This application claims priority from GB Patent Application No. 2306685.5, filed May 5, 2023, GB Patent Application No. 2308631.7, filed Jun. 9, 2023, and EP patent application Ser. No. 24/173,682.6, filed May 1, 2024, the disclosures of which is incorporated herein by reference in its entirety.
This specification relates to portable electric power tools for bending elongate objects such as rebar or linear conduits such as pipes or tubes.
Rebar is a term used for steel reinforcement bars around which concrete is poured during construction. The presence of rebar embedded within concrete improves the integrity of a concrete structure. Prior to concrete pouring rebar is arranged in a predetermined manner. Rebar is generally provided in the form of straight of rods having a range of standard diameters (thicknesses) to enable mass production, making it incumbent on construction workers to select rebar of the required thickness for their building project and bend such rods into required shapes. Different specifications of rebar each have a different bend radius which is the minimum radius which the rebar can be bent without compromising the rebar, in other words rebar of different diameters can be bent to different extents without compromising the rebar. Building regulations exist concerning the range of acceptable bend curvatures for rebar of different diameters. Generally, for bends of a certain angle, thick rebar must have a larger radius of curvature compared to bends of a similar angle in thin rebar as illustrated in
According to the invention there is provided a portable electric power tool for bending elongate objects according to claim 1, wherein optional features thereof are defined in claims 2 to 15. According to the invention there is also provided an abutment portion according to claim 16.
Various aspects and embodiments of the invention will now be described by way of non-limiting example with reference to the accompanying drawings, in which:
As will be explained in detail, the bias portion 24 is operatively coupled to an electric motor of the rebar bending power tool 10 so that the third abutment portion 40 can be linearly moved relative to the first and second abutment portions 30, 32 along a direction (denoted B-B in
Upon pulling a trigger 19 of the tool 10 the bias portion 24 of the bend mechanism 20 is movably driven relative to the support portion 22 of the bend mechanism 20 as shown in
During such movement the third abutment portion 40 exerts a force F1 on the rebar 42, the first abutment portion 30 exerts a force F2 on the rebar 42 and the second abutment portion 32 exerts a force F3 on the rebar 42; in the embodiment described the force F1 arises from pulling the bias portion 24 and thus retracting the finger 38 into the tool 10 whereas the forces F2 and F3 are reaction forces arising due to the rebar 42 being pressed against the first and second abutment portions 30, 32.
It will be appreciated that interaction of the rebar 42 with the first to third abutment portions 30, 32, 40 and the forces F1, F2, F3 exerted thereby on the rebar 42 cause the rebar 42 to bend. The further the third abutment portion 40 is moved relative to the first and second abutment portions 30, 32 the more the rebar 42 is bent.
Internal features of the portable electric rebar bending power tool 10 will now be described with reference to
The tool 10 has a controller 44 for determining that the trigger 19 has been pulled. In response to the controller 44 determining that the trigger 19 has been pulled the controller 44 generates a signal to activate an electric motor 46, which is a DC brushless motor. Persons skilled in the art will be able to select a suitable electric motor, however, an example of a suitable electric motor 46 is the BL41 DC brushless motor designed by Stanley Black & Decker Inc. and used in some commercially available DEWALT® branded power tools. The motor 46 is located in the handle 18 and has a motor output shaft 48.
Torque from the motor output shaft 48 is transferred via a transmission 50 to an input pinion 52 of a bevel gear arrangement 49. The transmission 50 comprises at least one planetary gear arrangement for reducing output speed while increasing torque. The motor output shaft 48 drives an input sun gear 50S1 of the first stage of the transmission 50. The input sun gear 50si meshes with a plurality of first stage planet gears 50P1 which mesh with a stationary outer ring gear 50R and are coupled to a first stage carrier 50C1. An axial extension of the first stage carrier 50C1 is the input sun gear 50S2 of the second stage of the transmission 50. The input sun gear 50S2 meshes with a plurality of second stage planet gears 50P2 which mesh with the stationary outer ring gear 50R and are coupled to a second stage carrier 50C2. An axial extension of the second stage carrier 50C2 is rotationally fixed to the input pinion 52 of the bevel gear arrangement.
The input pinion 52 of the bevel gear arrangement 49 thus rotates at a lower speed than the motor output shaft 48 however with an increased torque relative to the motor output shaft 48.
The motor output shaft 48, transmission 50 and input pinion 52 of the bevel gear arrangement 49 are aligned along a first axis A-A which extends along a longitudinal length of the handle 18. By also locating the battery attachment feature (and thus battery 14) on the first longitudinal axis A-A weight distribution of the tool 10 is improved, whereby the tool 10 feels balanced in a user's hand.
By locating the motor 46, the transmission 50 and the battery 14 on the same axis A-A extending along the length of the handle 18 improves weight distribution of internal features of the tool 10. Also, by providing the motor 40 within the handle 18 leaves more space available within the tool housing 12 above the handle 18, whereby there is more freedom to position features of the tool 10 in positions which improve weight distribution of internal features of the tool 10.
It will be appreciated that there is some design freedom in the transmission 50 between the motor output shaft 48 and the input pinion 52 of the bevel gear arrangement 49. In particular the number of planetary gear stages, and its (or their) configuration, forming the transmission 50 depends on the required gear ratio to be achieved between the motor output shaft 48 and the input pinion 52.
Given that it is well known that planetary gear stages step down rotation speed while stepping up torque persons skilled in the art, based on the disclosure given herein, will be able to decide upon a suitable transmission arrangement which achieves the required gear ratio for their tool to function; wherein the appropriate gear ratio depends on multiple factors including maximum achievable motor output torque, pitch of the ball screw arrangement described below, friction between moveable features within the tool 10 and the maximum permissible bending force (such as up to 100 kN). It will be appreciated that for some tools 10 a suitable transmission 50 may only have a single planetary gear stage, whereas for other tools a suitable transmission 50 may have a plurality of planetary gear stages arranged in series.
Continuing with reference to
When the input sleeve 56 is rotatably driven by the driving sleeve 54 this causes axial movement of the threaded rod 62. In other words, torque from the electric motor 46 is transferred through the transmission 50, through the bevel gear arrangement 49 to the input sleeve 56, whereby rotation thereof causes axial movement of the threaded rod 62. The threaded rod 62 is configured to move along a second longitudinal axis B-B of the tool 10. The threaded rod 62 can move forwards or backwards along the axis B-B depending on the motor driving direction, whereby the bias portion 24 moves with the threaded rod 62.
The anti-rotation bar 66 comprises a central hole 72 with a threaded inner surface which is tightly threadably engaged with a reciprocal threaded portion 74 at an end of the threaded rod 62 as shown in
The anti-rotation bar 66 comprises a first arm 74 and a second arm 76. The first and second arms 74, 76 are mounted in first and second slots 69, 70 within the housing 12. When the threaded rod 62 moves along the second longitudinal axis B-B, the first and second arms 74, 76 slide along the first and second slots 69, 70. The first and second slots 69, 70 extend along longitudinal axes which are parallel to the second longitudinal axis B-B.
With continued reference to
The threaded rod 62 extends through an opening 65 defined by the housing 12, specifically through an opening 65 defined by the metal part 12b of the housing 12.
The exterior of the section of the metal tool housing part 12b defining the opening 65 is threaded and forms a threaded connection with a frame support 61. The frame support 61 is part of the support portion 22 and carries the upper frame portion 26 and the lower frame portion 28, which can be formed integrally with the frame support 61 or be fixed thereto. In view of the foregoing it will be apparent that during tool use, when the threaded rod 62 is caused to move along the second longitudinal axis B-B, the finger 38 and third abutment portion 40 are caused to move within the space defined between the upper and lower frame portions 26, 28. A volume 68 is provided within the housing 12 for accommodating the threaded rod 62 when retracted into the tool 10.
Designers are free to select a suitable way for the controller 44 to control operation of the motor 46 in use to implement a bending operation. In other words designers are free to select a suitable way for the controller 44 to determine when the bend mechanism 20 has been actuated sufficiently for rebar 42 to be bent by a predetermined angle, in other words designers are free to select a suitable way for the controller 44 to determine when the third abutment portion 40 has been moved far enough linearly relative to the first and second abutment portions 30, 32 for rebar 42 to be bent by a predetermined angle.
For example, in a starting configuration of the portable electric rebar bending power tool 10 shown in
As a safety mechanism a mechanical switch may be provided within the power tool 10 for causing a reset operation upon the threaded rod 62 becoming retracted into the tool 10 by a predetermined amount. During a bending stage of operation, the threaded rod 62 is retracted into the tool 10. If the user does not release the trigger 19 eventually an arm 74, 76 of the anti-rotation bar 66 will engage a mechanical switch, whereby upon the controller 44 detecting that the mechanical switch is activated it causes the motor 46 to reverse direction and returns the bias portion 24 to the home position; a user must then release the trigger 19 before a subsequent bending operation can be implemented. In some embodiments instead of a mechanical switch an optical sensor can be used for detecting the presence of the anti-rotation bar 66 or threaded rod 62 for initiating a reset operation. Furthermore, in some embodiments a magnetic sensor is provided for detecting the presence of a magnet carried by the anti-rotation bar 66 for initiating a reset operation.
Alternatively in some embodiments the controller 44 is configured to receive user input via a user interface of the tool 10 which is indicative of the thickness of the rebar 42 and the required bend angle, wherein based on this user input the controller 44 determines the extent to which the bias portion 24 should be retracted upon pulling the trigger 19. During a bending operation, while the trigger 19 remains pulled the controller 44 will cause movement of the bias portion 24 for bending the rebar the required amount and then will reverse motor direction and return the bias portion 24 to the home position, whereby the trigger 19 must be released before a subsequent bending operation can be performed. At any time during a bending operation if the trigger 19 is released the controller 44 will cause reverse movement of the motor 46 and will return the bias portion 24 to the home position.
Moreover, designers are free to select a suitable way for the controller 44 to control operation of the motor 46 to implement a reset operation. In other words, designers are free to select a suitable way for the controller 44 to determine when the bias portion 24 (and thus the third abutment portion 40) has returned to the home position at which point in time reverse movement of the bias portion 24 is ceased. For example, a mechanical switch may be provided within the tool 10. Following a bending operation, upon initiation of reverse movement of the motor 46 for causing a reset operation, the controller 44 is configured to detect output from the mechanical switch indicative that an arm 74, 76 of the anti-rotation bar 66 actuates the mechanical switch, thereby indicating that the bias portion 24 (and thus the third abutment portion 40) has returned to the home position. Alternatively, an optical sensor may be provided within the tool 10 which generates output based on the presence or absence of the anti-rotation bar 66 or threaded rod 62 wherein based on output from the optical sensor the controller 44 can determine that the bias portion 24 (and thus the third abutment portion 40) has reached the home position. In some embodiments a magnetic sensor is provided for detecting the presence of a magnet carried by the anti-rotation bar 66 for generating output indicative that the bias portion 24 (and thus the third abutment portion 40) has reached the home position.
Looking at
It will be appreciated that there is some design freedom in the transmission 250 between the motor output shaft 248 and the drive sleeve 254 of the ball screw mechanism 258. In particular, the number of planetary gear stages, and its (or their) configuration, forming the transmission 250 depends on the required gear ratio to be achieved between the motor output shaft 248 and the drive sleeve 254 of the ball screw mechanism.
Similarly, as heretofore described in connection with the first embodiment the driving sleeve 254 is fixed to an input sleeve 256 due to a friction fit arrangement and an internal surface of the input sleeve 256 comprises a threaded surface for cooperating with a threaded surface of the threaded rod 262. Moreover, a plurality of balls, such as metal ball bearings, ride in the opposing threaded surfaces of the input sleeve 256 and threaded rod 262, thereby defining a ball screw arrangement 258.
A metal inner housing 213 supports the ball screw arrangement 258. A first axial bearing 267 is received between the internal surface of a first step portion 213a of the metal inner housing 213 and an external surface of a step portion 254a of the drive sleeve 254. A second axial bearing 269 is received between the internal surface of a second step portion 213b of the metal inner housing 213 and an end surface of the input sleeve 256. The input sleeve 256 is thus axially supported between the second axial bearing 269 and an inner surface of the drive sleeve 254. Additionally, the input sleeve 256 is supported in a radial direction by one or more bearings 260 which permit rotation of the input sleeve 256. In a radial direction the (or each) bearing 260 is (or are) located between the input sleeve 256 and the inner surface of the metal inner housing 213, whereby an outer race of the (or each) bearing 260 is friction fit with an inner surface of the metal inner housing 213 and an inner race of the (or each) bearing 260 is friction fit with the input sleeve 256. Looking at
In use, torque from the electric motor 246 is transferred through the transmission 250 to the input sleeve 254, whereby rotation thereof drives rotation of the driving sleeve 246 for causing axial movement of the threaded rod 262. The threaded rod 262 is configured to move along the longitudinal axis C-C of the tool 210. The threaded rod 262 can move forwards or backwards along the axis C-C depending on the motor driving direction, whereby the bias portion 224 moves with the threaded rod 262 causing actuation of the bend mechanism 220.
With continued reference to
The threaded rod 262 extends through an opening 265 defined by the inner metal housing 213. An exterior section of the metal inner housing 213 forms a threaded connection with the frame support 261. The frame support 261 is part of the support portion 222 and carries the upper frame portion and the lower frame portion, which can be formed integrally with the frame support 261 or be fixed thereto. A volume 268 is provided for accommodating the threaded rod 262 when retracted into the tool 210. The ingress of dirt and moisture through the opening 265 and into the metal inner housing 213 is blocked by a flexible bellow 251 provided between the front rim of the opening 265 and the connector 264. The flexible bellow 251 contracts and expands in length depending on the extent to which the threaded rod 262 is retracted into the tool 210. Comparing
Designers are free to select a suitable way for the controller 244 to control operation of the motor 246 in use to implement a bending operation. In other words designers are free to select a suitable way for the controller 244 to determine when the bend mechanism 220 has been actuated sufficiently for rebar to be bent by a predetermined angle, in other words designers are free to select a suitable way for the controller 244 to determine when the third abutment portion 240 has been moved far enough linearly relative to the first and second abutment portions 230, 232 for rebar to be bent by a predetermined angle.
For example, in a starting configuration of the portable electric rebar bending power tool 210 shown in
As a safety mechanism a mechanical switch may be provided within the power tool 210 for causing a reset operation upon the threaded rod 262 becoming retracted into the tool 210 by a predetermined amount. During a bending stage of operation, the threaded rod 262 is retracted into the tool 210. If the user does not release the trigger eventually the threaded rod 262 (or a feature provided thereon) will engage a mechanical switch, whereby upon the controller 244 detecting that the mechanical switch is activated it causes the motor 246 to reverse direction and returns the bias portion 224 to the home position; a user must then release the trigger before a subsequent bending operation can be implemented. In some embodiments instead of a mechanical switch an optical sensor can be used for detecting the presence of the threaded rod 262 for initiating a reset operation. Furthermore, in some embodiments a magnetic sensor is provided for detecting the presence of a magnet carried by the threaded rod 262 for initiating a reset operation.
Alternatively in some embodiments the controller 244 is configured to receive user input via a user interface of the tool 210 which is indicative of the thickness of the rebar and the required bend angle, wherein based on this user input the controller 244 determines the extent to which the bias portion 224 should be retracted upon actuating the trigger. During a bending operation, while the trigger remains actuated the controller 244 will cause movement of the bias portion 224 for bending the rebar the required amount and then will reverse motor direction and return the bias portion 224 to the home position, whereby the trigger must be released before a subsequent bending operation can be performed. At any time during a bending operation if the trigger is released the controller 244 will cause reverse movement of the motor 246 and will return the bias portion 224 to the home position.
Moreover, designers are free to select a suitable way for the controller 244 to control operation of the motor 246 to implement a reset operation. In other words, designers are free to select a suitable way for the controller 244 to determine when the bias portion 224 (and thus the third abutment portion 240) has returned to the home position at which point in time reverse movement of the bias portion 224 is ceased. For example, a mechanical switch may be provided within the tool 210. Following a bending operation, upon initiation of reverse movement of the motor 246 for causing a reset operation, the controller 244 is configured to detect output from the mechanical switch indicative that threaded rod 262 (or a feature provided thereon) actuates the mechanical switch, thereby indicating that the bias portion 224 (and thus the third abutment portion 240) has returned to the home position. Alternatively, an optical sensor may be provided within the tool 210 which generates output based on the presence or absence of the threaded rod 262 wherein based on output from the optical sensor the controller 244 can determine that the bias portion 224 (and thus the third abutment portion 240) has reached the home position. In some embodiments a magnetic sensor is provided for detecting the presence of a magnet carried by the threaded rod 262 for generating output indicative that the bias portion 224 (and thus the third abutment portion 240) has reached the home position.
More specific aspects of the bias portions 24, 224 will now be described with reference to
The bias portion 324 in
The upper end of the post 380 is provided with holes 384 which do not extend all the way through the post 380 and are configured to receive spring loaded pins 385. When the cap 383 is coupled to the fastener 382 the spring loaded pins 385 are urged against the cap 383. The lower side of the cap 383 is provided with a first set of depressions for receiving the spring loaded pins 385 when the cross-sectional profile of the cap 383 and post 380 are aligned and another set of depressions for receiving the spring loaded pins 385 when the cap 383 has been rotated 90 degrees away from such position. As such a user experiences tactile and audible (a click) feedback when the cross-sectional profile of the cap 383 and post 380 are rotated into alignment and when the cap 383 has been rotated 90 degrees away from such position.
The radius of curvature of the first bending surface portion 386a can range between 24 and 40 mm and in a specific example is 32 mm. The radius of curvature of the second bending surface portion 386b can range between 15 and 24 mm and in a specific example is 22 mm.
The surface portions 387a, 387b between either end of the first and second bending surface portions 386a, 386b are not curved around the axis Z.
In view of the foregoing, it will be appreciated that a user can mount the third abutment portion 340 to the finger 338 by sliding the opening 388 of the third abutment portion 340 around the post 380 and turning the cap 383 to axially lock the third abutment portion 340 to the finger 338; the cap 383 is provided with a projection 379 for facilitating gripping by a user. A user has flexibility to select which of the first and second bending surface portions 386a, 386b engages rebar during a bending operation as described in connection with
For example,
Looking again at
Another embodiment of the bias portions 24, 224 will now be described with reference to
Referring to
The post 480 has a first post section 480a and a second post section 480b. The outer surface 481a of the first post section 480a is non-circular. The outer surface 481b of the second post section 480b is circular and is narrower than the first post section 480a such that a step 482 is provided between the outer surface 481a of the first post section 480a and the outer surface 481b of the second post section 480b.
The inner surface 483a of the first post section 480a defines a volume with a circular cross-sectional profile. The inner surface 483b of the second post section 480b also defines a volume though having a width less than the diameter of the volume defined by the inner surface 483a such that a step 484s is provided between the inner surface 483a of the first post section 480a and the inner surface 483b of the second post section 480b; the portion of the inner surface 483a of the first post section 480a defining such step 484s is hereafter referred to as the inner step part 485. With continued reference to
The shape of the inner volume of the third abutment portion 440 is such that the third abutment portion 440 can receive and thus mate with the post 480. More specifically the third abutment portion 440 defines a first inner volume part and a second inner volume part. The first inner volume part defines a first inner surface 488 which can cooperate with the first post section 480a such that when the first post section 480a is received by the first inner volume part such features cooperate to block rotation of the third abutment portion 440 relative to the post 480; in other words the outer surface 481a of the first post section 480a cooperates with the first inner surface 488 of the third abutment portion 440 to block rotation of the third abutment portion 440 relative to the post 480. The second inner volume part of the third abutment portion 440 defines a second inner surface 489 such that the second post section 480b can be received by the second inner volume part of the third abutment portion 440.
Referring further to
Next the fastener 482 is inserted through the opening defined by the sleeve 483. As the distal end of the fastener 482 is progressively tightened into threaded engagement with the third abutment portion 440 the head 482a of the fastener is drawn towards the third abutment portion 440 and thus urges against an internally extending lip 483c within the sleeve 483 whereby the sleeve 483 is urged against the spring 484. In other words, as the fastener 482 is tightened against the third abutment portion 440 it causes the head part 483b of the sleeve 483 to compress the spring 484 against the lip 487. Such fastener 482 tightening/spring 485 compression is limited by engagement of the shaft part 483a of the sleeve 483 against the third abutment portion 440.
In
In order to rotate the third abutment portion 440 around the post 480 the third abutment portion 440 must first be pulled against bias of the spring 484 so that the first inner surface 488 of the third abutment portion 440 separated from the non-circular outer surface 481a of the first post section 480a; in other words the first inner surface 488 is moved above the non-circular outer surface 481a of the first post section 480a in
It will be appreciated that whilst various aspects and embodiments have heretofore been described the scope of the present invention is not limited thereto and instead extends to encompass all arrangements, and modifications and alterations thereto, which fall within the spirit and scope of the appended claims.
The male/female nature of the mechanism rotationally locking the third abutment portion 340 to the finger 338 may differ. Instead of the male feature (the post 380) being on the finger 338 and the female feature (the non-circular opening 388) being on the third abutment portion 340 these can be reversed such that a post is provided on the third abutment portion 340 instead of the non-circular opening 388 wherein such post is configured to be received in a non-circular opening defined by the finger 338.
The shape of the non-circular cross-sectional profile of the post 380, cap 383 and opening 388 illustrated in the drawings is just one example and it will be appreciated that a different non-circular shape could be used instead for example a square shaped cross-sectional profile.
The shape of the third abutment portion 340 illustrated in
In some embodiments the cap 383 is different. For example, the cap 383 may not cooperate with spring loaded pins 385 wherein such spring loaded pins 385 are omitted. In other embodiments the cap 383 may not have a cross-sectional profile similar to that of the post 380 and instead the cap 383 may have a cross-sectional profile different to that of the post 380 such that regardless of the rotational position of the cap 383 and post 380 the cap 383 blocks linear movement of the third abutment portion 340 when the cap 383 is coupled to the post 380; in such embodiments the cap 383 needs to be separated from the post 380 in order to permit relative linear movement between the post 380 and the third abutment portion 340 and persons skilled in the art will be able to envisage suitable releasable coupling mechanisms between the cap 383 and the post 380, for example the cap 383 may have an externally threaded projection which is configured to cooperate with a threaded opening in the post 380.
In some embodiments the depressions 30a, 32a, 40a are omitted.
In some embodiments the circumferential groove 399 is omitted.
In some embodiments the support portion 22 has a different configuration. The drawings show the first and second abutment portions 30, 32 to be fingers coupled to, and extending between, the upper frame portion 26 and lower frame portion 28. In some embodiments the support portion 22 is formed as a single piece, wherein the first and second abutment portions 30, 32 are formed by the edges of walls extending between the upper frame portion 26 and lower frame portion 28, wherein the walls are integrally formed with the upper frame portion 26 and lower frame portion 28.
In some embodiments the angle between the first longitudinal axis A-A and the second longitudinal axis B-B may not be 90 degrees and instead may range between 45 degrees to 145 degrees, which is achievable by adjusting the angle at which the input pinion 52 and the bevel gear 53 of the bevel gear arrangement 49 mesh.
In some embodiments the motor 46 is only partially received within the handle 18.
In some embodiments at least one planetary gear stage of the transmission 50 is received in the handle 18.
In some embodiments the motor 46 and the transmission 50 are received in the handle 18.
It has already been mentioned that by providing the motor 40 within the handle 18 leaves more space available within the tool housing 12 above the handle 18, whereby there is more freedom to position features of the tool 10 in positions which improve weight distribution of internal features of the tool 10. By providing the motor 46 only partially within the handle 18 achieves such advantage to a lesser extent. By providing the motor 46 and also at least part of the transmission 50 within the handle 18 achieves such advantage to a greater extent. By providing the motor 46 and also the transmission 50 within the handle 18 achieves such advantage to a fuller extent.
In some examples the battery 14, 214 is removable from the tool 10, 210 or alternatively the battery 14, 214 is integral to the tool 10, 210. Alternatively, or additionally, the tool 10, 210 may be configured to receive electric power from a mains power supply.
As shown in
The electric motor 46, 246 has been described as being a brushless motor and the controller 44, 244 cooperates with the brushless motor (in particular with its control electronics) in order to control the brushless motor. In other embodiments however the motor 46, 246 may be a brushed motor having a motor output shaft driven by a stator and having at least one magnet on the motor output shaft. It is here mentioned that in battery operated embodiments the motor 46, 246 is configured to operate using DC current, whereas in mains operated embodiments the motor is configured to operate using AC current.
In some embodiments the tool 10, 210 may have a roller screw mechanism (sometimes known as a planetary roller screw mechanism) instead of a ball screw mechanism 58, 258 for converting torque into linear force. A person skilled in the art will appreciate that this can be achieved by rotationally fixing the driving sleeve 54, 254 to an input sleeve of the roller screw mechanism; wherein a set of rollers (sometimes called planetary rollers) are provided between the internal surface of the input sleeve and an external surface of the threaded rod 62, 262. When the driving sleeve 54, 254 is caused to rotate it drives rotation of the input sleeve of the roller screw mechanism and thus via the rollers causes linear movement of the threaded rod 62, 262 and thus causes actuation of the bend mechanism 20, 220.
Various suitable types of connecter 64, 264 will be apparent to persons skilled in the art. For example, the connector 64, 264 has a first attachment portion for attaching to the finger 38, 238, 338, 438 and also a second attachment portion for attaching to the threaded rod 62, 262. The first attachment portion may be a plug and socket-type attachment arrangement for mating with an appropriately shaped part of the finger 38, 238, 338, 438 or a threaded attachment arrangement for threadably engaging with part of the finger 38, 238, 338, 438 or alternatively the first attachment portion may be attached to the finger 38, 238, 338, 438 via adhesive or welding. Similarly, the second attachment portion may be a plug and socket-type attachment arrangement for mating with an appropriately shaped part of the threaded rod 62, 262, or a threaded attachment arrangement for threadably engaging with the threaded rod 62, 262 or alternatively the second attachment portion may be attached to the threaded rod via adhesive or welding.
In some embodiments the connector 64, 264 is omitted and instead the threaded rod 62, 262 is fixed directly to the finger 38, 238, 338, 438 of the bias portion 24, 224, 324, 424 such as via a plug and socket-type attachment whereby one of the threaded rod 62, 262 and finger 38, 238, 338, 438 plugs into the other, or via a threaded attachment arrangement whereby one of the threaded rod 62, 262 and finger 38, 238, 338, 438 is threadably received by the other, or via an adhesive arrangement whereby the threaded rod 62, 262 is bonded to the finger 38, 238, 338, 438; in some embodiments the threaded rod 62, 262 and finger 38, 238, 338, 438 are welded together.
In some embodiments the frame support 61 is fixed relative to the housing 12 in a manner different to threadably engaging the frame support 61 to the metal part 12b of the housing 12 as heretofore described. In some embodiments the frame support 61 may be fixed to the metal part 12b of the housing 12 via adhesive, welding, or one or more bolts or screws. Alternatively in some embodiments one or more bolts extend between the frame support 61 and an internal frame (backbone) of the tool 10 located within the housing 12 for fixing the frame support 61 to the frame and thus relative to the housing 12.
In the foregoing the bias portion 24, 224, 324, 424 has been described as being driven relative to the stationary support portion 22, 222 for implementing a bending operation. In other embodiments such relative motion, and thus bending operation, can be achieved by alternatively configuring the tool 10, 210 so that the support portion 22, 222 is driven relative to a stationary bias portion 24, 224.
It will be appreciated that movement of the bias portion 24, 224 and support portion 22, 222 relative to each other is what enables a bending operation to occur, wherein based on the disclosure herein persons skilled in the art will envisage variations of the tool 10, 210 in which either a pulling or pushing of one of the bias portion 24, 224 and support portion 22, 222 relative to the other of the bias portion 24, 224 and support portion 22, 222 implements a bending operation.
The embodiment of the tool 10 described in connection with
Finally the heretofore described functionality need not necessarily be used exclusively in rebar bending tools but may be used in other contexts, namely portable electric power tools for bending elongate objects more generally such as metal conduits e.g. pipes or tubes.
Number | Date | Country | Kind |
---|---|---|---|
2306685.5 | May 2023 | GB | national |
2308631.7 | Jun 2023 | GB | national |
24173682.6 | May 2024 | EP | regional |