Angle grinder comprising a non-detachable guard

Abstract

An angle grinder includes an output shaft defining an axis of rotation, a housing extending therefrom the output shaft, and a flange coupled to the housing and surrounding the output shaft. The angle grinder further includes a first circumferential groove defined between the flange and the housing, a first array of radially outwardly extending slots in the flange and communicating with the first circumferential groove, and a keyway defined in the housing. The keyway is positioned collinear with a first radially outwardly extending slot in the first array. The angle grinder further includes a guard having a second array of radially inwardly extending protrusions and a key positionable within the keyway. The radially inwardly extending protrusions are received in the radially outwardly extending slots. The key is capable of closing the first radially outwardly extending slot in the first array to prevent removal of the guard from the housing.

Description

[0001] Cross-reference to related applications

[0002] This application claims priority to co-pending U.S. Provisional Patent Application No. 63 / 468,365, filed May 23, 2023, and co-pending U.S. Provisional Patent Application No. 63 / 483,573, filed February 7, 2023, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This utility model relates to handheld power tools, and more specifically to angle grinders. Background Technology

[0004] Power tools such as handheld angle grinders include rotating grinding tool elements or grinding discs that generate debris during operation on a workpiece. These angle grinders typically include a protective guard partially surrounding the grinding disc to protect the user from this debris. However, this guard is usually removable, exposing the entire outer circumference of the grinding disc for grinding work. Utility Model Content

[0005] In one aspect, the present invention provides an angle grinder including an output shaft defining an axis of rotation, a housing extending therefrom from the output shaft, and a flange coupled to the housing and surrounding the output shaft. The angle grinder also includes a first circumferential groove defined between the flange and the housing, a first array of radially outwardly extending slots in the flange and communicating with the first circumferential groove, and a keyway defined in the housing. The keyway is positioned collinear with a first radially outwardly extending slot in the first array. The angle grinder also includes a guard having a second array of radially inwardly extending protrusions and a key positionable within the keyway. The second array of radially inwardly extending protrusions is received in the first array of radially outwardly extending slots. The key is capable of closing the first radially outwardly extending slot in the first array to prevent removal of the guard from the housing.

[0006] On the other hand, the present invention provides an angle grinder including an output shaft defining a rotation axis, a housing extending therefrom the output shaft, and a flange connected to the housing and surrounding the output shaft. The angle grinder also includes a first circumferential groove defined between the flange and the housing, radially outwardly extending slots of a first array in the flange and communicating with the first circumferential groove, and a guard including a second array of inwardly extending protrusions. The inwardly extending protrusions of the guard are configured to receive in the radially outwardly extending slots of the first array. The angle grinder further includes a first stop disposed on the housing and a second stop formed on the guard and engageable with the first stop. The second stop engages the first stop to prevent the radially inwardly extending protrusions of the second array from realigning with the radially outwardly extending slots of the first array, thereby preventing removal of the guard from the housing.

[0007] On the other hand, the present invention provides an angle grinder including an output shaft defining a rotation axis, a housing extending therefrom the output shaft, a guard coupled to the housing and partially surrounding the output shaft, and a guard locking flange coupled to the housing. The guard locking flange is permanently affixed to the housing and configured to axially retain the guard to the housing.

[0008] Other aspects of this invention will become apparent from the detailed description and accompanying drawings. Attached Figure Description

[0009] Figure 1 This is a perspective view of an angle grinder according to an embodiment of the present invention.

[0010] Figure 2 yes Figure 1 An exploded perspective view of an angle grinder, showing the protective element and the key used to axially secure the protective element to the gearbox cover of the angle grinder.

[0011] Figure 3 yes Figure 1 An exploded perspective view of an angle grinder, showing a latch plate used to rotate and lock the protective element.

[0012] Figure 4 yes Figure 2 A partially assembled perspective view of the gearbox cover, guard, and key, showing the key removed from the gearbox cover.

[0013] Figure 5 yes Figure 2 A perspective view of the gearbox cover, showing the key in its installed position.

[0014] Figure 6A This is a partially assembled perspective view of an angle grinder according to another embodiment of the present invention, showing a key removed from the gearbox cover.

[0015] Figure 6B yes Figure 6A A perspective view of an angle grinder, showing the key in its installed position.

[0016] Figure 7 yes Figure 6B A cross-sectional view of an angle grinder, showing the key in its installed position.

[0017] Figure 8A This is a partially assembled perspective view of an angle grinder according to another embodiment of the present invention, showing a key removed from the gearbox cover.

[0018] Figure 8B yes Figure 8A A perspective view of an angle grinder, showing the key in its installed position.

[0019] Figure 9A This is a perspective view of an angle grinder according to another embodiment of the present invention.

[0020] Figure 9B yes Figure 9A An enlarged view of the angle grinder shows the stop on the rotatable guard that engages the anti-stop.

[0021] Figure 10 This is a perspective view of an angle grinder according to another embodiment of the present invention, showing a protective element and a protective element locking flange.

[0022] Figure 11 This is an enlarged sectional view of an angle grinder according to another embodiment of the present invention, showing a roller pin and a rotatable protective flange mounted in the gearbox cover.

[0023] Before explaining any embodiment of this utility model in detail, it should be understood that the application of this utility model is not limited to the details of the construction and arrangement of the components described in the following description or shown in the drawings. This utility model can have other embodiments and can be practiced or implemented in various ways. Furthermore, it should be understood that the wording and terminology used in this utility model are for illustrative purposes and should not be considered restrictive. Detailed Implementation

[0024] Figure 1A handheld power tool, such as an angle grinder 100, is shown, comprising a housing 104 that simultaneously defines a motor housing portion 114 and a gearbox portion 116 mounted to the front end of the motor housing portion 114. In the illustrated embodiment, the gearbox portion 116 includes a gearbox 118 and a gearbox cover 120, the gearbox cover 120 being fastened to the gearbox 118 by a plurality of gearbox fasteners 121. The angle grinder 100 also includes an output shaft 122 extending from the gearbox portion 116 along a rotation axis 126 perpendicular to a longitudinal axis 128 defined by the motor housing portion 114. The output shaft 122 is driven by a motor (not shown) positioned within the motor housing portion 114, and a gear train (also not shown) is positioned within the gearbox portion 116 for transmitting torque from the motor to the output shaft 122. A grinding disc or grinding wheel (not shown) may be mounted to the output shaft 122 to rotate with it about the rotation axis 126.

[0025] See Figure 2 The gearbox cover 120 includes a flange 130 extending therefrom and surrounding a rotation axis 126. In some embodiments, the gearbox portion 116 and the motor housing portion 114 may be integrally formed as a single piece, wherein the flange 130 is also integral with the housing 104. In other embodiments, the flange 130 may be a separate component and may be selectively coupled to the housing 104. The flange 130 includes an array of six radially outwardly extending slots 138 and a keyway 139 that coincides with or is inline with the first of the slots 138. The gearbox cover 120 defines a circumferential recess 134 below and adjacent to the flange 130, which allows the slots 138 to communicate with the circumferential recess 134. One of the slots 138 has a wider width than the remaining slots 138 and thus serves as an alignment slot 142, as explained in detail below. In other embodiments of the angle grinder 100, the flange 130 may include more or fewer slots 138. Furthermore, as explained in detail below, the keyway 139 is shaped to receive the key 141, which is used to axially hold the guard 146 to the gearbox cover 120.

[0026] See also Figure 2When the grinding disc is mounted to the output shaft 122, the guard 146 partially surrounds the grinding disc (not shown). Furthermore, the guard 146 is rotatable relative to the gearbox cover 120 to adjust the orientation of the guard 146 relative to the housing 104 and expose different areas of the grinding disc required for grinding operations. The guard 146 includes an array of six radially inwardly extending protrusions 150 and five holes 155 radially positioned around the guard 146. One of the protrusions 150 has a wider width than the others and thus serves as an alignment protrusion 158 to be received within an alignment slot 142 in the flange 130. When the alignment protrusion 158 is aligned with the alignment slot 142, the protrusions 150 on the guard 146 are aligned with the slot 138 in the flange 130 and can therefore be received through the slot 138 in the flange 130. After the protrusion 150 is inserted into the slot 138, the guard 146 is lowered until the protrusion 150 reaches the circumferential recess 134. Thereafter, the guard 146 can be rotated about the axis of rotation 126 so that the protrusion 150 is no longer aligned with the slot 138, thereby axially securing the guard 146 to the gearbox cover 120. Therefore, the guard 146 can only be removed from the circumferential recess 134 when the aligned protrusion 158 is realigned with the aligned slot 142, at which point the remaining portion of the protrusion 150 will become realigned with the corresponding slot 138.

[0027] See Figure 3The angle grinder 100 further includes a latch plate 162 for rotatably securing the guard 146 relative to the gearbox cover 120 to a desired orientation. The latch plate 162 includes an actuating portion 170 and a stop member 174. A compression spring 182 is positioned between spring seats 186 on the gearbox cover 120 and biases the stop member 174 toward the guard 146. In the illustrated embodiment, the spring seats 186 are recesses, and the compression spring 182 is positioned within the spring seats 186. In an alternative embodiment, the spring seats may be posts, and the compression spring 182 may be positioned and disposed around a post. The stop member 174 may be received in one of five holes 155 in the guard 146 to rotatably secure the guard 146 relative to the gearbox cover 120. As described above, when the guard 146 is mounted on the gearbox cover 120, the latch plate 162 is biased by the spring 182 to position the stop member 174 in one of the holes 155. By applying a force to the actuating portion 170 of the latch plate 162 in a direction away from the guard 146, the stop member 174 is removed from one of the holes 155 in the guard 146. The applied force removes the stop member 174 from one of the holes 155, after which the guard 146 can be freely rotated about the axis of rotation 126 to different rotational positions relative to the gearbox cover 120. Upon release of the actuating portion 170, the spring 182 rebounds and pushes the stop member 174 back toward the guard 146, thereby positioning the stop member 174 in the next hole 155 encountered as the guard 146 continues to rotate to the desired position.

[0028] See Figure 4 and Figure 5 When installed in the keyway 139, the key 141 prevents the guard 146 from being removed from the gearbox cover 120. In practice, the guard 146 is installed as detailed above, and then rotated until either protrusion 150 no longer obstructs the keyway 139, as... Figure 4 As shown, the keyway 139 is aligned with the slot between the two adjacent protrusions 150. When the keyway 139 is not obstructed, the key 141 can be inserted into the keyway 139. Once installed in the keyway 139, the key 141 can be secured to the gearbox cover 120 via a fastener or pin (not shown) to make it difficult for an unauthorized user to remove the key 141. The fastener or pin (not shown) is installed on the gearbox cover 120 using a tool (e.g., a hexagonal actuator). Figure 5 It is inserted into hole 184 in the key 141 and fixed thereto. Figure 4 The corresponding holes 188 are already aligned in the rotation axis 126. In some embodiments, the holes 184 are oriented transversely to the rotation axis 126. When the key 141 is installed, one of the slots 138 is connected to the flange portion 190 of the key 141. Figure 5The stop member 174 prevents any protrusion 150 from exiting through its designated slot 138. Therefore, the guard 146 can be prevented from being removed from the gearbox cover 120 at any time. However, since the key 141 includes a circumferential groove 192 that aligns with and has the same thickness as the circumferential groove 134 in the gearbox cover 120, rotational adjustment of the guard 146 is unimpeded. Thus, the guard 146 can rotate freely when the stop member 174 is removed from the hole 155.

[0029] exist Figure 6A , 6B Alternative embodiments of the angle grinder 500 are shown in Figures 7 and 8, wherein the same reference numerals are used to indicate the same features as those in the figures 7. Figure 1-5 The angle grinder 100 shown has the same features. In the illustrated embodiment, the guard 146 is still rotatable about the axis of rotation 126, but is not removable. As described above, the guard 146 is installed in a manner similar to that of the angle grinder 100. However, the key 541 does not include a hole, but instead includes a plurality of recesses 543, and corresponding fasteners (e.g., fixing screws 548) are clamped against the recesses 543 using a tool (e.g., a hex screwdriver). Each recess 543 includes an angled surface 544 and an adjacent bottom surface 545, such as Figure 7 As shown. When key 541 is installed in keyway 539, recess 543 aligns with a plurality of holes 584 formed in gearbox cover 520. Holes 584 are threaded, and each hole 584 receives a retaining screw 548 inserted into one of the recesses 543. In the illustrated embodiment, retaining screw 548 has a tapered end 547. When key 541 is not fully installed, the tapered end 547 of retaining screw 548 contacts angled surface 544. As retaining screw 548 is screwed further in, the tapered end 547 moves along angled surface 544, which in turn moves key 541 further into keyway 539. Key 541 is considered fully installed when key 541 contacts bottom 550 of keyway 539 and the tapered end 547 of retaining screw 548 contacts both bottom surface 545 and angled surface 544.

[0030] Figure 8A and 8B Alternative embodiments of key 541B and gearbox cover 520B are shown. Key 541B includes a single recess 543 that can receive a retaining screw 548. The retaining screw 548 can be received through a hole 584 in gearbox cover 520B.

[0031] exist Figures 9A-9B An alternative embodiment of the angle grinder 300 is shown, which is consistent with the one in the diagram. Figure 1-5The same features as those shown in the angle grinder 100 are indicated by the same reference numerals. In the illustrated embodiment, the guard 146 remains rotatable but not removable. The guard 146 is mounted in a manner similar to that of the angle grinder 100 described above. However, due to the interaction between the first stop 393 and the guard 146, the guard 146 cannot be removed from the gearbox cover 120. Figure 9B As shown, the first stop 393 has an L-shaped cross-section and is attached to the gearbox cover 120 by a fastener or pin (not shown) that is not easily removed. When installed, a second stop 394 (e.g., a radially outwardly extending protrusion) formed on the guard 146 contacts a notch 395 defined on the first stop 393 to prevent the guard 146 from rotating beyond a certain angle. Therefore, the guard 146 cannot be removed from the gearbox cover 120 because the protrusion 150 cannot be aligned with its corresponding slot 138.

[0032] Figure 10 An alternative embodiment of the gearbox cover 420 is shown, compared with... Figure 1-5 The same features as the gearbox cover 120 shown are indicated by the same reference numerals. In the illustrated embodiment, the guard 146 is axially held by a guard locking flange 498. The guard locking flange 498 holds the guard 146 to the gearbox cover 420 by a pair of reverse threads, a press fit, a roll pin, or a combination of all three, connected to a hub 499 on the gearbox cover 420. In the illustrated embodiment, the guard locking flange 498 includes a set of male reverse threads (not shown), while the hub 499 of the gearbox cover 420 includes a set of corresponding internal threads (not shown). If the guard locking flange 498 is mounted on the hub 499 of the gearbox cover 420, the guard locking flange 498 cannot be removed, and the rotatable guard 146 is axially held. In another embodiment, the guard locking flange 498 is press-fitted to the hub 499 of the gearbox cover 420. Once press-fitted, the guard locking flange 498 cannot be removed, and thus the guard 146 is axially held.

[0033] Figure 11 Alternative embodiments of the gearbox cover 620 and the protective locking flange 698 are shown. The gearbox cover 620 and the protective locking flange 698 include... Figure 10The gearbox cover 420 and the guard locking flange 498 shown are indicated by the same reference numerals and have the same features. In the illustrated embodiment, the guard 146 is axially held by the guard locking flange 698. To axially secure the guard 146, the guard 146 is first installed in the circumferential recess 634. Next, the guard locking flange 698 is press-fitted into the gearbox cover 620 above the guard 146, thereby permanently attaching the guard locking flange 698 to the angle grinder housing. Once the guard locking flange 698 is fully installed in the gearbox cover 620, a pin 652 press-fits through a first pin opening 654 in the gearbox cover 620 and then through a second pin opening 656 in the guard locking flange 698. The press-fit pin 652 then prevents the removal of the guard locking flange 698 and the guard 146 while still allowing the guard 146 to rotate in the circumferential recess 634. In other embodiments, the gearbox cover 620 and the protective locking flange 698 may be threaded together prior to the insertion pin 652.

[0034] Although the present invention has been described in detail with reference to certain preferred embodiments, variations and modifications may still exist within the scope and spirit of one or more independent aspects of the present invention.

[0035] The various features and advantages of this utility model are set forth in the appended claims.

Claims

1. An angle grinder, comprising: Output shaft, which defines an axis of rotation; Housing, from which the output shaft extends; A flange, which is coupled to the housing and at least partially surrounds the output shaft; A first circumferential groove is defined between the flange and the housing; The first array of radially outward extending slots is defined in the flange, and each slot in the first array communicates with the first circumferential groove. A keyway, defined in the housing and positioned collinear with one of the radially outwardly extending slots in the first array; A protective member, the protective member including a second array of radially inwardly extending protrusions, the second array of radially inwardly extending protrusions being configured to be received in a radially outwardly extending slot of the first array; and A key, which can be positioned within the keyway to close one of the radially outwardly extending slots in the first array, to prevent the protective element from being removed from the housing.

2. The angle grinder of claim 1, characterized in that The radially inwardly extending protrusions of the second array include at least one alignment protrusion, wherein the alignment protrusion has a wider width than the rest of the radially inwardly extending protrusions.

3. The angle grinder of claim 2, wherein The radially outward extending slot of the first array includes at least one alignment slot, wherein the alignment slot has a wider width than the rest of the radially outward extending slot, and wherein when the alignment protrusion is aligned with the alignment slot, the radially inward extending protrusion on the guard is aligned with the radially outward extending slot in the flange and can be received by the radially outward extending slot in the flange.

4. The angle grinder of claim 1, wherein The key includes a second circumferential groove, in which the radially inwardly extending protrusions in the second array can move when the rotational orientation of the protective member relative to the housing is adjusted.

5. The angle grinder of claim 4, wherein The first circumferential groove in the housing and the second circumferential groove in the key have equal thicknesses.

6. The angle grinder of claim 1, wherein The key includes a flange portion that, when the key is positioned in the keyway, is received within one of the radially outwardly extending slots in the first array, and wherein the flange portion of the key and the flange have equal thickness.

7. The angle grinder of claim 1, wherein The housing includes a hole configured to receive a fastener to secure the key within the keyway.

8. The angle grinder of claim 7, wherein The hole is oriented laterally to the axis of rotation.

9. The angle grinder of claim 7, wherein The fastener is a pin, and the key includes a corresponding receiving hole aligned with the hole in the housing.

10. The angle grinder of claim 7, wherein The fastener is a fixing screw, and the key includes a notch aligned with the hole in the housing.

11. The angle grinder of claim 10, wherein The notch includes a bottom surface and an angled surface.

12. The angle grinder of claim 11, wherein, The fastener can engage with the angled surface of the notch at a first position of the key within the keyway.

13. The angle grinder of claim 11, wherein, The fastener can engage with the bottom surface of the notch and the angled surface of the key in the second position of the key within the keyway.

14. An angle grinder, comprising: Output shaft, which defines an axis of rotation; Housing, from which the output shaft extends; A flange, which is coupled to the housing and at least partially surrounds the output shaft; A circumferential groove, the circumferential groove being defined between the flange and the housing; The first array of radially outward extending slots is defined in the flange, and each radially outward extending slot in the first array communicates with the circumferential groove. A protective member, the protective member including a second array of radially inwardly extending protrusions, the second array of radially inwardly extending protrusions being configured to be received in a radially outwardly extending slot of the first array; A first stop is disposed on the housing; and A second stop, formed on the protective member and engageable with the first stop, prevents the realignment of the radially inwardly extending protrusions of the second array with the radially outwardly extending slots of the first array, and the subsequent removal of the protective member from the housing.

15. The angle grinder of claim 14, wherein, The first stop has an L-shaped cross-section.

16. The angle grinder of claim 14, wherein, After the protective member is installed on the housing, the first stop is fastened to the housing.

17. The angle grinder of claim 14, wherein, The second stop is a radially outwardly extending protrusion.

18. The angle grinder as described in claim 14, characterized in that, The first stop includes a notch configured to receive the second stop.

19. An angle grinder, comprising: Output shaft, which defines an axis of rotation; Housing, from which the output shaft extends; A protective element, which is coupled to the housing and partially surrounds the output shaft; and A protective locking flange is coupled to the housing, the protective locking flange is permanently attached to the housing and configured to axially hold the protective element to the housing.

20. The angle grinder of claim 19, wherein the protective locking flange includes a first pin opening and the housing includes a second pin opening, and wherein the angle grinder further includes a pin press-fitted to the first pin opening and the second pin opening and cannot be removed from the first pin opening and the second pin opening to permanently attach the protective locking flange to the housing.

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