RANDOM ORBIT SANDER WITH A MULTI-MATERIAL DUST COLLECTION ASSEMBLY

Abstract

An orbital sander includes a housing, a motor within housing, the motor including a motor shaft defining a motor axis, an eccentric drive unit coupled to the motor shaft to convert rotation of the motor shaft to an orbit motion around the motor axis, a battery receptacle for receiving a battery pack, a backing pad coupled to the eccentric drive unit for orbital motion about the motor axis, and a dust collection assembly adjacent the backing pad for directing dust away from the backing pad. The orbital sander, including the housing, the motor, the eccentric drive unit, the battery receptacle, the backing pad, and the dust collection assembly, defines a center of gravity CG.sub.ROS located on a first side of the motor axis adjacent the battery receptacle. The dust collection assembly defines a center of gravity CG.sub.DCA on a second side of the motor axis opposite the first side.

Claims

1. An orbital sander comprising: a housing; a motor within housing, the motor including a motor shaft defining a motor axis; an eccentric drive unit coupled to the motor shaft and configured to convert rotation of the motor shaft to an orbit motion around the motor axis; a battery receptacle configured to receive a battery pack for providing electrical current to the motor; a backing pad coupled to the eccentric drive unit for orbital motion about the motor axis; and a dust collection assembly adjacent the backing pad configured for directing dust away from the backing pad; wherein the orbital sander, including the housing, the motor, the eccentric drive unit, the battery receptacle, the backing pad, and the dust collection assembly, defines a center of gravity CG.sub.ROS located on a first side of the motor axis adjacent the battery receptacle, and wherein the dust collection assembly defines a center of gravity CG.sub.DCA on a second side of the motor axis opposite the first side.

2. The orbital sander of claim 1, wherein the dust collection assembly includes a first material having a first density and a second material having a second density, wherein the second density is greater than the first density, and wherein the second material is located forward of the motor axis.

3. The orbital sander of claim 1, wherein the dust collection assembly comprises a lower shroud and an upper shroud coupled thereto.

4. The orbital sander of claim 3, wherein the lower shroud comprises a first lower portion and a second lower portion affixed thereto.

5. The orbital sander of claim 4, wherein the upper shroud includes a first upper shroud half having a first upper rearward portion and a first upper forward portion coupled thereto.

6. The orbital sander of claim 5, wherein the upper shroud includes a second upper shroud half having a second upper rearward portion and a second upper forward portion coupled thereto.

7. The orbital sander of claim 6, wherein the first lower portion of the lower shroud, the first upper rearward portion of the upper shroud, and the second upper rearward portion of the upper shroud comprise a first material.

8. The orbital sander of claim 7, wherein the second lower portion of the lower shroud, the first upper forward portion of the upper shroud, and the second upper forward portion of the upper shroud comprise a second material.

9. The orbital sander of claim 8, wherein the first material has a first density and the second material has a second density, and wherein the second density is greater than the first density.

10. The orbital sander of claim 9, wherein the second density is greater than or equal to five times the first density.

11. The orbital sander of claim 8, wherein the first material is a polymer.

12. The orbital sander of claim 11, wherein the second material is a metal.

13. The orbital sander of claim 1, wherein the dust collection assembly is integrally formed with the housing.

14. The orbital sander of claim 1, wherein the dust collection assembly is formed separately from the housing.

15. The orbital sander of claim 1, further comprising a brake pad bracket and a brake pad adjacent a first side of the backing pad.

16. The orbital sander of claim 15, wherein the dust collection assembly at least partially surrounds the brake pad bracket and brake pad.

17. The orbital sander of claim 15, wherein the brake pad bracket includes a first bracket portion located on the first side of the motor shaft and a second bracket portion located on the second side of the motor shaft and the second bracket portion is heavier than the first bracket portion.

18. The orbital sander of claim 1, wherein the dust collection assembly includes a first shroud and a second shroud, wherein the second shroud includes a first portion located on the first side of the motor shaft and a second portion located on the second side of the motor shaft, and wherein the second portion is heavier than the first portion.

19. An orbital sander comprising: a housing; a motor within housing, the motor including a motor shaft defining a motor axis; an eccentric drive unit coupled to the motor shaft and configured to convert rotation of the motor shaft to an orbit motion around the motor axis; a battery receptacle for receiving a battery pack for providing electrical current to the motor; a backing pad coupled to the eccentric drive unit for orbital motion about the motor axis; and a brake pad bracket and a brake pad adjacent a first side of the backing pad; wherein the orbital sander, including the housing, the motor, the eccentric drive unit, the battery receptacle, and the backing pad defines a center of gravity CG.sub.ROS located on a first side of the motor axis adjacent the battery receptacle, and wherein the brake pad bracket defines a center of gravity CG.sub.DCA on a second side of the motor axis opposite the first side.

20. The orbital sander of claim 19, further comprising a dust collection assembly adjacent the backing pad configured for directing dust away from the backing pad, wherein the dust collection assembly includes a first material having a first density and a second material having a second density, wherein the second density is greater than the first density, and wherein the second material is located on the second side of the motor axis.

21.-40. (canceled)

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0045] FIG. 1 is a perspective view of a random orbit sander.

[0046] FIG. 2 is side view of the random orbit sander of FIG. 1.

[0047] FIG. 3 is a bottom view of the random orbit sander of FIG. 1.

[0048] FIG. 4 is a cross-section view of the random orbit sander of FIG. 1 taken along Line 4-4 in FIG. 3.

[0049] FIG. 5 is a perspective view of a brake pad bracket of the random orbit sander of FIG. 1.

[0050] FIG. 6 is a side view of the brake pad bracket of FIG. 5.

[0051] FIG. 7 is a perspective view of a dust collection assembly of the random orbit sander of FIG. 1.

[0052] FIG. 8 is a perspective view of a lower shroud of the dust collection assembly of FIG. 7.

[0053] FIG. 9 is an exploded perspective view of a lower shroud of the dust collection assembly of FIG. 7.

[0054] FIG. 10 is a perspective view of an upper shroud of the dust collection assembly of FIG. 7.

[0055] FIG. 11 is an exploded perspective view of an upper shroud of the dust collection assembly of FIG. 7.

[0056] FIG. 12 is a top view of the dust collection assembly of FIG. 7.

[0057] FIG. 13 is a side view of the dust collection assembly of FIG. 7.

[0058] FIG. 14 is top view of an edge guard of the random orbit sander of FIG. 1.

[0059] FIG. 15 is a side view of the random orbit sander of FIG. 1 with the edge guard partially disengaged from the dust collection assembly.

[0060] FIG. 16 is a perspective view of alternative embodiment of a dust collection assembly of the random orbit sander of FIG. 1.

[0061] FIG. 17 is a perspective view of a lower shroud of the dust collection assembly of FIG. 16.

[0062] FIG. 18 is a perspective view of an upper shroud of the dust collection assembly of FIG. 16.

[0063] FIG. 19 is an exploded perspective view of an upper shroud of the dust collection assembly of FIG. 16.

[0064] FIG. 20 is a top view of the dust collection assembly of FIG. 16.

[0065] FIG. 21 is a side view of the dust collection assembly of FIG. 16.

[0066] FIG. 22 is a front view of the dust collection assembly of FIG. 16.

[0067] FIG. 23 is top view of an edge guard of the random orbit sander of FIG. 16.

[0068] FIG. 24 is a side view of the edge guard of FIG. 23 engaged with the dust collection assembly of FIG. 16.

[0069] FIG. 25 is a cross-section view of the edge guard and dust collection assembly of FIG. 24 taken along Line 25-25 in FIG. 24.

[0070] Before any embodiments of the present disclosure are explained in detail, it is to be understood that the embodiments described herein are not limited in scope or application to the details of construction and the arrangement of components set forth in the following description or as illustrated in the following drawings. The devices described herein are capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.

DETAILED DESCRIPTION

[0071] Referring to FIGS. 1-4, a random orbit sander 100 is illustrated. The random orbit sander 100 includes a housing 102 having a first housing shell 104 joined to a second housing shell 106 along a seam 108. Further, the housing 102 includes a motor housing 110 extending along a motor axis 112. A handle housing 114 extends from the motor housing 110 along a handle axis 116. In a particular aspect, the handle axis 116 is perpendicular to the motor axis 112. The random orbit sander 100 further includes a battery receptacle 118 formed in the handle housing 114 that is configured to receive a battery pack. Specifically, the battery receptacle 118 includes a pair of parallel guide rails 120, 122 that are configured to receive complementary features on a removable battery back. As such, the battery receptacle 118 is sized and shaped to slidably receive a removable battery pack therein. The removable battery pack is slidable parallel to the handle axis 116 in a first direction toward the motor axis 112 to be engaged with the battery receptacle 118 and in a second direction away from the motor axis 112 (opposite the first direction) to be disengaged from the battery receptacle. In a particular aspect, the removable battery pack provides approximately 324 kilojoules of energy and weighs approximately 0.82 kilograms. Therefore, the removable battery pack includes an energy density of approximately 395 kilojoules per kilogram.

[0072] As shown, the motor housing 110 includes a motor 130 disposed therein. For example, the motor 130 is a brushless direct current (BLDC) motor that receives electrical current, i.e., power, from the removable battery pack that is engaged with the battery receptacle 118. The motor 130 includes a motor shaft 132 that rotates on a first bearing 134 and a second bearing 136. The motor shaft 132 defines the motor axis 112. In other words, the motor shaft 132 rotates about the motor axis 112. An eccentric drive unit 140 is coupled to the motor shaft 132. The motor shaft 132 drives the eccentric drive unit 140 and the eccentric drive unit 140 is configured to convert rotation of the motor shaft 132 to an orbit motion around the motor axis 112. A backing pad 142 is removably attached to the eccentric drive unit 140. A sanding disc (not shown) is removably attached to the backing pad 142. FIG. 4 further shows a cooling fan 144 that is disposed on the motor shaft 132 above the second bearing 136. The cooling fan 144 rotates with the motor shaft 132 to pull air, and heat, away from the motor 130 during operation of the random orbit sander 100. An exhaust outlet 146 is formed in each of the housing shells 104, 106, opposite each other, to provide air exit channels for the air flow generated by the cooling fan 144.

[0073] As further illustrated in FIG. 4, a dust fan 148 is disposed on the motor shaft 132 below the second bearing 136 and above the eccentric drive unit 140 and the backing pad 142 mounted thereon. A dust collection assembly 150 surrounds the dust fan 148. The dust collection assembly 150 is formed separately from the housing 102. Alternatively, the dust collection assembly 150 is integrally, and monolithically, formed with the housing 102. During operation, the dust fan 148 rotates with the motor shaft 132 to pull air, and dust, away from the backing pad 142 and blow it into a dust collection bag attached to the dust collection assembly 150. FIG. 4 further shows a brake pad 152 removably mounted on a brake pad bracket 154. The brake pad 152 is fixed with respect to the brake pad bracket 154 while the backing pad 142 rotates relative to the brake pad 152. The brake pad 152 is flexible and is biased into contact with an upper surface 156 of the backing pad 142. The brake pad 152 slows the backing pad 142 when the motor 130 is de-energized. The random orbit sander 100 further includes an edge guard 160 that is removably engaged with the random orbit sander 100. The edge guard 160 at least partially surrounds the backing pad 142 and prevents the random orbit sander 100 and the backing pad 142 thereof from running into vertical structures extending from a workpiece, e.g., the inner wall of a cabinet.

[0074] FIGS. 5 and 6 show that the brake pad bracket 154 includes a first bracket portion 155 and a second bracket portion 157. In a particular embodiment, the brake pad bracket 154 is made from two different materials. In particular, the first bracket portion 155 is made from a first material. The second bracket portion 157 is made from a second material. The first material is a low-density material, and the second material is a high-density material. Specifically, the first material has a first density D1, and the second material has a second density D2. To provide acceptable balance for the random orbit sander 100, the second density D2 of the second material is greater than the first density D1 of the first material. Specifically, the second density D2 is greater than or equal to 5.00 times the first density D1, such as greater than or equal to 5.20 times the first density D1, greater than or equal to 5.40 times the first density D1, greater than or equal to 5.60 times the first density D1, greater than or equal to 5.80 times the first density D1, greater than or equal to 6.00 times the first density D1, or greater than or equal to 6.20 times the first density D1. Further, the second density D2 is less than or equal to 8.00 times the first density D1, such as less than or equal to 7.80 times the first density D1, less than or equal to 7.60 times the first density D1, less than or equal to 7.40 times the first density D1, less than or equal to 7.20 times the first density D1, less than or equal to 7.00 times the first density D1, less than or equal to 6.80 times the first density D1, less than or equal to 6.60 times the first density D1, or less than or equal to 6.40 times the first density D1. In any case. the second bracket portion 157 is heavier than the first bracket portion 155 and acts as a static counterbalance within the random orbit sander 100.

[0075] In another aspect, the first material is an anti-static plastic such as a filled polymer. Further, the first material is polycaprolactam (a.k.a. Nylon 6) that is filled with carbon fibers. Even further still, the first material is Nylon 6 that is 30% carbon fiber filled. In another aspect, the density D1 of the first material is less than or equal to 1.50 grams per cubic centimeters, such as less than or equal to 1.45 grams per cubic centimeters, less than or equal to 1.40 grams per cubic centimeters, less than or equal to 1.35 grams per cubic centimeters, less than or equal to 1.30 grams per cubic centimeters, less than or equal to 1.25 grams per cubic centimeters, or less than or equal to 1.20 grams per cubic centimeters. In another aspect, the density D1 of the first material is greater than or equal to 0.75 grams per cubic centimeters, such as greater than or equal to 0.80 grams per cubic centimeters, greater than or equal to 0.85 grams per cubic centimeters, greater than or equal to 0.90 grams per cubic centimeters, greater than or equal to 0.95 grams per cubic centimeters, greater than or equal to 1.00 grams per cubic centimeters, greater than or equal to 1.05 grams per cubic centimeters, greater than or equal to 1.10 grams per cubic centimeters, or greater than or equal to 1.15 grams per cubic centimeters. It is to be understood that the density D1 may be within a range between, and including, any of the maximum and minimum values of the density D1 disclosed herein.

[0076] In yet another aspect, the second material is a metal or metal alloy. For example, the second material is iron, steel, stainless steel, brass, bronze, nickel, tin, zinc, or a combination thereof. In a particular aspect, the density D2 of the second material is greater than or equal to 5.00 grams per cubic centimeters, such as greater than or equal to 5.50 grams per cubic centimeters, greater than or equal to 6.00 grams per cubic centimeters, greater than or equal to 6.50 grams per cubic centimeters, greater than or equal to 6.60 grams per cubic centimeters, greater than or equal to 6.70 grams per cubic centimeters, greater than or equal to 6.80 grams per cubic centimeters, greater than or equal to 6.90 grams per cubic centimeters, greater than or equal to 7.00 grams per cubic centimeters, or greater than or equal to 7.10 grams per cubic centimeters. In another aspect, the density D2 of the second material is less than or equal to 10.00 grams per cubic centimeters, such as less than or equal to 9.50 grams per cubic centimeters, less than or equal to 9.00 grams per cubic centimeters, less than or equal to 8.50 grams per cubic centimeters, less than or equal to 8.00 grams per cubic centimeters, less than or equal to 7.90 grams per cubic centimeters, less than or equal to 7.80 grams per cubic centimeters, less than or equal to 7.70 grams per cubic centimeters, less than or equal to 7.60 grams per cubic centimeters, less than or equal to 7.50 grams per cubic centimeters, less than or equal to 7.40 grams per cubic centimeters, less than or equal to 7.30 grams per cubic centimeters, or less than or equal to 7.20 grams per cubic centimeters. It is to be understood that the density D2 may be within a range between, and including, any of the minimum and maximum values of the density D2 disclosed herein.

[0077] Accordingly, the brake pad bracket 154 includes a low-density portion (e.g., the first bracket portion 155) located on a first side of the motor axis 112 adjacent the battery receptacle 118 and battery pack, e.g., rearward of the motor axis 112 of the random orbit sander 100 in which the brake pad bracket 154 is installed and a high-density portion (e.g., the second bracket portion 157) located on a second side of the motor axis 112 opposite the first side, e.g., forward of the motor axis 112. As such, the second bracket portion 157 provides additional weight forward of the motor axis 112 to account for the additional weight of a dust collection bag, or canister, that is installed on the dust collection assembly 150 (or the dust collection assembly 300, below) at a location distanced from the motor axis 112 and a battery (not shown) that is engaged with the battery receptacle 118 during use. The additional weight provided by the second bracket portion 157 serves to move the center of gravity of the random orbit sander 100 toward the motor axis 112 which results in greater balance of the random orbit sander 100.

[0078] FIG. 4 indicates that the random orbit sander 100 includes a center of gravity CG.sub.ROS and the center of gravity CG.sub.ROS is located behind the motor axis 112, i.e., on the same side of the motor axis 112 as the handle housing 114. Moreover, the center of gravity CG.sub.ROS is located a distance D.sub.ROS from the motor axis 112. It is to be understood that the center of gravity CG.sub.ROS is measured fully assembled with the dust collection assembly 150 and the brake pad bracket 154 installed therein and with the removable battery pack engaged with the random orbit sander 100 (e.g., the removable battery pack having the energy density described above) and with a full dust collection bag attached to the dust collection assembly 150. In another aspect, the center of gravity CG.sub.ROS is measured fully assembled with the dust collection assembly 150 and the brake pad bracket 154 installed therein and with the removable battery pack engaged with the random orbit sander 100 (e.g., the removable battery pack having the energy density described above) and with an empty dust collection bag attached to the dust collection assembly 150. In a particular embodiment, the distance D.sub.ROS of the center of gravity CG.sub.ROS from the motor axis 112 is less than or equal to 50.00 mm, such as less than or equal to 49.50 mm, less than or equal to 49.00 mm, less than or equal to 48.50 mm, less than or equal to 48.00 mm, or less than or equal to 47.50 mm. In another particular embodiment, the distance D.sub.ROS of the center of gravity CG.sub.ROS from the motor axis 112 is greater than or equal to 42.50 mm, such as greater than or equal to 42.75 mm, greater than or equal to 43.00 mm, greater than or equal to 43.25 mm, greater than or equal to 43.50 mm, greater than or equal to 43.75 mm, greater than or equal to 44.00 mm, or greater than or equal to 44.25 mm. In another aspect, the distance D.sub.ROS of the center of gravity CG.sub.ROS from the motor axis 112 equal to 44.30 mm. It is to be understood that the distance D.sub.ROS may be with a range between, and including, any of the maximum and minimum values of D.sub.ROS disclosed herein. It is to be understood that without the counterbalance provided by the dust collection assembly 150 and the brake pad bracket 154, the distance D.sub.ROS of the center of gravity CG.sub.ROS is substantially greater than disclosed above.

[0079] FIGS. 7 through 13 illustrate the details of the dust collection assembly 150. As shown, the dust collection assembly 150 includes a lower shroud 202 (or a first shroud) and an upper shroud 204 (or a second shroud) affixed to the lower shroud 202 by one or more fasteners. The upper shroud 204 is located above the lower shroud 202. The lower shroud 202 includes a first lower portion 210 and a second lower portion 212. In a particular aspect, the first lower portion 210 is molded around the second lower portion 212. For example, the second lower portion 212 is insert molded with the first lower portion 210. When assembled, or otherwise molded, as shown in FIG. 6, the lower shroud 202, and the parts thereof, define a lower portion 214 of a dust channel 216 that surrounds the dust fan 148.

[0080] The upper shroud 204 includes a first upper shroud half 220 and a second upper shroud half 222 affixed to the first upper shroud half 220 along a seam 224. The first upper shroud half 220 includes a first upper rearward portion 230 and a first upper forward portion 232 affixed to the first upper rearward portion 230. In particular, the first upper forward portion 232 is insert molded with the first upper rearward portion 230. The first upper forward portion 232 includes a plurality of holes 234 to facilitate molding the first upper rearward portion 230 thereto and to ensure a secure bond between the first upper forward portion 232 and the first upper rearward portion 230.

[0081] The second upper shroud half 222 includes a second upper rearward portion 240 and a second upper forward portion 242 affixed to the second upper rearward portion 240. In particular, the second upper forward portion 242 is insert molded with the second upper rearward portion 240. The second upper forward portion 242 includes a plurality of holes 244 to facilitate molding the second upper rearward portion 240 thereto and to ensure a secure bond between the second upper forward portion 242 and the second upper rearward portion 240. When assembled, or otherwise molded, as shown in FIG. 8, the upper shroud 204, and the parts thereof, define an upper portion 246 of the dust channel 216 formed around the dust fan 148 by the dust collection assembly 150.

[0082] In a particular embodiment, the dust collection assembly 150 is made from different materials. For example, the dust collection assembly 150 is made from two different materials. In such a case, the first lower portion 210, the first upper rearward portion 230, and the second upper rearward portion 240 are made from a first material. The second lower portion 212, the first upper forward portion 232, and the second upper forward portion 242 are made from a second material. The first material is a low-density material and the second material is a high-density material. Specifically, the first material has a first density D1 and the second material has a second density D2. To provide acceptable balance for the random orbit sander 100, the second density D2 of the second material is greater than the first density D1 of the first material. Specifically, the second density D2 is greater than or equal to 5.00 times the first density D1, such as greater than or equal to 5.20 times the first density D1, greater than or equal to 5.40 times the first density D1, greater than or equal to 5.60 times the first density D1, greater than or equal to 5.80 times the first density D1, greater than or equal to 6.00 times the first density D1, or greater than or equal to 6.20 times the first density D1. Further, the second density D2 is less than or equal to 8.00 times the first density D1, such as less than or equal to 7.80 times the first density D1, less than or equal to 7.60 times the first density D1, less than or equal to 7.40 times the first density D1, less than or equal to 7.20 times the first density D1, less than or equal to 7.00 times the first density D1, less than or equal to 6.80 times the first density D1, less than or equal to 6.60 times the first density D1, or less than or equal to 6.40 times the first density D1.

[0083] In another aspect, the first material is an anti-static plastic such as a filled polymer. Further, the first material is polycaprolactam (a.k.a. Nylon 6) that is filled with carbon fibers. Even further still, the first material is Nylon 6 that is 30% carbon fiber filled. In another aspect, the density D1 of the first material is less than or equal to 1.50 grams per cubic centimeters, such as less than or equal to 1.45 grams per cubic centimeters, less than or equal to 1.40 grams per cubic centimeters, less than or equal to 1.35 grams per cubic centimeters, less than or equal to 1.30 grams per cubic centimeters, less than or equal to 1.25 grams per cubic centimeters, or less than or equal to 1.20 grams per cubic centimeters. In another aspect, the density D1 of the first material is greater than or equal to 0.75 grams per cubic centimeters, such as greater than or equal to 0.80 grams per cubic centimeters, greater than or equal to 0.85 grams per cubic centimeters, greater than or equal to 0.90 grams per cubic centimeters, greater than or equal to 0.95 grams per cubic centimeters, greater than or equal to 1.00 grams per cubic centimeters, greater than or equal to 1.05 grams per cubic centimeters, greater than or equal to 1.10 grams per cubic centimeters, or greater than or equal to 1.15 grams per cubic centimeters. It is to be understood that the density D1 may be within a range between, and including, any of the maximum and minimum values of the density D1 disclosed herein.

[0084] In yet another aspect, the second material is a metal or metal alloy. For example, the second material is iron, steel, stainless steel, brass, bronze, nickel, tin, zinc, or a combination thereof. In a particular aspect, the density D2 of the second material is greater than or equal to 5.00 grams per cubic centimeters, such as greater than or equal to 5.50 grams per cubic centimeters, greater than or equal to 6.00 grams per cubic centimeters, greater than or equal to 6.50 grams per cubic centimeters, greater than or equal to 6.60 grams per cubic centimeters, greater than or equal to 6.70 grams per cubic centimeters, greater than or equal to 6.80 grams per cubic centimeters, greater than or equal to 6.90 grams per cubic centimeters, greater than or equal to 7.00 grams per cubic centimeters, or greater than or equal to 7.10 grams per cubic centimeters. In another aspect, the density D2 of the second material is less than or equal to 10.00 grams per cubic centimeters, such as less than or equal to 9.50 grams per cubic centimeters, less than or equal to 9.00 grams per cubic centimeters, less than or equal to 8.50 grams per cubic centimeters, less than or equal to 8.00 grams per cubic centimeters, less than or equal to 7.90 grams per cubic centimeters, less than or equal to 7.80 grams per cubic centimeters, less than or equal to 7.70 grams per cubic centimeters, less than or equal to 7.60 grams per cubic centimeters, less than or equal to 7.50 grams per cubic centimeters, less than or equal to 7.40 grams per cubic centimeters, less than or equal to 7.30 grams per cubic centimeters, or less than or equal to 7.20 grams per cubic centimeters. It is to be understood that the density D2 may be within a range between, and including, any of the minimum and maximum values of the density D2 disclosed herein.

[0085] Accordingly, the lower shroud 202 includes a low-density portion (e.g., the first lower portion 210) located rearward of the motor axis 112, i.e., on a first side, of the random orbit sander 100 in which the dust collection assembly 150 is installed and a high-density portion (e.g., the second lower portion 212) located forward of the motor axis 112, on a second side opposite the first side. Moreover, the upper shroud 204 includes at least one upper low-density portion (e.g., the first upper rearward portion 230 and/or the second upper rearward portion 240) and at least one upper high-density portion (e.g., the first upper forward portion 232 and/or the second upper forward portion 242). The least one upper high-density portion is located forward of the motor axis.

[0086] When assembled as shown in FIGS. 12 and 13, the dust collection assembly 150 has the higher density parts (e.g., the second lower portion 212, the first upper forward portion 232, and the second upper forward portion 242) forward or in front of motor axis 112. The weight displacement provided by the second lower portion 212, the first upper forward portion 232, the second upper forward portion 242, the second bracket portion 157 of the brake pad bracket 154 (not shown in FIGS. 12 and 13), or any combination thereof, shifts the center of gravity CG.sub.DCA of the dust collection assembly 150 to a second side that is forward or in front of the motor axis 112 opposite the center of gravity CG.sub.ROS of the random orbit sander 100, which as disclosed above, is located on a first side that is behind the motor axis 112, i.e., on the same side of the motor axis 112 as the handle housing 114 and the battery receptacle 118. The center of gravity CG.sub.DCA of the dust collection assembly 150 is located a distance D.sub.DCA from the motor axis 112. In a particular embodiment, the distance D.sub.DCA of the center of gravity CG.sub.DCA from the motor axis 112 is less than or equal to 61.50 mm, such as less than or equal to 61.00 mm, less than or equal to 60.00 mm, less than or equal to 59.50 mm, less than or equal to 59.00 mm, or less than or equal to 58.50 mm. In another particular embodiment, the distance D.sub.DCA of the center of gravity CG.sub.DCA from the motor axis 112 is greater than or equal to 54.00 mm, such as greater than or equal to 54.25 mm, greater than or equal to 54.50 mm, greater than or equal to 54.75 mm, greater than or equal to 55.00 mm, greater than or equal to 55.25 mm, greater than or equal to 55.50 mm, or greater than or equal to 55.75 mm. In another aspect, the distance D.sub.DCA of the center of gravity CG.sub.DCA from the motor axis 112 equal to 55.80 mm. It is to be understood that the distance D.sub.DCA may be with a range between, and including, any of the maximum and minimum values of D.sub.DCA disclosed herein. It is also to be understood that placing the higher density material forward of the motor axis 112 shifts the center of gravity CG.sub.ROS of the random orbit sander 100 forward and increases the balance of the random orbit sander 100. This, in turn, enhances the ergonomics of the random orbit sander 100 and makes the user experience with the random orbit sander 100 more pleasant. The combination of the different materials that comprise the dust collection assembly 150 also helps to dissipate static build-up in the random orbit sander 100 during use thereof. Further, by shifting the center of gravity CGROS of the random orbit sander 100 forward toward the motor axis 112, a relatively large removable battery pack may be used with the random orbit sander 100, e.g., the battery pack described herein with an energy density of approximately 395 kilojoules per kilogram.

[0087] Referring to FIG. 13, the dust collection assembly 150 further includes an edge guard slot 250 formed partially around the outer periphery of the first lower portion 210 of the lower shroud 202. The edge guard slot 250 includes an opening 252 formed in the edge guard slot 250 at each end 254 of the edge guard slot 250. FIG. 14 shows that the edge guard 160 includes a first tab 260 and a second tab 262 formed at each end 264, 266 of the edge guard 160 and extending inward from an inner lip 268 of the edge guard 160. As shown in FIG. 15, the inner lip 268 of the edge guard 160 fits into the edge guard slot 250 on the dust collection assembly 150 and the edge guard 160 may be slid into the edge guard slot 250 until the tabs 260, 262 on the edge guard 160 engage the openings 252 formed at each end 254 of the edge guard slot 250. The rigidity of the edge guard 160 acts as a spring to maintain the tabs 260, 262 in the openings 252. When fully engaged with the dust collection assembly 150, the edge guard 160 at least partially surrounds the backing pad 142 to prevent the backing pad 142 from bumping into objects extending upward from a workpiece (e.g., sidewalls inside of a cabinet). The edge guard 160 may be removed from the dust collection assembly 150.

[0088] FIGS. 16 through 22 illustrate the details of another dust collection assembly 300 that is configured to be installed within the random orbit sander 100 in lieu of the dust collection assembly 150 described above. As shown, the dust collection assembly 300 includes a lower shroud 302 and an upper shroud 304 affixed to the lower shroud 302 by one or more fasteners. The lower shroud 302 is a single monolithic piece. In other words, the lower shroud 302 is integrally formed, or molded, as a single piece. When molded as a single, monolithic piece, as shown in FIG. 17, the lower shroud 302 defines a lower portion 310 of a dust channel 312 that surrounds the dust fan 148 when the dust collection assembly 300 is installed in the random orbit sander 100.

[0089] The upper shroud 304 includes a first upper shroud half 320 and a second upper shroud half 322 affixed to the first upper shroud half 320 by one or more fasteners. When assembled, as shown in FIG. 18, the upper shroud 304, i.e., the shroud halves 320, 322 thereof, define an upper portion 324 of the dust channel 312 formed around the dust fan 148 by the dust collection assembly 300 when installed in the random orbit sander 100.

[0090] In a particular embodiment, the dust collection assembly 300 is made from different materials. For example, the lower shroud 302 and the first upper shroud half 320 are made from a first (low density) material and the second upper shroud half 322 is made from a second (high density) material. In particular, these are the same materials discussed above in conjunction with the dust collection assembly 150. In any case, the second upper shroud half 322 is heavier than the first upper shroud half 320 and acts as a static counterbalance within the random orbit sander 100.

[0091] When the dust collection assembly 300 is assembled as shown in FIGS. 20 and 21, the dust collection assembly 300 has the high-density parts, i.e., the second upper shroud half 322 and the second bracket portion 157, forward of the motor axis 112. The weight displacement provided by the second upper shroud half 322 and the second bracket portion 157 shifts the center of gravity CG.sub.DCA of the dust collection assembly 300 forward or in front of the motor axis 112 opposite the center of gravity CG.sub.ROS of the random orbit sander 100, which as disclosed above, is located behind the motor axis 112, i.e., on the same side of the motor axis 112 as the handle housing 114. The counterbalance provided by the dust collection assembly 300, the brake pad bracket 154, or a combination thereof, shifts the center of gravity CG.sub.ROS of the random orbit sander 100 forward toward the motor axis 112 from a location further away from the motor axis 112 without the counterbalance provided by the dust collection assembly 300 and the brake pad bracket 154.

[0092] By shifting the center of gravity CG.sub.ROS of the random orbit sander 100 forward toward the motor axis 112, a relatively large removable battery pack may be used with the random orbit sander 100, e.g., the battery pack described herein with an energy density of approximately 395 kilojoules per kilogram.

[0093] Referring to FIGS. 22 and 24, the dust collection assembly 300 further includes an edge guard slot 330 formed partially around the outer periphery of the lower shroud 302. The edge guard slot 330 includes a central locking post 332. A first slot portion 334 extends away from the central locking post 332 in a first direction and a second slot portion 336 extends away from the central locking post 332 in a second direction. The first slot portion 334 terminates at a first opening 338 formed at a distal end 340 of the first slot portion 334. The second slot portion 336 terminates at a second opening 342 at a distal end 344 of the second slot portion 336.

[0094] FIG. 23 shows another embodiment of an edge guard 350 that may be used with the random orbit sander 100 in lieu of the edge guard 160 described above. As shown, the edge guard 350 includes a first tab 360 and a second tab 362 that are formed at each end 364, 366 of the edge guard 160 and extend inward from an inner lip 368 of the edge guard 160. Further, the edge guard 350 includes a central clip 370 that is size and shaped to fit over and engage the central locking post 332 on the lower shroud 302 of the dust collection assembly 300 within the edge guard slot 330.

[0095] As shown in FIG. 25, the inner lip 368 of the edge guard 350 fits into the edge guard slot 330 (i.e., into the first slot portion 334 and the second slot portion 336 of the edge guard slot 330) on the dust collection assembly 300. The edge guard 350 may be slid into the edge guard slot 330 until the first tab 360 engages the first opening 338 formed at the distal end 340 of the first slot portion 334 of the edge guard slot 330 and the second tab 362 engages the second opening 342 formed at the distal end 344 of the second slot portion 336 of the edge guard slot 330. Moreover, when the edge guard 350 is installed in the edge guard slot 330, the central clip 370 of the edge guard 350 snaps over the complementarily shaped central locking post 332 located between the first slot portion 334 and the second slot portion 336. The interaction of the first tab 360 with the first opening 338, the interaction of the second tab 362 with the second opening 342, and the interaction of the central clip 370 with the central locking post 332 maintains the edge guard 350 in an engaged configuration with the dust collection assembly 300. When fully engaged with the dust collection assembly 300, the edge guard 350 at least partially surrounds the backing pad 142 to prevent the backing pad 142 from bumping into objects extending upward from a workpiece (e.g., sidewalls inside of a cabinet). The edge guard 350 may be removed from the dust collection assembly 300.

[0096] Although the disclosure has been described in detail with reference to certain preferred embodiments, variations and modifications exist within the scope and spirit of one or more independent aspects of the disclosure as described.