The present invention relates to tool bits. More particularly, the present invention relates to tool bits for use with hammer-type drills.
Rebar cutter bits are generally used with power tools such as rotary drills or hammer-type drills to cut through concrete that includes rebar. Rebar cutter bits include a cutting tip that is specifically designed to cut through rebar. Occasionally, rebar cutter bits are used with power tools that include an anvil that are operable in a rotary impact/hammer mode where the anvil strikes a bit during rotation to increase the cutting performance. However, for some rebar cutter bits, it is undesirable for the anvil to strike the bit as it may cause damage to the bit.
In one aspect, the invention provides a tool bit for use with a power tool having a chuck and an anvil. The tool bit has a first end, a second end opposite the first end, a body defining the first end of the tool bit, and a shank coupled to the body and defining the second end of the tool bit. The shank is configured to be inserted into the chuck of the power tool. The shank includes a slot formed through the second end. The slot is configured to receive a portion of the chuck to transfer rotational movement from the power tool to the tool bit. The shank also includes a ball detent spaced circumferentially from the slot. The ball detent is configured to receive a locking sphere of the chuck to lock the tool bit with the chuck. The slot is sized to limit insertion of the shank into the chuck, thereby providing a space between the second end of the tool bit and the anvil.
In some aspects, the space inhibits the second end of the tool from contacting the anvil during operation of the power tool.
In some aspects, the slot has a length. The length is between 0.2 inches and 1 inch.
In some aspects, the slot has a slot length and the ball detent has a ball detent length. A ratio of the ball detent length to the slot length is between 0.85 and 1.15.
In some aspects, the slot has a proximal slot end adjacent the second end of the tool bit and a distal slot end opposite the proximal slot end. The ball detent has a proximal ball detent end adjacent the second end of the tool bit and a distal ball detent end opposite the proximal ball detent end. The distal ball detent end is spaced generally the same distance from the first end of the tool bit as the second slot end.
In some aspects, the slot has a proximal slot end adjacent the second end of the tool bit and a distal slot end opposite the proximal slot end. The ball detent has a proximal ball detent end adjacent the second end of the tool bit and a distal ball detent end opposite the proximal ball detent end. The distal slot end is closer than the distal ball detent end to the second end of the tool bit.
In some aspects, the slot extends from the second end of the tool bit but does not extend past the ball detent in a direction parallel to an axis of rotation of the tool bit.
In some aspects, the slot is a first slot. The ball detent is a first ball detent. The shank further includes a second slot positioned diametrically opposite from the first slot and formed through the second end. The second slot is configured to receive another portion of the chuck to transfer rotational movement from the power tool to the tool bit. The shank further includes a second ball detent positioned diametrically opposite from the first ball detent. The second ball detent is configured to receive another locking sphere of the chuck to lock the tool bit within the chuck.
In some aspects, the ball detent is bounded on all sides.
In another aspect, the invention provides a tool bit for use with a power tool having a chuck and an anvil. The tool bit has a first end, a second end opposite the first end, a body defining the first end of the tool bit, and a shank coupled to the body and defining the second end of the tool bit. The shank is configured to be inserted into the chuck of the power tool. The shank includes a slot formed through the second end. The slot is configured to receive a portion of the chuck to transfer rotational movement from the power tool to the tool bit. The shank also includes a ball detent spaced circumferentially from the slot. The ball detent is configured to receive a locking sphere of the chuck to lock the tool bit with the chuck. The shank further includes a projection. The projection is configured to contact a surface of the chuck and limit insertion of the shank into the chuck, thereby providing a space between the second end of the tool bit and the anvil.
In some aspects, the space inhibits the second end of the tool from contacting the anvil during operation of the power tool.
In some aspects, the projection is a shoulder formed at an increased diameter portion of the shank. The shoulder extends continuously around a circumference of the shank.
In some aspects, the slot has a proximal end adjacent the second end of the tool bit and a distal end opposite the proximal end. The projection is adjacent the distal end of the slot.
In some aspects, the slot is a first slot. The ball detent is a first ball detent. The shank further includes a second slot positioned diametrically opposite from the first slot and formed through the second end. The second slot is configured to receive another portion of the chuck to transfer rotational movement from the power tool to the tool bit. The shank further includes a second ball detent positioned diametrically opposite from the first ball detent. The second ball detent is configured to receive another locking sphere of the chuck to lock the tool bit within the chuck.
In some aspects, the ball detent is bounded on all sides.
In another aspect, the invention provides a tool bit for use with a power tool having a chuck and an anvil. The tool bit has a first end, a second end opposite the first end, a body defining the first end of the tool bit, and a shank coupled to the body and defining the second end of the tool bit. The shank is configured to be inserted into the chuck of the power tool. The shank includes a first slot formed through the second end. The first slot is configured to receive a first portion of the chuck to transfer rotational movement from the power tool to the tool bit. The shank also includes a second slot positioned diametrically opposite from the first slot and formed through the second end. The second slot is configured to receive a second portion of the chuck to transfer rotational movement from the power tool to the tool bit. The shank further includes a first ball detent spaced circumferentially from the first and second slots. The first ball detent is configured to receive a first locking sphere of the chuck to lock the tool bit within the chuck. The shank also includes a second ball detent positioned diametrically opposite from the first ball detent. The second ball detent is configured to receive a second locking sphere of the chuck to lock the tool bit within the chuck. The shank is configured to limit insertion of the shank into the chuck such that the second end of the tool bit is not contacted by the anvil during operation of the power tool.
In some aspects, the first slot and the second slot are sized to limit insertion of the shank into the chuck.
In some aspects, the first slot and the second slot extend from the second end of the tool bit but do not extend past the first ball detent or the second ball detent in a direction parallel to an axis of rotation of the tool bit
In some aspects, the shank includes an increased diameter portion that is configured to contact a surface of the chuck to limit insertion of the shank into the chuck.
The above aspects may be used in any combination with each other. Other aspects of the invention will become apparent by consideration of the detailed description and accompanying drawings.
Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways.
With reference to
The illustrated body 30 includes a helical rib 38 that defines a flute 42. In the illustrated embodiment, the tool bit 10 includes a single rib 38 that defines a single flute 42. In other embodiments, the tool bit 10 may include more than one rib 38 that defines multiple flutes 42. In other embodiments, the body 30 may not include a rib 38. The ribs 38 and flutes 42 may be helically wrapped around the body 30 at a variable helix angle. In other words, the angle at which the flutes 42 wrap about the body 30 changes as the flutes 42 extend from the first end 18 towards the second end 22. The ribs 38 and flutes 42 facilitate chip removal from a workpiece during a cutting operation.
The illustrated body 30 also includes one or more apertures 46 that extend into a bore 50 of the tool bit 10. The apertures 46 facilitate removal of material (e.g., cutting chips, slugs, etc.) from the body 30 and may also be referred to as slug removal holes. For example, a user may remove the debris or slugs from the bore 50 by extending a pick or screwdriver into one of the apertures 46. In the illustrated embodiment, the body 30 includes two apertures 46. In other embodiments, the body 30 may only include a single aperture 46 or may include more than two apertures 46. In some embodiments (particularly for smaller diameter tool bits), the apertures 46 and the bore 50 may be omitted.
With reference to
With continued reference to
In the illustrated embodiment, a length L1 of each ball detent 94 is similar to a length L2 of each slot 98. In other words, a ratio of the length L1 of the ball detents 94 to the length L2 of the slots 98 is a range between 0.85 and 1.15. Further, the ball detents 94 and the slots 98 only extend along a portion of the shank 34. Specifically, in the illustrated embodiment, the length L1 of the ball detents 94 and the length L2 of the slots 98 extend between one-fifth and one-third a total length of the shank 34. As such, the slots 98 and detents 94 are shortened compared to other or standard SDS shanks. In further embodiments, if the length of the shank 34 were increased, the length L1 of the ball detents 94 and the length L2 of the slots 94 would remain constant. In such an embodiment, the length L1 of the ball detents 94 and the length L2 of the slots 94 may be between 0.2 inches and 1 inch.
The illustrated slots 98 do not extend past the ball detents 94 in a direction parallel to the axis of rotation 26 (
In other embodiments, the shank 34 may be made from a different material than the body 30. For example, the end of the shank 34 may be made of a softer material than the material used for the body 30. In such an embodiment, the end of the shank 34 would be operable to absorb an impact from the anvil 106 without harming the integrity of the tool bit 10. In further embodiments, the shank 34 may be spring loaded to absorb the impact energy from the anvil 106. In such an embodiment, the shank 34 may include a resilient member that biases the shank 34 away from the body. Then, if the shank 34 were to receive an impact force from the anvil 106, the shank 34 would move against the bias of the resilient member to absorb the impact energy from the anvil 106 preventing harm to the tool bit 10.
Providing a tool bit 10 with a modified SDS shank 34 that includes slots 98 inhibits the tool bit 10 from being impacted by an anvil 106 of a power tool 14 when received in the chuck 24 of the power tool 14, which may extend the life of the tool bit 10.
In some embodiments, shank 34 of the tool bit 10 or the shank 214 of the tool bit 210 may be SDS max designs. Providing a tool bit 10, 210 with a modified shank that inhibit impact from an anvil 106 allows for heavier rebar cutters that include an SDS max design. For example,
In the illustrated embodiment, the tool bit 310 includes a first or workpiece engaging end 314 and a second or rearward end 318 configured to be received in a tool holder or a chuck of a power tool. The tool bit 310 also includes a body 322 extending between the first and second ends 314, 318 and a shank 326 that defines the second end 318. In the illustrated embodiment, the shank 326 is a modified SDS max shank. In comparison, the shank 34 of the tool bit 10 shown in
In the illustrated embodiment, a length L3 of each ball detent 330 is similar to a length L4 of each slot 334a, 334b. In other words, a ratio of the length L3 of the ball detents 330 to the length L4 of the slots 334a, 334b is in a range between 0.85 and 1.15. Further, the ball detents 330 and the slots 334a, 334b only extend along a portion of the shank 326. Specifically, in the illustrated embodiment, the length L3 of the ball detents 330 and the length L4 of the slots 334a, 334b extend between one-tenth and seven-tenths a total length of the shank 34. In addition, the length L3 of the ball detents 330 and the length L4 of the slots 334a, 334b extend long enough to engage the chuck 24 of the power tool 14 to transfer rotation, but short enough to not receive impact from the anvil 106. As such, the slots 334a, 334b and detents 330 are shortened compared to other or standard SDS max shanks. In further embodiments, if the length of the shank 326 were increased, the length L3 of the ball detents 330 and the length L4 of the slots 334a, 334b would remain constant. In such an embodiment, the length L3 of the ball detents 330 and the length L4 of the slots 334a, 334b may be between 0.2 inches and 2 inches.
The illustrated slots 334a, 334b extend slightly past the ball detents 330 in a direction parallel to the longitudinal axis 338. Each slot 334a, 334b is formed through the second end 318 of the tool bit 310 and extends toward the first end 314. Each slot 334a, 334b has a proximal end 335a at the second end 318 and a distal end 335b opposite the proximal end 335a. The distal end 335b defines an inclined surface 342 that extends to the outer periphery of the shank 326. Each ball detent 330, in contrast, does not extend through the second end 318 such that the ball detents 330 are bounded on all sides. Each ball detent 330 has a proximal end 330a adjacent the second end 318 and a distal end 330b opposite the proximal end 330a. In conventional SDS shanks, the slots 334a, 334b typically extend a further distance along the shank 326 and past the ball detents 330. That is, the distal ends 335b of the slots 334a, 334b are typically closer than the distal ends 330b of the ball detents 330 to the first end 314 of the tool bit 310. Stated another way, in conventional SDS shanks, the distal ends 335b of the slots 334a, 334b are spaced further than the distal ends 330b of the ball detents 94 from the second end 318. In the illustrated embodiment, the distal ends 335b of the slots 334a, 334b are spaced generally the same distance from the first and second ends 314, 318 as the distal ends 330b of the ball detents 330. In some embodiments, the distal ends 335b of the slots 334a, 334b may be spaced further than the distal ends 330b of the ball detents 330 from the first end 314. In such embodiments, the distal ends 335b of the slots 334a, 334b may be closer than the distal ends 330b of the ball detents 330 to the second end 318.
The tool bit 310 is configured to be inserted into a chuck of a power tool that receives SDS max shanks. Generally, rotary power tools configured to receive SDS max tool bits are operable in two modes: a hammer only mode, in which an anvil provides only a percussive force to the end of a tool bit, and a rotary hammer mode, in which the anvil provides a percussive force to a tool bit while the tool bit is rotated. Similar to the tool bit 10, the shortened lengths of the ball detents 330 and the slots 334a, 334b prevent the shank 326 from fully inserting into the chuck of a SDS max rotary power tool. As such, during a cutting operation, an anvil 106 does not contact the shank 326 to impart an impact force on the tool bit 10.
In some embodiments, the tool bits 10, 210, 310, 410 may be coated with a rust preventive coating that is applied to the entire tool bit 10, 210, 310, 410. In further embodiments, the tool bits 10, 210, 310, 410 may be coated with a PVD (physical vapor deposition) coating, such as titanium-nitride coating or with black oxide.
In further embodiments, the shank 34 of the drill bit 10, the shank 214 of the drill bit 210, or the shank 326 of the drill bit 310 may be used with a number of different tool bits.
Although the invention has been described in detail with reference to certain embodiments above, variations and modifications exist within the scope and spirit of the invention. Various features and advantages of the invention are set forth in the following claims.
This application is a continuation of International Patent Application No. PCT/US2022/012536 filed on Jan. 14, 2022, which claims priority to U.S. Provisional Patent Application No. 63/137,518 filed on Jan. 14, 2021, and to U.S. Provisional Patent Application No. 63/160,080 filed on Mar. 12, 2021, the entire contents of which are incorporated by reference herein.
Number | Date | Country | |
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63160080 | Mar 2021 | US | |
63137518 | Jan 2021 | US |
Number | Date | Country | |
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Parent | PCT/US2022/012536 | Jan 2022 | US |
Child | 17697250 | US |