US2925253A

US2925253A - Remote control unit for hydraulically operated tools

Info

Publication number: US2925253A
Application number: US778704A
Authority: US
Inventors: John B Long
Original assignee: LONG Co
Current assignee: LONG Co
Priority date: 1958-12-08
Filing date: 1958-12-08
Publication date: 1960-02-16
Anticipated expiration: 1977-02-16

Description

J. B. LONG Feb. 16, 1960 REMOTE CONTROL UNIT FOR HYDRAULICALLY OPERATED TOOLS Filed Dec. 8, 1958 2 Sheets-Sheet 1 mm F. A 2 8 b w 0 8 n t O B 3 M llrr 3 n 5 l 2 v 2 V O 3 l 6 Q A I I 7 2 INVENTOR John B. Long WWV ATTORNEYS Feb. 16,

Filed Dec.

1960 J. B. LONG REMOTE CONTROL UNIT FOR HYDRAULICALLY OPERATED TOOLS 8, 1958 2 Sheets-Sheet 2:

A 72 l 74 -L 75 77 INVENTOR John 8. Long ATTORNEYJ United States Patent REMOTE CONTROL UNIT FOR HYDRAULICALLY OPERATED TOOLS John B. Long, Oak Hill, W. Va., assignor to The Long Company, Oak Hill, W. Va., a corporation of West Virginia Application December 8, 1958, Serial No. 778,704

1 Claim. (Cl. 255-47) This invention relates to remote control units for bydraulically operated tools and more particularly to a unit for controlling a hydraulic power plant by remote control from a hand held tool.

In the operation of certain hand tools, such as drills, it has been found that hydraulic actuation of the drill is necessary in order to provide the requisite power for the operation of the drill and the problem has arisen of providing such a drill that can be handled and manipulated by a single operator. The majority of such hydraulically operated drills and like tools have heretofore been provided with some form of hydraulic fluid by-pass valve, mounted upon the hand tool, that is actuated to divert the flow of the hydraulic fluid from the tool motor, so that the tool can be stopped and started as required. This by-pass valve is necessarily of a rather substantial construction and forms a considerable part of the total weight of the hand held portion of the tool. It is a primary object of my invention to provide a hydraulically operated hand held tool wherein such by-pass control is eliminated, providing a tool having a weight considerably less than tools heretofore provided, and yet wherein the actuation of the tool may be easily controlled from the hand held portion of the tool.

In the hydraulically operated hand held tools that have been heretofore provided the hydraulic fluid is continuously flowing through the conduits leading from the hydraulic power plant to the hand held tool, and back to the hydraulic power plant, and the pressure that is maintained in these conduits makes the handling and manipulation of the tools very diflicult and the back pressure developed through the use of a by-pass valve located on the hand held tool increases the rigidity of the conduits lead ing to the hydraulic power plant making such handling and manipulation of the tool even more diflicult. It is therefore a further object of my invention to provide a remote control switch that is directly mounted on the hand held tool, which switch will.control the actuation: of the hydraulic power plant, so that the power plant can be completely shut off when the tool is not being operated, resulting in substantially zero pressure in the.

conduits leading to the hand held tool, and thereby greatly increasing the ease of handling and manipulation of the tool.

In every tool it is to be desired that optimum efliciency be attained, and I have discovered that the hydraulically operated hand held tools that have heretofore been provided fall far short of this goal. This is because the constant operation of the hydraulic power plant and flow of the hydraulic fluid through the conduits builds up considerable heat within the hydraulic system and there is no time lag in the operation of the tool provided for the dissipation of the heat. Thus a much larger motor for the actuation of the hydraulic power plant is required and a much larger oil supply must also be provided to handle the extra heat generated. I have discovered that by providing a remote control switch for the actuation of the hydraulic plant that, upon actuation of the switch and shutting off of the hydraulic power plant, the time interval that elapses during the course of manipulation of the tool from one operation to another permits the dissipation of the heat that has been generated'during actual drilling operation and there is therefore required a smaller motor and smaller hydraulic fluid supply in order to provide the desired degree of power. By providing for the remote control of the hydraulic power plant I have also greatly increased the safety factor of operation of the tool, so that if one of the hydraulic conduits leading to the tool should rupture, the operator will not be sprayed for a long period of time by the hot hydraulic fluid, but he can instantaneously stop the pressure fiow of the hydraulic fluid. I have further provided the remote control switch as being spring operatedadd of the dead man type so that if the operator is injured, or rendered unconscious, the release of pressure upon the switch will automatically stop the tool.

Other objects and advantages of my invention will be apparent during the course of the following detailed description, taken in connection with the accompanying drawings, forming a portion of this specification, and in which drawings:

Fig. 1 is a top plan view of a hydraulic power plant and hydraulically operated hand held drill embodying my invention.

Fig. 2 is a side elevation of the unit of Fig. 1.

Fig. 3 is a diagrammatic view of a typical hydraulic system embodying my invention.

Fig.4 is a schematic'diagram of the electrical components of my invention.

In the drawings, wherein for the purpose of illustration is shown a preferred embodiment of the invention, and wherein similar reference characters designate corresponding parts throughout the several views, the letter A may generally designate the hydraulic power plant and B a hydraulically operated hand held tool.

The hydraulic power plant A preferably comprises a frame 10, a starter and intrinsically safe relay assembly 12, a motor 13, a hydraulic pump or compressor 15, and a fluid supply tank 17. I

The frame 10 preferably comprises a skid type unit that may be moved about either directly upon the ground or supported upon a truck carriage so that the entire hydraulic power plant is completely mobile and can be moved to any position where its power is to be utilized. This frame 10 includes

side members

19 and 20,

end members

22 and 23, and a base plate 25.

The particular power plant shown in the drawings is for use in a direct current electrical system and it has therefore been necessary to provide a starter in order to prevent the inrush of a heavy current to the motor at the instant of startingfwhich excessive current would probably burn out the motor and blow the fuses and circuit breakers. This starter is of conventional construction, as is Well known in the art, having a plurality.

of steps of resistance that are gradually cut out, permitting smooth acceleration of the motor. As this particular equipment has been primarily designed for use within coal mines, I have provided an intrinsically sa-fe relay within the switching circuit so that the likelihood of an incendiary spark upon the opening or closing of the switch is eliminated. This intrinsically safe relay is a device used to operate Bureau of Mines explosion tested control equipment from an open type switch and its construction and operation is well known in the art. The starter and intrinsically safe relay are mounted within an explosion-proof enclosure 26 that is secured upon the base plate 25 as by the nuts 27.

The motor 13 is likewise secured to the base plate 25 and is a conventional direct current motor that is con- 3 structed and housed according to the standards set up by the Bureau of Mines.

The hydraulic pump or compressor 15 is likewise of conventional construction and is mounted upon the base plate 25. A coupling 30 interconnects the drive shaft of the motor 13 and the driven shaft of the hydraulic pump 15.

The hydraulic fluid tank 17 contains a supply of hydraulic fluid and is secured to the base plate 25 as by the nuts 32. An inlet opening 33 is provided at the uppermost portion of the tank 17 for replenishing the hydraulic fluid, which opening is normally covered by the cap 34.

The hydraulically operated hand held tool B preferably comprises a casing 40, a hydraulic motor 41 housed within the casing 40, and handles 43 and 44 extending outwardly from opposite sides of the casing 40. In the tool shown in the drawings the hydraulic motor 41 has attached thereto a chuck 46 that supports a bit 47. The hydraulic motor 41, chuck 46 and bit 47 are of conventional construction, as is well known in the art, and the

handles

43 and 44 are positioned so that the drill may be operated by a single operator.

Housed within the handle 44 is a spring loaded hammer switch 56 for the actuation of the hydraulic power plant A. v v

'In the operational construction shown in Figs. 1 and 2, the electrical system includes a fused trolley tap 52, that is to be secured to the fhot or positive line; a large ground clamp 53, that is to be attached to the main ground line; and a small. ground clamp 54, that is to be attached to the secondary ground line. The

cables

55, 56 and 57, leading from the trolley 52, the ground clamp 53 and the ground clamp 54, respectively, are housed within a single trailing cable and hose conduit 59 and lead to the'starterr and intrinsically safe relay assembly 12. A strain relief clamp 60 may be secured about the conduit 59 and attached, by means of the chain 61, to the enclosure 26, so that if any pull is exerted upon the conduit 59 the terminal ends of the

cables

55, 56 and 57, within the enclosure 26, will not become displaced.

A motor cable and hose conduit 63 connects the intrinsically safe relay and starter 12 to the motor 13.

A flexible lead cable 66 connects the starter and intrinsically safe relay 12 to the switch 50.

'In the schematic showing of the electrical circuit in Fig. 4 I have eliminated a schematic showing of the starter and intrinsically safe relay, as these do not form a part of my invention, for the purpose of clarity. In this showing the cable 59 is shown as containing the

cables

55, 66 and 57 leading to the starter and relay unit 12; the conduit 63 containing the

cables

68 and 69 leading from the starter and relay 12 to the motor 13; and the conduit 66 containing the

cables

71 and 72 leading from the starter aid relay assemblylZ to the switch 50. To the cable 71 is secured the. switch arm 74 that is normally maintained out of contact with the terminal 75 of the cable 72 by the spring 77, forming a dead mans switch. When the spring arm 74 is depressed, the same will contact the terminal 75, closing the circuit and actuating the hydraulic power plant, and upon release of pressure the spring 77 will force the spring arm 74 out of contact with the terminal 75, opening the circuit and shutting off the hydraulic power plant. The cable 57 is merely for grounding the frame structures of the.

various component parts.

In Fig. 3 I have diagrammatically shown the fluid flow system for the operation of the hand held fluid driven power tool. The fluid is contained within the fluid containing means or tank 17 and flows through the outlet conduit 8%] into'the pump means 15 and the fluid is pumped through the outlet conduit 82 to the pressure relief valve 83. This pressure'relief valve 83 is pro- 4 vided to limit the fluid pressure that can be applied to the fluid driven power tool so that the motor of the same will not be damaged by over-loading. The relief valve 83 is provided with a by-pass conduit 85 for return ing the fluid directly to the fluid containing means 17 when the fluid pressure exceeds that to which the valve has been set, and is provided with a main conduit 86 for supplying fluid under pressure to the fluid motor 41 of the power tool. A fluid return conduit 83 is provided leading from the fluid motor 41 to the fluid containing means 17.

In the practical construction shown in Figs. 1. and 2, I have shown the

conduits

66, 86 and 88 as clamped together within the strain relief clamp 90 that is secured to tank 17 by means of the chain 91, so that in the event any pull is exerted upon these conduits by operation of the portable tool, the ends of these conduits attached to the power plant will not become displaced.

In operation the transportable unit containing the hydraulic power plant is moved into position adjacent the working face and the working face is prepared to receive the bit. The portable unit which, in the drawings is shown as a drill, is then positioned to the level required in order to drill a horizontal or an angularly sloping hole as required. The switch 50 on the drill handle 44 is then depressed, which actuates the motor 13, which in turn actuates the fluid flow system, supplying hydraulicfluid to the drill motor 41.. When the drilling 7 operation is completed the switch 50 is released, whereupon the motor 13 is immediately cut off and the hydraulic fluid is no longer supplied under pressure to the motor "41, and the pump motor 41 stops.

It will thus be seen that I have provided a tool that is hydraulically actuated and may be operated at a distance from the power plant supplying the hydraulic fluid pressure, and yet whereby the actuation of the hydraulic power plant is controlled by a switch means that is a part of the tool and remote from the hydraulic power plant itself. g

Various changes may be made to the form of invention herein shown and described without departing from the spirit of the invention or the scope of the following claim.

I claim:

Hydraulic drilling apparatus comprising, in one transportable unit, a hydraulic pump, an electric motor for operating said hydraulic pump, a starter and relay for said electric motor, a hydraulic supply tank connected to said hydraulic pump, and an overload relief valve connected to said hydraulic pump; in another transportable unit, a hydraulic motoig'drill means operatively connected to said hydraulic motor for actuation of said drill means upon operation of said hydraulic motor, supporting handles for said hydraulic motor and drill means, a spring loaded electric switch mounted in one of said handles; a pair of flexible conduits operatively connected to said hydraulic motor, one of said flexible conduits interconnecting said relief valve and said hydraulic motor, and the other of said flexible conduits interconnecting said hydraulic supply tank and said hydraulic motor, and flexible electric conduit means operatively connecting said starter motor and relay to said electric switch; and conduit securing means attached to said pair of flexible conduits and said flexible electric conduit for securing the same to said first mentioned transportable unit and maintaining them in proper interconnected relationship to their respective connections of said first mentioned transportable unit.

UNITED STATES PATENTS Howe Sept. 29, 1925 Slomer Feb. 28, 1956