US20080076333A1

US20080076333A1 - Throwing blade connection assembly for abrasive throwing wheel

Info

Publication number: US20080076333A1
Application number: US11/902,607
Authority: US
Inventors: Michael Krause; Michael T. Giroux
Original assignee: Pangborn Corp
Current assignee: Pangborn Corp
Priority date: 2006-09-22
Filing date: 2007-09-24
Publication date: 2008-03-27
Also published as: WO2008156465A1

Abstract

An abrasive throwing wheel assembly includes a runnerhead disposed within a housing and arranged to be rotatably driven about a center rotational axis. The runnerhead includes a plurality of radially extending dovetail shaped channels. In one embodiment, the channels each have a slot extending at an angle relative to a radially extending longitudinal axis of the channel. A throwing blade includes a throwing portion and a dovetail shaped base portion configured to be removably received within one of the plurality of dovetail shaped channels. In one embodiment, the base portion includes a slanted surface configured to extend at a same angle as the slot relative to the radially extending longitudinal axis of the channel when inserted within the channel. A U-shaped locking pin is configured to be received in the slot to prevent radially outward movement of the throwing blade. In another embodiment, the runnerhead channels include an L-shaped slot in a back surface thereof and the base portion of the throwing blade includes a slanted surface and a locking face, the locking face being arranged perpendicular to the slanted surface and substantially parallel to a radially extending longitudinal axis defined by the throwing portion. A substantially L-shaped locking pin is configured to be received in the slot to secure the base portion of the throwing blade within the channel.

Description

CROSS REFERENCE TO RELATED APPLICATIONS

This application is related to and claims the priority benefit of U.S. provisional patent application No. 60/846,352, filed Sep. 22, 2006, the entirety of which is hereby incorporated by reference.

BACKGROUND

1. Field of the Invention
The invention is related to abrasive throwing wheels (blasting machines) used in surface preparation, and more particularly to an improved throwing blade connection assembly for such abrasive throwing wheels to secure throwing blades (vanes) to a runnerhead while allowing removal and replacement of such throwing blades without the need to remove associated feedparts of the abrasive throwing wheel.
2. Related Art
Centrifugal blasting machines comprising rotors or wheels having a plurality of generally radially extending blades (vanes) installed thereon have been known in the art for many years. When rotated at high speeds, the blades propel an abrasive material against a work surface. Typical applications for abrasive surface preparation include cleaning of castings, descaling plate, cleaning weldments, shot peening and other special applications. Due to the action of the abrasive material on the throwing blades, however, the blades can exhibit considerable wear over a period of time. Attempts have been made to fabricate the blades from abrasion-resistant materials. In other cases, special blade configurations have been employed to minimize the effects of the abrasive material on the blades.
Notwithstanding these attempts to minimize wear and extend the life of the throwing blades, the blades must be periodically removed from a runnerhead and replaced. In most centrifugal blast machines, such periodic blade removal and replacement requires disassembly of internal feedparts such as, for example, the feed hose, feed spout, clamps, impeller, and impeller case before removing and replacing the blades. This procedure can be time consuming and often results in a loss of valuable operating time. Furthermore, while the blades must be removable, they must also be held securely enough to resist the tremendous forces exerted on them when the wheel is operating. U.S. Pat. Nos. 4,697,391, 4,249,350, and 2,869,289, and U.S. Patent Application Publication No. 2004-0166777 A1, discuss abrasive throwing wheels having improved blade assemblies, and are hereby incorporated by reference in their entireties.

SUMMARY OF THE INVENTION

Thus, there exists a need for an improved blade assembly for connecting and securing throwing blades to the throwing wheel runnerhead of a centrifugal blasting machine. The throwing blades must be securely mounted on the throwing wheel runnerhead to prevent movement of the blades in operation, especially in a radial outward direction. The blades should be easily removed and replaced without the need for special tools. Furthermore, when the blade is installed in the centrifugal blasting machine, it should be possible to replace the blade without removing the internal feedparts of the blast machine, such as the impeller or control cage conventionally found in such machines. Additionally, the throwing blades should be securely mounted to the runnerhead without the use of magnets. Many applications may also require a blade having a width of between 2-4″, for example, greater than or equal to 3.0″, or a length defining a wheel diameter of, for example, between 14″ and 17″. Thus, there is a need for an improved blade assembly that can provide improved support for the blade in the runnerhead, reduce the stresses on the blade during operation, and allow blade replacement or interchangeability without removing the feedparts.
According to one embodiment, an abrasive throwing wheel assembly is provided. The abrasive throwing wheel assembly includes a housing. A runnerhead may be disposed within the housing and arranged to be rotatably driven by a drive shaft about a center rotational axis. The runnerhead may include a plurality of radially extending dovetail shaped channels arranged on a face of the runnerhead. Each channel may include a slot extending at an angle relative to a radially extending longitudinal axis of the channel. The abrasive throwing wheel assembly may further includes a throwing blade. The throwing blade may include a throwing portion and a dovetail shaped base portion configured to be removably received within one of the plurality of dovetail shaped channels. The base portion may include a slanted surface configured to extend at a same angle as the slot relative to the radially extending longitudinal axis of the channel when inserted within the channel. The abrasive throwing wheel assembly may further include a U-shaped locking pin sized and configured to be removably received in the slot to secure the base portion of the throwing blade within the channel. When the base portion of the throwing blade is received within the channel of the runnerhead and the locking pin is received in the slot, the locking pin contacts the slanted surface to prevent radially outward movement of the throwing blade.
According to another embodiment, a throwing blade for an abrasive throwing wheel assembly is provided. The abrasive throwing wheel assembly may include a housing and a runnerhead disposed within the housing. The runnerhead may be arranged to be rotatably driven by a drive shaft about a center rotational axis and may include a plurality of radially extending dovetail shaped channels arranged on a face of the runnerhead. Each channel may include a slot extending at an angle relative to a radially extending longitudinal axis of the channel. The throwing blade may include a substantially planar throwing portion and a dovetail shaped base portion configured to be removably received within one of the plurality of dovetail shaped channels of the runnerhead. The base portion may include a slanted surface configured to extend at a same angle as the slot relative to the radially extending longitudinal axis of the channel when inserted within the channel. The slanted surface may be configured to engage a U-shaped locking pin removably received in the slot whereby the base portion of the throwing blade is secured within the channel.
According to yet another embodiment of the invention, an abrasive throwing wheel assembly includes a runnerhead disposed within a housing and arranged to be rotatably driven by a drive shaft about a center rotational axis. The runnerhead may include a plurality of radially extending dovetail shaped channels arranged on a face of the runnerhead. Each channel may include an L-shaped slot in a back surface thereof including a first portion extending radially and a second portion extending perpendicular to the first portion. The abrasive throwing wheel assembly further includes a throwing blade including a throwing portion and a dovetail shaped base portion configured to be removably received within one of the plurality of dovetail shaped channels of the runnerhead. The base portion may include a slanted surface and a locking face. The locking face may be arranged perpendicular to the slanted surface and substantially parallel to a radially extending longitudinal axis defined by the throwing portion. The abrasive throwing wheel assembly may further include a substantially L-shaped locking pin sized and configured to be received in the slot to secure the base portion of the throwing blade within the channel. The L-shaped locking pin may include a first leg, a second leg, and an angled surface between the first and second legs configured to engage the slanted surface of the base portion. When the base portion of the throwing blade is received in one of the plurality of channels and the second leg of the locking pin is disposed within the second portion of the slot, the angled surface of the locking pin contacts the slanted surface of the base portion to prevent radially outward movement of the throwing blade.
According to still another embodiment of the invention, a throwing blade for an abrasive throwing wheel assembly is provided. The abrasive throwing wheel assembly may include a runnerhead disposed within a housing and arranged to be rotatably driven by a drive shaft about a center rotational axis. The runnerhead may include a plurality of radially extending dovetail shaped channels arranged on a face of the runnerhead. Each channel may include an L-shaped slot in a back surface thereof including a first portion extending radially and a second portion extending perpendicular to the first portion. The throwing blade may include a throwing portion and a dovetail shaped base portion configured to be removably received within one of the plurality of dovetail shaped channels of the runnerhead. The base portion may include a slanted surface and a locking face. The locking face may be arranged perpendicular to the slanted surface and substantially parallel to a radially extending longitudinal axis defined by the throwing portion. The slanted surface may be configured to engage an angled surface of a substantially L-shaped locking pin when the base portion is received in the channel and a leg of the L-shaped locking pin is removably received in the second portion of the slot to secure the base portion of the throwing blade within the channel.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a detailed cross-sectional side view of an abrasive throwing wheel assembly according to a first embodiment of the invention;

FIG. 2 is a front view of a throwing wheel runnerhead of the abrasive throwing wheel assembly of FIG. 1;

FIG. 3A is a cross-sectional view of the throwing wheel runnerhead of FIG. 2 along section 3A-3A;

FIG. 3B is a detailed perspective view of a channel in the throwing wheel runnerhead of FIG. 2;

FIG. 4A is a side view of a throwing blade of the abrasive throwing wheel assembly of FIG. 1;

FIGS. 4B and 4C are top and rear views, respectively, of the throwing blade shown in FIG. 4A;

FIG. 5A is a front view of a lock pin of the abrasive throwing wheel assembly of FIG. 1;

FIGS. 5B and 5C are side and top views, respectively, of the lock pin shown in FIG. 5A;

FIG. 6A is a detailed cross-sectional side view of the abrasive throwing wheel assembly of FIG. 1;

FIG. 6B is a detailed cross-sectional side view of the abrasive throwing wheel assembly of FIG. 1 during removal of a throwing blade;

FIG. 7 is a schematic cross-sectional side view of the abrasive throwing wheel assembly of FIG. 1 during attachment of a throwing blade to the runnerhead;

FIG. 8A is a front view of a throwing wheel runnerhead of an abrasive throwing wheel assembly according to a second embodiment of the invention;

FIG. 8B is a cross-sectional view of the throwing wheel runnerhead of FIG. 8A along section 8B-8B;

FIG. 8C is a partial bottom view of the throwing wheel runnerhead of FIG. 8A;

FIG. 8D is a partial cross-sectional view of the throwing wheel runnerhead of FIG. 8A along section 8D-8D;

FIG. 9A is a side view of a throwing blade for attachment to the throwing wheel runner head of FIG. 8A according to the second embodiment of the invention;

FIGS. 9B and 9C are back and top views, respectively, of the throwing blade of FIG. 9A;

FIG. 10A is a side view of an L-shaped lock pin for use with the throwing wheel runner head and the throwing blade of FIGS. 8A and 9A, respectively, according to the second embodiment of the invention; and

FIGS. 10B and 10C are front and top views of the L-shaped lock pin of FIG. 10A.

DETAILED DESCRIPTION

Several embodiments of the invention are discussed in detail below. While specific example embodiments are discussed, it should be understood that this is done for illustration purposes only. In describing and illustrating the embodiments, specific terminology is employed for the sake of clarity. However, the invention is not intended to be limited to the specific terminology so selected. A person skilled in the relevant art will recognize that other components and configurations may be used without parting from the spirit and scope of the invention. It is to be understood that each specific element includes all technical equivalents that operate in a similar manner to accomplish a similar purpose. Each reference cited herein is incorporated by reference. The examples and embodiments described herein are non-limiting examples.
The invention is related to an improved throwing blade connection assembly for abrasive throwing wheels. Exemplary embodiments of the throwing blade connection assembly secure a throwing blade to the throwing wheel without bolts or other threaded fasteners and allow removal and replacement of throwing blades from the throwing wheel runnerhead without removing the feedparts.
FIGS. 1, 2, 3A-B, 4A-C, 5A-C, 6A-B, and 7 depict an abrasive throwing wheel assembly or blasting machine 10 according to a first embodiment of the invention. More particularly, the figures show a first embodiment of an improved throwing blade connection assembly for such a blasting machine 10. FIG. 1, for example, depicts a detailed cross-sectional side view of the blasting machine 10. The blasting machine 10 includes a housing 11 having a hinged access door D which can be opened or closed as desired for purposes of maintenance and the like. The blasting machine 10 includes a runnerhead 12 rotatably supported within the housing 11 by a shaft 14. The shaft 14 is arranged to be driven by a motor M. The runnerhead 12 is connected to the shaft 14 by a hub 16 and bolted fasteners 18. An impeller case 20 is concentrically aligned with the shaft 14. The impeller case 20 is supported by a portion of the housing 11 in a stationary position relative to the runnerhead 12 and includes a radial opening 19. An impeller 13 is coupled to the shaft 14 for rotation within the impeller case 20. A feed spout 21 is coupled to the housing 11 such that abrasive material can be fed through the feed spout 21 and into the housing 11 to the impeller 13.
FIG. 1 shows a plurality of throwing blades 30 (vanes) removably coupled to the runnerhead 12. Each throwing blade 30 includes an abrasive throwing portion 31 and a base portion 32. In the embodiment depicted in FIGS. 1-7, the base portion 32 has a dovetail shaped cross-section which is configured to be removably received in a dovetail shaped radial channel 24 in a face 23 of the runnerhead 12 (see FIG. 2). Each throwing blade 30 is held within the channel 24 by a locking pin 40 which engages the base portion 32 of the respective throwing blade 30. A spring 42 is also disposed within each channel 24 to bias the throwing blade 30 in a direction parallel to the axis of rotation of the runnerhead 12 such that the throwing blade 30 is held more securely within the channel 24 during operation.
FIGS. 2, 3A, and 3B depict several views of the runnerhead 12 according to the embodiment shown in FIG. 1. In the front view of the runnerhead 12 shown in FIG. 2, runnerhead 12 includes a face 23 which includes a plurality of radially extending channels 24. Each radially extending channel 24 has a dovetail shaped cross-section which is configured to receive the base portion 32 of one of the throwing blades 30. Although the embodiment shown in FIG. 2 includes eight channels 24, one of skill in the art will recognize that the runnerhead 12 may include any number of channels 24 equally spaced about the central axis so that the runnerhead 12 is balanced. Each channel 24 includes a back surface 25 which is offset from face 23. As shown in FIGS. 2 and 3A, each channel 24 includes a slot or recess 26 in back surface 25 which is configured to receive the locking pin 40. Furthermore, as shown in FIGS. 3A and 3B, each channel 24 may also include a cutaway portion 27 (e.g., a peripheral recess) at a radially outermost portion of the runnerhead 12 to facilitate acceptance of the base portion 32 of a respective throwing blade 30 during assembly. As can be seen in FIG. 3A, the slot 26 extends at an angle to the face 23, wherein the angle is some angle between zero and 90 degrees such as, for example, 60 degrees, although one of ordinary skill in the art will recognize that other angles may be sufficient.
FIGS. 4A-C depict side, rear, and top views, respectively, of the throwing blade 30 according to the embodiment shown in FIG. 1. The throwing blade 30 includes an abrasive material throwing portion 31 and a base portion 32. In the embodiment shown, the throwing portion 31 is substantially planar such that the throwing blade 30, when mounted to the runnerhead 12, is essentially bidirectional. That is, the runnerhead 12 can rotate clockwise or counterclockwise during operation and the throwing blade 30 will be effective in throwing the abrasive material. The throwing blade 30 includes a top 36 and bottom 37. The top 36 is positioned radially outward from the bottom 37 when the throwing blade 30 is coupled to the runnerhead 12. The dotted lines at the top 36 of the throwing blade 30 depicted in FIGS. 4A-B (see also FIG. 1) are intended to show that the throwing portion 31 of the throwing blade 30 may be of various sizes. For example, the throwing portions may be sized so that the rotational diameter of the throwing blade 30 on the runnerhead 12 is any one of 14″, 15″, 16″, or 17″. Other sizes are also possible. The base portion 32 of the throwing blade 30 may be dovetail shaped such that it can be received in the channel 24. The base portion 32 includes a surface 33 having a recess 34. The base portion 32 also includes a slanted surface 35.
FIGS. 5A-C depict various views of the locking pin 40. As shown in the depicted embodiment, the locking pin 40 is substantially U-shaped. This U-shaped profile helps during removal and insertion of the pin 40 into the slot 26 of the runnerhead 12 to effect removal or securement of the throwing blade 30. The locking pin 40 may have a hole or some other feature (not shown) provided at one end thereof to assist with removal by a tool.
FIG. 6A depicts a side cross-sectional view of the blasting machine 10 before, during, or after operation. As can be seen in FIG. 6A, the throwing blades 30 are secured within the channels 24 of the runnerhead 12 and cannot move radially outward due to the position of the locking pin 40 in slot 26. The spring 42 is disposed in recess 34 to stabilize the throwing blade 30 within the channel 24. During operation of the machine 10, the centrifugal force resulting from the rotation of the runnerhead 12 pulls the blades 30 radially outward such that the slanted surface 35 of the base portion 32 of throwing blade 30 contacts the locking pin 40. The bottom 37 of the throwing blade 30 is radially spaced from the impeller case 20.
When it becomes time to remove and/or replace one or more of the throwing blades 30, the access door D (see FIG. 1) is opened, and a blade 30 is removed as shown in FIG. 6B. First, the blade 30 is moved radially inward until the bottom 37 contacts the impeller case 20. Next, the locking pin 40, which is oriented within the slot 26 such that the open side of the U-shaped body faces outward, is removed. Lastly, the throwing blade 30 is pulled radially outwardly until the base portion 32 is freed from the channel 24 of the runnerhead 12. In order to insert a new throwing blade 30 into the vacated channel 24 of the runnerhead 12, the foregoing steps are performed in reverse order as depicted in FIG. 7. None of the elements in FIGS. 1-7 should be magnetized or otherwise configured to include any magnetic elements because the abrasive material and the blade 30 are generally made of metal materials which would be attracted to a magnetic element. This could potentially prevent any one of the elements from seating properly in the runnerhead 12 and thereby cause a failure. If, for example, the blade 30 and/or the pin 40 do not seat properly in the runnerhead 12 then the blade 30 can shift out of the runnerhead 12 and cause the wheel to fail.
Another embodiment of the invention is depicted in FIGS. 8A-D, 9A-C, and 10A-C. According to this embodiment, the blasting machine may be the same as that depicted in FIG. 1, except that the runnerhead, throwing blades, and locking pins have a different construction for added security in preventing the locking pin from falling out inadvertently. More particularly, in FIG. 8A, a front view of a runnerhead 112 is shown. The runnerhead 112 includes a face 123 which includes a plurality of radially extending channels 124. Each radially extending channel 124 has a dovetail shaped cross-section which is configured to receive the base portion 132 of one of the throwing blades 130 (see FIGS. 9A-C). Although the embodiment shown in FIG. 8A includes eight channels 124, one of skill in the art will recognize that the runnerhead 112 may include any number of channels 124. Each channel 124 includes a back surface 125 which is offset from face 123. As shown in FIGS. 8A and 8B, each channel 124 includes a slot or recess 126 in back surface 125 which is configured to receive a locking pin 140. The slot 126 is substantially L-shaped and includes a first radially extending portion 126 a extending inwardly from an outer peripheral surface of the runnerhead 112. The slot 126 further includes a second tranverse portion 126 b which extends substantially perpendicular to the first radially extending portion 126 a. The first radially extending portion 126 a extends parallel to a central longitudinal axis (not shown) defined by channel 124 but is offset from such radially extending central axis.
FIGS. 9A-C depict various views of the throwing blade 130 according to the second embodiment of the invention. As shown in FIG. 9A, the throwing blade 130 includes an abrasive material throwing portion 131 and a base portion 132. In the embodiment shown, the throwing portion 131 is substantially planar such that the throwing blade 130, when mounted to the runnerhead 112, is essentially bidirectional. That is, the runnerhead 112 can rotate clockwise or counterclockwise during operation and the throwing blade 130 will be effective in throwing the abrasive material. The throwing blade 130 includes a top 136 and bottom 137. The top 136 is positioned radially outward from the bottom 137 when the throwing blade 130 is coupled to the runnerhead 112. The dotted lines at the top 136 of the throwing blade 130 depicted in FIGS. 9A-B are intended to show that the throwing portion 131 of the throwing blade 130 may be of various sizes. For example, the throwing portions may be sized so that the rotational diameter of the throwing blade 130 on the runnerhead 112 is any one of 14″, 15″, 16″, or 17″. Other sizes are possible. The base portion 132 of the throwing blade 130 is dovetail shaped such that it can be received in the channel 124 of the runnerhead 112. The base portion 132 includes a surface 133 having a recess 134 for receiving a spring (not shown). The base portion 132 also includes a slanted surface 135 bordered on one side by a locking face 138. The locking face 138 lies in a plane substantially perpendicular to a plane defined by the slanted surface 135 and which is substantially parallel to a longitudinal axis of the throwing blade 130 extending between in the bottom 137 and top 136 of the throwing blade 130 (see FIGS. 9B and 9C).
FIGS. 10A-C depict various views of a locking pin 140. As shown in the depicted embodiment, the locking pin 140 is substantially L-shaped and includes a first portion 141 and a second portion 142. This L-shaped profile helps to secure the throwing blade 130 within the channel 124 by ensuring that the pin 140 will not inadvertently fall out of position in the slot 126. As shown in FIG. 10A, the locking pin 140 includes several peripheral surfaces including surfaces 143, 144, and 145. Surfaces 143 and 145 are disposed at a right angle with respect to one another and define part of the first portion 141 of the locking pin 140. Surface 144, however, is shown as being at an angle of approximately 30 degrees with respect to surface 143. Other angles may be possible so long as the angle between surfaces 144 and 143 is substantially the same as the angle between surfaces 133 and 135 on the throwing blade 130. The locking pin 140 may also include a through hole 146 on the second portion 142 to help with removal and insertion of the pin 140 into the slot 126 in the runnerhead 112.
In order to secure the throwing blade 130 to the runnerhead 112, the dovetail shaped base portion 132 of the throwing blade 130 is inserted into the radially extending channel 124 and moved radially inward until the bottom 137 of the throwing blade 130 contacts the impeller case (see FIG. 1). The locking pin 140 is then inserted into the first radially extending portion 126 a of the slot 126 in channel 124. The orientation of the locking pin 140 is such that surface 143 faces the back surface 125 of the channel 124, and the surface 144 faces away from the back surface 125. The surface 145 of the locking pin faces radially outward from the center rotational axis of the runnerhead 112. The locking pin 140 is pushed radially inward along first slot portion 126 a and then transversely so that the first portion 141 of the locking pin 140 is disposed within transverse portion 126 b of the slot 126. The throwing blade 130 is then moved radially outward until slanted surface 135 contacts surface 144 of the locking pin 140. Surface 145 of the locking pin 140 opposes surface 152 (see FIG. 8A) of the transverse portion 126 b of the slot 126 and, consequently, the locking pin 140 and throwing blade 130 are prevented from further radially outward movement. Additionally, the locking face 138 of the throwing blade 130 is positioned such that it prevents any transverse movement of the locking pin 140 to a position within first portion 126 a of the slot 126 where removal of the locking pin 140 from the slot 126 would otherwise be possible. In this way, the throwing blade 130 is effectively secured to the runnerhead 112 within the channel 124. Removal of the throwing blade 130 can be achieved by repeating the foregoing steps in reverse order beginning with moving the throwing blade 130 radially inward.
In the above-described embodiments, the throwing blades may be bi-directional and may have a width of between approximately 2-4 inches as defined in a direction extending parallel to the rotational axis of the runnerhead when mounted thereon. Other widths may also be possible depending on the dimensions of the housing. The housing may be configured such that throwing wheels having blades of various sizes can be housed therein. For example, the housing may be configured to accommodate runnerheads having blades with widths of between 2 to 4 inches attached thereto. The housing may also be configured to accommodate runnerheads having blades mounted thereon that define rotational diameters of between approximately 14 to 17 inches. One of skill in the art will recognize that blades having other dimensions and/or which are not bidirectional may also be possible.
While various embodiments have been described above, it should be understood that they have been presented by way of example only, and not limitation. Thus, the breadth and scope of the present invention should not be limited by any of the above-described embodiments, but should instead be defined only in accordance with the following claims and their equivalents.

Claims

1. An abrasive throwing wheel assembly, comprising:

a housing;

a runnerhead disposed within the housing and arranged to be rotatably driven by a drive shaft about a center rotational axis, wherein the runnerhead comprises a plurality of radially extending dovetail shaped channels arranged on a face of the runnerhead, each channel including a slot extending at an angle relative to a radially extending longitudinal axis of the channel;

a throwing blade including a throwing portion and a dovetail shaped base portion configured to be removably received within one of the plurality of dovetail shaped channels, wherein the base portion includes a slanted surface configured to extend at a same angle as the slot relative to the radially extending longitudinal axis of the channel when inserted within the channel; and

a U-shaped locking pin sized and configured to be removably received in the slot to secure the base portion of the throwing blade within the channel, wherein when the base portion of the throwing blade is received within the channel of the runnerhead and the locking pin is received in the slot, the locking pin contacts the slanted surface to prevent radially outward movement of the throwing blade.

2. The abrasive throwing wheel assembly according to claim 1, further comprising an access door hingedly attached to the housing so as to be moveable between an open position whereby the throwing blade can be attached to or removed from the runnerhead and a closed position whereby the abrasive throwing wheel assembly can operate.

3. The abrasive throwing wheel assembly according to claim 1, wherein the channels include at least one peripheral recess at a radially outermost portion of the channel to facilitate receiving the base portion of the throwing blade during assembly.

4. The abrasive throwing wheel assembly according to claim 1, wherein the number of channels on the runnerhead is eight.

5. The abrasive throwing wheel assembly according to claim 1, wherein the angle at which the slot extends relative to radially extending longitudinal axis of the channel is approximately 30 degrees.

6. The abrasive throwing wheel assembly according to claim 1, wherein the substantially planar throwing portion of the throwing blade defines a length between a bottom and a top, and wherein the length defines a rotational diameter of between about 14 and 17 inches when the throwing blade is attached to the runnerhead.

7. The abrasive throwing wheel assembly according to claim 6, wherein the substantially planar throwing portion of the throwing blade defines a width of between about 2 and 4 inches.

8. The abrasive throwing wheel assembly according to claim 1, wherein no portion of the abrasive throwing wheel assembly includes a magnet or is magnetized.

9. The abrasive throwing wheel assembly according to claim 1, wherein the throwing portion of the throwing blade is substantially planar.

10. A throwing blade for an abrasive throwing wheel assembly having a housing and a runnerhead disposed within the housing, the runnerhead arranged to be rotatably driven by a drive shaft about a center rotational axis and including a plurality of radially extending dovetail shaped channels arranged on a face of the runnerhead, each channel including a slot extending at an angle relative to a radially extending longitudinal axis of the channel, the throwing blade comprising:

a substantially planar throwing portion; and

a dovetail shaped base portion configured to be removably received within one of the plurality of dovetail shaped channels of the runnerhead, wherein the base portion includes a slanted surface configured to extend at a same angle as the slot relative to the radially extending longitudinal axis of the channel when inserted within the channel, and wherein the slanted surface is configured to engage a U-shaped locking pin removably received in the slot whereby the base portion of the throwing blade is secured within the channel.

11. An abrasive throwing wheel assembly, comprising:

a runnerhead disposed within a housing and arranged to be rotatably driven by a drive shaft about a center rotational axis, wherein the runnerhead comprises a plurality of radially extending dovetail shaped channels arranged on a face of the runnerhead, each channel including an L-shaped slot in a back surface thereof including a first portion extending radially and a second portion extending perpendicular to the first portion;

a throwing blade including:

a throwing portion; and

a dovetail shaped base portion configured to be removably received within one of the plurality of dovetail shaped channels, wherein the base portion includes a slanted surface and a locking face, the locking face being arranged perpendicular to the slanted surface and substantially parallel to a radially extending longitudinal axis defined by the throwing portion; and

a substantially L-shaped locking pin sized and configured to be received in the slot to secure the base portion of the throwing blade within the channel, wherein the L-shaped locking pin includes a first leg, a second leg, and an angled surface between the first and second legs configured to engage the slanted surface of the base portion, wherein when the base portion of the throwing blade is received in one of the plurality of channels and the second leg of the locking pin is disposed within the second portion of the slot, the angled surface of the locking pin contacts the slanted surface of the base portion to prevent radially outward movement of the throwing blade.

12. The abrasive throwing wheel assembly according to claim 11, wherein when the slanted surface of the base portion engages the angled surface of the locking pin, the locking face of the base portion is positioned to prevent transverse movement of the locking pin into the first radially extending portion of the slot.

13. The abrasive throwing wheel assembly according to claim 11, wherein the number of channels on the runnerhead is eight.

14. The abrasive throwing wheel assembly according to claim 11, wherein the throwing portion of the throwing blade is substantially planar and defines a length between a bottom and a top, and wherein the length defines a rotational diameter of between about 14 and 17 inches when the throwing blade is attached to the runnerhead.

15. The abrasive throwing wheel assembly according to claim 14, wherein the substantially planar throwing portion of the throwing blade defines a width of between about 2 and 4 inches.

16. The abrasive throwing wheel assembly according to claim 11, wherein the L-shaped locking pin includes a hole extending through the first leg to facilitate removal of the locking pin from the slot.

17. A method of attaching the throwing blade to the runnerhead of the an abrasive throwing wheel assembly of claim 12, the method comprising:

inserting the base portion of the throwing blade into the channel;

moving the throwing blade radially inward towards the center rotational axis;

radially inserting the locking pin into the first portion of the slot, wherein the locking pin is oriented such that the first leg extends substantially radially and the second leg extends substantially parallel to the center rotational axis such that the angled surface is positioned to engage the slanted surface of the base portion of the throwing blade;

moving the locking pin transversely so that the second leg of the locking pin is positioned within the second portion of the slot; and

moving the throwing blade radially outward away from the center rotational axis until the slanted surface of the base portion engages the angled surface of the locking pin.

18. A throwing blade for an abrasive throwing wheel assembly having a runnerhead disposed within a housing and arranged to be rotatably driven by a drive shaft about a center rotational axis, the runnerhead including a plurality of radially extending dovetail shaped channels arranged on a face of the runnerhead, each channel including an L-shaped slot in a back surface thereof including a first portion extending radially and a second portion extending perpendicular to the first portion, the throwing blade comprising:

a throwing portion; and

a dovetail shaped base portion configured to be removably received within one of the plurality of dovetail shaped channels of the runnerhead, wherein the base portion includes a slanted surface and a locking face, the locking face being arranged perpendicular to the slanted surface and substantially parallel to a radially extending longitudinal axis defined by the throwing portion, and wherein the slanted surface is configured to engage an angled surface of a substantially L-shaped locking pin when the base portion is received in the channel and a leg of the L-shaped locking pin is removably received in the second portion of the slot to secure the base portion of the throwing blade within the channel.