Heaw-Dutv PEX Clamp Installation Tool

Technical Field

The present invention relates generally to tools for use with clamps, and more particularly to a heavy-duty installation crimping tool for forming the "ears" commonly found on pinch-type clamps.

Background Art

Clamps are available in a wide variety of configurations for meeting the requirements of particular applications. For example, hose clamps are commonly used for mounting hose ends on various objects, such as radiators, water pumps, heaters, etc. Plastic pipe is used in many plumbing applications and for irrigation applications.

Different types of clamps are available. U.S. Patent No. 2,614,304, to Oetiker, discloses a clamp having outwardly-projecting, deformable ears to facilitate installation. Once the clamp is in place, the ears are squeezed together with a suitable tool such as a pair of pliers to hold the clamp in place and to prevent leakage from the hose or pipe. Clamp structures provided with so-called "Oetiker" ears have enjoyed enormous commercial success.

U.S. Patent No. 3,402,436 discloses an ear stiffening rib that improves the ability of such clamps to carry load while at the same time eliminating the need for special crimp tools. An ear with the stiffening rib would form into an acceptable ovate shape as opposed to a much weaker dunce-cap form associated with the prior art.

U.S. Patent No. 5,070,580 discloses an Externally Strengthened Ear. By placing a secondary and heavier gauge ear cap over the existing clamp ear and then crimping both parts in unison, the holding ability of the clamp is increased.

U.S. Patent No. 5,282,295 discloses a more robust stiffening rib to improve upon the "ears" load bearing capacity.

U.S. Patent No. 5,669,113 discloses an improvement for the clamp and illustrates that by forming lobes on the upper corners of the "ear" a secure purchase with the crimp tool jaw is created, thus effectively eliminating clamps damaged by faulty crimps (i.e. slippage of the jaw off the ear at installation).

All of these improvements were directed at improving the load bearing capacity of the ear. The need for increased load was market driven by such things as use on pressurized applications (versus non-pressure or very low pressure), use on hose/tube materials that are of increased hardness (i.e. underground sprinkler / irrigation systems), and use in the home construction market for PEX plumbing applications.

Current market applications are particularly challenging in that PEX tubing (per ASTM F 876-01) is very hard and rigid. PEX tubing can be used for both hot and cold water systems that may be at pressures of up to 100 psi for prolonged periods of time. Generally speaking, this market is a professional contractors market, however, it is expected that the market will expand into the home repair and do-it- yourself markets as well.

Ear type clamps rely upon pinching down of a portion of the clamp to close the diameter of the clamp. Such pinching action places the band portion of the clamp in tension causing the band to stretch lengthwise during the pinching process, and forms the ear into a more circular shape. Current versions of clamps are made of heavier gauge and wider materials than previously seen in the industry, but still have stiffening ribs in the ear portion to locally increase the stiffness, the load carrying ability, and to prevent vertical buckling or "dunce-capping" of the ear. The robust

nature of the new clamp puts increased stress and strain on both the installation tools used and the operators installing such clamps.

There remains a need, then, for a robust device that can achieve the squeezing of a heavy gauge clamp. There remains a need for a tool that can provide sufficient force to crimp the ears on a clamp without requiring extra human effort. Moreover, there remains a need for a tool that can squeeze the clamp and re- flatten the ear after squeezing.

The present invention addresses these problems encountered in installing such clamps. Heretofore there has not been a clamp installation tool with the advantages and features of the present invention. These improvements result in a significant increase in load bearing capacity of the "ears", resistance to tube pull-off type loading, increased ability to create a seal between clamped components, and decreased operator effort.

Disclosure of Invention The present invention is concerned with the ergonomics of a new tool as well as the degree of tightness achieved by pinch-type (PEX) clamps in the field.

Throughout the history of pinch clamp usage, operators often wondered just how tight is the clamp being installed and is it tight enough for the specific application. An installed pinch clamp should provide a sufficient seal such that, pull- off resistance of the clamp is sufficiently high to cause the tube to fail mid-length while the clamped end remains attached to its fitting, without drifting from its original position. Once the clamp is put on and the installation tool is removed, the ear opens slightly due to natural spring-back of the clamp material, due to the tensile load stored in the band, and due to energy stored in the compressed tubing. The general guideline offered to the concerned public is that the "ear will spring open slightly" after

installation and for general purposes a visible gap at the root of the pinched ear will be around 1/32". The problem comes about by the fact that many operators are not capable of determining the gap size with any degree of precision and/or consistency. In order to provide a pinch clamp with tighter seal of heavier gauge material, a more robust, heavy-duty tool is needed to install the clamp successfully. Additionally, over repeated installations the pivot points of existing installation tools wear, the wear being compounded by the higher forces needed for heavy duty PEX clamp. As this wear occurs gradually with time, it is not readily apparent to the operator. Eventually, worn-out tools are inadvertently used to make clamp installations resulting in large gaps that do not meet the standard of what the clamping system can tolerate. The consequence is failed connections and leaking water supply systems.

It has been learned that the tighter the ear remains, the higher the tube pull-off resistance, and the better the resultant seal. One approach to creating a tighter clamp is to use heavier gauge material. However, a difficulty with using heavier gauge material and trying to obtain a tighter seal is that present installation tools cannot withstand the demand of the workload. Of particular concern is the amount of grip strength required to successfully close a tool. While the effort is high at normal room temperatures, the effort required grows in magnitude at a cold work site or for test assemblies prepared at cold temperatures. Such activity requiring large human effort will result in:

1. operator injuries and/or medical claims

2. mis-aligned, side-loaded, or otherwise damaged clamps

3. premature tool failure or wear beyond the anticipated service limit.

In testing of prior art tools (Figure 1), an operator was required to 109 pounds of gripping type force in order to fully crimp a 1 " PEX clamp. Despite the fact that

two hands may be used on a prior art tool, the effort is too extreme for most people to manage safely. In addition, the span or angle of the two levers when jaws first make contact with a clamp is too large (10 ¹ Zi") for most people and well beyond industry recommendations of 3 ¹ A" max. In contrast, the present invention has greatly reduced the operator effort to a comfortable 37 pounds and the mechanical advantage offered by the toggle arrangement allows this effort to drop off to nearly zero at the completion of the squeezing cycle.

It has been determined, through experimentation, that two stage forming of the ear results in a better seal; the first stage being squeezing the ear, the second stage being re- flattening the ear. The re-flattening of the ear tends to cause the clamp to retain its sealed position better.

Figures 2a-d illustrate the history of the problem and attempted solutions associated with ear style clamps. In Figure 2a, an un-ribbed ear clamp is pinched by a standard tool resulting in a weak dunce-cap shaped ear form, leaving a gap of dimension "a". In Figure 2b, an un-ribbed clamp is installed with a prior art tool having a flat insert to limit the ear deformation, which yields an ear form that is stiffer and of lower profile having a gap of dimension "b". Figure 2c shows an improved ribbed-ear clamp installed with a standard prior art tool, illustrating that the flat tool insert is not needed if a ribbed-ear type clamp is used. The resulting profile is low and has a gap of dimension "c". Figure 2d illustrates an improved ribbed-ear clamp installed with the tool of the present invention using a two-step pinching and reforming process. The resulting clamp has a low profile and leaves a gap of dimension "d". In all cases, gap "d" is smaller than gap "c", which is smaller than gap "b", which, in turn, is smaller than gap "a". This demonstrates that the ear reforming process creates the tightest seal.

An objective of the present invention is to do away with the subjective ear root gap size concern by providing a robust tool that allows the operator to visually see that the ear root gap has been diminished to zero (i.e. the clamp is fully closed) while the clamp is in the process of being crimped and then re-forms the bulging (ovate) shaped ear into a much stiffer and stronger geometry. By re-forming the ear in such a two-stage manner the spring-back (or opening) of a pinched ear is virtually eliminated. The minor gap that ultimately results is generally less than .010 inches and usually appears to a layperson as if there is no gap at all.

In testing, PEX clamps installed with standard prior art tools offer a measured ear root gap of greater than lmm (.040 inch). In Pull-Off tests of 5/8", 3/4", and 1 " PEX assemblies it was found that the tubes would pull off the fittings. Whereas the same type clamps assembled with a tool of the present invention were tight enough to retain the tubes on the fittings with failure occurring in the length of tube between the fittings. It is, therefore, an object of the present invention to provide a pinch-type clamp installation tool that avoids the disadvantages of the prior art.

Another object of the present invention is to provide an installation tool with large handgrips to move the major load to the operator's pectoral muscles. A related object of the present invention is to increase the lever arms and handle length to reduce installation effort.

Another objective of the present invention is to move away from a tool design that requires the operators to have a high degree of handgrip strength. History has shown that repetitive work activity, especially those requiring a high level of grip type exertion, have a tendency to develop medical complications such as carpal-tunnel syndrome. By eliminating the grip style levers in favor of two power grips, strain is

taken off the muscles involved with grip strength and transferred to the larger and stronger pectoral group of the chest.

Another object is to enable an installation tool that is fully field strippable for oiling, cleaning, inspection, and part replacement. Another objective of the present invention is to provide an easy method for in-the-field adjustment of the tool jaw spacing such that an operator can restore a well-used tool to factory new performance levels with little effort or required skill. This is accomplished by providing the present invention with split bearing blocks, on either side of the main jaws, that are cross-bolted together and which have a stack of shims between the bearing blocks. In this simple manner, an operator observing that the ear roots do not touch during installation may remove one or more shims from both the left and right side bearing block assemblies to adjust for the observed wear.

Another objective of the present invention is to improve the means by which the main jaws are synchronized during their opening and closing movements. Prior art uses a length of dowel pin, free floating in matched semi-circular cutouts on each jaw. In combination, the three components form a simple yet effective gear train, with both jaws moving in unison and counter-rotating directions (see Figures 7 and 8). Inasmuch as it is an objective of this invention to have a moveable auxiliary punch between the two main jaws, a length of dowel pin cannot be used. Instead, two disc- shaped synchronizers create a portal between the jaws and the discs, such that the auxiliary punch may pass through.

It is another object of the present invention to provide an installation tool that has two stage forming of the clamp ear. A related object is to provide an installation tool that squeezes the clamp ear in a first stage and then re-flattens the clamp ear in a second stage.

Another objective of the present invention is to provide for single stage forming by way of a fixed position auxiliary punch. While testing has shown that this type of forming cannot deliver the extreme tightness found in dual stage forming, it nonetheless has economic advantages to many markets where the extreme tightness and robust clamp strength may not be required, such as irrigation and sprinkler systems. Here the operator would benefit by way of crimps that are tighter than prior art tools, improved ergonomics by way of reduced effort, a visual sighting of tool wear, and an improved method of in-field wear adjustment.

Yet another objective of the present invention is to enable the combination of a tool head as described above albeit actuated by means other than human strength and levers. Actuation could be by way of a drill motor with an integral torque-link that would then allow the crimping of an "ear" clamp with need of a single hand only. Likewise, an arrangement of hydraulic and/or pneumatic cylinders or actuators could be used for the initial force input to such a tool head. hi accordance with the above objects, a clamp installation tool is provided for squeezing the ears of a pinch-type clamp. A pair of lever arms operates a pair of jaw members to engage a pinch ear. Once the ear of the clamp is crimped, an auxiliary form punch is used to flatten the ear, resulting in a tighter installed clamp configuration. The installation tool includes a pair of jaw members with clamp edges forming a lip for receiving the clamp ears. A pair of extension arms connects the jaw members to a pair of lever arms. The extension arms are pivotally interconnected intermediate the jaw member section so that closing the handle ends of the lever arms translates the jaw members towards a closed position thereof, thus squeezing the clamp ear. ^

Other objects and advantages of this invention will become apparent from the following description taken in conjunction with the accompanying drawings wherein are set forth, by way of illustration and example, certain embodiments of this invention. The various features of novelty that characterize the invention will be pointed out with particularity in the claims of this application.

Brief Description of the Drawings

The above and other features, aspects, and advantages of the present invention are considered in more detail, in relation to the following description of embodiments thereof shown in the accompanying drawings, in which: Fig. 1 shows a side view and plan view of a prior art installation tool.

Figs. 2a-d shows crimp "ear" forming using prior art tools and the present invention.

Fig. 3 shows a plan view of an installation tool in an open position according to one embodiment of the present invention. Fig. 4 shows a plan view of the installation tool of Figure 3 in a closed position.

Fig. 5 shows an enlarged view of the head of the installation tool of Figure 3. Fig. 6 shows a side view of the installation tool of Figure 3 with an auxiliary tool lever aligned with a matching drive unit. Fig. 7 shows a prior art configuration of the head of an installation tool.

Fig. 8 illustrates a prior art solution.

Fig. 9 shows an enlarged view of the head of an installation tool in an open position according to an embodiment of the present invention.

Fig. 10 shows a cross section of the head of Figure 9, taken along the line A- A.

Fig. 11 shows the head of an installation tool of Figure 9 in a closed position, with the auxiliary punch retracted.

Fig. 12 shows the head of an installation tool of Figure 9 in a closed position, with the auxiliary punch extended. Fig. 13 shows the head of an installation tool in an open position according to another embodiment of the present invention.

Fig. 14 shows the head of an installation tool of Figure 13 in a closed position, with the optional punch extended.

Fig. 15 shows an optional punch according to a second embodiment of the present invention.

Fig. 16 shows a powered installation tool according to another embodiment of the present invention.

Figs. 17a-c show the head of the installation tool of Figure 16 in open and closed configurations. Figs. 18a-b show a powered installation tool according to another embodiment of the present invention.

Figs. 19a-c show the head of the installation tool of Figures 18a and b in open and closed configurations.

Best Mode(s) for Carrying Out the Invention Referring to the drawings, Figures 3 and 4 show a tool, indicated generally as

10, according to a first embodiment of the present invention. Figure 3 shows tool 10 in an open position and Figure 4 shows tool 10 in a closed position. Tool 10 comprises a pair of lever arms 13, 14 and rotatable arm 17. Lever arms 13, 14 are attached to head 20, shown in more detail in Figure 5. The distal ends of lever arms 13, 14 are provided with handle forming extensions 25, 26, that may be offset from

the centerline of lever arms 13, 14 to enable sufficient room for an operator's hands during use. The handle forming extensions 25, 26 are of generous proportion and sculpted to fit the hand without pressure points. Tool 10 is also provided a spring- loaded releasable latching mechanism 30 that snaps into a mating pin bracket 31 when the tool 10 is fully closed, and will hold the lever arms 13, 14 in the closed position. An operator can selectively release the latching mechanism 30 following operation of the tool 10.

As shown in Figure 5, head 20 comprises extension arms 33, 34 and jaw members 37, 38 having oppositely facing clamp edges 43, 44. The proximal end of extension arm 33, 34 are T-shaped, having an opening for a pivot point on each end of such T. The inner point of the T for each extension arm 33, 34 is joined to each other at toggle point 40. The outer point of the T for each extension arm 33, 34 is pivotally attached to jaw members 37, 38, respectively, by means of pivot pins and snap rings. The spacing between jaw members 37, 38 is maintained by the center-to-center distance established by cross-bolted bearing blocks 41 and a stack of shims 42, which shims 42 are intended to be removed systematically as wear to the pivotal joints occur with extended tool use, thus restoring the jaw spacing to the optimal. Jaw members 37, 38 pivot about pivot pins 46, 47, respectively. By moving lever arms 13, 14 outward causes extension arms 33, 34 to pivot around toggle point 40, drawing the attached end of jaw members 37, 38 inward, resulting in opening of the clamp edges 43, 44. hi a preferred embodiment, clamp edges 43, 44 should be able to open at least approximately 0.5 inches. By moving lever arms 13, 14 inward causes extension arms 33, 34 to pivot around toggle point 40, drawing the attached end of jaw members 37, 38 outward, resulting in closing of the clamp edges 43, 44. hi a preferred embodiment, clamp edges 43, 44 should be able to close to within at least

approximately 0.07 inches. When tool 10 is closed such that the clamp edges 43, 44 are sufficiently close, latching mechanism 30 will latch to hold the lever arms 13, 14 in the closed position.

Side plates 52, 53 (not shown) hold the jaw members 37, 38 such that the toggle pivots align to a common plane for maximum mechanical advantage. Portal cutouts, such as 54, are made in both side plates 52, 53 (not shown) to facilitate the visual inspection of a clamp being installed for full clamp closure. Note that tool wear will start to show up at this location with a gradual widening of the ear roots.

Referring to Figure 6, a rotatable arm 17 is provided with a socket 55 that matches to drive 56 on the tool 10. Such socket 55 and drive 56 may be hex-shaped, square-shaped, or some other appropriate matching socket and drive combination. The drive 56 is attached to a cam 50. When the socket 55 is attached to drive 56 and the rotatable arm 17 makes a 180° rotation, cam 50 rotates to force auxiliary form punch 58 toward the clamping end of the tool 10. Cam 50 is pivotally mounted and free floating between side plates 52, 53 (not shown). In some embodiments, a detent can be provided to keep rotatable arm 17 and form punch 58 in a full up or full down position, as desired.

Figures 7 and 8 show a pivot arrangement of the prior art. Tools that use a toggle mechanism to develop large forces usually synchronize the action of the jaws 70, 71 with a dowel pin 75 free floating in semi circular cutouts located between the jaws 70, 71. This allows the jaws to move in unison thus preventing a staggered jaw condition if the feature were to be omitted. Figure 7 illustrates the misalignment resulting from removal of dowel pin 75. Since the present invention passes the auxiliary form punch 58 through the space between the jaws, a dowel pin cannot be used.

The auxiliary punch 58 is free floating in the space between the two jaw members 37, 38 and two floating disc synchronizers 80, 83. Figures 9 and 10 illustrate an embodiment of the present invention using two floating disc synchronizers 80, 83 to synchronize the jaws 37, 38. The floating discs 80, 83 are held between side plates 52, 53 (not shown) and provide an opening through which the auxiliary form punch 58 can pass. The disc-synchronizers 80, 83 are free floating in slightly oversized clearance pockets machined into the main jaw members 37, 38. Clearance cuts made into the two jaw members 37, 38 should be deep enough such that the discs 80, 83 will not bind with the jaws, nor will the punch 58 bind with the jaws.

Figure 11 shows the arrangement of the main jaw members 37, 38 pivotally mounted to side plates 52, 53 (not shown) by way of pivot pins 46, 47 and snap rings (not shown). The auxiliary punch 58 is equipped with a cam roller 84 that is free spinning on axle 86, which rides in slot 87 (Figure 5) cut through side plates 52, 53 (not shown) to provide centering of the auxiliary punch 58 within the space provided between the main jaw members 37, 38. In Figure 11, the auxiliary punch 58 is in the retracted position.

Figure 12 shows the arrangement of the main jaw members 37, 38 with the auxiliary cam 50 rotated through 180 degrees to extend the auxiliary punch 58, which reforms the ovated ear pinched between main jaw members 37, 38 at the location indicated at 88.

In use, lever arms 13, 14 are moved to the open position and head 20 is placed over a clamp ear such that clamp edges 43, 44 are inserted between the lobes and the outer band end portions of the clamp ring with clamp edges 43, 44 engaging the sidewall of the ear of the clamp ring. Rotatable arm 17 should be positioned such that

the auxiliary form punch 58 is in the retracted position. The lever arms 13, 14 are then moved to the closed position until the latch mechanism 30 latches. While the maximum load is being applied to the clamp, the operator perceives a drop-off in effort. Portal cutouts 54 may be provided in the side plates 52, 53 (not shown), so that the operator can visually witness full closure of the ear. With the lever arms latched in the closed position, rotatable arm 17 is rotated to cause the auxiliary form punch 58 to extend and flatten the ear of the clamp. The tool 10 can then be removed by releasing latch mechanism 30 and moving lever arms 13, 14 to the open position.

Tool 10 is longer in both the lever arm length and jaw length than the instrument illustrated in Figure 1 thereby providing more mechanical advantage. The more robust tool provided by the present invention enables operation with clamps of higher thickness and provides a tighter seal.

Figures 13 and 14 show an alternate embodiment of the present invention. The cam configuration is replaced with guide bushing 90 that is pivotally mounted on bosses 93, 94, which are turned on either end of the guide bushing 90. The bosses 93, 94 engage the two side plates 52, 53 (not shown). Optional form punch 96 is aligned through the guide bushing 90 such that a free end 99 comes in contact with the toggle joint 40. Figure 14 illustrates the benefit of this embodiment in that as the tool 10 is closed, the toggle joint 40 will align as illustrated and will move the optional form punch 96 in the direction indicated by arrow 102, to re-form the ovated ear of a clamp pinched between the clamp edges 43, 44 of the two main jaw members 37, 38 at the location indicated 105. With a toggle arrangement as shown, there is nearly no operator effort required to close tool lever arms 13, 14 through the last 5 degrees of rotation and just prior to latch 30 engaging in the closed position. This decrease in effort affords the opportunity to redirect the operator's strength and the combined

leverage of tool 10 to raise the optional form punch 96 for useful work, and thereby eliminating the extra motion needed to crank the rotatable arm 17 through its required arc. Figure 15 shows a side view of the guide bushing 90, bosses 93, 94, and optional form punch 96. Figure 16 illustrates a powered version, indicated generally as 100, of the installation tool according to the present invention. In the illustrated example, a power head 103 is installed on a Ridgid® Compact 100-B power tool. The power tool 100 is a lightweight, cordless, battery powered, hydraulic ram with rapid reverse. Tool 100 includes an operating switch 106 that, when depressed causes an internal electric motor 109 to power a hydraulic pump 111. The motor 109 is powered by a suitable battery 114, mounted in a handle 117 comprising part of the tool 100. hi a preferred embodiment, the battery 114 is a Nickel-Metal Hydride rechargeable battery or a Nickel-Cadmium rechargeable battery. Other types of batteries can be used. The operating switch 106 controls power to the motor 109. The battery 114 is connected to the motor 109 by suitable wires through the switch 106. The hydraulic pump 111 forces fluid into an internal cylinder of the tool 100, forcing a ram 120 outward and applying thousands of pounds of pressing force onto the power head 103. The entire cycle duration is approximately seven (7) seconds. Once the cycle begins to deform a clamp, it will automatically continue until completion. When used with appropriate power head 103, the tool 100 is designed to mechanically press fittings onto tubing in order to create a tight and permanent seal.

Figures 17a-c illustrate cross sections of the power head 103. The power head comprises jaw members 123, 124, and a reforming plunger 127. The hydraulic ram 120 includes two rollers 130, 131. As the hydraulic ram 120 extends outward (from right to left in the drawings), the rollers 130, 131 spread the back ends 133, 134 of jaw

members 123, 124 apart causing the clamp edges 137, 138 to crimp on a clamp. Figure 17b shows the power head 103 in the first stage with the jaw members 123, 124 closed. To complete the two-stage reforming process, the hydraulic ram 120 continues to extend so that the rollers 130, 131 push against the end block 140 of the reforming plunger 127. Figure 17c shows the power head 103 at the end of the second stage re-forming of the ear. Note that second stage forming occurs when the rollers 130, 131 are on the flat or dwell portion of the jaws cam surfaces. By timing in this manner the jaw members 123, 124 are essentially finished with crimping the ear (i.e. stationary), so that all of the force of the ram 120 is directed toward the ear re-forming stage.

Figures 18a and b illustrate another embodiment of the powered tool, indicated generally as 146, that works with a commercially available drill motor. In the illustrated example, a power head 150 is installed on a DeWalt® 14.4 volt Model DW983K-2. The power tool 146 is a lightweight, cordless, battery powered, 1 /2-inch heavy-duty cordless driver/drill with adjustable clutch. Other makes are also suitable. Tool 146 includes an operating switch 153 that, when depressed causes an internal fan-cooled motor 156 to rotate. The motor 156 is powered by a suitable battery 160, mounted in a handle 163 comprising part of the tool 146. In a preferred embodiment, the battery 160 is a Nickel-Metal Hydride rechargeable battery or a Nickel-Cadmium rechargeable battery. Other types of batteries can be used. The operating switch 153 controls power to the motor 156. The battery 160 is connected to the motor 156 by suitable wires through the switch 153. Figure 18b shows the same tool head 150 rotated about the input axis for ease of use by an installer / plumber.

Figures 19a-c illustrate cross sections of the power head 150. The power head comprises jaw members 166, 167, and a reforming plunger 170. This tool head

functions in the same manner as the one described with reference to Figures 16 and 17 except that it is actuated by rotary motion. A cam spade 173 is mounted on a jackscrew 176. As the drill motor 156 rotates the jackscrew 176, the cam spade 173 extends outward and causes the extension ends 179, 180 of the jaw members 166, 167 to spread open causing the jaw members 166, 167 to crimp on a clamp. Figure 19b shows the power head 150 in the first stage with the jaw members 166, 167 closed. To complete the two-stage reforming process, the cam spade 173 continues to extend so that the reforming plunger 170 can reshape the ear. Figure 19c shows the power head 150 at the end of the second stage re-forming of the ear. In a preferred embodiment, the drill motor would one be of the types having an adjustable slip such that the operator can sense the end of travel of the spade cam 173. Tool reset would be accomplished by putting the drill motor in reverse and backing off until the jaw members 166, 167 are wide enough to accept another fresh clamp, or full mechanical return is reached, in which case the clutch would trip out again.