Cordless clamping handle tubing cutter tool

A hand tool for cutting tubular workpieces such as copper tubing used for plumbing includes a rotary cutting head which has a slot for receiving a length of tubing to be cut, a gear drive mechanism for rotating the cutting head, and a clamping handle which supports the gear drive mechanism, which is rotatably driven by a battery powered electric motor. to thus rotate the cutting head to sever a length of tubing. The clamping handle includes a pair of longitudinally disposed, generally semi-cylindrically-shaped handle shells which are pivotable apart from one another to receive a length of tubing to be cut, and pivotable to a closed position and compressed in the palm of a workman's hand to press against and clamp the tool to a length of tubing being cut.

BACKGROUND OF THE INVENTION

A. Field of the Invention

The present invention relates to hand tools. More particularly, the invention relates to a hand tool for cutting tubular workpieces such as copper tubing used in plumbing systems which is operated by a pull-cord mechanism or an integral battery powered drive motor and thus does not require an electrical or pneumatic power source.

B. Description of Background Art

Plumbing used for hot and cold water service in most contemporary residences and other buildings employs copper tubing to distribute the water to various sites within the building, including bathrooms, showers, kitchens, laundry rooms, etc. At each such site, an elongated length of copper tubing connected to a source such as a water main or hot water heater must be cut to size and connected by a fitting to a water faucet, shower head, toilet tank, or other such fixture.

The number of individual fixture connections and hence number of tubing cuts which must be made during original construction or retrofitting of a building can be substantial. For example, an average full bathroom with a single sink and shower head requires at least 5 separate tubing cuts, and adding another sink increases the total to 7 cuts. Each additional bathroom adds 5 to 7 cuts, the kitchen adds at least 2 cuts for a sink and another 1 or 2 more cuts for a water purifier.

For residences which include a laundry room and/or one or more additional bathrooms, the number of cuts increases by 2 to 7 for each such additional site. Thus, as a bare minimum, even a very small apartment construction requires cutting at least 7 different lengths of copper tubing. A more typical apartment with 2 full baths, each having a double sink, and a kitchen requires making about 20 separate cuts. Thus, for a 100-unit apartment complex, typical plumbing installations would require making 2,000 or more separate cuts in copper tubing.

A traditional method of cutting copper tubing which is still in use consists of using a standard hacksaw to cut tubing to a length required for connecting the tubing to a faucet or other such fixture. A disadvantage of this method is that it is relatively slow, and typically results in a rough, non-square severed cut edge which can make connecting the cut edge of the tubing to a fixture problematic.

Other prior art methods of cutting copper tubing and similar tubular members employ a device which is clamped to a length of pipe or tubing with a screw clamp arrangement, and rotated multiple times around the circumference of the tubing. The device has a cutting blade which presses against the outer circumferential wall surface of the tubing, eventually severing the tubing to a required length. This method, while achieving cleaner, squarer cuts than a hacksaw is substantially time consuming.

In response to the above-described limitations of prior art tubing cutting methods and apparatus, the present inventor invented and disclosed in U.S. Pat. No. 7,845,080 a tubing cutting apparatus which includes a rotary cutting mechanism that has an open area for receiving a length of tubing and has a cutting head provided with a cutting blade for engaging the tubing. The cutting mechanism is powered by rotary power source such as a hand-held power tool, or by a self-contained drive motor. The apparatus includes a gear system for coupling rotary power from a rotary power source to the cutting mechanism and thereby rotating the cutting head and blade about a length of tubing. One embodiment of the disclosed apparatus includes a clamp comprising a slotted tubular leaf spring which protrudes from a handle case of the apparatus in longitudinal alignment with an open slotted area of the cutting mechanism. The apparatus clampingly engages a length of tubing to be cut by pushing opposed flanged edges of the leaf spring against the length of tubing, thus causing the edges to be pried apart against tension exerted by the spring. The edges than spring back to grip the tubing. This arrangement facilitates use of the apparatus in locations with limited accessibility, such as within a space behind a wall board of a structure.

The tubing cutting apparatus disclosed in U.S. Pat. No. 7,845,080 provides other substantial advantages over prior art tubing cutting tools. For example, the tubing cutter apparatus disclosed in U.S. Pat. No. 7,845,080 can be positioned and secured in place on a length of tubing, and used to make a clean, square, accurately located severing cut in the tubing, in a much shorter time than prior art cutting tools which require manual clamping operations. However, the present inventor has perceived the need for another type of tubing cutter apparatus which could be operated by hand power alone.

An apparatus powered by hand would be useful in remote areas which do not have a convenient source of electrical power or pneumatic power supplied by pressurized air. Also, it would be desirable to have a tubing cutter tool which was not electrically powered and could thus be used in hazardous locations containing combustible liquids or vapors without the possibility of an electric spark from a drive motor igniting a fire. Moreover, for some applications, it would be desirable to provide a tool for cutting tubular workpieces in which functions of providing a handle for holding the tool, and a mechanism for firmly gripping a length of tubing which was being cut by the tool, could be combined into a single structure.

Also, it would be desirable to provide a tubing cutter with a clamping handle and integral battery powered electric drive motor.

It would also be desirable to provide a tubing cutter tool which afforded the capability to a workman to readily adjust the number of rotations of a rotatable cutter head to the minimum number required to sever a length of tubing. Prior art powered tubing cutter tools typically are operated in a mode which causes a cutter head of the tool to rotate more than a minimum number to turns around the circumference of a tube, to ensure that a complete severing cut is made. The additional number of often unneeded turns requires additional valuable time which could be saved by a manually operated tubing cutter tool which a workman could readily operate in a mode in which a cutting head was rotated just a sufficient number of turns to cleanly sever a length of tubing but without any additional time consuming rotations of the cutting head. The foregoing considerations were motivating factors for the present invention.

OBJECTS OF THE INVENTION

An object of the present invention is to provide a portable hand-held tool for cutting tubular workpieces such as copper tubing, which includes a rotating cutting head that is driven by a hand-operated pull-cord mechanism.

Another object of the invention is to provide a portable hand-held tubing cutter tool which has a clamping handle that facilitates using a single hand to both hold the tool and clampingly engage a length of tubing to the cut.

Another object of the invention is to provide a pull-cord powered portable hand tool for cutting tubing, which has a handle that has a handle grip for supporting the tool and clamping jaws for clamping the tool to a length of tubing to be cut when the handle is grasped and squeezed.

Another object of the invention is to provide a portable hand tool for cutting tubing which has a body and handle grip for supporting the tool and clamping jaws for clamping the tool to a length of tubing to be cut when the handle is grasped and squeezed, and that has attached to the body a rotatable cutting head which is rotatably driveable by an integral battery powered electric motor.

Various other objects and advantages of the present invention, and its most novel features, will become apparent to those skilled in the art by perusing the accompanying specification, drawings and claims.

It is to be understood that although the invention disclosed herein is fully capable of achieving the objects and providing the advantages described, the characteristics of the invention described herein are merely illustrative of the preferred embodiments. Accordingly, we do not intend that the scope of our exclusive rights and privileges in the invention be limited to details of the embodiments described. We do intend that equivalents, adaptations and modifications of the invention reasonably inferable from the description contained herein be included within the scope of the invention as defined by the appended claims.

SUMMARY OF THE INVENTION

Briefly stated the present invention comprehends a hand-held portable tool for cutting tubular workpieces such as copper tubing used in plumbing systems, which include a clamping handle and a novel pull-cord powering mechanism or an electric motor powered by a self-contained battery.

A basic embodiment of a portable hand held tubing cutter tool according to the present invention includes a pull-cord drive wheel mechanism for converting linear pulling power exerted by a workman into rotary motion of a drive wheel pulley. The tool includes a gear drive mechanism mounted on top of the pull-cord drive wheel mechanism, and a cutting mechanism including a crescent-shaped, slotted cutting head mounted on top of the gear drive mechanism. Rotary power generated by the pull-cord drive wheel mechanism in response to a workman's brisk pulling on a handle at the outer end of a pull-cord wrapped around a drive wheel is coupled through the gear drive mechanism to the cutting mechanism. Rotation of a blade in the cutting mechanism in contact with the outer circumferential surface of a length of tubing positioned in the slot of the cutter head is effective in severing the tubing.

The pull-cord drive wheel mechanism includes a spirally wound, flat tension spring which is similar to a clock main spring, and is effective in rotating the drive wheel in an opposite direction to thus retract and re-wind the pull-cord around the drive wheel pulley, when tension is released on the drive cord pull handle.

The tubing cutter tool according to the present invention includes a clamping handle which protrudes downwardly from the gear-drive mechanism. The clamping handle includes a pair of longitudinally disposed generally semi-cylindrically-shaped handle shells which are pivotable apart to form an open space for receiving a length of tubing. The handle is moved laterally towards a vertically disposed length of tubing to encompass a length of tubing in the open space between the handle shells, which are then pivoted towards one another to form a cylindrical space in which the tubing is located. Opposed inner concave sides of the handle shell exert a compressive gripping force on the tubing when the outer surface of the handle shells are grasped in the palm of a workman's hand.

An alternate embodiment of a portable tubing cutter tool with clamping handle according to the present invention includes a gear drive mechanism which has rotary power input socket that is rotatable by a complementary shaped drive pin which is inserted into the socket and rotated by of an external rotary power source such as a power drill.

Another embodiment of a portable tubing cutter tool with clamping handle according to the present invention includes a rotary electric motor rather than a pull-cord drive wheel mechanism for providing rotary power to the gear drive mechanism and cutting mechanism. The motor is located in a housing below the gear drive mechanism, and is powered by an integral electric battery located in a battery housing which extends rearward from the lower end part of the clamping handle.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIGS. 1-10illustrate embodiments of a tubing cutter with a clamping handle according to the present invention which are powered by a pull-cord mechanism.FIG. 11illustrates another embodiment of a tubing cutter with a clamping handle according to the present invention, which is powered by an external rotary power source such as an electric drill.

FIGS. 12-17Billustrate another embodiment of the tubing cutter which has an internal electric drive motor and battery.

Referring toFIGS. 1 and 2, a pull-cord operated tubing cutter10with clamping handle according to the present invention may be seen to include a pull-cord drive wheel mechanism11for converting linear pulling power to rotary drive power, a gear drive mechanism13, rotatable by the pull-cord drive wheel mechanism, a crescent-shaped cutter head12mounted on top of and rotatably driven by the gear drive mechanism and an elongated clamping handle14which is depends perpendicularly downwards from the gear drive mechanism, in coaxial alignment with the cutter head. As shown inFIGS. 1-5, gear drive mechanism13has an elongated flat base plate15. Clamping handle14protrudes downwards from a front part of the lower surface of the base plate15, and pull-cord drive mechanism11protrudes downwardly from a rear part of the lower surface of the base plate15.

As may be seen best by referring toFIGS. 1, 2 and 5, clamping handle14is constructed of two generally semi-cylindrically-shaped vertically elongated shells16and17including a fixed handle shelf16that is mounted fixedly to the lower surface of gear mechanism base plate by a first, upper attachment pin18. Handle14includes a second, pivotable handle shell17which has a shape that is generally mirror symmetric to that of fixed handle shell16, through a vertical longitudinal medial plane of the handle. Pivotable handle shell17is pivotably mounted at an upper end thereof to a lower part of upper attachment pin18, and at a lower end thereof to the lower end portion of fixed handle shell16by a second, vertically disposed, lower pivot pin19. (SeeFIG. 5.)

As may be seen best by referring toFIG. 2, fixed handle shell16and pivotable handle shell17have disposed longitudinally or vertically through their lengths elongated semi-circular cross section bores21,22which are have secured to concave wall surfaces thereof elongated semi-cylindrically-shaped elastomeric or friction pads23,24.

As shown inFIGS. 1 and 2, when handle shells16and17are pivoted towards one another and a compressive force exerted on the outer surfaces of the handle shells by being gripped in the palm of a person's hand, a compressive gripping force may be exerted on the outer circumferential surface of a length of tubing T or pipe to thus retain the tool10in a fixed position relative to the tubing, as shown inFIG. 1.

Optionally, as shown inFIG. 2, the outer vertically disposed longitudinal edges of handle shells16and17opposite pivot pins18and19may have formed therein tongue-and-groove type interlocking edges16A,17A, to help maintain a compressive force on a pipe, length of tubing, or other such tubular workpiece.

As shown inFIG. 5, the rear longitudinally disposed surface of handle14preferably has a curved shape to facilitate grasping the handle in a workman's hand, and includes a convex arcuately curved elongated center section14A, and an arcuately inwardly curved upper and lower end sections14B,14C.

As shown inFIG. 5, the rear longitudinally disposed surface of handle14preferably has a curved shape to facilitate grasping the handle in a workman's hand, and includes a convex arcuately curved elongated center section14A, and arcuately inwardly curved upper and lower end sections14B,14C, respectively.

Referring toFIGS. 3, 4A and 4B, it may be seen that gear drive mechanism13includes in planar arrangement and sequence of connection, a C-shaped gear25, a pair of intermediate circular gears27,28that do not engage each other, and a circular driving gear29. Both intermediate gears27,28engage on front sides thereof C-shaped gear25and on rear sides thereof engage driving gear29. In this manner driving gear29engages and simultaneously rotates both intermediate gears27,28and in turn intermediate gears27,28engage and simultaneously rotate C-shaped gear25.

As shown inFIG. 4B, two intermediate gears27,28are required because for some rotational positions, one or the other of intermediate gears27,28will be in the gap42in the C-shaped gear defined by shoulders26A,26B and hence will be out of contact with C-shaped gear25. Thus, intermediate gears27,28are positioned so that at least one of these gears is always in contact with the C-shaped gear25such that there is no break in the rotation of C-shaped gear25. C-shaped gear25has a raised portion25A for attachment to cutting head12as will be described.

As shown inFIGS. 4A, 4B and 5, base plate15of gear drive mechanism13has two mounting posts22c, which rotatably support intermediate gears27,28to base plate15. Driving gear29is pinned to the shank of a drive pin148which protrudes upwardly from pull-cord drive wheel mechanism11through a hole in the base plate15of the gear drive mechanism. Gear drive mechanism13has a cover plate13A which is secured to base plate15by screws13B, thereby capturing gear mechanism21. As shown inFIG. 4B, a semi-cylindrical bearing sleeve22ais vertically attached to base plate15and when the cutting apparatus is assembled extends upward through the open area of C-shaped gear25to provide a bearing about which gear25rotates.

As may be envisioned by referring toFIGS. 1 and 3-4B, rotation of circular driving gear29causes cutter head12to rotate in contact with the outer circumferential wall surface of a tube T disposed through a longitudinally disposed slot12A in the cutter head to thereby cause a cutting blade which is urged through a transversely disposed slot in an inner wall of slot12A to form a circular cut through the tube. The construction and operation of gear mechanism13and cutter head12are exactly similar to those of the gear system21and cutter12described in U.S. Pat. No. 7,845,080, the description of which is hereby incorporated in its entirety into the present specification. Cutter head12is attached to C-shaped gear25by screws (not shown) which protrude downwards from the cutter head and are received in threaded bores25B in the upper surface of the C-shaped gear.

FIGS. 7B-7Dillustrate the manner in which a tension spring70is used in cutting head12to urge retraction of a rotary cutting blade head51from a length of tubing20when a locking lever50is an open position; lever50having a cammed part50athat at the closure of lever50overcomes force exerted by spring70to urge cutting contact of the cutting blade51with the tubing20.FIG. 7Billustrates initial positioning of the cutting blade within the cutting head12with the locking lever50in the open position. The cammed part50aof locking lever50rides on tension spring70, which has an extension arm70awith a slot70bfor receiving cutting blade51therein. When lever50is in the open position spring70is in an unloaded state in which cutting blade51does not forcibly contact tube20.FIG. 7Cillustrates partial closure of the locking lever50with the cammed part50aof the lever depressing to partially load spring70thereby urging the cutting blade51into contact with tubing20.FIG. 7Dillustrates complete closure of the locking lever50whereby the spring70is loaded sufficiently to force cutting blade51to cut the tubing20. After cutting of the tubing30the lever50is opened, thereby unloading spring70whereby the cutting blade51returns to its non-cutting mode.

The structure and operation of pull-cord drive wheel mechanism11of tubing cutter10may be best understood by reference toFIGS. 1, 5, 6, 7A and 9. As shown inFIGS. 5 and 7Apull-cord power drive wheel mechanism11includes a housing100which has generally the shape of a short, circular cross-section cylindrical box that has a circular base plate101and a circular cross-section, cylindrically-shaped, uniform thickness flange wall102which protrudes perpendicularly upwards from the outer circumferential edge of the base plate.

As shown inFIGS. 5 and 7A, housing100of drive wheel mechanism11has between base plate101and cylindrical flange wall102a hollow cylindrically-shaped interior space103which contains a rotatable circular cross section drum or pulley104. As shown inFIG. 7A, pulley104has at a lower or base end thereof a transversely disposed annular ring-shaped flange or lower pulley sheave105which protrudes radially outwards from a vertically disposed, longitudinally centrally located cylindrically-shaped central body106of the pulley. Pulley104also has at an upper end thereof an annular ring-shaped flange or upper pulley sheave107. Upper pulley sheave107has a size and shape similar to that of lower pulley sleeve105, and also protrudes radially outwards of central body106of the pulley.

As may be seen best by referring toFIGS. 5 and 7A, pulley104has protruding perpendicularly upwards from a lower face108thereof into central body106thereof a circular blind bore109which has a diameter that is slightly less than that of cylindrical central body106of the pulley. Bore109terminates in an upper transversely disposed end wall110, and forms with the upper surface113of pulley housing base plate101a hollow cylindrically-shaped space114.

As shown inFIGS. 5, 7A and 8, hollow cylindrically-shaped space114within pulley104contains a flat, spirally wound recoil spring115which has a construction similar to that of the main spring of a table clock. Recoil spring115consists of single elongated rectangular strip of spring steel wound into a spiral which has flat, vertically oriented coils. A radially inwardly located end of the strip terminates in a folded-over inner tang116, and a radially outwardly located end thereof terminates in a folded-over, outer tang117.

As shown inFIGS. 7A and 8, inner tang116at the inner end of recoil spring115is hooked into and retained by a vertical slot118in the wall119of a small diameter cylindrical flange120which protrudes perpendicularly upwards from the center of the upper surface113of housing base plate101. As shown inFIG. 8, outer tang117of recoil spring115engages a groove122in the inner circumferential wall surface123of pulley104.

Referring now toFIGS. 6 and 9, it may be seen that pull-cord power drive mechanism11of tool10includes a pull-cord125which is wrapped around the outer circumferential surface133of central body106of pulley104located between inner facing, opposed upper and lower horizontally disposed annular ring-shaped shoulders126,127of upper and lower pulley sleeves107and105, respectively.

As shown inFIGS. 5, 6 and 9, an inner knotted end128of pull-cord125is secured in a notch129located in a pull-cord retainer flange130which protrudes upwardly from the upper circular end wall131of the central body106of pulley104. Pull-cord125pays radially outwards from notch129, and vertically downwards through a hole132in upper end wall131of pulley104, and thence is wrapped spirally around the outer circumferential wall surface133of central body106of the pulley.

As shown inFIG. 6, pull-cord125has an outer end portion124that protrudes radially outwards from the hollow interior space103of pull-cord housing100through the bore135of a bushing136which protrudes radially outward from the housing and communicates with the hollow interior space103of the housing. As is also shown in the figures, pull-cord125has attached to an outer end thereof a transversely disposed T-shaped pull handle137which receives the end of the pull-cord in a bore138disposed through a centrally located outwardly longitudinally disposed leg139of the handle, which has a transversely disposed hand grip140.

FIGS. 3-6illustrate structural and functional details of how a linear putting force exerted on handle140causes drive pulley104and drive gear29, and hence cutter head12to rotate.

As may be understood by referring toFIGS. 5 and 6, grasping hand grip140of handle137and pulling the handle and attached cord125wrapped around pulley104causes the pulley to rotate. As shown inFIG. 6, pulley104has mounted on the horizontal upper surface131thereof a hexagonally-shaped drive socket141which has therein a hexagonally-shaped recess142. Tool10includes a hexagonally-shaped “dog-bone” drive nut143which is of an appropriate size to be received vertically downwards into recess142of drive socket141.

As may be seen best by referring toFIG. 6, drive nut143has protruding vertically downwards from an upper surface144thereof a bore145having a central circular cross-section part146and a pair of radially opposed slots147a,147bwhich protrude radially outwards from diametrically opposed sides of the central circular cross-section bore. Bore145of drive nut143receives vertically downwardly therein a gear drive shaft148which has a central circular cross-section shank149and a pair of radially outwardly protruding pins150A,150B, which are of an appropriate size and shape to fit conformally downwards into the central circular part of bore146in drive nut143, and the radiating opposed slots147A and146B in the drive nut.

As may be seen best by referring toFIGS. 5 and 9, drive shaft148is pinned at an upper end thereof to drive gear29of gear mechanism11.

FIGS. 1, 2 and 5illustrate how pull-cord operated tubing cutter tool10is used to make a severing cut through the wall of a tubular workpiece such as a copper pipe or tube T.

As shown in phantom inFIG. 2, pivotable handle shell17of clamping handle14of tool10is pivoted away from fixed handle shell16to thereby form between inner opposed concave edges of the two handle shells a longitudinally elongated concave space for receiving therein a length of tubing T. Then, as shown inFIG. 1, tool10is moved laterally towards a length of tubing T to be cut, the tubing centered within the bore B formed between inner concave surfaces of handle shells16and17, and pivotable handle shell17is pivoted towards fixed handle shell16. Handle14is then grasped in the palm of a workman and squeezed as shown inFIG. 1, thus causing the inner concave surfaces of the handle shells to exert a compressive gripping force on the outer circumferential wall surface of tubing T.

Next, as shown inFIG. 1, hand grip140of pull-cord handle137is grasped in the other hand of the workman, and pulled briskly outwards. Radially outward motion of pull-cord125from pull-cord housing100causes pulley104to rotate. Rotation of pulley104in turn causes drive shaft148and thus drive gear29to rotate, thus causing cutter12to rotate around and cut through the wall of tubing T.

When tensional pulley force on pull-cord handle137is released, tension in recoil spring115exerts a torque on pulley104, causing the pulley to rotate in a reverse direction, thus retracting pull-cord125into housing100thereby rewinding the cord on the pulley, and readying tool10to be used for another cutting operation.

FIG. 10illustrates an alternate embodiment210A of a pull-cord operated tubing cutter according to the present invention, in which the drive pulley304A is mounted on the upper surface of upper cover plate213A of a gear drive mechanism213.

FIG. 11illustrates another embodiment410of the tubing cutter with clamping handle according to the present invention which has a gear mechanism413that may be rotatably driven by an external rotary power apparatus R such as an electric drill. The structure and function of the gear mechanism413and cutter412of tubing cutter410are exactly analogous to those of corresponding elements of the tool shown in FIGS. 1 and 2 of U.S. Pat. No. 7,845,080.

Optionally, alternate embodiment210A shown inFIG. 10may be modified by providing it with a removable or preferably, a disengageable retractor spring, and a centrally located drive socket which protrudes upwardly from drive pulley304A and is engageable by a rotary power source, in an arrangement of the type shown for embodiment410inFIG. 11. With this modified construction, the alternate embodiment of the tubing cutter210A shown inFIG. 10can be operated alternatively by a pull cord or external rotary power source, at the option of a user of the cutter.

FIGS. 12-15illustrate another embodiment510of a tubing cutter tool with clamping handle according to the present invention. The construction and function of tool510are similar to that of the basic pull-cord embodiment of the tool shown inFIGS. 3, 4A, 4B and 5and described above. However, as is explained in detail below, tubing cutter tool510uses a rotary electric motor511instead of a pull-cord drive wheel mechanism to provide rotary drive power to a gear drive mechanism513which in turn rotatably drives a crescent-shaped cutter head512mounted on the top of the gear drive mechanism. Tubing cutter tool510also has an elongated clamping handle514which depends downwardly from the gear drive mechanism513, and has a somewhat different construction than handle14.

As shown inFIG. 12, tubing cutter510also includes a battery560which is located in a battery housing561which extends rearward from a lower end part562of handle514. Battery560is connected through wires563,564, and a series electrical switch565to motor511. Motor511is located in a housing556which extends rearward from an upper end of handle514. As shown inFIG. 12, output shaft548of motor511is pinned to input driving gear529of gear drive mechanism513.

Referring now toFIGS. 12 and 14, it may be seen that clamping handle514is constructed of two generally semi-cylindrically-shaped vertically elongated shells including a fixed rear shell516that is mounted fixedly to the lower surface of gear mechanism base plate515. Handle514includes a second, pivotable handle shell517which has an inner shape that is generally mirror symmetric to that of fixed handle shell516, through a vertical longitudinal medial plane of the handle. As shown inFIGS. 14 and 15, pivotable handle shell517is pivotably mounted to rear fixed handle shell516by a longitudinally disposed, piano-hinge type hinge518which joins confronting longitudinally disposed edges516A and517A of rear and front handle shells516,517, respectively. Hinge518has interdigitated tubular sections519A,519B which are hingedly joined by a disposed hinge pin520disposed longitudinally through the sections.

As may be seen best by referring toFIG. 14, fixed rear handle shell516and pivotable front handle shell517have disposed longitudinally or vertically through their lengths elongated semi-circular cross-section bores521,522, to which are secured elongated, thin elastomeric pads521A,522A which have the shape of thin, semi-cylindrical shells.

As shown inFIGS. 12 and 14, when handle shells516and517are pivoted towards one another and a compressive force exerted on the outer surfaces of the handle shell by being gripped in the palm of a person's hand, a compressive gripping force may be exerted on the outer circumferential surface of a length of tubing T or pipe to thus retain the tool510in a fixed position relative to the tubing, as shown inFIG. 12.

A preferred embodiment of tubing cutter tool510includes one or more releasable fastener clamps to hold handle514in secure compressive contact with a length of tubing to be cut. Thus, as shown inFIGS. 12 and 14, confronting longitudinal edges570,571of rear and front handle516,517have protruding circumferentially outwards therefrom upper and lower snap clip-on spring clasp fasteners572U,572L.

Each fastener572consists of an outwardly concave U-shaped leaf spring523which has a U-shaped groove574protruding outward from one handle shell, and an inwardly concave U-shaped leaf spring575which has an outwardly concave U-shaped groove576which protrudes outwards form the other handle shell. When the handle shells516,517are squeezed towards one another to grip the outer circumferential surface of a length of tubing to be cut, the end tab577of the inwardly concave clip springs into an outwardly concave groove in the other spring tab, and the end tab578of the outwardly concave spring clip springs into the inwardly concave groove of the other spring clip, thus securing the spring tabs into locking engagement. The spring clips573,575are effective in holding handle shells516,517tightly clamped together and onto a length of tubing to be cut until manually disengaged by a workman after the tubing has been cut.

FIGS. 16A to 17Billustrate a modified fastener582which uses a modification of spring clips573and575. One or both modified spring clips588,590are provided with multiple interlocking grooves591,592which are spaced circumferentially apart from one another. As shown inFIGS. 17A and 17B, this construction enables positioning confronting free edges516A and516B spaced apart at different distances, thus facilitating clamping handle514to tubing of different diameters, such as ½ inch and ¾ inch.

As is also shown inFIGS. 16A and 16B, one or more of modified spring clips588,590is optionally provided with a circumferentially inwardly protruding lever595. Pressing radially inwards on lever595causes the spring tab at the other end of the spring fastener to move radially outwards from engagement in the groove of the other spring fastener, thus facilitating clamp disengagement and removal of handle514from a length of tubing.