A tool adapter for concrete surface processing machines

Abstract

A tool adapter (300) for a surface processing machine (100), the adapter (300) comprising a tool carrier (230) extending in a plane (P), where the tool carrier (230) is arranged to hold one or more surface processing tools (250) on a tool side (301) of the carrier opposite to a machine side (302) of the tool carrier, a plurality of fastening elements (310) rotatably arranged in holes extending through the tool carrier (230) from the tool side (301) to the machine side (302), where each fastening element (310) comprises a T-nut part (312) on the machine side (302), the T-nut part (312) having a length (L) exceeding a width (W) in the plane (P).

Description

[0001] TITLE

[0002] A TOOL ADAPTER FOR CONCRETE SURFACE PROCESSING MACHINES

[0003] TECHNICAL FIELD

[0004] The present disclosure relates to floor grinders and tools for grinding and polishing hard material surfaces such as concrete and stone surfaces.

[0005] BACKGROUND

[0006] Concrete surfaces are commonly used for flooring in both domestic and industrial facilities. The size of concrete surface floors ranges from a few square meters for a domestic garage floor to thousands of square meters in larger industrial facilities. Concrete surfaces offer a cost efficient and durable flooring alternative and have therefore gained popularity over recent years.

[0007] A floor grinder is a surface processing machine that can be used to efficiently process a concrete surface using abrasive tools in order to, e.g., obtain a level surface having a uniform topology and / or a surface having a desired surface texture. Floor grinders can also be used to polish concrete surface in order to obtain a glossy surface finish. Most floor grinders can also be used to process stone surfaces, as well as other hard material surfaces.

[0008] Surface processing machines can also be used to clean and to polish dirty surfaces, such as linoleum floors and the like by the use of abrasive tools and / or pads with abrasive compounds.

[0009] EP1955809A1 describes tools and tool holders for efficient and convenient processing of concrete surfaces. However, further improvements are desired.

[0010] SUMMARY

[0011] It is an objective of the present disclosure to provide improvements in both methods and equipment for processing surfaces such as concrete and stone surfaces. This objective is at least in part obtained by a tool adapter for a surface processing machine. The adapter comprises a planar tool carrier, i.e., a tool carrier that extends in a plane. The tool carrier is arranged to hold one or more surface processing tools on a tool side of the carrier opposite to a machine side of the tool carrier. The tool carrier is also arranged to hold a plurality of fastening elements rotatably arranged in holes extending through the tool carrier from its tool side to its machine side. Each fastening element comprises a T-nut part arranged on the machine side, which T-nut part has a length exceeding a width measured in the plane. This adapter can be attached to an existing tool holder comprising slots or other elongated apertures, even if the upper part of the existing tool holder cannot be accessed by an operator, which is an advantage. The attachment between the existing tool holder of the surface processing machine and the tool carrier is mechanically sturdy, but can still be released easily, which is another advantage. The tool carrier of the adapter can be arranged to hold one or more abrasive concrete surface processing tools, such as grinding tools and polishing pads.

[0012] According to some aspects, the tool adapter comprises at least one guide pin, and preferably a plurality of guide pins, extending out from the machine side of the tool carrier in direction normal to the plane. The guide pin or pins align the adapter with the existing tool holder in an efficient manner, thereby ensuring that the adapter is correctly positioned in relation to, e.g., a rotation axis of the existing tool holder. Three fastening elements and three guide pins arranged interleaved and evenly spaced in an annulus in the plane centered on an axis of rotation of the adapter have been shown to give satisfactory results in both centering of the adapter and when it comes to mechanical strength of the attachment to the existing tool holder.

[0013] The tool carrier may also comprise a plurality of inspection apertures, where each inspection aperture is arranged in connection to a respective fastening element. An operator can use the inspection apertures to visually verify that the fastening elements are correctly positioned to hold the adapter in position relative to the existing tool holder. This is an advantage since the upper side, i.e., the machine side, of the existing tool holder is often not accessible.

[0014] Each fastening element optionally comprises a bolt extending through the tool carrier to engage threads in the T-nut part. Thus, as torque is applied to the bolt on the tool side of the adapter, a rotation of the T-nut part is induced, whereby the adapter is pressed against the existing tool holder in the desired manner. The T-nut part is preferably a rotary T-nut part arranged rotatable over a predetermined angular range. This simplifies the assembly, since the operator does not need to make sure that the T-nut part rotates too much. Rotary T-nut parts have been used in other applications previously and can therefore be sourced in a cost efficient manner. The range of rotation is preferably less than 180 degrees, and preferably about 90 degrees.

[0015] According to some aspects, the T-nut part has a wedge shape in direction normal to the plane. The vertex of this edge shape is then directed towards the tool side of the carrier. The wedge shape can be matched to an angle of slots formed in the existing tool holder, to improve the mechanical connection between the adapter and the existing tool holder. The T-nut part may also be configured with a tapered shape in the plane along its length, to match a gradually narrowing slot formed in the existing tool holder.

[0016] Surface processing machines comprising the above tool adapter are also disclosed herein, and also methods that can be used to allow use of different types of tools by a surface processing machine.

[0017] Generally, all terms used in the claims are to be interpreted according to their ordinary meaning in the technical field, unless explicitly defined otherwise herein. All references to “a / an / the element, apparatus, component, means, step, etc.” are to be interpreted openly as referring to at least one instance of the element, apparatus, component, means, step, etc., unless explicitly stated otherwise. The steps of any method disclosed herein do not have to be performed in the exact order disclosed, unless explicitly stated. Further features of, and advantages with, the present invention will become apparent when studying the appended claims and the following description. The skilled person realizes that different features of the present invention may be combined to create embodiments other than those described in the following, without departing from the scope of the present invention.

[0018] BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The present disclosure will now be described in more detail with reference to the appended drawings, where

[0020] Figures 1A-B illustrate an example floor grinder;

[0021] Figures 2A-C show example concrete surface processing tool holders;

[0022] Figure 3 illustrates a tool adapter with t-nut fastening elements;

[0023] Figures 4-5 illustrate assembly of a tool adapter;

[0024] Figures 6A-B show an example tool adapter fastening element; and

[0025] Figure 7 is a flow chart illustrating a method.

[0026] DETAILED DESCRIPTION

[0027] The invention will now be described more fully hereinafter with reference to the accompanying drawings, in which certain aspects of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments and aspects set forth herein; rather, these embodiments are provided by way of example so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout the description.

[0028] It is to be understood that the present invention is not limited to the embodiments described herein and illustrated in the drawings; rather, the skilled person will recognize that many changes and modifications may be made within the scope of the appended claims. Figures 1A and 1 B illustrate a floor grinder 100 for processing a concrete and / or stone surface 101 , i.e., an example of a surface processing machine. It is appreciated that most floor grinders can be used to process both concrete and stone as well as other hard material surfaces such as metal surfaces and some plastic surfaces. However, some abrasive tools and machines are tailored specifically for concrete, and some are tailored specifically for stone. There are also surface processing machines for cleaning and refurbishing surfaces. The teachings herein are applicable to all tools and machines for processing surfaces and in particular hard surfaces such as concrete and stone surfaces. The example floor grinder 100 comprises a first electric motor 110 arranged to rotatably drive a number of tool holders 120 about respective axes A. The tool holders 120 on the example machine 100 are comprised on a body section 130. A second optional electric motor 1 15 is arranged to rotate the body section 130 about its central axis B. The type of drive system shown in Figures 1A-B is generally referred to as a planetary drive system. Abrasive tools of varying grit and specifications can be mounted onto the tool holders 120. The grit, grit number, or grit size of a tool indicates the abrasive grade of the tool. A lower grit number indicates a coarse abrasive tool, while a higher grit number indicates a finer abrasive product. A low grit number tool normally removes more material from the surface compared to a high grit number tool. A surface processing machine may also use pads in combination with an abrasive compound to process a surface.

[0029] Electrically powered floor grinders like that illustrated in Figures 1A-B are generally known. Floor grinders driven by combustion engines, such as propane-fueled combustion engines, are also known. The tools and techniques disclosed herein are applicable with both electrically powered and combustion engine powered surface processing machines.

[0030] The machine 100 can be used to grind and to polish concrete and stone surfaces. Depending on the desired concrete processing operation to be performed, tools of varying grit size are attached to the tool holders 120. The grit size of an abrasive element is usually stated as a number that is inversely related to the abrasive particle size. A small number such as 20 or 40 indicates a coarse grit, while a large number such as 1800 indicates a fine grit. The techniques disclosed herein may be used with advantage for a wide variety of different grit sizes, ranging from, e.g., 30 to about 3000.

[0031] A radial direction R is to be construed broadly herein to mean a direction pointing generally outwards from a center region of an object arranged to rotate about an axis of rotation comprised in the center region. A radial direction R is for instance not necessarily exactly aligned with a radius of an annular member arranged to rotate about a center axis of rotation. Rather, a radial direction is some general direction forming an acute angle with the radius of the annular member. A tangential direction T is transversal to the radial direction R. That a first object is located radially outwards relative to a second object means that the first object is further from the rotation center compared to the second object. Example radial and tangential directions are indicated in Figure 2A.

[0032] Figure 2A illustrates a first example of a tool holder 120 that can be used to hold surface processing tools. The tool carrier 210, in this case a disc, is attached to the machine 100, e.g., by bolts, and the grinding tools are then held in the slots 220. The slots 220 are tapered such that the slots become more narrow towards the outer periphery of the tool carrier 210 as illustrated by the dashed lines in Figure 2A. The slots 220 also have angled side walls 221 which form an acute angle with vertex pointing towards the surface 101 in use. This tapered and angled slot form allows a tool to be wedged in the slot if inserted and pushed radially outwards R. Tool holders of this type are generally known as “Redi lock” tool holders which are manufactured and sold by the Applicant.

[0033] Figure 2B illustrates another example of a tool holder 120 that can be used to hold surface processing tools. The tool carrier 230, in this case a disc, is attached to the machine 100, e.g., by bolts, and the grinding tools are then held by the wedge shaped heels 240. The heels 240 are tapered such that become wider towards the outer periphery of the tool carrier 230, and also have angled side walls which form an acute angle with vertex pointing towards the surface 101 in use. This tapered and angled form allows a surface processing tool 250 to be wedged onto the heels 240 if pushed radially outwards R. Tool holders of this type are generally known as EZ tool holders and are manufactured and sold by the Applicant. The insert in Figure 2B shows an example of this type of tool 250, in this case carrying an abrasive segment 260. Figure 2C illustrates another type of surface processing tool 250 that has been wedged onto one of the heels 240. The tool 250 is first placed onto the heel 240, and then pushed radially outwards R, whereby it becomes wedged in place and thus held in position relative to the tool carrier 230.

[0034] It is desired to provide a versatile surface processing machine, which can be used with more than one type of surface processing tool holder type. Towards this end, a tool adapter is described herein which can be attached to an existing tool holder in order to hold different types of tools. It is particularly desired to provide conversion between existing Redi lock tool holders (as exemplified in Figure 2A) and EZ tool holders (as exemplified in Figures 2B and 2C). A problem related to attaching tool adapters to existing tool holders is that the upper parts of the existing tool holders 120, i.e., the sides facing away from the surface 101 , are difficult to access, since they are covered by parts of the machine 100. The tool adapters described herein therefore comprise fastening elements which can be operated without access to the upper part of the existing tool holders. Another problem is that the existing legacy tool holders 120 do not comprise prepared fastening mechanisms for tool adapters, such as threaded holes or the like. The tool adapters described herein are therefore designed to cooperate with the tool attachment structures on legacy tool holders, such as the slots on a Redi lock tool holder.

[0035] Figure 3 shows an example of a tool adapter 300 that can be used with a surface processing machine 100, such as the machine illustrated in Figure 1. The adapter 300 comprises a tool carrier 230 extending in a plane P. In this case the tool carrier 230 is planar and disc-shaped, although other planar forms are also possible, such as hexagonal plates, elliptical plates, and so on. According to an example, the tool carrier 230 is a planar disc with a diameter of at least 140mm, such as at least 160mm. Discs up to a diameter of about 400mm or more can be used with advantage together with the adapters described herein. Hence, the tool carriers discussed herein may be inscribed in a circle with a radius between about 50mm to about 250mm, such as between 70-200mm.

[0036] The tool carrier 230 is arranged to hold one or more surface processing tools 250 on heels 240 such as abrasive tools or pads for grinding, polishing and / or cleaning floors and other surfaces. The surface processing tools are held on a tool side 301 of the carrier 230 opposite to a machine side 302 of the tool carrier. The tool side 301 of the carrier 230 faces downwards D (towards the surface) in use, while the machine side 302 faces upwards U towards the machine 100 in use, as indicated in Figure 3.

[0037] A plurality of fastening elements 310 are rotatably arranged in holes extending through the tool carrier 230 from the tool side 301 to the machine side 302. Each fastening element 310 comprises a T-nut part 312 arranged on the machine side 302. The T-nut part 312 has a length L that exceeds a width W in the plane P, which allows it to enter into a slot or other elongated aperture if aligned with the slot, and to resist an axial force acting on the fastening member if the T-nut part is rotated relative to the slot. An elongated member extends through the tool carrier to the T-nut part. Each fastening element 310 may, e.g., comprise a bolt 31 1 or a threaded rod that extends through the tool carrier 230 to engage threads 610 in the T-nut part 312 (shown in Figure 6). The T-nut parts can be shaped to enter through the slots 220 of a Redi lock tool carrier, as illustrated in Figure 4 or some other tool carrier comprising radially extending slots. Once the T-nut parts 312 have entered into the slots 220 of a tool holder 120, they can be rotated as illustrated in Figure 5, in order to secure the tool adapter 300 to the tool holder 120 on the machine 100.

[0038] To attach the tool adapter 300 to a tool holder 120 comprising radially extending slots 220, the T-nut parts 312 are first aligned with the radially extending slots 220. The tool adapter 300 and the existing tool holder 120 are then brought together, as shown in Figure 4, such that the T-nut parts 312 enter through the slots 220 to the upper side of the tool holder 120. The T-nut parts 312 can now be rotated by the bolts 31 1 as illustrated in Figure 5, whereby the tool adapter 300 becomes fixedly attached to the tool holder 120. This way a tool adapter 300 can be secured onto a tool holder 120, even though access to the upper side of the tool holder is not possible, which is an advantage.

[0039] To simplify assembly, and to improve alignment between tool holder 120 and the tool adapter 300, the tool adapter 300 may comprise at least one guide pin 320 extending out from the machine side 302 of the tool carrier 230 normal to the plane P, as shown in Figures 3-5. In the example of Figures 3-5, the guide pins enter into every other slot to align and the adapter 300 with the tool holder 120. According to some examples the guide pins are arranged around the outer periphery of the tool adapter 300, where they enter into the end portions of the slots 220, which has the function of centering the tool adapter relative to the axis of rotation A of the tool holder 120. A configuration with three fastening elements 310 and three guide pins 320 arranged interleaved and evenly spaced in an annulus in the plane P, as illustrated in the drawings, has been found to give good results in terms of ease of use and mechanical durability.

[0040] The tool carrier 230 may furthermore comprise a plurality of inspection apertures 330 arranged in connection to respective fastening elements 310. A user of the adapter 300 can see the T-nut parts through the inspection apertures 330 and thus verify that the T-nut parts are correctly placed and rotated in order to hold the adapter fixedly in position relative to the tool holder 120 on the machine 100.

[0041] Figures 6A-B illustrate an example T-nut part 312. This T-nut part is a rotary T-nut part which is arranged to rotate in a slot 220 over a predetermined range. In this example the T-nut part can rotate 90 degrees due to the rounded parts 620, before the flat surfaces 630 engage the side walls 221 of the slot, see the insert in Figure 5. Once rotated, the wings 640a, 640b extend transversally with respect to the slot 220, thereby holding the fastening element in position and allowing the tool adapter to be secured to the tool holder 120. It is appreciated that the T-nut part 312 may be formed as a rotary T-nut part that is arranged rotatable over a predetermined angular range. This predetermined angular range is less than 180 degrees, and preferably about 90 degrees as in the example of Figures 6A-B.

[0042] According to a preferred realization, the T-nut part 312 has a wedge shape in direction normal to the plane P. The vertex of the edge shape is directed towards the tool side 301 of the carrier. This wedge shape can be matched to the shape of the slots 220, e.g., the slots of a Redi lock tool holder system. The T-nut part 312 may also be formed with a tapered shape in the plane P along its length L, as illustrated in Figure 6B, to further improve the matching to the slots of the tool holder 120.

[0043] Figure 7 is a flow chart illustrating a method of assembling one or more surface processing tools 250 on a surface processing machine 100 comprising one or more tool holders 120. The method comprises providing S1 a tool carrier 230 extending in a plane P, where the tool carrier 230 is arranged to hold the one or more surface processing tools 250 on a tool side 301 of the carrier opposite to a machine side 302 of the tool carrier, providing S2 a plurality of fastening elements 310 rotatably arranged in holes extending through the tool carrier 230 from the tool side 301 to the machine side 302, where each fastening element 310 comprises a T-nut part 312 on the machine side 302, the T-nut part 312 having a length L exceeding a width W in the plane P, and attaching S3 the tool carrier 230 to the tool holder 120 of the surface processing machine 100 by the fastening elements 310.

Claims

CLAIMS1 . A tool adapter (300) for a surface processing machine (100), the adapter(300) comprising a tool carrier (230) extending in a plane (P), where the tool carrier (230) is arranged to hold one or more surface processing tools (250) on a tool side(301 ) of the carrier opposite to a machine side (302) of the tool carrier, a plurality of fastening elements (310) rotatably arranged in holes extending through the tool carrier (230) from the tool side (301 ) to the machine side (302), where each fastening element (310) comprises a T-nut part (312) on the machine side (302), the T-nut part (312) having a length (L) exceeding a width (W) in the plane (P).

2. The tool adapter (300) according to claim 1 , where the tool carrier (230) is a planar disc with a diameter of at least 140mm, and at most 400mm.

3. The tool adapter (300) according to claim 1 or 2, where the tool carrier (230) is arranged to hold one or more abrasive concrete surface processing tools (250).

4. The tool adapter (300) according to any previous claim, further comprising at least one guide pin (320) extending out from the machine side(302) of the tool carrier (230) normal to the plane (P).

5. The tool adapter (300) according to claim 4, comprising three fastening elements (310) and three guide pins (320) arranged interleaved and evenly spaced in an annulus in the plane (P).

6. The tool adapter (300) according to any previous claim, where the tool carrier (230) comprises a plurality of inspection apertures (330), where each inspection aperture is arranged in connection to a respective fastening element (310).

7. The tool adapter (300) according to any previous claim, where each fastening element (310) comprises a bolt (31 1 ) extending through the tool carrier (230) to engage threads (610) in the T-nut part (312).

8. The tool adapter (300) according to any previous claim, where the T-nut part (312) is a rotary T-nut part arranged rotatable over a predetermined angular range.

9. The tool adapter (300) according to claim 8, where the range is less than 180 degrees, and preferably about 90 degrees.

10. The tool adapter (300) according to any previous claim, where the T-nut part (312) has a wedge shape in direction normal to the plane (P), where the vertex of the edge shape is directed towards the tool side (301 ) of the carrier.11 . The tool adapter (300) according to any previous claim, where the T-nut part (312) has a tapered shape in the plane (P) along its length (L).

12. A surface processing machine (100) comprising one or more tool adapters (300) according to any previous claim.

13. A method of assembling one or more surface processing tools (250) on a surface processing machine (100) comprising one or more tool holders (120), the method comprising providing (S1 ) a tool carrier (230) extending in a plane (P), where the tool carrier (230) is arranged to hold the one or more surface processing tools (250) on a tool side (301 ) of the carrier opposite to a machine side (302) of the tool carrier, providing (S2) a plurality of fastening elements (310) rotatably arranged in holes extending through the tool carrier (230) from the tool side (301 ) to the machine side (302), where each fastening element (310) comprises a T-nut part (312) on the machine side (302), the T-nut part (312) having a length (L) exceeding a width (W) in the plane (P), attaching (S3) the tool carrier (230) to the tool holder (120) of the surface processing machine (100) by the fastening elements (310).

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