CA1064253A - Cutting bit for percussion tool - Google Patents
Cutting bit for percussion toolInfo
- Publication number
- CA1064253A CA1064253A CA280,459A CA280459A CA1064253A CA 1064253 A CA1064253 A CA 1064253A CA 280459 A CA280459 A CA 280459A CA 1064253 A CA1064253 A CA 1064253A
- Authority
- CA
- Canada
- Prior art keywords
- blade
- shank
- tool
- bit
- percussive tool
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- E—FIXED CONSTRUCTIONS
- E04—BUILDING
- E04G—SCAFFOLDING; FORMS; SHUTTERING; BUILDING IMPLEMENTS OR AIDS, OR THEIR USE; HANDLING BUILDING MATERIALS ON THE SITE; REPAIRING, BREAKING-UP OR OTHER WORK ON EXISTING BUILDINGS
- E04G23/00—Working measures on existing buildings
- E04G23/08—Wrecking of buildings
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
- B25D—PERCUSSIVE TOOLS
- B25D17/00—Details of, or accessories for, portable power-driven percussive tools
- B25D17/02—Percussive tool bits
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
- B25D—PERCUSSIVE TOOLS
- B25D3/00—Hand chisels
Abstract
ABSTRACT
A percussive tool is provided with a bit which comprises a shank, by which the bit is held in the tool, and a flexible blade made from a springy metal such as bainitic steel or phosphor bronze. 1.5mm has been found to be a particularly satisfactory thickness for the tip portion of the blade. Deposits of plaster, cement, caked oil and other deposits all of which can be highly resistant to removal by rigid-bladed bits from surfaces on which they have become hardened have proved surprisingly easy to remove using a springy metal blade. The new blade is also very effective in removing tiles which have been cemented to a surface.
A percussive tool is provided with a bit which comprises a shank, by which the bit is held in the tool, and a flexible blade made from a springy metal such as bainitic steel or phosphor bronze. 1.5mm has been found to be a particularly satisfactory thickness for the tip portion of the blade. Deposits of plaster, cement, caked oil and other deposits all of which can be highly resistant to removal by rigid-bladed bits from surfaces on which they have become hardened have proved surprisingly easy to remove using a springy metal blade. The new blade is also very effective in removing tiles which have been cemented to a surface.
Description
~O~i4Z53 This invention relates to percussive tools i.e. motorized tools which operate to apply impact forces to a holder for a tool-bit.
According to this invention there is provided a percussive tool equipped with a cutting bit comprising a shank held by one end in the tool and a blade secured to the other end of the shank so that the blade extends in substantially the same direction as the shank, said blade being made from a springy metal.
Bainitic steel and phosphor-bronze have been found to be particularly suitable materials for the blade. The thickness of the blade is preferably 5mm. or less if a single thickness of material is used, but the blade may be of laminated form in some cases. 1.5mm has been found to be a particularly effective thickness for the tip portion of the blade.
Such a cutting bit used in con~unction with a percussive tool has been found to be remarkably effective, for reasons which are not clear, in ren~ving dropped plaster and concrete, paint, caked oil and other deposits, and tiles from floors, walls and ceilings.
In certain applications the blade may be inclined to the shank, e.g. at an angle of 30, to provide a clearance for the body of the ~- cutting tool, as where the bit is used to cut silage and hay disposed in a stack.
m e blade m~y be brazed or welded to the shank but it is preferred to make the blade detachable from the shank. For this purpose, the said one end of the shank may be formed as a yoke to embrace an edge s of the blade, the blade being secured by one or more rivets or threaded : bolts extending throu~h the blade and the yoke. m us one blade may be exchanged for another and a gasket or gaskets may be disposed between the blade and the yoke to reduce the risks of fatigue failure and high-frequency noise. In order to avoid the gasket or gaskets becoming lost it
According to this invention there is provided a percussive tool equipped with a cutting bit comprising a shank held by one end in the tool and a blade secured to the other end of the shank so that the blade extends in substantially the same direction as the shank, said blade being made from a springy metal.
Bainitic steel and phosphor-bronze have been found to be particularly suitable materials for the blade. The thickness of the blade is preferably 5mm. or less if a single thickness of material is used, but the blade may be of laminated form in some cases. 1.5mm has been found to be a particularly effective thickness for the tip portion of the blade.
Such a cutting bit used in con~unction with a percussive tool has been found to be remarkably effective, for reasons which are not clear, in ren~ving dropped plaster and concrete, paint, caked oil and other deposits, and tiles from floors, walls and ceilings.
In certain applications the blade may be inclined to the shank, e.g. at an angle of 30, to provide a clearance for the body of the ~- cutting tool, as where the bit is used to cut silage and hay disposed in a stack.
m e blade m~y be brazed or welded to the shank but it is preferred to make the blade detachable from the shank. For this purpose, the said one end of the shank may be formed as a yoke to embrace an edge s of the blade, the blade being secured by one or more rivets or threaded : bolts extending throu~h the blade and the yoke. m us one blade may be exchanged for another and a gasket or gaskets may be disposed between the blade and the yoke to reduce the risks of fatigue failure and high-frequency noise. In order to avoid the gasket or gaskets becoming lost it
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-or they may be adhesively secured to the blade.
One embodiment of the invention will now be described by way of example with reference to the accompanying drawings in which:
: Figure 1 shows in elevation a cutting bit for a percussive tool according to the invention;
Figure 2 is a side elevation of the bit partly sectioned on ` line 2-2 of Figure l; and Figures 3 and 4 are respectively front and rear end views of the bit shown in Figures 1 and 2.
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1064;~53 Referring to the drawings, the bit comprises a shank 10 having a blade 11 secured to one end thereof. To hold the blade a yoke 12 is secured on a self-locking tapered s?igot 13 on the end of the shank, the spigot being ; driven into a correspondingly tapered socket in the yoke.
In the illust~ated construction the blade is rectangular and is clamped in a rebate in the yoke by a plate 14, two bolts 15 extending through holes in the plate, blade and yoke and being secured by nuts 16. Heavy duty gaskets 17 are adhesively bonded to both sides of the blade between the plate 14 and the yoke to reduce the risks of fatigue-failure and high-frequency noise.
The blade is made from bainitic steel or from phosphor-bronze and is thus relatively springy by comparison with the usual type of cutting or chisel bit where the shank and a heavy rigid blade are forged integrally with each other from a tough steel.
In an alternative construction, the yoke has instead of the rebate and plate 14 a slot into which the back edge portion of the blade fits. In this construction also, heavy duty gaskets, made for example from red fibre, are secured by an adhesive to the faces of the blades where it fits in the , . .
slot. The blade is secured in the slot by bolts and nuts as in the illustrated arrangement.
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1~642S3 ~ e releasable attachment of the yoke to the shank enables different lengths and types of shank to be used lnterchangeably, but the yoke may be for~ed integrally with the shank or may be brazed or welded or press-fitted to the shank. The yoke may be a steel forging or a spheroidal graphite iron casting.
In addition to its use in con~unction with a percusslve tool for removing concrete and plaster droppings, tiles, paint and caked oil from floors, walls and ceilings, the bit may have a sharpened blade and be used for cutting such materials as silage and hay for feeding farm animals. The bit can be used with any type of percllssive tool including those, known as buzz drills, which em~loy high frequency, low energy vibrations.
Where the bit is to be used for cutting silage or hay disposed in a stack the blade may be inclined to the general lengthwise dimension of the shank, i.e. to the direction of the percussion or vibration, at an angle which should not exceed 30, to provide a clearance for the body of the percussive tool. m e blade can be so disposed for example by forming a bend in the shank near its forward end, by arranging the yoke at an angle to the shank, or by inserting packing pieces of appropriate forn between the yoke and the b1Idb.
, .:
,, , '' ' ~ -5-:, ~ , , , ~ . -:: , - , -: .. , . ~ ~ , . .
.; .
:.............................................................. ~
:-. .. .. ~
,"~ : ', - - ~ , , ~ .
-or they may be adhesively secured to the blade.
One embodiment of the invention will now be described by way of example with reference to the accompanying drawings in which:
: Figure 1 shows in elevation a cutting bit for a percussive tool according to the invention;
Figure 2 is a side elevation of the bit partly sectioned on ` line 2-2 of Figure l; and Figures 3 and 4 are respectively front and rear end views of the bit shown in Figures 1 and 2.
''' :::
:'',, ...
., ., .
~ ' ''' : ~ .
.` ~ _3_ :
.
,. . .
' . : ~ .`~ -;, ~, i . . .... . .
~ ~ .. . . . .
1064;~53 Referring to the drawings, the bit comprises a shank 10 having a blade 11 secured to one end thereof. To hold the blade a yoke 12 is secured on a self-locking tapered s?igot 13 on the end of the shank, the spigot being ; driven into a correspondingly tapered socket in the yoke.
In the illust~ated construction the blade is rectangular and is clamped in a rebate in the yoke by a plate 14, two bolts 15 extending through holes in the plate, blade and yoke and being secured by nuts 16. Heavy duty gaskets 17 are adhesively bonded to both sides of the blade between the plate 14 and the yoke to reduce the risks of fatigue-failure and high-frequency noise.
The blade is made from bainitic steel or from phosphor-bronze and is thus relatively springy by comparison with the usual type of cutting or chisel bit where the shank and a heavy rigid blade are forged integrally with each other from a tough steel.
In an alternative construction, the yoke has instead of the rebate and plate 14 a slot into which the back edge portion of the blade fits. In this construction also, heavy duty gaskets, made for example from red fibre, are secured by an adhesive to the faces of the blades where it fits in the , . .
slot. The blade is secured in the slot by bolts and nuts as in the illustrated arrangement.
. ' , - 4 - ~
., .
, . . .
,. .
-. , :
:
1~642S3 ~ e releasable attachment of the yoke to the shank enables different lengths and types of shank to be used lnterchangeably, but the yoke may be for~ed integrally with the shank or may be brazed or welded or press-fitted to the shank. The yoke may be a steel forging or a spheroidal graphite iron casting.
In addition to its use in con~unction with a percusslve tool for removing concrete and plaster droppings, tiles, paint and caked oil from floors, walls and ceilings, the bit may have a sharpened blade and be used for cutting such materials as silage and hay for feeding farm animals. The bit can be used with any type of percllssive tool including those, known as buzz drills, which em~loy high frequency, low energy vibrations.
Where the bit is to be used for cutting silage or hay disposed in a stack the blade may be inclined to the general lengthwise dimension of the shank, i.e. to the direction of the percussion or vibration, at an angle which should not exceed 30, to provide a clearance for the body of the percussive tool. m e blade can be so disposed for example by forming a bend in the shank near its forward end, by arranging the yoke at an angle to the shank, or by inserting packing pieces of appropriate forn between the yoke and the b1Idb.
, .:
,, , '' ' ~ -5-:, ~ , , , ~ . -:: , - , -: .. , . ~ ~ , . .
.; .
Claims (9)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A percussive tool equipped with a cutting bit comprising a shank held by one end in the tool and a blade secured to the other end of the shank so that the blade extends in substantially the same direction as the shank, said blade being made from a springy metal.
2. A percussive tool as claimed in claim 1, wherein the blade is made from bainitic steel.
3. A percussive tool as claimed in claim 1 wherein the blade is made from phosphor-bronze.
4. A percussive tool as claimed in claim 1 wherein the blade has a thickness not exceeding 5mm.
5. A percussive tool as claimed in claim 4 wherein the tip portion of the bit has a thickness of 1.5mm.
6. A percussive tool as claimed in any one of claims 1, 4 and 5 wherein the plane of the blade is inclined to the lengthwise axis of the shank.
7. A percussive tool as claimed in claim 1 wherein the blade is made separately from and is secured to the shank.
8. A percussive tool as claimed in claim 7 wherein one end of the shank carries a yoke to which is secured the rear edge of the blade.
9. A percussive tool as claimed in claim 8 wherein at least one gasket is interposed between the rear edge portion of the blade and the yoke.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB2481276A GB1579333A (en) | 1976-06-15 | 1976-06-15 | Percussive power tool with a flexible blade |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1064253A true CA1064253A (en) | 1979-10-16 |
Family
ID=10217624
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA280,459A Expired CA1064253A (en) | 1976-06-15 | 1977-06-14 | Cutting bit for percussion tool |
Country Status (7)
| Country | Link |
|---|---|
| AU (1) | AU507749B2 (en) |
| CA (1) | CA1064253A (en) |
| DE (1) | DE7718583U1 (en) |
| ES (1) | ES237301Y (en) |
| FR (1) | FR2354855A1 (en) |
| GB (1) | GB1579333A (en) |
| IT (1) | IT1083834B (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4395825A (en) * | 1980-07-24 | 1983-08-02 | Lock Trevor S | Device for removing vehicle windscreens |
| SE436549B (en) * | 1981-06-24 | 1985-01-07 | Atlas Copco Ab | HANDHALL VIBRATION DUMP DEVICE TOOL |
| EP0148546A1 (en) * | 1984-01-11 | 1985-07-17 | The Stanley Works Limited | A chisel |
| GB9004200D0 (en) * | 1990-02-24 | 1990-04-18 | Atha Alfred | Improvements relating to tools for removing tiles and the like from flat surfaces |
| DE10259517A1 (en) * | 2002-12-19 | 2004-07-01 | Robert Bosch Gmbh | Chisel and machine tool with such a chisel |
| EP2502709B1 (en) * | 2011-03-22 | 2017-02-01 | Black & Decker Inc. | Chisels |
-
1976
- 1976-06-15 GB GB2481276A patent/GB1579333A/en not_active Expired
-
1977
- 1977-06-13 DE DE19777718583 patent/DE7718583U1/en not_active Expired
- 1977-06-14 ES ES1977237301U patent/ES237301Y/en not_active Expired
- 1977-06-14 CA CA280,459A patent/CA1064253A/en not_active Expired
- 1977-06-14 FR FR7718173A patent/FR2354855A1/en active Granted
- 1977-06-15 AU AU26106/77A patent/AU507749B2/en not_active Expired
- 1977-06-15 IT IT2471077A patent/IT1083834B/en active
Also Published As
| Publication number | Publication date |
|---|---|
| ES237301U (en) | 1978-10-01 |
| FR2354855B3 (en) | 1980-04-18 |
| GB1579333A (en) | 1980-11-19 |
| ES237301Y (en) | 1979-02-01 |
| FR2354855A1 (en) | 1978-01-13 |
| AU2610677A (en) | 1978-12-21 |
| DE7718583U1 (en) | 1977-10-20 |
| IT1083834B (en) | 1985-05-25 |
| AU507749B2 (en) | 1980-02-28 |
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