In general, the invention relates to powder-actuated tools, and more specifically to an adapter for a powder-actuated tool.
An electrical transmission grid is used to transmit power from power plants to individual buildings using a combination of overhead transmission lines and buried or underground transmission lines. The transmission grid is configured to be modular, allowing for utility workers to replace old or damaged power lines, and additionally, to connect existing transmission lines to new lines. While a variety of connectors are used for these purposes, one particular wedge connector, referred to as an AMPACT® tap connector, has been widely used. While AMPACT® tap connectors are made in a variety of shapes and dimensions for any number of unique connections, the method of installation is relatively universal: a tapered wedge is forced between two conductors within a C-shaped housing or sleeve. This type of wedge connector generally ensures a solid electrical connection that can reliably withstand the elements, including weathering and thermal expansion.
Installation of these wedge connectors has become relatively efficient with the use of a powder-actuated tool. Variations on this tool have been used for some time; a more recent example is shown in U.S. Pat. No. 6,851,262 to Gregory et al., which is incorporated by reference in its entirety. This tool is commonly referred to as an AMPACT® connecting tool, and has become standard for utility crews working on high-voltage electrical lines. The AMPACT® tool uses the explosive force of a powder charge or cartridge to drive a steel ram that pushes the wedge of the connector into place, thus making a secure connection.
Despite the availability of pneumatic and electric versions of the AMPACT® tool, the powder-actuated version remains the most popular, as the powder-actuated tool does not require additional cables or batteries that may impede workflow. However, installing and removing the cartridge from the AMPACT® tool requires removal of a threaded breech. Loosening and tightening that breech takes time. Furthermore, the repetitive motion of loosening and then tightening the tool's breech can potentially cause strain to the operator's hands and wrists over time.
The usual solution to such issues of repetitive motion and hand strain is to use a tool to perform the task in question. However, hand tools may be difficult to use in threading and unthreading the breech, and offer the user little relief, either in terms of time or physical effort. A power tool, such as a battery-powered screw gun, would be able to perform the function, but for one problem: AMPACT® tools are not configured to accept or be manipulated with other tools. The knob that releases the breech is typically knurled for hand gripping, but is too large in diameter to grip with common socket drivers. Moreover, that portion of the breech carries the firing pin and various gas-release ports, which cannot be obstructed if the tool is to function properly.
One aspect of the invention relates to an AMPACT® powder-actuated ram connecting tool with a gas release knob that has been modified so that it can be turned using a torque-applying tool. The modification comprises an adapter that is attached to the rearward-most surface of the gas release knob. The adapter itself has a form that can be easily engaged by torque-applying tools, and is typically of lesser width or diameter than gas release knob itself. For example, the adapter may have the form of a hexagonal nut or drive head, so that it can be driven by a hex wrench or socket, and may be arranged on the gas release knob in such a way that it does not obstruct gas release ports in the gas release knob.
Another aspect of the invention relates to a part assembly for an AMPACT® powder-actuated ram connecting tool. The part assembly is designed to replace the gas release knob and related structures of a typical tool, and includes a hollow cylindrical portion with a set of external threads that is capped on one end by a gas release knob of greater diameter than the cylindrical portion. Formed on the rearward-most surface of the gas release knob is an adapter that allows the gas release knob to be turned by a torque-applying tool. The adapter may, for example, have the shape and features of a hex head. The adapter is solid, and gas release ports extend through both the gas release knob and the adapter, terminating and opening at the rearward-most surface of the adapter. In some embodiments, a raised striking surface may protrude a small height from the rear of the adapter.
Other aspects, features, and advantages of the invention will be set forth in the description that follows.
The invention will be described with respect to the following drawing figures, in which like numerals represent like features throughout the figures, and in which:
As illustrated in
The tool 12, as illustrated in
The power unit 52 generally comprises the threaded coupling 32, the ram 26, and a coupling nut 36. The coupling 32 is threaded in order to allow for relatively fine adjustments of the power unit 52 relative to the tool head 50. Adjustments to the length of the tool 12 may be made by rotating the coupling nut 36, which is configured to allow for a variety of sizes of wedge connectors 20 be used. As shown in
The coupling 32 serves as a housing for the ram 26, in that the ram 26 is slideable within and may fully retract into the coupling 32. One end of the ram 26 is used as a striking surface that extends past the coupling 32 (i.e., for striking the wedge 18 during installation, or striking the sleeve 22 in order to remove the connection 20), whereas the opposite end of the ram 26 has a firing pin (not shown) and is configured to be driven by an explosive force produced by a cartridge housed within the breech cap assembly 58. The striking end of the ram 26 is configured to protrude from the coupling 32 a fixed amount, such that the drive end of the ram 26 is prevented from leaving the coupling 32 and the breech cap assembly 58.
Additionally, near one end of the breech cap assembly 58 is the gas release knob 56, which is threaded and removably attached to the breech cap sleeve 54. The rear surface of the gas release knob 56 serves as a striking point for a hammer H, as the impact force of the hammer H on the knob 56 drives a firing pin into a powder cartridge within the breech cap sleeve 54 to fire it. Prior to firing the charge, the gas release knob 56 would be tightened in place, such that the breech is sealed and the gases produced by the firing drive the ram 26 forward a fixed distance, out of the coupling 32. Once a cartridge has fired, the gas release knob 56 is usually loosened partially, allowing gas to escape. However, during routine operation, the gas release knob 56 is not detached completely from the breech cap sleeve 54, as will be described in more detail below.
As shown in
The adapter 24 does not alter the basic way in which an AMPACT® tool is used and allows for normal operation of the tool 12 using an operator's hands, if the operator so desires. However, the adapter 24 also allows an operator to use a torque-applying hand or power tool to assist in both opening and closing the gas release knob 56 and the breech cap sleeve 54. As those of skill in the art will appreciate, this allows tool-driven clockwise and counterclockwise rotation of the gas release knob 56, with the axis of rotation aligned with the longitudinal centerline of the tool 12.
Any type of torque-applying tool may be used to engage and drive the adapter 24. In this description, a torque-applying tool is any type of tool other than a human hand that can engage and apply torque to the adapter 24 to turn the gas release knob 56. Torque-applying tools may include traditional fixed-size wrenches, adjustable wrenches, socket wrenches, flare wrenches, and screw guns. The term “screw gun,” as used in this description, refers to a handheld, powered torque-applying tool. While a screw gun is typically electrically powered (e.g., by a rechargeable battery pack), pneumatic and hydraulic screw guns may be used as well. The use of a power tool may reduce the “cycle time” of the tool—i.e., the amount of time it takes to release gas from the breech and re-load another powder cartridge.
As is shown in
Any part of the adapter 24 may be engaged to drive the gas release knob 56 and breech cap sleeve 54. For example, if the adapter 24 has threads disposed along an interior surface 72, an appropriately threaded rod may be used to engage the adapter 24.
Of course, the adapter 24 need not resemble a hex nut; in other embodiments, the adapter 24 could be of any size or shape, and it could be either male or female—so long as it can be engaged by a hand tool or power tool. If the adapter 24 is male, it may resemble, e.g., a square nut, a cap nut, etc. A female adapter may have a socket for, e.g., an Allen or Torx® key. In some cases, the adapter 24 could have both male and female engaging features. For example, the exterior surface of the adapter 24 may be configured to engage with a hex socket, while the interior surface 72 of the adapter 24 may be configured to engage with an Allen key.
In
Furthermore, as
In
While
As shown in
Once the retaining spring 64 catches on the threads of the gas release knob 56, continued operation of the screw gun will ultimately remove the breech cap, as shown in task 114.
Method 100 continues with task 116, and the user either replaces a spent cartridge with a new one or simply inserts a new cartridge. Once task 116 is complete, the breech cap assembly 58 is replaced on the power unit 52 using a screw gun engaged with the adapter 24, as shown in task 118. Once task 118 is completed, the gas release knob 56 may be tightened using the adapter 24 and a screw gun, as shown in task 120 of method 100. While shown separately for ease in description, there may be very little distinguishing task 118 from task 120; these two tasks 118, 120 may be completed in one swift motion using a screw gun.
Once task 120 has been executed, the tool 12 is prepared for use, and it is tightened against the wedge 18 (task 122), before being fired by striking the adapter 24 with a hammer H or any suitable impact device (e.g., the butt-end of a torque applying tool), as shown in task 124. Once task 124, has been completed, a wedge connection has been formed, and method 100 is complete.
Like in the tool 12 described above, an adapter 214 is fixedly attached to the rear surface 216 of the gas release knob 202. The adapter 214 of the illustrated embodiment is male and, like the adapter 24 described above, has a hexagonal shape, mirroring that of a hexagonal drive head suitable for use with a traditional hex socket driver. Of course, other shapes are possible. Like the adapter 24, the adapter 214 is of a smaller diameter or width than that of the gas release knob 202, such that it is adapted to be engaged and driven by a torque-applying tool. A ¾-inch width, adapted for a ¾-inch socket, is particularly suitable in the case of a hex-shaped adapter 214, although other widths may be used as well.
The adapter 214 differs from the adapter 24 in some respects. For example, as was described briefly above, adapters according to embodiments of the present invention may be solid. More particularly, where the adapter 24 has a large opening 70 that permits access to gas portholes 60 that extend through the gas release knob 202, the adapter 214 has no such opening. Instead, the adapter 214 is solid. The necessary portholes 218, 220, as well as the center hole 222 that is aligned with the firing pin, extend through the thickness of the gas release knob 202 and the adapter 214.
The adapter 214 differs from the adapter 24 in some other respects as well. For example, the gas release knob 202 of the adapter 214 is not knurled. While the gas release knob 202 may be knurled in some other embodiments, since the adapter 214 allows the assembly 200 to be actuated with a tool, the need for knurling, which allows for easier manual actuation, is vastly reduced.
Additionally, as can be seen best in
The projection 224, which may extend a few millimeters beyond the main portion of the adapter 214, is not long enough to cause problems seating a socket or other driver on the adapter 214. However, it provides a flat striking surface for striking the rear of the assembly 200 to fire the powder charge and actuate the tool 12, as illustrated in
As with the adapter 24 of
While the invention has been described with respect to certain embodiments, the embodiments are intended to be exemplary, rather than limiting. Modifications and changes to the invention may be made within the scope of the invention.
This application claims priority to U.S. Provisional Patent Application No. 62/489,938, filed Apr. 25, 2017, the contents of which are incorporated by reference in their entirety.
Number | Date | Country | |
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62489938 | Apr 2017 | US |