carriage. Arm 40 is urged upwardly with respect to the At its forward end the arm 40 carries another transverse pivot pin 52 which extends into and is rockable in a slideblock 54. The slideblock 54 is slidably overfitted on rod 35, containing a clearance hole 55 through which the rod 35 extends. Block 54 is attached by means of machine screws 56 to the base flange 61 of control cone member 60. The block 54 and control cone 60 correspond to the similar parts disclosed in the aforementioned prior application.

As best shown in FIGS. 3 and 4, the control cone is provided with around bottomed longitudinal groove 62 in its upper surface to accommodate the support rod 35. Secured in the groove 62 as by welding at the positions designated 64, 65 is a tubular extension sleeve 66 slidably overfitted on the support rod 35 and extending rearwardly from the cone, carrying at its rear end a knob 68. The entire control assembly consisting of the slideblock 54, cone 60, extension tube 66, and knob 68 travels with the carriage. When the carriage and lance tube are retracted most of the convolutions of the heli cally coiled cable are supported on the extension tube and controled cone, as shown in FIG. 2. As the control assembly moves forwardly to extend the cable, the knob 68 resists escape of the convolutions, but it is so proportioned that the successive convolutions are pulled off relatively easily and with an amount of resistance which results in the convolutions becoming spaced relatively uniformly along the rod as they drop onto the rod during such forward movement. The tendency of the knob to retain the convolutions on the moving control assembly prevents undue stretching of the cable and eliminates the drag resistance of the convolutions which remain on the control assembly during extensive movement, so that the tendency of the convolutions to constrict, at long extensions, to such an extent as to bind on the rod in the manner diagrammatically indicated in FIG. 6, is prevented.

In a successful construction which has been under test, wherein the travel of the carriage is 45 feet, the flexible four-conductor electric cord having a synthetic rubber cover has an outside diameter of approximately 0.63 inch. It is wound in a tight helix having an inside diameter of 2% inches, making a coil approximately 50 inches long when fully collapsed. The outside diameter of the extension tube is 34 inch. The knob 68 is formed of nylon impregnated with molybdenum disulphide and has a diameter of 1% inches. The slideblock 54 is made of similar material. The length of the complete control assembly as shown in FIGS. 2 and 3 is 50% inches. The proportions are such that the tendency of the successive convolutions to ride over the knob 68 is restrained sufficiently so that each convolution is released after the preceding one is a short distance from the knob, and the successive spacings are substantially uniform. The proportioning of the knob to achieve this effect may vary somewhat with the composition of the insulating sheathing on the cable, but has not been found to be critical or difficult to achieve. In the proportions indicated, the system works well with a vertical wall, as indicated at 69, on the forward side of the knob. Each convolution closest to the knob, on the forward side of the knob, rises and rides over the knob as the control assembly moves forwardly, apparently assisted by the fact that a pulling effect is exerted on the bottom portion of each convolution, tending to pull it upwardly as well as to twist it. The intermediate position of a convolution riding over the knob is shown at 72 in FIG. 2. The rear'face of the knob is provided with a wall 74 which slopes at 45 to assist the convolutions to ride back over the knob and return to the sleeve during rearward movement and contraction of the helix.

The control cone 60 prevents the convolutions closest to the leading end of the cord, where attached to the base of the cone, from being twisted severely and overstressed when the cord is fully extended, in the manner disclosed in the aforemenioned prior application. It has been found, however, that if the required travel does not necessitate fully extending all of the convolutions, the control cone may be eliminated, and the controlling effect derived entirely from a sleeve and knob assembly directly attached to the block 54 by the securing flange 76 and comprising the elements 66, 68' shown in FIG. 9. Other parts of this embodiment are designated by corresponding reference characters primed, and will not require redescription. If the cone is eliminated in this manner, it is necessary to provide more convolutions than would otherwise be necessary, in order to reduce twisting and stressing close to the combined slideblock and towing member 54. This of course necessitates lengthing the entire control assembly somewhat, so that where limitations as to length are severe it is considered preferable to incorporate the control cone as well as the knob and sleeve assembly. This also assures maximum protection of the core near the leading end.

As previously indicated, the soot blower construction may correspond to that disclosed in US. Pat. No. 3,439,376. In such constructions the entire carriage is rockable about a transverse axis at the position designated 75 in FIG. 1. Such rocking is permitted by virtue of the fact that the entire carriage assembly is supported on trunnion rollers (not shown) located upon the axis 75. As thecarriage moves to its extreme forward position it is rocked counterclockwise, as viewed in FIG. 1, to tilt the attached end of the lance upwardly for the purpose of offsetting sag of the lance within the boiler. The means for tilting the carriage in this manner is disclosed in the patent referred to and will not require redisclosure here. In order to prevent distortion of the control assembly and the supporting rod 35, pivotal connections are provided at the positions of the previously-mentioned towing pins 42, 52 so that, when the carriage rocks counterclockwise and its front end rises as is indicated in dot-dash lines in FIG. 2, the arm 40 and roller 50 are not overstressed and retain their same relationship to the top web of the beam. The spring 45 at such time is stressed by the upward movement of the abutment 48, to accommodate such rocking of the carriage, while the spring maintains the roller in proper raised position at all times.

This Detailed Description of Preferred Forms of the Invention, and the accompanying drawings, have been furnished in compliance with the statutory requirement to setforth the best mode contemplated by the inventor of carrying out the invention. The prior portions consisting of the Abstract of the Disclosure and the Background of the Invention are furnished without prejudice to comply with administrative requirements of the Patent Office.

What is claimed is:-

1. Means for providing power conductive communication between two components one of which is movable relative to the other including a helically coiled flexible member having one end fast with respect to one of said components and its other end fast with respect to the other component, whereby the helix is extended and contracted axially during movement of said components from and toward one another, and a rod extending through the helix to support said member, characterized by a sleeve attached to one of said components and slidably overfitted upon the rod within the helix, and a knob attached to the sleeve at a position spaced from the component to which the sleeve is attached, said knob being of a size to frictionally oppose but permit successive escape of convolutions of the flexible member during extension of the helix.

2. Power conductive communication means as defined in claim 1 wherein the knob has an inclined wall on its end which faces away from the component to which the sleeve is attached, to assist the convolutions to pass over the knob and onto the sleeve during contraction of the helix.

3. Means for providing power conductive communication between two components one of which is movable relatively to the other including a helically coiled flexible member having one end fast with respect to one of said components and its other end fast with respect to the other component, whereby the helix is extended and contracted axially during movement of said components from and toward one another, a rod extending through the helix to support said member, and a generally conic extension controlling member attached to one of said components and extending into and part way through the helix from one end, characterized by a sleeve secured with respect to said extension controlling member and extending an additional distance through said helix and slidably overfitted on the rod, and a knob attached to the sleeve at a position spaced from said extension controlling member, said knob being of a size to frictionally oppose but permit successive escape of convolutions of the flexible member during extension of the helix.

4. In a soot blower construction of the type having a supporting beam, a carriage movable along the beam, said carriage being limitedly rockable with respect to the beam about an axis transverse to the beam, and a motor movable 'with the carriage, means for supplying power to the motor including a flexible conductor helically coiled about an axis extending longitudinally of the beam, a rod fixed to the beam and extending through and supporting the conductor, one end of the conductor being fixed to the beam and the other end fast with respect to the motor and carriage whereby movement of the carriage along the beam extends and contracts the helix, an extension controlling member at least partly surrounding thr rod and movable along the rod and beam with the carriage, said controlling member extending into the helix and having portions radially outspaced from the rod and engageable by portions of the conductor at a position spaced from said other end of the conductor to oppose relative axial movement between such engageable portions of the conductor and the carriage, characterized by means articulating the extension controlling means to the carriage on a transverse axis whereby undesired vertical forces on the extension controlling means in response to rocking of the carriage are prevented.

5. A soot blower power supplying means as defined in claim 4 wherein the articulating means includes an arm extending lengthwise of the beam, a transverse pivot portion connecting one end of the arm to the carriage, a second transverse pivot portion connecting the other end of the arm to the controlling means, and a roller appurtenant to said other end of the arm and rollably engaging the beam to maintain the relative positioning of the beam and controlling means independently of rocking movement of the carriage.

6. Means as defined in claim 5 including biasing means yieldably urging the arm and roller upwardly against a longitudinal guiding portion on the beam.

Claims

4. In a soot blower construction of the type having a supporting beam, a carriage movable along the beam, said carriage being limitedly rockable with respect to the beam about an axis transverse to the beam, and a motor movable with the carriage, means for supplying power to the motor including a flexible conductor helically coiled about an axis extending longitudinally of the beam, a rod fixed to the beam and extending through and supporting the conductor, one end of the conductor being fixed to the beam and the other end fast with respect to the motor and carriage whereby movement of the carriage along the beam extends and contracts the helix, an extension controlling member at least partly surrounding thr rod and movable along the rod and beam with the carriage, said controlling member extending into the helix and having portions radially outspaced from the rod and engageable by portions of the conductor at a position spaced from said other end of the conductor to oppose relative axial movement between such engageable portions of the conductor and the carriage, characterized by means articulating the extension controlling means to the carriage on a transverse axis whereby undesired vertical forces on the extension controlling means in response to rocking of the carriage are prevented.