AU2006246503A1 - Cutting tools - Google Patents

Description

/pg9e /o IND Cutting Tools.

This invention relates to several models of cutting tools. The tools can be fitted with 0 a variety of blades and can be fitted to both drills and jig saws. They can be z 0attachments or formed into the body of the tool making them a complete tool. The same tools can be fitted to battery powered drills and jig saws.

S) A common nibbling tool sold as an attachment to a drill, while cutting flat material well has limitations. Similar tools are made in U.S.A. and China.

These tools require two hands to operate, one on the tool itself and the other on the C, drill. The material being cut requires clamping and a large hole is required to be made in the material to fit the barrel when an aperture is required.. ,Most of these tools cut on the down stroke as metal is passed through a web, the web being thinner than the cutter blade. The latter is usually a round bodied punch generally 3 to 5 m.m.

in diameter.

A tool as described is shown in drawing Figure shows the body portion, a driving spindle fits into the drill chuckA handle is shown at the upper body portion. A vertical barrel, which is adjustable in length is shown at The barrel is shown slotted at and below the slot a web is formed. This web is thinner than the round bodied punch shown at Thus when metal is passed through the web the reciprocating punch makes a cut, the chips emerging from the forepart of the barrel.

The reciprocating punch is shown .at The reduced forepart is the cutting edge, (2 O) the inner forepart of the barrel being the anvil. The tool is adjustable but is not suitable for negotiating the curves of corrugated or other roofing or going around a right angle such as in a gutter.

Several models of my invention will now be shown both fitted to drills and jig saws and described with relation to drawing "B" p'oxe ;7, Drill Models.

I Most drills have a 43 m.m. parallel portion behind the drill chuck. To this parallel 0 portion may be fitted an aluminium clamp to hold a barrel, the chuck being removed z and a body portion holding an angled ball race fitted in place of the drill chuck. The latter can be refitted to use the tool as a drill.

A Description of the Invention. iO 1 W

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The drill chuck is removed and an aluminium clamp I portion (10) fitted to the parallel portion (11) of a drill body. The aluminium clamp has an upper cylindrical portion (12) to hold the barrel which is secured by a grub screw and locknut (13) On the threaded portion of the drill spindle is fitted an angled ball race body (14) machined eccentric and fitted with a narrow ball race (15) retained onto the body by a circlip The ball race, can have the rim barrel shaped at To the forepart of the body portion (15) is fitted a male thread (18) to enable the drill chuck to be refitted when a hole or holes are required to fit the blade and or the pivot of a circle cutter described later.) The barrel.

The barrel (19) is round bodied and fitted with an enlarged forepart made eccentric to the rear portion. The barrel is slotted from beneath for its full length at (21) for a flat cutter blade which has a central saddle portion to straddle the rim of the ball race (see blades) The barrel fits the upper cylindrical portion (12) The forepart of the barrel is shaped at (22) to follow the curves of roofing and guttering An adjustable and removable foot is shaped likewise. (described later together with a thin knurled nut fitted to a thread on the barrel to give fine adjustment to the foot.

Behind the forepart of the barrel is fitted a cross slot (23) to allow the chips to emerge O as the notched cutting blade enters the end of the barrel, now called the anvil.

To retain the blade, the barrel is fitted with a longitudinal peg (24) which can be held 0 Z in with "Locktite"or made a friction fit. The flat blades are a neat fit in the barrel.

Cc Blades C, Blades can be flat or circular. (Circular blades will be described later).

\Drawing shows a flat blade (25) which has cutting notches (26) at each end to N allow the blade to be reversed. One end of the blade is shown narrowed for cutting curves or apertures after a hole is drilled for the narrow cutter blade.Alternatively a series of small holes slotted out for the narrow flat blade. Blades are longer than l o) required between the cutting notch and the end of the blade This prevents the blade from jumping out of the cut when using the tool with the foot removed. (see foot) Blades have a central saddle portion (28) which straddles the barrel shaped rim rim (17) of the ball race. Clearance is given to the cutter blade by grinding the forepart of the blade below the top edge between the forepart of the blade and the cutting notch. Blades could also be tapered or hollow ground. Blades can be resharpened by grinding forward in the cutting notch. After several grinding operations the cutting notch may not fully enter cutting anvil. Further life may be given to the blades by fitting a narrow collar (29) behind the aluminium clamp, thus bringing it and the barrel forward to reduce the gap between the end of the barrel and the foot.

The Foot.

The foot serves an important purpose as it allows the cutting of material at arms length without vibration. It is adjustable and removable for cutting apertures and curves. The foot consists of three parts. First, a collar portion (30) which fits and can slide on the enlarged forepart portion of the barrel. To this is fitted a foot bar (31) at 1 201 e the forepart of the collar (30) To the foot bar is fitted a petal shaped foot (32) Both the end of the barrel being shaped to cut corrugated and other roofing and guttering.

0 Z Not mentioned in the description of the barrel is the fine adjustment to the foot. The c barrel is threaded at (33) behind flats (34) for the fitting of a circle cutter. (described c later) A knurled narrow nut (35) fits the thread and when the nut is advanced \forward the gap between the petal shaped foot and the end of the barrel is increased.

C1 This gap is made narrow for flat material, wider for corrugated and other roofing and

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wider still to go around the right angles of a gutter.

Drill Models fitted with a Barrel Having Two Cutting Anvils.

Drawing shows such a barrel. It is shown fitted to a jig saw. The jig saw has a much longer stroke. Mostjig saws have a stroke of 18 m.m. and others a stroke of 26 m.m. The latter give a better performance when the tool is used as a tile cutter. (see later) At first glance the barrel with two cutting anvils resembles the Falcon nibbler barrel. The Falcon as mentioner earlier, cuts on the downstroke, the chips coming out of the forepart of the barrel. By making the tool cut on the upstroke the tool can be made to not only cut at the forepart of the barrel, but at an anvil behind the first slot, when metal is passed through the web, the chips coming out of a second slot behind the first..Later a tool will be described which cuts also on the down stroke.

The tool will be described in drawing as fitted to ajig saw.

C969) The base plate ofajig saw, (not shown) is removed and replaced by a metal or plastic casting. (36) It is held to the jig saw by two screws (37) The casting is slotted in its base at (38) to allow it to fit different models of jig saws. It has an upper cylindrical portion (39) which has a central hole (40 to hold the barrel. A grub screw and locknut (41) secure the barrel. To the barrel may be fitted with any of three types of (zoo) barrels. First there is the barrel with the foot, described earlier. Barrels fitted to jig saws only need to be short. The drawing of the barrel with the foot is repeated at the top of drawing barrel with the foot is shown, below are other barrels The Jig saw fitted with a barrel having two cutting anvils.

Drawing shows such a barrel at Sor) (41) It has an enlarged forepart (42) made eccentric to the rear round bodied

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portion (43) A hole is drilled from the rear of the barrel, this hole being the same diameter as the depth of the flat blade. At the forepart a smaller hole is made, then broached for the flat blade.

An alternative method is to slot the barrel on its upper side and cut cross slots to which are fitted hardened anvils (45) and (46) This alternative barrel is shown below the first., the anvils being shaded.

Both the barrels described are cut with vertical slots. The first slot (47) behind the forepart has a web portion (48) cut under the first slot. This web is made thinner than the flat cutter blade. The latter usually being about 1.5 m.m. thick. Thus the web thickness can be approx 1.4 m.m. thick. Behind the first slot is a second slot (49).

Because the blade cuts on the upstroke the tool can cut metal at the two anvils. First it can cut at the very forepart of the barrel ,the chips coming out of the first slot (47) above the web. By passing metal through the web, the chips come out of the second slot.(49) The tool can also be made to cut on the down stroke by passing metal through the web, the chips emerging from the forepart of the barrel as does the Falcon nibbling tool attachment. also described later in the description of the round bodied cutter. The barrels shown all have flats (50) on one or both ends for the fitting of a circle cutter, described later.. Jig saw models are cheaper to produce as only a casting a barrel and blade are required. Furthermore it can be used as a tile cutter.

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Blades for each of these are shown below the barrels.

0 Nibbler blades need only be slab sided and can be cut from high speed steel power hacksaw blade blanks. Such a blade is shown at (51) Like the drill model blades it has cutting notches at each end at Clearance is given by making the blade narrower under the cutting notches 52) Like the drill model blades, a longer portion j .than necessary is shown at (53) to prevent the blade from jumping out of the cut.

IA narrowed blade (54) shown below, is used for cutting apertures. The material is rested upon a sheet of Polystyrene foam. Both blades shown have a shallow notch at each end for fixing into the jig saw. The narrowed blade has only have one end notched.

Blade Fixing on Jig Saws.

Many jig saws have a cubical die cast block into which the jig saw blade is clamped. This method is not suitable for nibbler blades due to the greater load when cutting and the blade will pull out of the block.

A better method is to replace the cubical block with a steel block (56) slotted at its 04) ~forepart at (57) to insert the flat blade. To retain the blade a cross peg (58) is fitted low down in the slotted block To retain the blade a top clamping plate (59) and cap screws (60) are fitted. By fitting two compression springs (61) to the block the top clamping plate can be raised when the screws are slackened. The blade will then release There are other methods of fitting blades. Many jig saws have a bayonet type ~fitting which can be reproduced onto a nibbler blade. The blade can only be single ended when this method is used Another simpler method is to fit the blade to a block drilled longitudinally and fitted with an enlarged recess and a slot at its forepart.. The winged blade is inserted and rotated. to lock it in place.

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C-q Cc, \o \o Nibblers with Round Bodied Punches and Fitted to Jig Saws..

Round bodied punches have some advantages over flat blade cutters in that the barrel is easier to make and the punch may be rotated to give an almost squared corner with a radius half that of the diameter of the punch. Further, a narrow cut, less than the diameter of the punch may be made by grinding flats on the side of the tool.

Blade fixing is not a problem.

The fitting of round bodied punches to the drill model will be described later.

A Description of the Tool with relation to drawing' Shown first fitted to a barrel with the foot. A plain barrel (62) is drilled and reamed at (63) for the punch. It is slotted behind the forepart at (64) for the chips to emerge. Behind that are flats 'fo) for the fitting of the circle cutter. The forepart of the barrel is shaped at (66) to allow the tool to follow the curves of corrugated and other roofing. A foot (67) and its adjustment, described earlier is fitted. It is like wise shaped as is the barrel.

The Punch Cutter Blade.

This can be stock high speed steel rod, cut to length, ,it is shown at (68) A cutting notch (69) is ground behind the forepart, leaving sufficient metal to prevent the tool from jumping out of the cut when cutting without the foot fitted. The notch can be made eccentric in order to give it more strength. A flat at the distal end of the punch is for securing it. The punch cuts on the upstroke as the notch (69) enters the barrel. Small diameter punches are vulnerable to breakage and o) can only be used on thin material such as aircraft cladding. When a narrower cut is required, flats can be fitted to the sides of the blade.

Securing the Punch to the Jig Saw.

INDThe flat blade holding block on ajig saw is replaced Sby another, shown at (71) into which the punch can fit. A grub screw secures the 0 punch.

z A Round Bodied Punch Fitted to a Barrel with Two Cutting Anvils. (Drawing Shown below the Cc barrel with a foot, is a barrel with two cutting anvils.

IDA barrel (72) drilled and reamed for the punch at (73) is shaped at its forepart (74) and has two cross slots (75) and (76) Below the first cross slot a web (77) is formed..

SThis web is a made thinner than the diameter of the cutter punch and may even be thinner if flats are made on the side fthe round bodied cutter in order to make a narrower cut.

The punch (78) shown below the barrel, has a cutting notch 79) similar to that fitted "8 y) to the tool with a foot.

The forepart of the barrel forms an anvil to cut when the cutting notch enters the barrel, the chips coming out of the first slot. The tool can also cut by passing metal through the web, the chips emerging from the second slot. The stroke of ajig saw is more than sufficient to allow the tool to cut at both anvils.

The tool can also be made to cut on the down stroke as does the Falcon. Another punch or an altered punch is required. Shown below at (80) is a punch stepped at its forepart at (81) This punch is similar to that fitted to the Falcon attachment.

The tool just described can now cut at three different anvils. It can cut on the upstroke at both the forepart and when metal is passed through the web. As well as that it can cut on the down stroke when fitted with the stepped punch, the chips emerging from the forepart of the barrel as does the Falcon.

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cI Nibblers with Round Bodied Punches and Fitted to Jig Saws..

0 Round bodied punches have some advantages over flat blade cutters in that the barrel z is easier to make and the punch may be rotated to give an almost squared ¢€3 corner with a radius half that of the diameter of the punch. Further, a narrow cut, less 0than the diameter of the punch may be made by grinding flats on the side of the tool.

Blade fixing is not a problem.

The fitting of round bodied punches to the drill model will be described later.

A Description of the Tool with relation to drawing' S 3 Shown first fitted to a barrel with the foot. A plain barrel (62) is drilled and reamed at (63) for the punch. It is slotted behind the forepart at (64) for the chips to emerge. Behind that are flats for the fitting of the circle cutter. The forepart of the barrel is shaped at (66) to allow the tool to follow the curves of corrugated and other roofing. A foot (67) and its adjustment, described earlier is fitted. It is like wise shaped as is the barrel.

The Punch Cutter Blade.

This can be stock high speed steel rod, cut to length, ,it is shown at (68) A cutting notch (69) is ground behind the forepart, leaving sufficient metal to prevent the tool from jumping out of the cut when cutting without the foot fitted. The notch can be made eccentric in order to give it more strength. A flat at the distal end of the punch is for securing it. The punch cuts on the upstroke as the notch (69) enters the barrel. Small diameter punches are vulnerable to breakage and can only be used on thin material such as aircraft cladding. When a narrower cut is required, flats can be fitted to the sides of the blade.

o) Securing the Punch to the Jig Saw.

P"3- f~ A Round Punch Nibbler with Two cutting Anvils and fitted to A Drill The tool requires altering to use a round bodied cutter. This is accomplished by fitting 0 the punch to a round bodied shuttle on the lower side of the shuttle is made or fitted a 0 saddle portion which straddles the angled ball race. The punch can be long enough to be reversed. The barrel thus requires an enlarged hole at its rear and a smaller hole at 0 the forepart of the barrel for the punch.

This tool will now be described with relation to drawing 0 The Barrel.

A barrel is shaped at the forepart at (83) to cut roofing. Behind the forepart which forms the first anvil, are two cross slots (84) and (85) Behind that again are two ,,51 flats (86) for the circle cutter.

Below the first cross slot a web is formed at When metal is passed through the Web, which is made thinner than the diameter of the punch, the chips come out of a second slot (85) When cutting is done at the forepart the cuttings emerge from the first slot as the tool cuts on the upstroke. Like the previously mentioned tool, the 2Z^io round bodied blade can be fitted with flats on its sides to make a narrower cut. To use such a blade the web is required to be thinner. Like the Falcon, the tool can be made to cut on the down stroke when metal is passed through the first slot. An altered punch is required.

The cutting punch.

(z 46) Like the previous tool the punch is a length of high speed steel of the required diameter. Two punches are required if the tool is also to be used for cutting on the down stroke.

The first punch for cutting on the upstroke is shown at 88). It has a ground step (89) which can be eccentric to the body The second punch (90) for cutting on the 0 z A 9 down stroke has a spigot (91) at the very forepart of the punch. When metal is passed through the web (87) the chips come out of the forepart of the barrel as the tool cuts on the down stroke as does the Falcon.

The Shuttle.

The prototype shuttle has been made from a round body drilled longitudinally for the round bodied punch and fitted with a saddle portion (93) beneath the round section. A grub screw (94) fitted centrally from beneath, secures the punch, a flat (95) being fitted to the punch. The barrel is slotted from neath at (96) for the shuttle (93) to operate

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A Drill Body with the Barrel holding Tube Portion incorporated O# AVAW ",C There are two versions of how this can be accomplished. The first is a removable tube portion (97) with a section beneath This section being shaped like the letter turned on its side.

This part is fitted between the half cases of a drill body.. Another version has spigoted buttons fitting holes in the drill case. (see inset) The same drawing shows two halves of the tubular portion (97) moulded into each half of the drill case.

When the case halves are assembled, the barrel may be fitted to the hole (103) To hold the drill case together, an additional screw (100) is required at the distal end of the tube To hold the forepart, a metal sleeve (101) is fitted. This also allows a grub screw and locknut (102) to be fitted to secure the barrel into the drilled forepart (103) Z¢ By incorporating the barrel holding tubular portion into a drill body makes the tool more presentable for sales. Furthermore, it makes the tool easier to assemble and allows the tool to be used to cut on the down stroke as there is no clamp to be pulled off the parallel portion of the barrel. This was not a problem with metal case drills.

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A Jig Saw Version which Fits the Existing Base of a Jig Saw.

To fit this version of ajigsaw, knife, jigsaw or-tile cutter, the existing base Z need not be removed, now described with relation to drawng "G" c Another base,(104), has turned down ends at (105) and a tensioning screw or screws Cc (106) is fitted with a short tubular section (107) to hold the barrel. A barrel securing t screw (108) holds the barrel. Because the tubular section (107) may need to be lined N'7f up with the blade, the tubular section could be made adjustable by fitting it to an elongated hole (109) in the base (104). The tubular portion (107) can be secured by a nut (110) fitted to either the top side or underside of the base.

Some cheap jig saws have soft bases and can flex or bend when cutting. This method of fitting a shoe may be limited to those jig saws with a strong base.

A Version of a Drill Model Attachment which does away with an Aluminium Clamp Drawing shows a Plastic or metal housing (111) fitted with an upper tubular barrel portion (112) with a central hole (113) for the barrel. Below the tubular portion the housing (111) can be clamped to the parallel portion (115) of a drill). The housing (111) is fitted with a bearing (116) at its forepart. To this bearing is fitted a 8- driving spindle ((117) fitted with a male thread (118) at its forepart and an enlarged rear portion (119) which can be a nut socket orjust slotted to drive a hexagon nut (120) fitted to the drill spindle and replacing the drill chuck To the threaded forepart of the threaded spindle can be fitted either an angled ball race assembly 121) or a recessed cam (122). Cutting blades fit a shuttle (123) Jt) which operates in the barrel. The shuttle (123) is slotted at its forepart for a flat blade or drilled for a round bodied blade. A securing screw (124) holds the latter. The shuttle, which is a sliding fit in the barrel has two threaded peg holes for vertical threaded pegs (125) which have some of the thread removed and project downwards

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O to straddle the rim of the angled ball race. This provides the reciprocation. The heads S 9cj of the threaded cap screws can operate in a slot (126) in the top of the barrel tube.

0 Z Below the angled ball race is shown a recessed cam (127) threaded at (128) to fit the c n drill spindle. This is an alternative drive to provide reciprocation. Only one driving Cc peg (129) is required to enter the cam groove (130) in the cam (127) in the cam. The 1 peg can be retained in the shuttle by a spring loaded ball (131) entering an indent in N, (300 the driving peg (129) Any of the different types of barrels and cutter blades may be fitted to the shuttle A safety cover, not shown is fitted over the mechanism.

The Circle Cutter.

A circle cutter can fit all the different barrel models A metal or plastic plate (132) is slotted for an adjustable pivot (133) The enlarged portion is slotted at (134) to fit the }flats on the barrel. A securing cap screw (135 is shown.) Attachments to Drills and Jig Saws Both jig saws and drills may be fitted to a stand, comprising ofa base (136), a pillar (137) fitted with a table (138). Beneathe the table is a collar portion (139) to which can be fitted both drills and jig saws, the barrels of which enter the collar and are clamped. This enables the operator to use both hands to cut sheet material by manipulating it under the cutter. To hold the material under the cutter an adjustable foot (1 4? can be bought down and clamped above the sheet to prevent vibration.

Another Foot Adjustment for the Foot on a Drill or Jig Saw Barrel.

Drawing shows another fine adjustment to a foot The barrel (141)) has a knurled cam (14) which when rotated against a peg (143) adjusts the foot forward.

A locking screw in the collar (I/4 can then be tightened.

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