Joint for connecting elements to a surface finishing tool

Abstract

There is disclosed a joint for connecting to a float for finishing a surface. The joint comprises a float interface for attaching to a float, the float extending longitudinally and defining a plane; a handle interface for receiving a handle; and a vibration unit arrange to, in use when the float interface is attached to the float, drive the float interface to: vibrate biaxially in a direction parallel to the longitudinal axis of the float and in a direction perpendicular to the plane of the float; or vibrate uniaxially in one direction selected from: a direction parallel to the longitudinal axis of the float, a direction perpendicular to the plane of the float, or a direction perpendicular to the longitudinal axis of the float in the plane of the float.

Description

FLOAT JOINTTECHNICAL FIELD

[0001] The present disclosure relates to a joint for a bull float for finishing a surface such as concrete.BACKGROUND

[0002] It is known to use a bull float to help smooth the surface of freshly poured concrete. A bull float comprises a blade for moving over the concrete to smooth it, and a long handle or pole attached to the blade so that the user can move the blade over the concrete in hard-to-reach areas, without stepping or kneeling in the fresh concrete. As the bull float is moved over the concrete, the blade is usually angled so that the trailing edge of the blade is in contact with the concrete to smooth the surface. Bull floats are designed to be moved back and forth over the surface of the concrete, so the bull float can tilt to change which edge of the blade is in contact with the surface of the concrete.

[0003] The concrete can contain imperfections such as air bubbles which can be difficult to remove during the finishing process using a conventional bull float. Air bubbles in the top layer of the concrete are undesirable because they detract from the finished look of the concrete. It has been proposed to vibrate the bull float as it moves over the concrete to try to remove the air bubbles. However, this can make the bull float more difficult to manipulate for the user.

[0004] US 2018 / 0327981 discloses a concrete float, float assembly, float adapter and interface and float vibration apparatus. US 2023 / 0330698 discloses a trowel for finishing a material surface having a blade, a pitch mechanism coupled to the blade, and an optional vibration device. Whilst the floats disclosed in these documents may help remove air bubbles from the concrete, the floats may still be difficult to manipulate for the user due to the vibrations. US 2024 / 0410119 discloses a vibration mechanism for a concrete finishing tool which is housed within the handle of the float, rather than on the joint of the float, and therefore also does not prevent vibrations from being transmitted to the user through the handle.SUMMARY

[0005] This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.

[0006] According to one aspect, there is provided a joint for connecting to a float for finishing a surface, the joint comprising:a float interface for attaching to a float, the float extending longitudinally and defining a plane;a handle interface for receiving a handle; anda vibration unit arranged to, in use when the float interface is attached to the float, drive the float interface to:vibrate biaxially in a direction parallel to the longitudinal axis of the float and in a direction perpendicular to the plane of the float; orvibrate uniaxially in one direction selected from: a direction parallel to the longitudinal axis of the float, a direction perpendicular to the plane of the float, or a direction perpendicular to the longitudinal axis of the float in the plane of the float.

[0007] The vibration unit may be arranged, in use when the float interface is attached to the float, not to drive the float interface to vibrate in a direction perpendicular to the longitudinal axis of the float in the plane of the float.

[0008] The vibration unit may be arranged to generate vibrations using one or more vibrating elements arranged to vibrate along one or more axes of vibration, the vibration unit being configured to translate vibrations along said one or more axes of vibration to drive the float interface to vibrate biaxially or uniaxially.

[0009] The vibration unit may be arranged to, in use when the float interface is attached to the float, drive the float interface to vibrate biaxially in a direction parallel to the longitudinal axis of the float and a direction perpendicular to the plane of the float, wherein the vibration unit comprises an eccentric mass, driven to rotate by a motor about a rotation axis so as to generate the biaxial vibrations.

[0010] In use when the float interface is attached to the float, the rotation axis of the eccentric mass may be perpendicular to the longitudinal axis of the float and parallel to the plane of the float.

[0011] The eccentric mass may be located at a periphery of the joint.

[0012] The vibration unit may be arranged to, in use when the float interface is attached to the float, drive the float interface to vibrate uniaxially in a direction parallel to the longitudinal axis of the float.

[0013] The vibration unit may be arranged to, in use when the float interface is attached to the float, drive the float interface to vibrate uniaxially in a direction perpendicular to the plane of the float.

[0014] The vibration unit may be arranged to drive a vibrating element to reciprocate in one direction to drive the float interface to vibrate uniaxially in said one direction.

[0015] The vibration unit may comprise two eccentric masses. The vibration unit may be arranged to drive the eccentric masses to rotate so as to drive the float interface element to vibrate uniaxially in one direction.

[0016] The handle interface may be rotatably attached to the joint by a ball joint.

[0017] The handle interface may be rotatably attached to the joint at a pivot point having a pivot axis that is perpendicular to the axis of rotation of the eccentric mass.

[0018] The pivot point may lie on a central axis of the joint which, in use when the float interface is attached to the float, is perpendicular to the plane of the float, wherein the eccentric mass is offset from the central axis.

[0019] The joint may comprise a housing having an attachment structure configured to releasably attach a battery to the housing.

[0020] The attachment structure for the battery may be on a side of the housing opposing the vibration unit.

[0021] The joint may comprise a wireless tool control module arranged to control the motor in response to receiving a signal from a remote controller.

[0022] The joint may comprise a speed dial for adjusting the speed of the motor.

[0023] There may be provided a surface finishing tool comprising:a float for contacting a surface;the joint as described herein, the float interface being attached to the float; and a handle connected to the handle interface of the joint for moving the float over the surface.

[0024] According to another aspect, there is provided a joint for connecting to a float for finishing a surface, the joint comprising:an attachment structure on a first side of the joint, the attachment structure being adapted to releasably attach a battery to the joint;a float interface for attaching to a float, the float extending longitudinally and defining a plane; anda vibration unit arranged to drive an eccentric mass to rotate to generate vibrations, the eccentric mass being located on a second side of the joint opposing the first side,wherein, in use when the float interface is attached to the float, the first and second side of the joint lie on either side of a central plane through the joint that is parallel to the longitudinal axis of the float and perpendicular to the plane of the float.

[0025] The joint may comprise a handle interface for connecting to a handle, wherein the handle interface is biased to receive the handle from the second side of the joint.

[0026] The joint may comprise a handle interface for connecting to a handle, the handle interface being rotatably connected to the joint and having a greater degree of rotational motion on the second side of the joint than the first side.

[0027] The joint may comprise a handle interface for connecting to a handle, wherein the handle interface is biased to receive the handle from the first side of the joint.

[0028] The joint may comprise a handle interface for connecting to a handle, the handle interface being rotatably connected to the joint and having a greater degree of rotational motion on the first side of the joint than the second side.

[0029] The attachment structure may be adapted to, in use when the float interface is attached to the float, receive a battery in a direction substantially parallel to the plane of the float, and release the battery in a direction substantially parallel to the plane of the float.

[0030] The battery may be longest in one direction. The attachment structure may be adapted to hold the battery such that, in use when the float interface is attached to the float, said one direction is substantially parallel to the plane of the float.

[0031] The attachment structure may be arranged to, in use when the float interface is attached to the float, receive a battery in a direction substantially perpendicular to the plane of the float and release the battery in a direction substantially perpendicular to the plane of the float.

[0032] According to another aspect, there is provided a joint for connecting to a float for finishing a surface, the joint comprising:an attachment structure adapted to releasably attach a battery to the joint;a float interface for attaching to a float, the float extending longitudinally and defining a plane; anda vibration unit arranged to drive the float interface to vibrate,wherein the attachment structure is arranged to, in use when the float interface is attached to the float, receive a battery in a direction towards the plane of the float, and release the battery in a direction away from the plane of the float.

[0033] The attachment structure may be arranged to, in use when the float interface is attached to the float, receive a battery in a direction substantially perpendicular to theplane of the float and release the battery in a direction substantially perpendicular to the plane of the float.

[0034] The attachment structure may be configured to slideably receive a battery and slideably release the battery.

[0035] The above features may be combined as appropriate, as would be apparent to a skilled person, and may be combined with any of the aspects of the examples described herein.BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Examples will now be described in detail with reference to the accompanying drawings in which:

[0037] Figure 1 shows an example finishing tool.

[0038] Figure 2 shows an example joint attached to a float. The joint is shown with a battery attached.

[0039] Figure 3 shows an example joint with a battery attached.

[0040] Figure 4 shows a cross-section of an example joint from the side. The joint is shown attached to a float and a battery.

[0041] Figure 5 shows a cross-section of an example joint from the rear of the joint. The joint is shown attached to a float.

[0042] Figures 6a and 6b depict different vibration directions of a float with respect to a concrete surface.

[0043] Figure 7 shows a system comprising the joint, battery, and user interface.DETAILED DESCRIPTION

[0044] The following description is presented by way of example to enable a person skilled in the art to make and use the invention. The present invention is not limited to the embodiments described herein and various modifications to the disclosed embodiments will be apparent to those skilled in the art. Embodiments will now be described by way of example only.

[0045] Figure 1 shows an example finishing tool 1 for finishing a surface such as concrete. In this example, the finishing tool is a bull float for finishing concrete, but the finishing tool may be used to finish any suitable surface (e.g. plaster, cement). The finishing tool 1 comprises a float 3 attached to a handle 4 by a joint 2. The float 3 may equivalently be referred to as a blade or a bar. The float 3 comprises a lower surface (not shown) for contacting and smoothing a surface, e.g. wet concrete. The lower surface ofthe float is typically planar. The upper surface of the float may comprise ridges 30 (see figure 4) which may be used to attach the joint 2 to the float. The float 3 is separate to and detachable from the joint 2. As is known in the art, floats come in a variety of widths and lengths. Different sized floats may be attached to the joint 2 depending on the application.

[0046] Generally, the float defines a plane. Generally, the float extends longitudinally. That is, the float has a length which is greater than its width and depth. The longitudinal axis of the float runs centrally down the length of the float. The longitudinal axis L of the float 3 is depicted in figure 1. The longitudinal axis L of the float is typically perpendicular to the direction in which the float is moved over the concrete (e.g. as depicted by the arrows in figure 1). The float is designed to contact a surface along its lengthwise edges. During use, the float may be tilted so that one of its lengthwise edges (the trailing edge with respect to the movement of the float) contacts the concrete. The longer the float, the greater the section of concrete the float can smooth in one motion.

[0047] The handle 4, which may equivalently be referred to as a pole or stick, is typically long to maximise the reach of the float. The handle 4 has a longitudinal axis which is transverse to the longitudinal axis of the float. The handle may be connected to the float by the joint in such a way that the longitudinal axis of the handle 4 is perpendicular to the longitudinal axis of the float when attached via the joint 2, but this may not always be the case. The handle 4 is separate to and detachable from the joint 2. The handle 4 and the float 3 may be produced and sold separately to the joint 2.

[0048] The float 3 will be used to define a series of orthogonal axes which will be referred to herein as the X, Y, and Z axes (or equivalently the X, Y, and Z directions), as depicted in figures 1 and 2. The Z axis is perpendicular to the plane of the float. When the plane of the float is horizontal, the Z axis is vertical. The Y axis is parallel to the longitudinal axis of the float and in the plane of the float. The X axis is perpendicular to the longitudinal axis of the float and in the plane of the float. The X axis is perpendicular to the Y axis and the Z axis. Features of the joint that are described with reference to the X, Y, or Z axes are to be understood in the context of when the joint is attached to the float, but it is to be understood that the float is not part of the joint.

[0049] As mentioned above, even after a surface has been finished by a finishing tool such as a standard bull float, imperfections such as air bubbles may still be present on the surface which can detract from the finished look. To help remove imperfections such as air bubbles, the finishing tool may be vibrated as it moves over the surface, for example by incorporating a vibrating unit into the handle 4 or the joint 2. However, such vibrations can be transferred through the handle 4 to the user, which may cause discomfort to the user and result in the user having less control over the motion of the finishing tool.Vibrating the finishing tool can also make it more difficult to move the finishing tool over the surface because the float may no longer glide (or “float”) over the surface as easily.

[0050] The inventors have devised a vibrating joint for a finishing tool aimed at overcoming the above difficulties. Specifically, the inventors have recognised that to reduce the vibrations transferred to the user through the handle 4, vibrations in the X direction as depicted in figure 1 should preferably be reduced and further preferably avoided altogether. The inventors have also discovered that vibrating the float in the Y and / or Z direction shown in figure 1 can produce a smoother finish on the surface by reducing imperfections, whilst helping the float to glide more easily over the surface. The inventors have devised a joint for a finishing tool such as a bull float which can impart vibrations to the float only in these desired directions, as will be described further below.

[0051] Figure 2 depicts an example vibrating joint 200 for a finishing tool (e.g. a bull float). The vibrating joint 200 may be equivalently referred to as a bracket, powered joint, or simply a joint. In this example, the joint 200 is shown attached to a float 3, but as mentioned above, the float 3 is not part of the joint 200.

[0052] The joint 200 comprises a float interface 203, a handle interface 202, and a vibration unit 250. The joint 200 may further comprise a housing 201. The housing 210 may house internal components of the joint such as parts of the vibration unit 250. The housing may comprise an attachment structure 205 to which a battery 5 may be attached and electrically connected to the vibration unit to power the vibration unit, as will be described later. The battery may be separate to and detachable from the joint 200.Alternatively, the battery 5 may be built into the joint and rechargeable.

[0053] The float interface 203 is configured to attach the joint to the float 3. The float interface 203 is on the bottom of the joint. The bottom of the joint is the side of the joint that attaches to the float. The float interface may form part of the housing 201, e.g. as the base of the housing. The float interface may be rigidly attached to the housing. That is, the float interface may be fixed relative to the housing. The float interface 203 interfaces with the float to facilitate attachment thereto. For example, as shown in figure 2, the float interface may comprise a base plate 213 having one or more holes through which fasteners such as a screws or bolts can be positioned to secure the float interface to the float. Any suitable means for attaching the float interface to the float can be used, as is known in the art.

[0054] In an example in which the float interface comprises a base plate 213 for interfacing with the float (as shown in figure 2), when the base plate 213 is connected to the float, the plane of the plate 213 may be parallel to the plane of the float, and thelongitudinal axis of the plate 213 may be parallel to the longitudinal axis of the float. In these cases, the X, Y, and Z directions defined above with respect to the float may equivalently be defined with respect to the plate 213 of the float interface. However, the float interface may take any suitable form and it may not always be the case that the float interface defines a plane that is parallel to the plane of the float when connected, and / or that the float interface has a longitudinal axis that is parallel to the longitudinal axis of the float. So, references to the X, Y, and Z direction herein refer to the X, Y, and Z direction defined with respect to the float, unless otherwise specified.

[0055] The handle interface 202 is configured to connect to a handle 4, such as a pole. The handle interface 202 may equivalently be referred to as a handle connector or pole connector. The handle interface 202 is mounted on the top of the joint. The top of the joint is the opposite side to the bottom of the joint. The handle interface may comprise a body for receiving the handle at one end, with the other end being attached to the joint. In an example, the body is cylindrical. The body may extend rearwardly from the joint, e.g. when in use. The handle interface is configured to attach to the handle such that movement of the handle causes corresponding movement of the handle interface. The handle interface may comprise any suitable fastening means for securing the handle to the handle interface, as is known in the art. For example, the handle interface may be threaded to allow a handle to be screwed onto the handle interface. In another example, the handle interface may comprise depressible locking pins which spring into corresponding holes in the handle when the handle slides over the handle interface in the correct orientation. The handle interface may be fixedly attached to a handle, i.e. it need not be disconnectable from the handle. For example, the handle interface may be a part of the handle closest to the joint - i.e. where the handle meets the joint.

[0056] Preferably, the handle interface is rotatably mounted to the joint. For example, the handle interface may be rotatably attached to the housing 201. The rotatable connection of the handle interface to the joint can allow the joint to be manipulated more easily by the user. It also allows the user to tilt the float interface and hence the float when attached, for example to change which edge of the float is in contact with the concrete. The handle interface may be rotatably attached to the joint using any suitable pivoting connection. In the example shown in the figures, the handle interface 202 is pivotably mounted to the housing 201 at one end by a pivot pin 204. The handle interface 202 rotates about the pivot axis P which in this example is parallel with the Y axis. The handle interface 202 may be constrained (e.g. by the pivotable connection) to rotate with only one degree of freedom. For example, the handle interface may only rotate in pitch. In other examples, the handle interface may rotate with more than one degree of freedom withrespect to the joint. For example, the handle interface may be rotatably attached to the housing using a ball joint. In an example, the handle interface may rotate in pitch and yaw. This may allow the handle to be kept still, even when the joint is vibrating. The handle interface may be free to rotate through any angle along its rotation axis / axes. In practice, the extent of rotation of the handle interface may be limited by the other components on the joint, such as the battery.

[0057] The joint 200 comprises a vibration unit 250 for generating vibrations. The vibration unit is arranged to generate vibrations and transmit vibrations to the float interface. Suitably, the float interface is rigidly attached to the vibration unit. In this way, when the float is attached to the float interface, the vibration unit drives the float interface to vibrate, which causes the float to vibrate.

[0058] In one example, the vibration unit is arranged to, in use when the float interface is attached to the float, drive the float interface to vibrate in a direction parallel to the longitudinal axis of the float and in a direction perpendicular to the plane of the float (i.e. the Y and Z directions). The vibration unit may be said to drive the float interface to vibrate biaxially (i.e. along two axes). That is, the vibration unit may be arranged to cause the float interface to vibrate biaxially such that in use when the float interface is attached to the float, the float interface transmits vibrations to the float in the Y and Z directions. This may cause the float to vibrate in said two directions. For example, the vibration unit may be configured to vibrate the float interface such that in use when the float interface is attached to the float, the float is vibrated in a direction parallel to the longitudinal axis of the float and a direction perpendicular to the plane of the float.

[0059] Vibrating the float biaxially in the Y and Z direction may be beneficial for several reasons. By vibrating the float in the Z direction, imperfections such as air bubbles can be removed which improves the quality of the finish. Vibrating the float in the Y direction can make it easier for the float to be manipulated over the concrete by reducing the friction between the concrete and the float. By driving the float interface to vibrate biaxially in the Y and Z direction, both the quality of the finish and the user experience may be improved whilst reducing the vibrations transferred through the handle to the user.

[0060] In another example, vibration unit may be arranged to, in use when the float interface is attached to the float, drive the float interface to vibrate in one direction out of: a direction parallel to the longitudinal axis of the float, a direction perpendicular to the plane of the float, or a direction perpendicular to the longitudinal axis of the float in the plane of the float (i.e. in one of the Y, Z, or X directions). In this case, the vibration unit may be said to vibrate the float interface uniaxially - i.e. along one axis. That is, the vibration unit may be arranged to cause the float interface to vibrate uniaxially such that in use when thefloat interface is attached to the float, the float interface transmits vibrations to the float in one (e.g. only one) direction. This may cause the float to vibrate in said one direction. For example, the vibration unit may be arranged to vibrate the float interface uniaxially such that in use when the float interface is attached to the float, the float vibrates in one direction.

[0061] In one example, the vibration unit is arranged to drive the float interface to vibrate uniaxially in a direction perpendicular to the plane of the float (i.e. the Z direction) when the float interface is attached to the float. This may cause the float to vibrate in the Z direction. Vibrating the float in the Z direction is depicted in figure 6a. The joint and handle have been omitted from figures 6a and 6b. As mentioned above, vibrating the float in the Z direction can produce a smoother finish on the concrete, e.g. by reducing the air bubbles in the top layer of the concrete.

[0062] In another example, the vibration unit is arranged to drive the float interface to vibrate uniaxially in a direction parallel to the longitudinal axis of the float (i.e. the Y direction) when the float interface is attached to the float. This may cause the float to vibrate in the Y direction. Vibrating the float in the Y direction is depicted in figure 6b by the cross, indicating that the float is being vibrated in a direction into (and out of) the page (i.e. along the longitudinal axis of the float). As mentioned above, vibrating the float in the Y direction can reduce the friction between the float and the concrete, allowing the float to float better over the concrete.

[0063] It will be appreciated that there are a variety of ways in which the vibration unit may be arranged to produce vibrations and transmit vibrations to the float interface in the desired directions, e.g. using any number of linkages, cranks, gearing systems etc.Generally, the vibration unit will comprise one or more vibrating elements (e.g. a mass, film, or diaphragm) driven to vibrate about one or more axes of vibration. It is not necessary for the axis / axes of vibration(s) of the vibrating element(s) to be the same as the axis / axes of vibration(s) that the float interface is ultimately driven to vibrate at by the vibration unit. For example, the vibration unit may generate vibrations using a linearly vibrating element which vibrates uniaxially and translate those generated vibrations into biaxial vibrations using a linkage so as to drive the float interface to vibrate biaxially. There are many types of vibrators which may provide the vibrating element, such as pneumatic vibrators (e.g. rotary pneumatic vibrators) and electric vibrators. Several specific examples are provided below. However, it is to be understood that the vibration unit may generate vibrations in any suitable manner and direction, provided that the vibration unit is arranged (e.g. using suitable linkages) to convert (if necessary) the generated vibrations into vibrations in the desired directions for driving the float interface.

[0064] Generally, the vibration unit may comprise a motor 251 (see figure 4). The motor may be a linear drive unit. The motor may be a radial drive unit. The motor may be an electric motor such as a brushless DC motor. Any suitable motor may be used. The motor 251 may be arranged to cause the float interface to vibrate, e.g. by driving the vibration of the vibrating element(s). The motor may be powered by the battery 5, as depicted functionally in figure 7. The joint may comprise a controller 260 (see figure 7) which may monitor and control the operation of the motor (e.g. the current applied to the motor windings, the temperature of the motor, etc), as is known in the art.

[0065] In one example, the vibration unit comprises an eccentric mass 252 (e.g. an imbalance). The eccentric mass 252 is best seen in figure 4. The eccentric mass can rotate about a rotation axis Re. Due to the imbalance of weight around its rotation axis, when the eccentric mass rotates about its rotation axis it generates vibrations. The motor 251 is arranged to drive the eccentric mass to rotate about its rotation axis. The rotation axis Reof the eccentric mass may be coincident with the rotation axis of the motor, Rm, e.g. as shown in figure 4. For example, the eccentric mass may be located directly on the output shaft of the motor. In other examples, the vibration unit may comprise a transmission system between the motor and the eccentric mass for transmitting drive from the motor to a rotatable shaft on which the eccentric mass is fixed (e.g. via one or more drive train components) so as to drive the eccentric mass to rotate.

[0066] In one example, the eccentric mass 252 is positioned in the vibration unit such that when the float interface is attached to the float, the rotation axis Reof the eccentric mass is perpendicular to the longitudinal axis of the float and parallel to the plane of the float. In other words, the rotation axis of the eccentric mass is parallel to the X axis, as shown in figures 2 and 4. By positioning the eccentric mass in this way with respect to the float, when the eccentric mass is rotated about its rotation axis, it produces vibrations in a direction parallel to the longitudinal axis of the float and a direction perpendicular to the plane of the float (i.e. in the Y and Z directions). Because the rotation axis of the eccentric mass is parallel to the X axis direction, no vibrations are generated in the X direction. So, in use, fewer vibrations are transmitted through the handle interface 202 to the handle 4.

[0067] As mentioned above, in some cases, the float interface may comprise a plate having a plane which, when connected to the float, is parallel to the plane of the float, and having a longitudinal axis which, when connected to the float, is parallel to the longitudinal axis of the float. For example, the float interface 203 shown in figures 4 and 5 comprises such a plate 213. In these cases, the rotation axis Reof the eccentric mass can be said to be perpendicular to the longitudinal axis of the plate of the float interface and parallel to the plane of the plate of the float interface.

[0068] In cases where the handle interface is pivotably attached to the joint by a pivot joint, preferably the pivot axis of the pivot pin is perpendicular to the axis of rotation of the eccentric mass. This may reduce the chances of unwanted twisting in the joint when being vibrated biaxially. Additionally, it may reduce the vibrations transmitted up the handle to the user.

[0069] As mentioned above, the handle may be attached to the joint using a ball joint. This may be particularly advantageous if the vibration unit is configured to drive the float interface to vibrate biaxially because the ball joint can allow the vibrating joint to move independently of the handle, thus reducing the vibrations that are transferred to the user through the handle.

[0070] The frequency of vibrations of the eccentric mass may be directly proportional to the rotational speed of the motor. The vibration unit may comprise one or more gears (e.g. speed reduction gears) between the motor and the eccentric mass to adjust the rotational speed of the eccentric mass. The vibration unit may comprise a dampening component between the motor and the eccentric mass to reduce vibrations transmitted back to the motor from the eccentric mass to avoid damaging the motor, as is known in the art. For example, the vibration unit may comprise a gear 253 having a resilient element to absorb vibrations transmitted to the motor output shaft. The dampening component may be used in conjunction with any type of vibrator in the vibrator unit, not just the eccentric mass.

[0071] As shown in figure 4, the eccentric mass may be located at the periphery of the joint. The eccentric mass may protrude from the joint. The eccentric mass may be positioned off-centre from (i.e. remote from) the joint. This may enhance the effects of the vibrations generated by the rotating eccentric mass. For example, the eccentric mass may be located at the edge of the joint to increase the wobble of the joint. In one example, the point at which the handle interface attaches to the housing may define a central axis C of the joint, which is parallel to the Z axis when the joint is attached to the float. The eccentric mass may be offset from the central axis of the joint.

[0072] In the figures, the eccentric mass is located on the rear face of the joint. In other examples, the eccentric mass may be located on a different side of the joint. For example, the eccentric mass may be located on the front face of the joint. A preferred arrangement of the eccentric mass with respect to the battery will be described later.

[0073] In another example, the motor 251 is arranged to drive a linear vibrator (not shown). The linear vibrator may be a pneumatic linear vibrator, such as that produced by NetterVibration ®. The linear vibrator may be an electromagnetic linear vibrator. A linear vibrator comprises a vibrating element which is reciprocated back and forth, or oscillated,along one axis. The motor may be arranged to drive a vibrating element to reciprocate in one direction to produce vibrations in said direction. For example, the motor may be arranged to drive a linear vibrator in the Y direction so as to vibrate the float interface in the Y direction. In another example, the motor may be arranged to drive a linear vibrator in the Z direction so as to vibrate the float interface in the Z direction. Any suitable mechanism which translates rotational motion to linear motion may be used at the output of the motor to drive the linear vibrator, as is known in the art.

[0074] In another example, the vibrator unit comprises at least two eccentric masses. As mentioned above, rotation of an imbalanced mass around a rotation axis produces vibrations in two directions. As would be understood by the skilled person, a plurality of eccentric masses may be arranged to rotate out of phase with each other to counteract vibrations in one direction. In this way, two eccentric masses can be used to produce vibrations in one desired direction. Other arrangements of rotating masses or linear vibrators may be used to generate uniaxial vibrations, as is known in the art.Battery and handle interface arrangement

[0075] As mentioned above, a removable battery 5 may be connected to the joint for powering the vibration unit, e.g. the motor 251. The housing 201 may comprise an attachment structure 205 for receiving a battery 5 (e.g. a 20V battery). The attachment structure may be configured to releasably attach the battery to the joint. The attachment structure may comprise any suitable features for allowing the battery to be releasably attached to the joint in such a way that the vibration unit may be in electrical connection with the battery. For example, the attachment structure may comprise grooves for receiving corresponding slots on the battery. The attachment structure may be configured to slideably engage the battery. For example, the attachment structure may be arranged to slideably receive a battery and lock the battery into place.

[0076] The attachment structure may advantageously be positioned on a side of the joint opposing the vibration unit. That is, the attachment structure may be positioned on a side of the joint opposing the side of the joint in which the one or more vibrating elements of the vibration unit is located. For example, if the vibration unit comprises an eccentric mass (e.g. eccentric mass 252), the attachment structure may be positioned on a side of the joint opposing the eccentric mass. In another example, if the vibration unit comprises a linear vibrator having a reciprocating mass, the attachment structure may be positioned on a side of the joint opposing the reciprocating mass. Generally, having the attachment structure on the side of the joint opposing the vibration unit (or more specifically the vibrating element(s) of the vibration unit) may help to balance the weight distribution of thejoint when a battery is attached to the attachment structure. This can make the float to which the joint attaches easier to manipulate.

[0077] The attachment structure may be located on a first side of the joint, and the eccentric mass may be located on a second side of the joint, the first side opposing the second side. In use when the float interface is attached to the float, the first and second sides of the vibrating joint lie on either side of a central plane through the joint that is parallel to the longitudinal axis of the float and perpendicular to the plane of the float.

[0078] As mentioned above, the handle interface is mounted to the top of the joint. The handle interface may attach to the middle of the joint (i.e. along its central plane).Alternatively, the handle interface may attach to the joint at a point that is closer to the first side than the second side, or vice versa. Preferably, the handle interface attaches to the joint at a point closer to the second side of the joint (the side on which the eccentric mass is located) than the first side. This may prevent the battery, when attached to the attachment structure, from interfering with the handle interface and handle.

[0079] The handle interface is preferably rotatably mounted to the joint, e.g. by a pivot pin or a ball joint. In such cases, the handle interface has a range of motion relative to the joint. For example, the handle interface may be able to rotate from a position in which the handle interface is parallel to the plane of the float, when the float is attached to the joint, as shown in figure 4, through 90 degrees to a vertical position in which the handle interface is perpendicular to the plane of the float. In some cases, the range of motion of the handle may be greater than 90 degrees, such that the handle interface may be able to switch from being on the first side of the joint to the second side of the joint (or vice versa). The handle interface may be disposed to preferentially receive a handle from the first side of the joint, or the second side of the joint. For example, if the handle interface is disposed to preferentially receive a handle on the first side of the joint, the handle interface may have a greater range of motion on the first side of the joint than the second. When the float is attached to the joint, the handle interface may only be able to rotate to a position in which the handle interface is parallel with the plane of the float on one side of the joint. Said one side is the side that the handle interface is biased to receive a handle.

[0080] Preferably, the handle interface is biased to receive a handle from the second side of the joint. This means that the attachment structure is on the opposite side of the joint to the side in which the handle interface is preferentially disposed to receive the handle. Having the attachment structure on the side of the joint opposing the handle interface can make it easier to access and replace the battery because the battery is more accessible. It may also prevent the battery from interfering with the rotational movement of the handle interface.

[0081] In another example, the handle interface may be biased to receive a handle from the first side of the joint - i.e. the same side of the joint on which the attachment structure is disposed.

[0082] The attachment structure may be configured to, in use when the float interface is attached to the float, releasably engage a battery in a direction substantially parallel to (e.g. to within 10 or 15 degrees either side of) the plane of the float. That is, the attachment structure may be arranged to receive a battery in a direction substantially parallel to the plane of the float. The attachment structure may be arranged to release the battery in a direction substantially parallel to the plane of the float. This may allow the battery to be removed from the housing without interfering with the handle interface or handle. The direction in which the battery is received and released may be the same.

[0083] In another example, the attachment structure may be arranged to, in use when the float interface is attached to the float, receive a battery in a direction substantially perpendicular to (e.g. to within 10 or 15 degrees either side of) the plane of the float. The attachment structure may be arranged to, in use when the float interface is attached to the float, release the battery in a direction substantially perpendicular to (e.g. to within 10 or 15 degrees either side of) the plane of the float. That is, the attachment structure may be arranged to receive a battery in a direction towards the plane of the float. The attachment structure may be arranged to release the battery in a direction away from the plane of the float. The direction in which the battery is received and released may be the same. Having the attachment structure arranged in this way can improve the ergonomics of the joint by making it easier for the user to attach and remove the battery.

[0084] Generally, the joint as described herein may benefit from the attachment structure being arranged to receive and release the battery in either mode described above, regardless of the direction(s) in which the vibration unit is arranged to drive the float interface to vibrate. In other words, the attachment structure as described herein may be a part of any joint comprising a float interface as described above and a vibration unit arranged to drive the float interface to vibrate.

[0085] In an example in which the battery to be connected is longest in one particular direction, as depicted in figures 2 to 4, the attachment structure may be configured to hold the battery such that said one direction is substantially parallel to the plane of the float, in use when the float interface is attached to the float. This may be particularly advantageous if the handle interface is biased to receive a handle from the first side of the joint. Having the attachment structure arranged to hold the battery in an orientation in which the longest side of the battery is substantially parallel to the plane of the float, whenthe float interface is attached to the float, may prevent the battery from interfering with the motion of the handle interface.Wireless control and speed dial

[0086] As shown in figure 7, the joint may comprise a controller 260 for controlling the operation of the vibration unit. The controller 260 may be responsible for controlling the operation of the motor in the vibration unit. The joint may comprise an on / off button on the housing for turning the vibration unit on or off, which can be carried out by the controller. It may be desirable to control the operation of the vibration unit from a distance, for example during the finishing process when the joint is inaccessible. The controller 260 may comprise a wireless transceiver or wireless tool connect (WTC) module 206 for wirelessly connecting to a user interface 6 such as a remote control (e.g. via Bluetooth) which can be used to control the vibration unit. The remote 6 may conveniently be held by a user or attached (e.g. via the strap visible in figure 2) to an accessible point at the end of the handle 4. The joint may comprise a WTC connect button 207 (see figure 5) for activating the WTC module, e.g. by switching on or off connection mode in the controller 260. The WTC module may be located on a lateral face of the joint. The WTC connect button 207 may be located on a lateral face of the joint opposing the side on which the WTC module is located.

[0087] The joint may comprise a speed dial 208 for adjusting the speed of the motor and hence the vibration frequency of the vibration unit. The speed dial 208 may comprise a physical dial for the user to manually rotate to control the speed of the motor, which can be carried out by the controller 260. Alternatively or additionally, the speed of the motor may be wirelessly controlled using the user interface / remote 6.

[0088] The applicant hereby discloses in isolation each individual feature described herein and any combination of two or more such features, to the extent that such features or combinations are capable of being carried out based on the present specification as a whole in the light of the common general knowledge of a person skilled in the art, irrespective of whether such features or combinations of features solve any problems disclosed herein. In view of the foregoing description it will be evident to a person skilled in the art that various modifications may be made within the scope of the invention.

Claims

CLAIMS1. A joint for connecting to a float for finishing a surface, the joint comprising:a float interface for attaching to a float, the float extending longitudinally and defining a plane;a handle interface for receiving a handle; anda vibration unit arranged to, in use when the float interface is attached to the float, drive the float interface to:vibrate biaxially in a direction parallel to the longitudinal axis of the float and in a direction perpendicular to the plane of the float; orvibrate uniaxially in one direction selected from: a direction parallel to the longitudinal axis of the float, a direction perpendicular to the plane of the float, or a direction perpendicular to the longitudinal axis of the float in the plane of the float.

2. The joint as claimed in claim 1 , wherein the vibration unit is arranged, in use when the float interface is attached to the float, not to drive the float interface to vibrate in a direction perpendicular to the longitudinal axis of the float in the plane of the float.

3. The joint as claimed in claim 1 or 2, wherein the vibration unit is arranged to generate vibrations using one or more vibrating elements arranged to vibrate along one or more axes of vibration, the vibration unit being configured to translate vibrations along said one or more axes of vibration to drive the float interface to vibrate biaxially or uniaxially.

4. The joint as claimed in any of claims 1 to 3, wherein the vibration unit is arranged to, in use when the float interface is attached to the float, drive the float interface to vibrate biaxially in a direction parallel to the longitudinal axis of the float and a direction perpendicular to the plane of the float, wherein the vibration unit comprises an eccentric mass, driven to rotate by a motor about a rotation axis so as to generate the biaxial vibrations.

5. The joint as claimed in claim 4, wherein, in use when the float interface is attached to the float, the rotation axis of the eccentric mass is perpendicular to the longitudinal axis of the float and parallel to the plane of the float.

6. The joint as claimed in claims 4 or 5, wherein the eccentric mass is located at a periphery of the joint.

7. The joint as claimed in any of claims 1 to 3, wherein the vibration unit is arranged to, in use when the float interface is attached to the float, drive the float interface to vibrate uniaxially in a direction parallel to the longitudinal axis of the float.

8. The joint as claimed in any of claims 1 to 3, wherein the vibration unit is arranged to, in use when the float interface is attached to the float, drive the float interface to vibrate uniaxially in a direction perpendicular to the plane of the float.

9. The joint as claimed in claims 7 or 8, wherein the vibration unit is arranged to drive a vibrating element to reciprocate in one direction to drive the float interface to vibrate uniaxially in said one direction.

10. The joint as claimed in claims 7 or 8, wherein the vibration unit comprises two eccentric masses, the vibration unit being arranged to drive the eccentric masses to rotate so as to drive the float interface element to vibrate uniaxially in one direction.

11. The joint as claimed in any preceding claim, wherein the handle interface is rotatably attached to the joint by a ball joint.

12. The joint as claimed in any of claims 4 to 6 wherein the handle interface is rotatably attached to the joint at a pivot point having a pivot axis that is perpendicular to the axis of rotation of the eccentric mass.

13. The joint as claimed in claim 12, wherein the pivot point lies on a central axis of the joint which, in use when the float interface is attached to the float, is perpendicular to the plane of the float, wherein the eccentric mass is offset from the central axis.

14. The joint as claimed in any preceding claim, comprising a housing having an attachment structure configured to releasably attach a battery to the housing.

15. The joint as claimed in claim 14, wherein the attachment structure for the battery is on a side of the housing opposing the vibration unit.

16. The joint as claimed in any preceding claim, comprising a wireless tool control module arranged to control the motor in response to receiving a signal from a remote controller.

17. The joint as claimed in any preceding claim comprising a speed dial for adjusting the speed of the motor.

18. A surface finishing tool comprising:a float for contacting a surface;the joint as claimed in any of claims 1 to 17, the float interface being attached to the float; and19a handle connected to the handle interface of the joint for moving the float over the surface.

19. A joint for connecting to a float for finishing a surface, the joint comprising:an attachment structure on a first side of the joint, the attachment structure being adapted to releasably attach a battery to the joint;a float interface for attaching to a float, the float extending longitudinally and defining a plane; anda vibration unit arranged to drive an eccentric mass to rotate to generate vibrations, the eccentric mass being located on a second side of the joint opposing the first side,wherein, in use when the float interface is attached to the float, the first and second side of the joint lie on either side of a central plane through the joint that is parallel to the longitudinal axis of the float and perpendicular to the plane of the float.

20. The joint as claimed in claim 19, comprising a handle interface for connecting to a handle, wherein the handle interface is biased to receive the handle from the second side of the joint.

21. The joint as claimed in claim 19 or 20, comprising a handle interface for connecting to a handle, the handle interface being rotatably connected to the joint and having a greater degree of rotational motion on the second side of the joint than the first side.

22. The joint as claimed in claim 19, comprising a handle interface for connecting to a handle, wherein the handle interface is biased to receive the handle from the first side of the joint.

23. The joint as claimed in claim 19 or 22, comprising a handle interface for connecting to a handle, the handle interface being rotatably connected to the joint and having a greater degree of rotational motion on the first side of the joint than the second side.

24. The joint as claimed in any of claims 19 to 23, wherein the attachment structure is adapted to, in use when the float interface is attached to the float, receive a battery in a direction substantially parallel to the plane of the float, and release the battery in a direction substantially parallel to the plane of the float.

25. The joint as claimed in any of claims 19 to 24, wherein the battery is longest in one direction and the attachment structure is adapted to hold the battery such that, in use20when the float interface is attached to the float, said one direction is substantially parallel to the plane of the float.

26. The joint as claimed in any of claims 19 to 23, wherein the attachment structure is arranged to, in use when the float interface is attached to the float, receive a battery in a direction substantially perpendicular to the plane of the float and release the battery in a direction substantially perpendicular to the plane of the float.

27. A joint for connecting to a float for finishing a surface, the joint comprising:an attachment structure adapted to releasably attach a battery to the joint;a float interface for attaching to a float, the float extending longitudinally and defining a plane; anda vibration unit arranged to drive the float interface to vibrate,wherein the attachment structure is arranged to, in use when the float interface is attached to the float, receive a battery in a direction towards the plane of the float, and release the battery in a direction away from the plane of the float.

28. The joint as claimed in claim 27, wherein the attachment structure is arranged to, in use when the float interface is attached to the float, receive a battery in a direction substantially perpendicular to the plane of the float and release the battery in a direction substantially perpendicular to the plane of the float.

29. The joint as claimed in claim 27 or 28, wherein the attachment structure is configured to slideably receive a battery and slideably release the battery.

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