The present invention relates to a lightweight, high pressure tool assembly. More particularly, the present invention relates to a high pressure tool assembly operable from a bucket truck. Still more particularly, the present invention relates to a high pressure tool assembly including an intensifier for increasing pressure of an operating fluid, a hand control valve connected to a tool for controlling operation thereof, and a hydraulic manifold connected to the intensifier and the hand control valve to control to control operation of the intensifier responsive to the hand control valve.
There is a growing demand for lighter weight, ergonomic utility tools, such as crimping and cutting tools, to reduce operator injury. Of particular interest is the need for lighter weight tools that are used by utility workers. Much of the work performed by utility workers is performed while standing within the bucket of a bucket truck. The nature of the work often requires the workers to hold a crimp tool in position on an electrical connector with their arms extended. The utility tools are generally heavy and awkward to operate. With rising concerns regarding preventing personal injury while operating such equipment, ergonomics are an important consideration. The weight of the utility tool becomes critical, as does the crimp cycle times.
Crimping and cutting tool designs vary in size, weight and configuration. Although most utility tools are high pressure (10,000 psi), low pressure (1500-3000 psi) utility tools are also used when working from the bucket of the bucket truck.
Low pressure crimp tools can be heavy and very unbalanced. However, in most cases, low pressure crimp tools crimp quickly. These low pressure crimp tools are typically powered by a hydraulic pump source, such as directly from the bucket truck. Low pressure operated crimp tools traditionally incorporate a large piston that is subjected to 1500-3000 psi operating pressure. The disadvantage of these tools is that they are heavy, big and not well balanced. From an ergonomic point of view, they score very low.
High pressure crimp tools are relatively light weight and ergonomic, however, they crimp slowly. These tools may also require gripping in an area of high pressure, which can be dangerous if there is a failure.
High pressure crimp tools are usually operated with an intensifier or a booster pump, which is powered by a bucket truck circuit. The booster or intensifier operates on low pressure and increases or intensifies the output to the 10,000 psi operating pressure requirement for high pressure tools. The booster pump may incorporate a hydraulic motor, such as gerotor or gear motor type, which can drive a high pressure pump to deliver 10,000 psi oil to a remote crimp head via a hydraulic hose. These units tend to be very slow during the high pressure delivery cycle as a result of low volumetric flow rates. There are also intensifiers that have reciprocating pistons that incorporate shuttle spools to sequence the pistons. These units are slow and have many moving parts.
Accordingly, a need exists for an improved high pressure tool that is easily handled and operates quickly.
Accordingly, it is a primary objective of the present invention to provide a high pressure tool that is lightweight and easy to operate.
A further objective of the present invention is to provide a high pressure tool that operates quickly.
Another objective of the present invention is to provide an improved intensifier for a high pressure tool.
Another objective of the present invention is to provide an improved hydraulic manifold for an intensifier for a high pressure tool.
The foregoing objectives are basically attained by a high pressure tool assembly including a tool and a hand control valve connected to the tool. A hydraulic manifold is fluidly connected to the hand control valve. An intensifier is fluidly connected to the hydraulic manifold and to the tool. The intensifier increases the pressure of an operating fluid supplied to the tool. A first fluid circuit is formed between the hand control valve, the hydraulic manifold and the intensifier. The first fluid circuit operates at a first pressure. A second fluid circuit is formed between the intensifier and the tool. The second fluid circuit operates at a second pressure. The second pressure is larger than the first pressure. The second fluid circuit is isolated from the first fluid circuit.
The foregoing objectives are also basically attained by a method of operating a high pressure tool. A hand control valve sends a signal to a hydraulic manifold. A first operating fluid is supplied from the hydraulic manifold to a first connection of an intensifier responsive to the received signal. A second operating fluid is pressurized to a high pressure with a piston assembly of the intensifier responsive to the operating fluid received by the first connection. The high pressure second operating fluid is supplied to the tool.
Other objects, advantages and salient features of the invention will become apparent from the following detailed description, which, taken in conjunction with the annexed drawings, discloses exemplary embodiments of the present invention.
As used in this application, the terms “front,” “rear,” “upper,” “lower,” “upwardly,” “downwardly,” and other orientational descriptors are intended to facilitate the description of the exemplary embodiments of the present invention, and are not intended to limit the structure thereof to any particular position or orientation.
The above aspects and features of the present invention will be more apparent from the description for an exemplary embodiment of the present invention taken with reference to the accompanying drawings, in which:
Throughout the drawings, like reference numerals will be understood to refer to like parts, components and structures.
DETAILED DESCRIPTION OF AN EXEMPLARY EMBODIMENT
The exemplary embodiment of the present invention provides a quick-operating and lightweight tool that is easily handled and operated. The following description is directly to a high pressure crimping tool, although the present invention is equally applicable to any high pressure tool, such as a cutting tool.
The exemplary embodiments of the present invention include a bucket truck tool assembly 11 operable by a user from a bucket truck 12, as shown in
The bucket truck tool assembly 11 includes a hand control valve 17, an intensifier 18 and a hydraulic manifold 15 for operating a high pressure crimping tool 16, as shown in
A first fluid circuit is formed between the hand control valve 17, the hydraulic manifold 15 and the intensifier 18, as shown in
A plurality of pilot lines 37, 38 and 39 are connected to the hand control valve 17, as shown in
Operating fluid, such as hydraulic oil, is supplied between the intensifier 18 and an oil reservoir 10 on the truck, as shown in
A guard 59 is connected to the hand control valve housing 46, as shown in
The intensifier 18, as shown in
Mounting tabs 51 extend outwardly from opposite sides of the hand control valve housing 46, as shown in
The crimping tool 16 has a fixed crimping member 56 and a movable crimping member 57, as shown in
When the trigger 31 of the hand control valve 17 is actuated, a pilot signal (preferably, hydraulic) is sent to a directional control valve 60 in the hydraulic manifold 15 through the third pilot line 39, as shown in
Releasing the trigger 31 of the hand control valve 17 stops the pilot signal being sent to the directional control valve 60 through the third pilot line 39, which turns the directional control valve 60 off by moving the directional control valve to the retract position 67. The supply of operating fluid from the first pilot line 37 is no longer connected to the third pilot line 39 when the trigger 31 is released, such that the third pilot line 39 does not send the operating fluid to the directional control valve 60. A spring member 74 moves the directional control valve 60 to the retract position 67, such that the directional control valve 60 directs the ram of the crimping tool 16 to return to a home position in preparation for the next crimp cycle in response to the signal from the hand control valve 17. The ram is driven in the second direction by supplying oil to a first connection 68 of the intensifier 18 to retract a piston assembly 78 therein, thereby discharging the hydraulic oil from the intensifier 18 through a second connection 69 to a return line 58.
The intensifier 18 is directed by the directional control valve 60 of the hydraulic manifold 15 to perform the desired function, i.e., crimping or retracting the ram to the home position. The directional control valve 60 of the hydraulic manifold 15 is directed by the hand control valve 17 to cause the intensifier to provide the operating fluid pressure for the tool to perform the function (crimping or retracting) selected by the user.
The intensifier 18 increases or intensifies the pressure of supplied hydraulic oil and a hydraulic manifold 15 is connected to the intensifier to control the supply of hydraulic oil thereto. The hydraulic oil is supplied from the intensifier 13, through the hydraulic manifold 15 to the tool 16, such as a crimping or cutting tool. The hand control valve 17 is directly mechanically connected to the tool 16 to control operation of the hydraulic oil supplied to the tool 16.
The intensifier 18 uses low pressure hydraulic oil supplied at approximately 1500 psi and intensifies the pressure to 10,000 psi, thereby obtaining an intensification ratio of approximately six. The low pressure oil is supplied through a supply line 21 from the truck pump 93 to the intensifier 18. The piston assembly 78 movably disposed in the intensifier 18 is preferably unitarily formed as a single member.
Operation and Assembly
The bucket truck valve 32, as shown in
When the bucket truck valve 32 is in the first or open position 64, hydraulic oil is supplied to the directional control valve 60 through the supply line 21 and to the hand control valve 17 through the first pilot line 37. The directional control valve 60 is movable between the crimping or second position 66 and a retract or return or first position 67, as shown in
A flow control valve 72 is disposed in the hydraulic manifold and is connected to the supply and return lines 21 and 58 before the directional control valve 60, as shown in
A pressure reducing valve 73 is disposed in the hydraulic manifold 60, as shown in
Hydraulic oil is supplied to the hand control valve 17 through the first pilot line 37, as shown in
First, second and third ports 82, 83 and 84 in the hydraulic manifold 15 receive the first, second and third pilot connections 40, 41 and 42, respectively. As shown in FIGS, 6, 10 and 11, the directional control valve 60 of the hydraulic manifold 15 is spring-biased to the first position 75 such that the second and third pilot lines 38 and 39 are in fluid communication. A port 85 in a valve member 86 connects the second and third pilot lines 38 and 39. Accordingly, operating fluid is not supplied to the directional control valve 60 such that the directional control valve is in the retract position 67 because the first pilot line 37 is not connected to the third pilot line 39.
Activating the trigger 31 of the hand control valve 17 moves the valve member 86 to overcome the spring bias of the spring member 77, such that the port 85 connects the first and third pilot lines 37 and 39, as shown in
To achieve intensification, hydraulic oil is supplied to the second side 71 of the large diameter (e.g., 5.68 inch diameter), low pressure flange 65 of the piston assembly 78 disposed in the intensifier 18 through a crimping inlet port 23, as shown in
To perform the crimping cycle, the user activates the trigger 31 of the hand control valve 17. Hydraulic oil is directed to the hydraulic manifold 15, which redirects oil to the large diameter piston 65 of the intensifier, which starts the crimp cycle. Hydraulic oil at 1500 psi acts on the second side 71 of the piston flange 65 and applies a high force onto the small diameter piston rod 24. The small diameter piston rod then compresses the hydraulic oil in the small cylinder 27 to approximately 10,000 psi. The intensified high pressure oil is forced out of the intensifier 18 through a high pressure hose 29 connected to a high pressure outlet 28, which is connected to the remote crimp tool 16. The remote crimp tool 16 is designed to make a good crimp at 10,000 psi operating pressure. When the recommended pressure of 10,000 psi is reached, a pressure relief valve 61 opens to relieve the pressure back to an intensifier reservoir 30, as shown in
The intensifier reservoir 30 is isolated from the truck reservoir 10 in the truck. The crimp cycle is complete when the pressure relief valve 61 opens. When the pressure relief valve 61 opens, an audible pop is detected, and the 10,000 psi hose 29 connected coupled to the remote crimp tool 16 flexes as pressure is quickly released. The audible pop of the pressure relieve valve 61 and the flex of the hydraulic hose 29 are indications to the operator that the crimp cycle is complete. Additionally, the large piston 65 in the intensifier 18 bottoms against a lower surface 94 of the cylinder 26 and the thump noise is heard.
As a result, the operator releases the activate trigger 31 on the hand control valve 17 and oil is no longer directed to the hydraulic manifold 15 from the hand control valve, thereby redirecting oil to the rod side on the first side 70 of the piston flange 65 from the supply line 21. The spring member 77 moves the hand control valve 17 to the first position 75, such that the first and second pilot lines 37 and 39 are no longer connected. The spring member 74 of the directional control valve 60 then biases the directional control valve 60 to the retract position 67. The shift of the directional control valve 60 causes the hydraulic oil supplied to the directional control valve 60 to be directed through the first line 68 to the connection port 22 in the intensifier and through conduit 25 to the low pressure cylinder 26 on the first side 70 of the piston flange 65. Accordingly, the piston assembly 78 retracts to the home position, as shown in
The intensifier 18 is powered by a bucket truck circuit 32 and provides intensified oil that is directed through the high pressure hydraulic hose 29 to the crimping tool 16. Intensification of the oil is performed with a single stroke motion of the piston assembly 78 within the intensifier 18. The oil delivery to the crimping tool 16 is pressure limited to approximately 10,000 psi by the pressure relief valve 61 within the intensifier 18. This intensifier 18 causes the tool 16 to perform a full crimp in approximately two seconds because it displaces a large amount of hydraulic oil in a single stroke motion. The intensifier 18 also has few moving parts, thereby simplifying assembly and operation thereof. The pressure relief valve 61 within the high pressure cylinder 27 of the intensifier 18 opens to relieve pressure when a predetermined pressure value (10,000 psi) is reached for a good crimp.
When the pressure relief valve 61 opens, a large amount of oil from the high pressure cylinder 27 and the tool 16 is relieved into the intensifier's reservoir 30. The high pressure relief valve 61 stays open until the piston flange 65 reaches the bottom of its stroke. At an end of the stroke, the relief valve 61 closes. When the user releases the hand control valve lever 31, the intensifier 18 enters retraction mode. As the piston rod 24 retracts, a check valve 32 within the high pressure cylinder 27 is forced open, allowing the high pressure cylinder 27 to fill with oil from the intensifier reservoir 30. Thus, the hydraulic oil in the intensifier reservoir 30 and the tool 16 is isolated from the truck oil and is therefore less susceptible to contamination.
The intensifier 18 is operator controlled by the low pressure hand control valve 17, which is held in the palm of the user's hand and allows activation with the push of the lever 31 and retraction with the release of the lever 31. The hand control valve 17 provides the handle 34 that shifts the center of gravity of the crimping tool 16 and hand control valve 17 to a more ergonomic position, thereby reducing operator strain. There are no high pressure components held in the user's hand. The hand control valve 17 is modular and can be removed by the user for crimp and cut tool swap out. The protective shield 59 (
The hydraulic manifold 15 allows the user to operate the intensifier 18 in crimping and retract positions 66 and 67. When the directional control valve 60 of the hydraulic manifold 15 is in the retract position 67, the piston assembly 78 of the intensifier 18 returns to the home position in preparation for the next crimp cycle.
Although described with regard to the crimping tool 16, the present invention is also applicable to other hydraulically operated tools, such as a cutting tool. As shown in
The foregoing embodiment and advantages are merely exemplary and are not to be construed as limiting the scope of the present invention. The description of an exemplary embodiment of the present invention is intended to be illustrative, and not to limit the scope of the present invention. Various modifications, alternatives and variations will be apparent to those of ordinary skill in the art, and are intended to fall within the scope of the invention as defined in the appended claims and their equivalents.
This application claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Application Ser. No. 61/663,830, filed Jun. 25, 2012, which is hereby incorporated by reference in its entirety. This application contains subject matter related to co-pending U.S. patent application Ser. No. (to be assigned), entitled “Bucket Truck Intensifier,” filed Jun. 24, 2013.
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