EP1658930A1

EP1658930A1 - Tool sharpening apparatus

Info

Publication number: EP1658930A1
Application number: EP05257115A
Authority: EP
Inventors: Nigel Roberts
Original assignee: GMCA Pty Ltd
Current assignee: GMCA Pty Ltd
Priority date: 2004-11-23
Filing date: 2005-11-17
Publication date: 2006-05-24
Also published as: US20060111026A1; CN1781663A; AU2005237103A1; GB0425705D0

Abstract

The invention relates to apparatus for use in the sharpening of tools and in particular to apparatus for the sharpening of selected ones of a plurality of different tools, said apparatus including a grinding wheel and a plurality of tool holders. At least one of the tool holders is connected to the apparatus so as to be movable between out-of-use and in-use positions thereby allowing the tool holder to be positioned accurately. In one embodiment the housing is provided on a base which is provided with storage means for other sharpening implements and/or accessories.

Description

The invention to which this application relates is apparatus to be used to allow for the sharpening of blades or cutting edges of a plurality of tools and with the apparatus being adaptable to allow particular sharpening means to be available for use with respect to particular tools.
Although the following description refers almost exclusively to use of hingedly connected adaptors for presenting tools to a grinding wheel, it will be appreciated by persons skilled in the art that adaptors could be rotatably mounted or connected in alternative ways to secure the same.
The provision of apparatus which allows the sharpening of blades of tools is well known. Typically, the apparatus comprises a rotating grinding wheel which has a coating of abrasive material thereon. The particular abrasive material which is selected can be from any of a range of known materials to suit particular quality and/or practical requirements.
The wheel is provided to rotate, typically driven by a motor and there is provided at least one adaptor which can be presented to a surface or surfaces of a grinding wheel and into which the blade to be sharpened is fitted such that when the adaptor is presented to the grinding wheel, the blade in the adaptor is presented to the grinding wheel at an appropriate orientation to facilitate the sharpening of the blade by the removal of material from the blade to leave an edge of required shape. The tools which can be sharpened include drill bits, knife blades, scissor blades, chisel blades or the like and typically, a series of different adaptors are required to be provided for each or each group of tools so as to ensure that said tools are respectively presented to the grinding wheel at the appropriate orientation for the particular sharpening requirement.
It is known to provide a series of adaptors, each of which can be located with respect to the grinding wheel either by screwing the adaptors in position to thereby provide the most effective and secure location of the adaptor in position or, alternatively, by providing an automatic latching means which allows the adaptor to be slid into engagement means and latched in position with respect to the grinding wheel and a housing in which the grinding wheel is provided. In practical terms however, a problem is experienced with the automatic latching means in that the tolerances of the manufacture of the adaptor and/or housing means that the adaptors can move to a limited degree with respect to the housing and hence the grinding wheel thereby causing inferior sharpening to be achieved on the blade held in the adaptor.
The aim of the present invention is to provide apparatus which allows for the selective sharpening of blades of different tools by providing a series of adaptors which can be selectively positioned with respect to a grinding wheel and secured in the required position so as to present the tool at the required orientation to the grinding wheel.
In a first aspect of the invention there is provided Apparatus for the sharpening of a blade or cutting edge of a tool, said apparatus including a rotatable grinding wheel, a motor connected to said grinding wheel, and a plurality of tool holders, at least one of which is movable between an out of use position and an in-use position with respect to the grinding wheel and, in the in-use position, the said at least one tool holder provides a location for a tool to be in the appropriate position such that an edge or point of said tool can be sharpened in contact with said grinding wheel and wherein said at least one tool holder is attached to a base and/or housing in which the motor and grinding wheel are provided, said connection retained in both in-use and out-of-use positions, and when moved between said positions.
In one embodiment, the tool holders can be secured by securing means in the in-use position and/or out-of-use position with respect to the housing.
In one embodiment, the securing means is any or any combination of screws, nuts, catches, latches, clips, grips, magnets, springs and/or the like.
In one embodiment the securing means is mounted on the housing. Typically the securing means passes through an aperture in the tool holder and is actuated to secure the same.
In a preferred embodiment, a plurality of the tool holders are hingedly connected with respect to the housing and/or base such that the same are independently moved to the in-use position, and in one embodiment the same move over centre so that the effect of gravity on the holder acts to bring the holder into contact with the housing thereby aiding the ability for the tool holder to be kept in a fixed position with respect to the housing during use. It will be appreciated that the tool holders could otherwise be rotatably mounted to achieve a similar effect.
In one embodiment, a plurality of tool holders are provided for sharpening blades of tools each hinged with respect to the housing so that each is hingedly moved to a respective side of the said housing.
In one embodiment, at any given time, one of the tool holders can be selectively moved to an in-use position for use of the apparatus for sharpening a tool held thereon. In another embodiment, a plurality of the tool holders can be moved to an in-use position and used for sharpening tools which arc held in the respective tool holder by the user and/or fixing means.
In one embodiment, further tool holders are provided in the form of one or more access ports and/or notches provided on the housing to allow tools to be sharpened by application to the grinding wheel therethrough.
Typically the tool holders are designed to hold any or any combination of scissors, blades, knives, chisels, screwdrivers, drill bits, and/or the like.
Typically each of the tool holders includes a suitable location formation to allow a tool to be held in or on the tool holder and at a suitable orientation to the grinding wheel for sharpening.
In one embodiment adjustment means are provided to allow the grinding wheel to be adjusted in height with respect to the housing, to take into account wear of the same. Typically the adjustment means is located on the underside of the device, and adjusts the height of the motor within the device, thereby adjusting the height of the wheel connected thereto.
Typically the housing can be secured to a base in the form of a tray and/or a supporting surface. Typically the tray is provided with a storage means for storing accessories. In one embodiment storage means include any or any combination of a lid, recesses, drawers and/or the like. Typically the accessories include any or any combination of drill bits, grinding wheels, finishing stones, spanners, a water bath, cleaning brushes, safety glasses, and/or the like.
In one embodiment the apparatus base includes an area for the collection of liquid to be used during the sharpening process.
The base can also include storage for additional grinding wheels which may be straight replacement wheels or may have different grinding or sharpening characteristics and thereby allow the same to be selectively fitted and used for specific sharpening processes. In one embodiment the apparatus includes a carborundum finishing stone.
In one embodiment the grinding wheel can be reversibly mounted with respect to a shaft leading from the motor so as to allow full use of the grinding wheel to be achieved and any wear of the same to be taken into account.
Typically the grinding wheel is mounted with respect to the motor so as to have a substantially vertical axis of rotation.
In one embodiment the housing includes a notched section to allow for the passage of a drill bit therethrough to be applied to the grinding wheel for sharpening. In this arrangement the drill bit is held in a chuck which is positionable with respect to the housing.
In one embodiment retention means are provided to allow the tool holders to be retained in an out of use position.
In one embodiment the apparatus includes a base on which the housing is mounted, and a lid which is engageable with the base and movable between a closed storage position and a partially open guard position to protect the user of the apparatus from sparks or other debris from the grinding process.
In a further aspect of the invention there is provided apparatus for allowing the sharpening of a blade or cutting edge of a tool, said apparatus including a rotatable grinding wheel having a coating of abrasive material thereon, said wheel driven by a motor to rotate, said motor and grinding wheel provided in a central housing and wherein there are provided a plurality of tool holders, said tool holders movable between an out-of-use position and an in-use position with respect to the said housing and, in the in-use position, providing a location for a tool such that said tool is oriented in the appropriate position such that an edge and/or point of said tool can be sharpened in contact with said grinding wheel and wherein at least one of the tool holders is attached to the housing when in the in use and out of use positions and moving between said positions.
A specific embodiment of the invention is now described wherein:-

Figure 1 illustrates a perspective view of the sharpening apparatus with the base according to one embodiment of the invention;
Figure 2 illustrates the sharpening apparatus with the base removed with a tool holder secured in the in-use position; and
Figure 3 illustrates the base and lid of the sharpening apparatus.

With reference to the Figures 1 and 2 there is illustrated a sharpening device 2 which is mounted on a base in the form of tray 4 and secured to the same by screws 6. The tray 4 may also be fixed to a supporting surface by screws 8.
The sharpening device 2 includes a housing 10 and a grinding wheel 12 rotatably mounted a shaft of a motor (not shown) within the housing in a substantially horizontal plane i.e. with a substantially vertical rotational axis. For safety, the majority of the wheel 12 is positioned within the housing 10, with the upper face and a portion of the side face presented to the user. The housing 10 includes an angled recess or notch 16 to allow tools such as a drill bit to be presented to the side face of the wheel 12. When power is supplied to the motor by switching the on/off switch 18, the grinding wheel 12 rotates allowing any tools applied to the face or edge thereof to be sharpened due to the abrasive nature of the surface of the grinding wheel.
The grinding wheel 12 is secured to the motor within the housing 10 via conventional means such as a nut or shaft 14. The grinding wheel 12 can thus be removed and reversed to allow both faces to be used or be replaced with other forms of grinding and/or polishing wheels. A shaft lock can be provided to lock the shaft when the grinding wheel 12 is removed.
The tray 4 and/or lid 11 as shown in Figure 3 may also be provided with a series of holes 30 for storing drill bits therein, and other tool accessories. For example, a drill height guide 32 for collars 34 may be provided, an additional grinding wheel may be mounted on the reverse face of the housing 10, and further storage may be provided for spanners, a water bath, cleaning brushes, safety glasses, and additional grinding or carborundum finishing stones. The lid can also be used as a guard for sparks and/or water when moved to an open or partially open position as shown in Figure 3 in bold lines and the lid can be moved to a closed position for transport and/or storage in which the lid periphery 52 contacts the base periphery 54.
The housing is illustrated with a tool holder 20 with a scissor guide 20 and a tool holder 22 with a knife guide both connected thereto. The tool holders 20, 22 are hingedly connected to the lower part of the housing 10 so they can each be pivoted upwards from the out-of-use position as shown in Figure 1 to an in-use position as indicated by arrows 24. The tool holders, when moved to an in use position preferably are angled beyond vertical towards the housing 10 i.e have passed over centre of the pivot locations 25, 27 in the in-use position such that gravity biases the tool holders 20, 22 towards the housing.
The housing 10 is provided with securing means in the form of a rotatable catch 26 for each holder which passes through an aperture 28 in the respective tool holders 20, 22, when the tool holder is moved to an in-use position. The catch can then be rotated to the lock the same in position.
The angled recess or notch 16 acts as another tool holder to allow a collar or bit holder 34 to be positioned therein, and hence positioning the drill bit in the collar for sharpening against the grinding wheel 12. Alternatively the drill bit or other tools can be positioned in the recess 16 directly.
An access port 46 is also provided to allow access to the grinding wheel 12 to sharpen and/or tidy up other tools, especially those with flat narrow edges such as screwdrivers.
Referring to Figure 2, there is illustrated the sharpening apparatus mounted directly on a supporting surface 38 rather than a base or tray, and with one of the tool holders, in this case the one with the scissor guide 20 in an in-use position. The scissor guide is secured in position by rotating the catch 26 which passes through an aperture in the scissor guide 20.
In use, for sharpening scissors a user holds one scissor blade along the angled edge 42 of the scissor guide, such that the edge of the first scissor blade is in contact with the grinding wheel 12. With the grinding wheel rotating as indicated by arrow 44, the first scissor blade is positioned on the face 42 at the correct angle to be sharpened. To allow the full length of the first blade to be sharpened, the scissor guide includes a recess or gap 40 in which the pivot part of the scissors sits. As scissor blades overlap to facilitate the shearing action, without the recess the overlapping part of the second scissor blade would prevent the overlapped portion of the first scissor blade from contacting the grinding wheel.
Similarly, the tool holder 22 can be pivoted into an in-use position such that the blade 48 placed thereon against the angled head 46 of the tool holder are held at the correct angle for sharpening against the grinding wheel 12 when the tool holder is moved to the in-use position which is possible even if the tool holder 20 remains in the in-use position shown. Figure 3 illustrates tool holder 22 in the in-use position with blade 49 being sharpened with the handle 50 being held by the user (not shown) and the lid 11 in position as a guard.
Protrusions 36 on the face of the tool holder 20, 22 maintain the rool holder in a position above the rotating grinding wheel 12 so the tool holder themselves are not worn by the same.
The location of the tool holders 20, 22 on the housing to be pivotally movable between the out-of-use and in-use positions ensures that the same can be accurately located with respect to the grinding wheel on each occasion of use, especially given the over centre movement of the same to the in-use position. This is important as the position of the blades when the respective holders with respect to the grinding wheel needs to be correct in order to ensure that the grinding action on the blade edge actually acts to sharpen the same rather than damage the blade edge, which is what can occur if the blade edge is not correctly positioned.
It will be appreciated by persons skilled in the art that the present invention also includes further additional modifications made to the method which does not effect the overall functioning of the method, such as the provision of decoration to provide improved aesthetic appearance, and/or the like.

Claims

Apparatus for the sharpening of a blade or cutting edge of a tool, said apparatus including a rotatable grinding wheel, a motor connected to said grinding wheel, and a plurality of tool holders, at least one of which is movable between an out of use position and an in-use position with respect to the grinding wheel and, in the in-use position, the said at least one tool holder provides a location for a tool to be in the appropriate position such that an edge or point of said tool can be sharpened in contact with said grinding wheel and wherein said at least one tool holder is attached to a base and/or housing in which the motor and grinding wheel are provided, said connection retained in both in-use and out-of-use positions, and when moved between said positions.
Apparatus according to claim 1, wherein the said tool holder is pivotally movable between said in-use and out-of-use positions.
Apparatus according to claim 1 wherein securing means are mounted on the housing to secure the tool holder in the in-use position with respect to the housing.
Apparatus according to claim 2 wherein when the said at least one tool holder is moved to the in-use position, it moves over centre of the pivotal connection of the tool holder thereby aiding the ability of the tool holder to be kept in a fixed position with respect to the housing in the in-use position.
Apparatus according to claim 1 wherein a plurality of the tool holders are provided in a hinged pivotally movable relationship with the housing.
Apparatus according to claim 5 wherein each of the tool holders is mounted with respect to a different face of said housing.
Apparatus according to claim 5 wherein each of said tool holders can be selectively moved independently between in-use and out of use positions with respect to the grinding wheel.
Apparatus according to claim 1 wherein at least one tool holder is provided in the form of an access port are provided on the housing to allow a tool to be sharpened by to the grinding wheel by placing the tool through said port.
Apparatus according to claim 1 wherein each tool holder is provided with location means for supporting a particular tool in the correct orientation with respect to the grinding wheel.
Apparatus according to claim 1 wherein adjustment means are provided to allow the grinding wheel to be adjusted in height with respect to the housing.
Apparatus according to claim 10 wherein the adjustment means are located to adjust the height of the motor within the housing and thereby adjust the height of the grinding wheel connected to the said motor.
Apparatus according to claim 1 wherein the housing is secured to a base, said base provided with storage means for storing any or any combination of tool holders and/or accessories for use with the apparatus.
Apparatus according to claim 12 wherein the base includes an area for the collection of liquid to be used during the sharpening process.
Apparatus according to claim 12 wherein the base includes storage for additional grinding wheels.
Apparatus according to claim 1 wherein the apparatus includes a carborundum finishing stone.
Apparatus according to claim 1 wherein the grinding wheel can be reversibly mounted with respect to a shaft leading from the motor.
Apparatus according to claim 1 wherein the grinding wheel is mounted with respect to the motor so as to have a substantially vertical axis of rotation.
Apparatus according to claim 1 wherein the housing includes a notched section to allow for the passage of a drill bit therethrough to be applied to the grinding wheel.
Apparatus according to claim 18 wherein the drill bit is held in a chuck which is positionable with respect to the housing.
Apparatus according to claim 1 wherein retention means arc provided to allow the tool holders to be retained in an out of use position.
Apparatus according to claim 1 wherein the apparatus includes a base on which the housing is mounted, and a lid which is engageable with the base and movable between a closed storage position and a partially open guard position to protect the user of the apparatus from sparks or other debris from the grinding process.