Bench Grinder Apparatus

Abstract

The present invention relates to a bench grinder apparatus. The object of the invention is to provide a bench grinder apparatus and a method for safe and exact grinding of tools, and at the same time minimizing the damage to the tools and to the user during grinding. Bench grinder apparatus for grinding tools comprising: —at least one grinding wheel with a grinding surface arranged in a wheel casing, where the wheel casing is provided with one working opening which provides an access to a part of the grinding surface, —an operational means arranged in relation to said grinding wheel, capable of rotating the grinding wheel, —at least one tool rest moveably attached to the wheel casing, and arranged in a predefined distance to the grinding wheel, —at least one angle adjustable means capable of moving the tool rest in said predefined distance to the grinding wheel from a first grinding angle position to a second grinding angle position.

Claims

1. Bench grinder apparatus for grinding tools comprising: at least one grinding wheel with a grinding surface arranged in a wheel casing, where the wheel casing is provided with one working opening which provides an access to a part of the grinding surface, an operational means arranged in relation to said grinding wheel, capable of rotating the grinding wheel, at least one tool rest moveably attached to the wheel casing, and arranged substantially adjacent in a predefined distance to the grinding wheel, and at least one angle adjustable means capable of moving the tool rest in said predefined distance to the grinding wheel from a first grinding angle position to a second grinding angle position.

2. Bench grinder apparatus according to claim 1, wherein the angle adjustable means is capable of moving the tool rest stepless using at least one sliding means.

3. Bench grinder apparatus according to claim 1, wherein the distance between the tool rest and the grinding wheel is adjustable using distance adjustable means.

4. Bench grinder apparatus according to claim 1, wherein said tool rest comprises attachment means for attaching at least one tool holding device to the tool rest, such that, the tool holding device is arranged in relation to said grinding wheel and the angle adjustable means are capable of moving the tool holding device from a first position to a second position relative to the grinding wheel, when moving the tool rest.

5. Bench grinder apparatus according to claim 1, wherein the grinding angle is adjusted automatically with the use of controlling means to adjust the tool rest relative to the grinding wheel, such that the tool rest is moved in said predefined distance to the grinding wheel from said first grinding angle position to said second grinding angle position.

6. Bench grinder apparatus according to claim 1, where said operational means controls a rotational speed of said grinding wheel.

7. Bench grinder apparatus according to claim 1, where said operational means controls a rotational direction of said grinding wheel, so that the grinding wheel is capable of switching between rotating clockwise and counterclockwise relative to an axis of rotation.

8. A tool rest for a bench grinder, wherein the tool rest comprises attachment means for attaching the tool holding device to the tool rest in a predefined position.

9. A tool rest according to claim 8, wherein the tool rest comprises apertures for attaching the tool holding device to the tool rest using said attachment means.

10. A tool rest according to claim 8, wherein the tool holding device comprises stepless adjustable attachment means, such that the tool holding device is stepless adjustable relative to the tool rest.

11. A tool holding device for a bench grinder, wherein the tool holding device is capable of being attached to a tool rest in the bench grinder.

12. A tool holding device according to claim 11, wherein said tool holding device comprises at least one holding means, wherein said holding means is capable of holding a tool in a grinding position.

13. Method of adjusting a tool rest in a grinding apparatus, comprising the steps of arranging said tool rest in predefined distance to the grinding wheel using distance adjustable means, moving said tool rest from a first grinding angle position to a second grinding angle position using at least one angle adjustable means, while maintaining the predefined distance to the grinding wheel.

14. Method of grinding tools using a grinding apparatus according to claim 13, comprising the steps: providing a tool to be grinded, arranging said tool on the tool rest or in a tool holding device on a tool rest, and arranging said tool relative to a grinding surface, placing the tool such that a tool part is resting against the grinding surface of the grinding wheel in a predefined angle, and rotating said grinding wheel.

15. Method according to claim 14, comprising further steps: moving the tool rest from a first grinding angle position to a second grinding angle position using at least one angle adjustable means.

Description

DESCRIPTION OF THE DRAWING

[0068] The embodiments of the invention are described in the following with reference to:

[0069] FIG. 1: Illustrating an embodiment of a bench grinder apparatus

[0070] FIG. 2: Illustrating an embodiment of a bench grinder apparatus comprising a tool holding device in a first side view.

[0071] FIG. 3: Illustrating an embodiment of a bench grinder apparatus comprising a tool holding device in a second side view.

[0072] FIG. 4: Illustrating an embodiment of a bench grinder apparatus comprising a grinding angle scale.

[0073] FIG. 5a,b,c: Illustrating an embodiment of a bench grinder apparatus comprising a tool rest arranged in different grinding angle.

[0074] FIG. 6a,b: Illustrating an embodiment of a tool rest.

[0075] FIG. 7a,b,c,d: Illustrating an embodiment of a tool holding device placed in different positions on a tool rest.

[0076] FIG. 8a,b: Illustrating a grinding wheel comprising rubber surface.

DETAILED DESCRIPTION OF THE INVENTION

[0077] An embodiment of the invention is explained in the following detailed description. It is to be understood that the invention is not limited in its scope to the following description or as illustrated in the drawings. The invention is capable of other embodiments and of being practiced or carried out in various ways.

[0078] FIG. 1 illustrates an embodiment of a bench grinder apparatus 1. The bench grinder apparatus 1 comprises a portable base housing 2 having a handle 3. The bench grinder apparatus 1 also comprises an operational means, such as a motor 4, a control unit 5 and a wheel casing 6. Within the wheel casing 6, a grinding wheel 7 is arranged so the grinding wheel can be rotated by the motor 4. The wheel casing 6 is provided with one working opening 8, which provides an access to part of the grinding surface on the grinding wheel 7.

[0079] A tool rest 9 is moveably attached to the wheel casing 6 using distance adjustable means 10, so the tool rest 9 is capable of changing position relative to the wheel casing 6 and the grinding wheel. The distance adjustable means 10 may be a threaded rod and not and/or nuts, which may be tightened on each side of the tool rest 9 and/or the wheel casing 6. The tool rest 9 may be arranged in a predefined position substantially adjacent to the grinding wheel 7. The tool rest 9 is arranged in a predefined position which provides a gap between the tool rest 9 and the grinding surface of the grinding wheel 7, so the tool rest 9 unintendedly becomes grinded and/or damaged by the grinding wheel 7.

[0080] A shield cover 11 is a safety shield which is arranged above the tool rest 9 covering the hole or parts of the working opening 8. The shield cover 11 is pivotably attached to the wheel casing, so the shield cover 11 is capable of pivoting upwards and away from the tool rest 9. The shield cover 11 may be a transparent and/or magnifier plate.

[0081] The bench grinder apparatus 1 is provided with a control unit 5, where the control unit 5 comprises operational means for controlling for example the on/off function and the rotational speed and rotational direction of the grinding wheel 7.

[0082] The rotational direction of said grinding wheel 7 can be switched between clockwise and counterclockwise rotation when switching the operational means into the selected rotational direction. The rotational speed of said grinding wheel 7 is adjustable, when adjusting the operational means stepwise and/or stepless. The rotational direction and the rotational speed may be operated at the same time and in relation to each other, when grinding the tool.

[0083] During grinding of the knife, the grinding wheels 7 rubber surface and/or the belt might heat up. To prevent an overheating during grinding, the rubber may be provided with a serrated surface for a cooling purpose. The recesses in the rubber for cooling the wheel, provides the serrated surface. The working opening 8 and the recesses in the rubber provides the air flow generated when the grinding wheel 7 is rotation. This prevents the heat of the wheel from increasing the temperature during grinding. The grinding wheel 7 has an improved serrated dynamically balanced and grinder wheel design for high work efficiency, which increases security and durability of the bench grinder apparatus 1.

[0084] FIG. 2 illustrates an embodiment of a bench grinder apparatus 1 comprising a tool holding device 12 in a first side view. The tool holding device 12 is holding a knife which is to be sharpened using a grinding wheel 7. The tool holding device 12 is arranged in relation to said tool rest 9. Part of the tool holding device 12 is arranged above the tool rest 9 and part of the tool holding device 12 is arranged below the tool rest 9. The part of the tool holding device 12, which is arranged above the tool rest 9, is partly covered by the shield cover 11, so part of the tool holding device 12 is arranged between the shield cover 11 and the grinding wheel 7. The knife 13 is capable of engaging the grinding surface of the grinding wheel 7.

[0085] The tool holding device 12 comprises a tool plate or flange, so that the knife 13 may be held in a fixed position during grinding. The tool holding device 12 is capable of fixing different sizes or shapes of knifes 13 or other types of tools. If the tool holding device 12 comprises two plates or two flanges, the knife 13 may be arranged firmly between the two plates or two flanges. The distance between the two plates may vary accordantly for holding the knife 13 in a correct grinding position.

[0086] The cutting side on the blade of the knife 13 is turned upwards and away from the tool rest 9. The edge of the cutting side is meant to be sharp in order to fulfill the purpose of a good knife 13. If the edge of the cutting side is blunt, the blade may be sharpened using a bench grinder with a grinding wheel 7. The edge of the blade is pressed carefully towards the rotating grinding wheel 7. The edge of the cutting side is grinded, until the cutting side becomes sharp again.

[0087] The distance between the tool holding device 12 and the grinding wheel 7 is adjustable using distance adjustable means adjusting the tool holding device 12 in a predefined distance to the grinding wheel 7. The adjustable tool holding device 12 is adjusted so that the knife 13, fixed in the tool holding device 12, is provided with a predefined distance optimal for the grinding effect on the blade of the knife 13. Also, the knife 13, fixed in the tool holding device 12, is provided with a predefined pressure towards the grinding surface for optimal grinding effect on the blade of the knife 13. If the predefined distance and/or pressure for the grinding effect are not optimal, the grinding effect may cause irreversible damage to the knife 13 or tool.

[0088] An axis X illustrates the axis of the blade of the knife 13 and an axis Y is the tangent axis of the grinding surface of the wheel 7. The angle between the axis X and the axis Y is the grinding angle φ. The grinding angle φ of the blade of the knife 13 relative to the the grinding wheel 7 is adjusted, by adjusting the tool holding device using angle adjustable means. The grinding angle φ of the blade of the knife 13 in relation to the grinding surface causes a grinding effect on the blade of the knife 13 when the grinding wheel 7 is rotating. The grinding angle of the blade of the knife 13 relative to the the grinding wheel 7 may be varied during grinding. If the predefined grinding angle is not optimal, the grinding effect may cause an extended grinding time and/or irreversible damage to the knife 13 or tool.

[0089] The tool holding device is adjustable in a horizontal direction relative to said grinding wheel using sliding means. These sliding means are not shown on the FIG. 2. The sliding means may be rails, which are capable of sliding the tool holding device 12 to a first side or a second side relative to the grinding wheel 7. The sliding means provides an even grinding effect to the blade of the knife 13, when the blade of the knife 13 is kept in a predefined position during grinding.

[0090] FIG. 3 illustrates an embodiment of a bench grinder apparatus comprising a tool holding device in a second side view. A method of grinding a blade of a knife 13 using a grinding apparatus 1 comprising one or more of following steps: First one or more knifes 13 is provided, where the blade of the knife 13 needs to be sharpened. The knife is arranged in the tool holding device 12, and the tool holding device 13 is arranged in relation to the tool rest 9 and the grinding wheel 7. The shield cover 11 is arranged in a position so the shield cover 11 covers part of the knife 13 and the tool holding device. The tool holding device 12 is fastened in a fixed position to the bench grinder apparatus 1 during grinding.

[0091] The distance between the tool holding device 12 and the grinding wheel 7 is arranged so that the blade of the knife 13 is placed in a predefined position relative to the grinding wheel 7. The grinding angle φ, as showed in the FIG. 2, of the blade of the knife 13 is also arranged in a predefine position relative to the grinding wheel 7.

[0092] The rotational direction of said grinding wheel 7 is set to rotate clockwise or counterclockwise. The rotational speed of said grinding wheel 7 is adjusted to a predefined rotational speed, for example slow speed for sharpening edges of the blade of the knife 13 or high speed for quick and rough metal removal. The blade of the knife 13 tool is pressed against a grinding surface of the grinding wheel, thereby sharpening the edge of the blade. During the grinding process, the grinding angle, rotational speed and the rotational direction may be altered to provide a perfect grinding result.

[0093] FIG. 4 illustrates an embodiment of a bench grinder apparatus comprising a grinding angle scale. The distance from the tool rest 9 to the grinding wheel 7 is kept constant to ensure a precise grinding of the tool. Some part of the tool may be grinded in one grinding angle and another part of the tool may be grinded in another grinding angle. The bench grinder apparatus comprises a visual grinding angle scale 18. The grinding apparatus 1 comprises at least one angle adjustable means, which comprises a handle 3 and a rail or a recess 19. The angle adjustable means may comprise at least one releasable locking means, which may be the handle which can be screwed in a tight position to lock the tool rest in a predefined position relative to the grinding surface.

[0094] FIG. 5a,b,c illustrates an embodiment of a bench grinder apparatus comprising a tool rest arranged in different grinding angle. The angle adjustable means is capable of moving the tool rest upwards and downwards in an angled position and at the same time in said predefined distance to the grinding wheel. The tool rest may slide from a first grinding angle position to a second grinding angle position. The angle adjustable means is also capable of moving the tool rest 9, illustrated by the dotted line, while rotating said grinding wheel. FIG. 5a shows the tool rest 9 in a grinding angle of approximately 70° positioned by the handle 3.sup.1 in the rail. FIG. 5b shows the tool rest 9 in a grinding angle of approximately 25° positioned by the handle 3.sup.2 in the rail. FIG. 5c shows the tool rest 9 in a grinding angle less than 15° positioned by the handle 3.sup.3 in the rail. The user does not have to stop the grinding process in order to change the grinding angle or adjusted the tool rest further.

[0095] FIG. 6a,b illustrates an embodiment of a tool rest. The wheel casing is provided with one working opening, which provides an access to a part of the grinding wheel 17 and a part of the grinding surface 7. Through the working opening an airflow F may be provided. The airflow F is generated by the rotation of the grinding wheel 17, and the dust and/or sparks from grinding is extracted away from the working area. The dust and/or sparks may be extracted through the tool rest 9 or part of the tool rest 9 and away from the bench grinder apparatus 1. The tool rest 9 may be provided with apertures 22,23, such that dust and/or sparks may be extracted through the apertures 22,23 and away from the working area. Some of the apertures 23 may be elongated and providing a larger area for airflow. The dust and/or sparks may be removed using an exhaustion system. An external exhausting system and exhausting means may be arranged in relation to bench grinder apparatus 1, not showed on the FIG. 6a,b.

[0096] FIG. 7a,b,c,d illustrates an embodiment of a tool holding device placed in different positions on a tool rest. The tool rest 9 may also use the apertures for attaching the tool holding device 12 to the tool rest 9 using said attachment means 23. The attachment means 23 may be splits, screws or bolts. The tool rest comprises attachment means for attaching the tool holding device 12 to the tool rest in a predefined position. The tool holding device's 12 attachment means may engage two different apertures 22,23 to maintain the position during grinding, showed in FIG. 7a,b. FIG. 7c shows the tool holding device 12′, 12″, which is divided in two parts capable of holding the tool in the right position during grinding. FIG. 7 d. shows one embodiment of a tool holding device 12 holding a drill. The tool holding device 12 is capable of holding different sizes of drills. The tool holding device 12 is capable of being slid from side to side. The tool holding device 12 comprises stepless adjustable attachment means, such that the tool holding device is stepless adjustable relative to the tool rest 9, not shown on FIG. 7a,b,c,d.

[0097] FIG. 8 illustrates a grinding wheel 7′ comprising a rubber surface. The bench grinder apparatus 1 is provided with a replaceable grinding wheel 7′ and/or belt 7″, so the user may be able to change the grinding wheel 7′ and/or belt 7″, so the grinding wheel is optimal for the tool to be grinded. When replacing the grinding wheel 7′ and/or belt 7″, the wheel casing 6 is opened by pivoting part of the wheel casing 6 upwards and away from the base housing 2, uncovering the grinding wheel 7′ and the belt 7″.

[0098] FIG. 8a shows an open wheel casing 6. The rotational axle 14 is ready to receive a grinding wheel 7′. The grinding wheel 7′ may comprise an aluminum wheel 15 with durable rubber layer 16, provided with a predefined serrated pattern on the surface 17. A belt 7″ with a grinding surface 18 is suitable for grinding knifes and tools. The belt 7″ fits the circumference of the grinding wheel 7′. The predefined pattern on the surface 17 is related to the type of item to be grinded and/or the rotation speed to be used during grinding.

[0099] FIG. 8b shows an open wheel casing 6 comprising a grinding wheel 7′ receiving a belt 7″. The grinding wheel 7′ and/or the belt 7″ are replaced easily and fast. The belt 7″ may be moveable attached to the grinding wheel 7′. During the grinding process, when the grinding wheel 7′ is rotating, the rubber will be forced away from the rotating axle, due to a force opposite the centripetal force. The rubber will expand outwards and tightened the belt 7″ to the grinding wheel 7′, so the belt 7″ becomes firmly attached to the surface of the grinding wheel 7′.