Patent Application
20180345463
This invention relates to tools for making up and breaking out conduit connections and more particularly to a safety wrench for coupling and uncoupling hammer union type pipe connections.
Fluids, gases, and solids are often transported through conduits such as pipe and hoses which can be subjected to internal pressures. These conduits are typically comprised of multiple conduit segments that are connected together by threaded couplings. One such threaded coupling, a hammer union, utilizes an internally threaded nut having a plurality of lugs extending from its outer peripheral surface to threadedly secure conduit segments having corresponding adjoining male and female ends. A typical threaded union may have only 3 to 4 threads per inch so as to provide a robust connection with the least amount of nut rotation necessary in order to reduce the time required for tightening and loosening the union nut and correspondingly reduce the cost of assembling and disassembling conduit segments. However, the nut must still be tightened to a torque sufficient to avoid leakage of the fluids, gases, and solids being contained and to withstand the anticipated conduit internal fluid pressure to prevent the risks associated with unwanted disengagement of the connected adjoining conduits. Rotation of the lugged nut in one direction will tighten or makeup the union to couple the adjoining conduit segments together at a desired torque to prevent leaks. Rotation of the lugged nut in the opposite direction will loosen or breakout the union for uncoupling of the connected conduit segments. The lugged nut of a hammer union may be rotated by a variety of devices and methods.
One device used to rotate the lugged nuts is a manual handheld wrench or tong that has an elongated handle attached to a head that engages one or more of the outer lugs on the nut. The lugged nut is rotated by securing the wrench head to the lugs on the union nut and applying force to the elongated handle in the desired direction of rotation. Another device and method use to rotate union nut is a handheld sledge-type hammer. A worker uses the handheld hammer to strike the extending lugs on the union nut in a desired direction to rotate the nut to makeup and breakout the hammer union connection.
When conduit connections are made with a hammer or wrench it is often difficult to achieve or verify the torque required or desired for effectively mating the adjoining conduit segments. This is partially due to the differences is size, strength, and fatigue of the worker using the hammer. A larger worker may strike the union lug with more force than a smaller worker thus producing inconsistent torque values to the union being connected. Further, use of a handheld hammer is among the top causes of on-the-job injuries to workers. A worker swinging a hammer or striking or dropping a hammer can cause muscle strains, pinch points, broken limbs, smashed or broken fingers, or other injuries to the worker or others that may get in the way of the hammer. A hammer blow may also cause the hammer or union components to separate and produce shrapnel-like shards of flying metal that may cause eye injuries or other physical injuries to the worker or others in the vicinity. This danger is readily apparent because the makeup or breakdown of lugged nut on a hammer union requires a worker to apply repeated hammer blows to the lugs of the hammer union nut when workers or others are in close proximity. Workers working in such close proximity is common because it is often necessary to have one or more workers holding the conduit segments when another worker is striking the union lugs with the hammer in order to makeup or breakout the conduit connection.
Further, conduits are often assembled or disassembled in an area where flammable gases may be present. Striking a lug on a union nut with the head of a sledgehammer may lead to a glancing blow that creates sparks. These sparks can ignite such flammable gases. The use of such manual hammers increases the risk of explosions and fires that can cause severe burns or even death of surrounding workers and extensive property damage at the location.
Other problems are created when manual tongs or wrenches are used to makeup and breakdown the lugged nuts of hammer unions. Such manual tongs or wrenches require a worker to apply a torque with the handle of the tong or wrench sufficient to turn the lugged nut to a desired torque to makeup the connection of adjoining conduit segments and then to turn the lugged nut in the opposite direction with a torque sufficient to breakout the connection of the adjoining pipe segments. Often the moment force or torque applied to the threaded union by the tong jaws is not sufficient to adequately seal the conduit ends together which may result in leaks or cause the conduit to decouple under pressure. Further, a manual tong or wrench exposes the worker to the risk of back injuries when applying force on the handle of the tong or wrench the necessary to makeup or breakout the connection. Often the conduit segments are located in areas were a worker cannot be in a position to apply sufficient or consistent torque with a manual tong or wrench to properly makeup or breakout a union connection. Variables associated with the size and strength of a worker using a manual tong or wrench may result in the application of improper torque on the union connections and lead to inconsistent results when the connections are madeup. A union connection madeup with the application of improper torque may lead the connection to fail causing leakage of conduit contents and increase the risk of personal injuries and property damage associated with such leakage.
From the above it can be seen that there is a need for a replacement of conventional handheld hammers and manual wrenches and tongs used to makeup and breakdown the unions used to connect adjoining conduit segments in order to reduce the time to make conduit connections, reduce conduit sealing problems, and reduce the risk of harm for the workers and the risk of property damage at the work site location.
The present invention provides a safety wrench for coupling and uncoupling hammer union type connections that will eliminate the need for workers to use manual wrenches or tongs or manual hammers to makeup or breakout a threaded hammer union connection. The safety wrench is generally intended for use on unions having a plurality of lugs that extend radially from the outer peripheral surface of the union. Such unions are used to connect the adjacent threaded ends of conduit segments.
The safety wrench has a retractable bolt made from ferrous or non-ferrous metals with a hammer face that applies an impact force to the union lugs for rotation of the union. The bolt of the safety wrench is cocked or engaged to apply a blow to a union lug by a ratchet mechanism. When the bolt is cocked or engaged by the ratchet mechanism, the bolt is retracted against a compression spring positioned within a spring bore in the bolt to a position away from the lug of the union to be rotated. When the bolt is disengaged from the ratchet mechanism, the compression spring moves the bolt rapidly so that the bolt is extended toward the lug of the union to impact the bolt hammer face against the union lug with a predetermined impact force. The impact of the hammer face of the extended bolt on the union lug will rotate the union to threadedly connect or makeup the adjoining threaded conduit segments. The safety wrench may also be positioned on the union to allow the hammer face of the retractable bolt to impact the union lug in the opposite direction in order to rotate the union to disconnect or breakdown adjoining conduit segments.
The retractable bolt is slidably retained within the frame of the safety wrench in a bolt race slot to facilitate retraction and extension of the bolt within the hammer frame. In one embodiment the ratchet mechanism employed to engage and disengage the bolt includes a hydraulic or pneumatic cylinder and piston. In an alternate embodiment the ratchet mechanism employed to engage and disengage the bolt includes a hand operated lever. In still another embodiment the ratchet mechanism employed to engage and disengage the bolt includes a pinion gear mechanism.
Use of safety wrench will eliminate the need for worker to use manual hammers and manually manipulated wrenches and tongs and serve to insure that all unions are consistently madeup to a predetermined desired torque. Use of the safety wrench will thus reduce the aforementioned risks of injuries to workers or damage to property and will result in an overall reduction in the costs associated with the use of hammer union connections.
In the drawings, features that are well established in the art and do not bear upon points of novelty are omitted in the interest of descriptive clarity. Such omitted features may include the details for operation of hydraulic or pneumatic cylinders such as pumps, fluid lines, and valves and connection components such bolts, nuts, screws, washers, bearings, screws, threaded junctures, weld lines, sealing elements.
Bolt 20, shown in
As shown in
Lever plates 40 are pivotally mounted between the side plates 14 of the frame 12 to pivot on bolt pin 26 that extends transversely between side plates 14 of frame 12 through the lever plates 40 and the forward bolt race slots 23A of bolt 20. Lever plates 40 have an upper section 45 above bolt pin 26 and a lower section 47 below bolt pin 26. A pawl pin 28 is mounted on the lower section 47 of the lever plates 40 so that pawl pin 28 will extend transversely between side plates 14 of frame 12 through in lever slots 17 in the side plates 14. When the upper section 45 of lever plates 40 are pivoted on bolt pin 26 toward the forward end 11 of safety wrench 10, the lower section 47 of the lever plates 40 are pivoted toward the rearward end 9 of safety wrench 10 to move pawl pin 28 rearward along the lever slots 17.
The bolt 20 is releasable restrained from forward movement and engaged for rearward movement with respect to frame 12 by bolt restraint 31. The bolt restraint 31 is comprised of pawl 27 pivotally mounted on pawl pin 28. Pawl 27 is biased toward the lower surface of the bolt 20 by torsion springs 30, shown separately in
A hydraulic cylinder and piston assembly comprised of a cylinder 42 and a piston rod 44 is provided to pivot the lever plates 40. The cylinder 42 is pivotally attached to the frame 12 by cylinder mount 46. The piston rod 44 is pivotally attached to the lever 40 by piston mount 48.
When the pawl 27 is engaged in the most rearward ratchet tooth 29, continued forward pivotal movement of the upper section 45 the lever plates 40 will disengage pawl 27 from the bolt restraint 31 causing compression spring 21 to rapidly extend, which in turn will rapidly move bolt 20 toward the forward end 11 of frame 12 as shown in
Compression spring 21 is shown as a coiled compression spring but may be any type of compression spring including a gas compression spring. Compression spring 21 may be selected to provide a desired predetermined spring force on bolt 20. Additional compression springs 22 as shown in
The sequence of operation of safety wrench embodiment 100 is shown in
Moving the lever handle 41 toward the forward end 11 of safety wrench 100 will pivot the lever plates 40 about bolt pin 26 and move the lower section 47 of the lever plates 40 rearward. The rearward movement of lower section 47 of the lever plates 40 will move the pawl pin 28 rearward in lever slots 17 as shown in
When the pawl 27 is engaged in the most rearward ratchet tooth 29, continued forward pivotal movement of the upper section 45 the lever plates 40 will disengage pawl 27 from the bolt restraint 31 causing compression spring 21 to rapidly extend, which in turn will rapidly move bolt 20 toward the forward end 11 of frame 12 as shown in
As best illustrated in
The rack and pinion mechanism 50 of safety wrench 200 shown in
The pinion gear 60 has an extending gear shaft 64 shown in
Because many varying and different embodiments may be made within the scope of the inventive concept disclosed in this specification, and because many modifications may be made in the described embodiments, it is to be understood that the details herein are to be interpreted as illustrative and not in any limiting sense.
