1. Field of the Invention
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.
2. Background of the Prior 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. Pat. 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. Pat. 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. Pat. 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. Pat. No. 5,282,295 discloses a more robust stiffening rib to improve upon the “ears” load bearing capacity.
U.S. Pat. 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.
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:
In testing of prior art tools (
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.
a-d illustrate the history of the problem and attempted solutions associated with ear style clamps. In
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 0.010 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 1mm (0.040 inch). In Pull-Off tests of ⅝″, ¾″, 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
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.
In 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.
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:
a -d shows crimp “ear” forming using prior art tools and the present invention.
a-c show the head of the installation tool of
a-b show a powered installation tool according to another embodiment of the present invention.
a-c show the head of the installation tool of
The invention summarized above and defined by the enumerated claims may be better understood by referring to the following description, which should be read in conjunction with the accompanying drawings in which like reference numbers are used for like parts. This description of an embodiment, set out below to enable one to practice an implementation of the invention, is not intended to limit the preferred embodiment, but to serve as a particular example thereof. Those skilled in the art should appreciate that they may readily use the conception and specific embodiments disclosed as a basis for modifying or designing other methods and systems for carrying out the same purposes of the present invention. Those skilled in the art should also realize that such equivalent assemblies do not depart from the spirit and scope of the invention in its broadest form.
Referring to the drawings,
As shown in
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
The auxiliary punch 58 is free floating in the space between the two jaw members 37, 38 and two floating disc synchronizers 80, 83.
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
a-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.
a 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, ½-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.
a-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
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.
The invention has been described with references to exemplary embodiments. While specific values, relationships, materials and steps have been set forth for purposes of describing concepts of the invention, it will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the invention as shown in the specific embodiments without departing from the spirit or scope of the basic concepts and operating principles of the invention as broadly described. It should be recognized that, in the light of the above teachings, those skilled in the art can modify those specifics without departing from the invention taught herein. Having now fully set forth the preferred embodiments and certain modifications of the concept underlying the present invention, various other embodiments as well as certain variations and modifications of the embodiments herein shown and described will obviously occur to those skilled in the art upon becoming familiar with such underlying concept. It should be understood, therefore, that the invention may be practiced otherwise than as specifically set forth herein. Consequently, the present embodiments are to be considered in all respects as illustrative and not restrictive.
This application is based upon and claims benefit of copending and co-owned U.S. Provisional Patent Application Ser. No. 60/673,168 entitled “Heavy-Duty PEX Installation Tools”, filed with the U.S. Patent and Trademark Office on Apr. 20, 2005 by the inventor herein, the specification of which is incorporated herein by reference.
Number | Date | Country | |
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60673168 | Apr 2005 | US |