Rotary hydraulic valve

Abstract

A power tool includes a manifold, a pump housing coupled to the manifold, and a camshaft that is supported by the pump housing. A drive sprocket is positioned in the manifold and has a first end that is coupled to the distal end of the camshaft. The drive sprocket includes a plurality of pawls. A sprocket bearing is coupled between a second end of the drive sprocket and the manifold, and a valve body having a first drive member and a second drive member. The valve body rotates in a first direction when the plurality of pawls engages the first drive member and rotates in a second direction when the plurality of pawls engages the second drive member.

Description

Attorney Docket No. 660114.0132976237- 1001 -WO01ROTARY HYDRAULIC VALVERELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 680,023, filed August 6, 2024, which is incorporated herein by reference in its entirety7.BACKGROUND

[0002] Crimpers and cutters often include a crimping head with opposed jaws that include certain crimping and cutting features, depending on the particular configuration of the tool. Some crimpers and cutters are hydraulic power tools that include a piston that can exert force on the crimping or cutting head, which may be used for closing the jaws to perform crimp, compression, or cutting work at a targeted location. A valve can be used to direct hy draulic fluid, including high pressure hydraulic fluid, in and out of chambers of the piston.SUMMARY

[0003] Examples of the invention provide systems and methods of valve assemblies that can be used in hydraulic circuits.

[0004] In some aspects, a power tool can include a manifold and a pump housing coupled to the manifold. A camshaft can be supported by the pump housing, with the camshaft having a distal end that extends. A drive sprocket can be positioned in the manifold, with the drive sprocket having a first end that can be coupled to the distal end of the camshaft. The drive sprocket can include a plurality of pawls. A sprocket bearing can be coupled between a second end of the drive sprocket and the manifold. A valve body can have a first drive member and a second drive member, with the valve body rotating in a first direction when the plurality7of pawls engages the first drive member and the valve body rotating in a second direction when the plurality of pawls engages the second drive member.

[0005] In some examples, the plurality7of pawls can include a first set of pawls that engage the first drive member and a second set of pawls that engage the second drive member, with the first set of pawls being axially spaced from the second set of pawls.

[0006] In some examples, the valve assembly can define a first pin that can be received in a first bore defined in the pump housing, and the valve assembly can define a second pin that can be received in a second bore defined in the manifold.

[0007] In some examples, the second pin can be coupled to a shaft of the valve body and the first pin can be formed as a unitary component with the shaft.QB\97854476.2 1Attorney Docket No. 660114.0132976237- 1001 -WOOl

[0008] In some examples, a valve body can include a bushing positioned between the first drive member and the pump housing.

[0009] In some examples, the second drive member can include an orifice that can be aligned with a seal in a first rotational position and that can be unaligned from the seal in a second rotational position, with the seal received in a cavity' defined in the manifold.

[0010] In some examples, the second end of the drive sprocket can define a pin that can be received in the sprocket bearing.

[0011] In some examples, a fastener can be inserted through a bore in the drive sprocket to engage the camshaft, with the drive sprocket trapped between a head of the fastener and the camshaft.

[0012] In some examples, the fastener can be a pin that forms a press fit connection with the camshaft.

[0013] In some examples, the first end of the drive sprocket can define a recess that receives the camshaft.

[0014] In some examples, the plurality’ of pawls can include a first set of pawls that can be retained in the drive sprocket by the sprocket bearing, and a second set of pawls that can be retained in the drive sprocket by a washer that can be positioned between a body of the drive sprocket and the camshaft.

[0015] In some examples, the camshaft can define a recess that receives the first end of the drive sprocket.

[0016] In some examples, the plurality' of pawls can include a first set of pawls that can be retained in the drive sprocket by a first retainer that can be positioned between the sprocket bearing and a body of the drive sprocket, and a second set of pawls that can be retained by a second retainer that can be positioned between the body of the drive sprocket and the camshaft.

[0017] In some examples, the first retainer can be a snap ring and the second retainer can be a snap ring.

[0018] In some examples, the second drive member can define a peninsula-shaped portion defining a drive portion on one lateral side and a stop portion on an opposite lateral side, with the stop portion configured to engage a stopper of the manifold to prevent rotation of the valve body.

[0019] In some aspects, a method of assembling a power tool can include coupling a first end of a drive sprocket to camshaft that can be rotatably coupled to a pump housing. The method can include inserting a valve body into a recess defined in a manifold. The method canQB\97854476.2 2Attorney Docket No. 660114.0132976237- 1001 -WO01 include coupling the pump housing with the drive sprocket to the manifold so that the drive sprocket can be received in the recess.

[0020] In some examples, the method can further include coupling a sprocket bearing to a second end of the drive sprocket, with the sprocket bearing retaining a first set of pawls in a body of the drive sprocket.

[0021] In some examples, the method can further include inserting a pin through a bore defined in the drive sprocket, with the pin engaging the camshaft with a press-fit connection.

[0022] In some examples, the method can further include coupling a retainer to the first end of the drive sprocket, with the retainer retaining a second set of pawls in the body of the drive sprocket, and the second set of pawls being axially spaced from the first set of pawls.

[0023] In some examples, the retainer can be a washer that can be received on the camshaft.BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The accompanying drawings, which are incorporated in and form a part of this specification, illustrate examples of the invention and, together with the description, serve to explain the principles of examples of the invention:

[0025] FIG. 1 is an axonometric view of a valve assembly according to an example of the invention.

[0026] FIG. 2 is an exploded axonometric view of the valve assembly of FIG. 1.

[0027] FIG. 3 is an axonometric view of a sprocket and rotary valve system of the valve assembly of FIG. 1.

[0028] FIG. 4 is a cross-sectional side view of the valve assembly of FIG. 1, taken at 1-1.

[0029] FIG. 5 is an axonometric view of the sprocket and rotary' valve system in a pressure holding position, including a partial cross-sectional view of the sprocket bearing of the systems.

[0030] FIG. 5 A is a perspective view of the sprocket and rotary valve system in a pressure holding position, including a plurality pawls in an extended configuration.

[0031] FIG. 5B is a perspective view of the sprocket and rotary valve system in a pressure holding position, including another plurality' of pawls in an extended configuration.

[0032] FIG. 6 is an axonometric view of the sprocket and rotary valve system in a pressure dump position, including a partial cross-sectional view of the sprocket bearing of the systems.

[0033] FIG. 7 is an axonometric view of a rotary' valve body of the valve assembly of FIG.1.

[0034] FIG. 8 is an axonometric view of the rotary' valve body within a manifold of the valve assembly.QB\97854476.2 3Attorney Docket No. 660114.0132976237- 1001 -WOOl

[0035] FIG. 9 is an axonometric view of a valve assembly according to another example of the invention.

[0036] FIG. 10 is an exploded view of a valve assembly according to another embodiment of the invention.

[0037] FIG. 11 is an axonometric view of a sprocket and rotary valve system of the valve assembly of FIG. 10.

[0038] FIG. 12 is a cross-sectional side view of the valve assembly of FIG. 10.

[0039] FIG. 13 is an exploded view of a valve assembly according to another example of the invention.

[0040] FIG. 14 is an axonometric view of a sprocket and rotary valve sy stem of the valve assembly of FIG. 13.

[0041] FIG. 15 is a cross-sectional side view of the valve assembly of FIG. 13.

[0042] FIG. 16 is an example tool that utilizes the valve assembly of FIG. 1DETAILED DESCRIPTION

[0043] The following discussion is presented to enable a person skilled in the art to make and use examples of the invention. Various modifications to the illustrated examples will be readily apparent to those skilled in the art, and the generic principles herein can be applied to other examples and applications without departing from examples of the invention. Thus, examples of the invention are not intended to be limited to examples shown, but are to be accorded the widest scope consistent with the principles and features disclosed herein. The following detailed description is to be read with reference to the figures, in which like elements in different figures have like reference numerals. The figures, which are not necessarily to scale, depict selected examples and are not intended to limit the scope of examples of the invention. Skilled artisans will recognize the examples provided herein have many useful alternatives and fall within the scope of examples of the invention.

[0044] Before any examples of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the attached drawings. The invention is capable of other examples 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. For example, the use of “including,"’ “comprising,’" or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items.QB\97854476.2 4Attorney Docket No. 660114.0132976237- 1001 -WO01

[0045] As briefly described above, certain hydraulic tools can be used to perform cuts crimps, or press work, such as on a cable or connector, for example. Generally, hydraulic tools include a cylinder and piston configuration, where the piston is configured to extend and retract within the cylinder, and thus, move jaws, or any other implement coupled to the piston to perform a task (crimping, cutting, etc.). Hydraulic fluid can be directed in and out of chambers of the cylinder and piston configuration to cause the piston to extend and retract. The hydraulic fluid can be directed by a valve, such as a rotary valve.

[0046] Some examples of the invention provide a rotary shear seal valve. More particularly, some examples of the invention provide a compact or miniature shear seal valve. For example, examples of the invention provide a shear seal valve that may be approximately 20% smaller than conventional valves. This allows for a smaller, more compact hydraulic tool that includes less material and is lighter weight. In general, a shear seal valve can be used to hold pressure within a piston configuration of a tool so that the tool can perform work. The shear seal valve can then release pressure when desired (e.g., instructed) or once the work has been performed.

[0047] A shear seal valve system can include several subassembly components and may benefit from simplified and streamlined assembly processes. For example, a shear seal valve system can include a valve subsystem, a pump subassembly, and a manifold subassembly. The pump subassembly and manifold subassembly can generally house the valve assembly. Furthermore, the pump subassembly can support and facilitate coupling of a cam shaft (e.g., of a tool) with a sprocket of the valve assembly and the manifold subassembly can support and facilitate fluid flow through the valve system and the tool.

[0048] In general, examples of the invention provide a compact miniature shear seal valve system that can be used in smaller and lighter weight hydraulic tools compared to conventional shear seal valves. Other advantages of examples of the valve system described herein include pre-assembled subassemblies that can be assembled with minimal alignment requirements and poka-yoke configuration.

[0049] Examples of the shear seal valve described herein include a valve assembly having a sprocket. In use, the sprocket can rotate causing pawls of the sprocket to move radially outward due to centrifugal force. Based on the direction of rotation of the sprocket, a pawl can engage with the rotary valve to rotate the valve. This rotation of the rotary valve can align a pressure line with a metallic face seal holding the pressure. Or the rotation can align the pressure line with a cross hole of the rotary valve to dump or vent pressure to the atmosphere.QB\97854476.2 5Attorney Docket No. 660114.0132976237- 1001 -WOOl

[0050] With reference now to the figures, FIGS. 1 and 2 illustrate a shear seal valve system that includes a valve assembly 100. The valve assembly 100 can be incorporated into different ty pes of power tools to control fluid flow therein. In some examples, the valve assembly 100 can be incorporated into a power tool 101, such as the tool illustrated in FIG. 16.

[0051] Referring again to FIGS. 1 and 2, the valve assembly 100 includes a housing formed at least partially by a pump housing 102 and a manifold 104. Each of the pump housing 102 and the manifold 104 house and support a valve subsystem 106 therein. The manifold 104 can include a plurality of conduits used to direct fluid (e.g., hydraulic fluid) within a system, such as ahydraulic tool. As illustrated in FIGS. 2 and 4, the pump housing 102 supports and partially houses a camshaft 112 that is configured to provide rotary action to a drive sprocket 114 of the valve subsystem 106.

[0052] As shown in FIGS. 3 and 4, the drive sprocket 114 can be secured to the camshaft 112. In the illustrated example, a distal end of the camshaft 112 is secured to a distal end of the drive sprocket 114. The camshaft 112 can be press-fit into a recess of the sprocket 114 to mechanically couple the camshaft 112 and the drive sprocket 114. In the illustrated example, and the other examples described herein, the camshaft 112 does not extend through the entirety (or the even the majority7) of the drive sprocket 114 in an axial direction, that extends through a center of the camshaft 112, or a center of rotation of the camshaft 112. In some conventional shear seal valves, a camshaft extends through the entire body of a sprocket and requires a bearing or other support at or near the end of the sprocket that sits in the manifold. Advantageously, the camshaft 1 12 does not require a bearing or support within the manifold 104 beyond the engagement with the sprocket 114. In general, having a relatively shorter camshaft 112 compared to some conventional valves can reduce weight, material / parts cost, and assembly time.

[0053] In some examples, the recess of the sprocket 114 may define a variable diameter between a first axial end of the sprocket 114 (e.g., where the camshaft 112 is inserted), and a second axial end of sprocket 114, opposite the first axial end. For example, an opening 133 of the recess of the sprocket 114 may be larger at the first axial end than at the second axial end. In such examples, the camshaft 112 may only fit in the opening 133 at the first axial end. Furthermore, in such examples, the variable width of the recess of the sprocket 114 may ensure that the sprocket 113 and that camshaft 112 can be easily and reliably assembled without assembly mistakes. As described below, in some examples, a pin can be inserted into theQB\97854476.2 6Attorney Docket No. 660114.0132976237- 1001 -WOOl opening at the second axial end and through the recess to couple the camshaft 112. In such examples, the pin may aid the coupling of the sprocket 114 to the camshaft 112.

[0054] With continued reference to FIGS. 3 and 4. the drive sprocket 1 14 can include a plurality of drive pawls 120 mounted (e g., pivotably coupled) to a sprocket body 115. The pawls 120 are configured to interact with drive members 122, 124 of the valve body 126. In the illustrated example, the drive sprocket 114 includes two rows 128, 130 of drive pawls 120 (e.g.. a first plurality of drive pawls and a second plurality of drive pawls). The first row 128 includes two drive pawls 120 and the second row 130 includes four drive pawls 120. The first row 128 and the second row 130 can be axially offset from one another relative to the axial direction. The first row 128 of drive pawls 120 are configured to engage the first drive member 122 of the valve body 126 when the drive sprocket 114 is rotated in a first direction and the second row 130 of drive pawls 120 are configured to engage the second drive member 124 of the valve body 126 when the drive sprocket 114 is rotated in a second direction (see for example FIGS. 5 A and 5B).

[0055] The pawls 120 are pivotably coupled to the drive sprocket 114 (i.e., allowed to pivot relative to the drive sprocket 114) so that the pawls 120 can move radially outward due to a centrifugal force when the drive sprocket 114 rotates. In use, when the drive sprocket 114 rotates in a first direction, the first row 128 of pawls 120 are configured to engage the first drive member 122 of the valve body 126 and when the drive sprocket 114 rotates in a second direction, the second row 130 of pawls 120 are configured to engage the second drive member 124 of the valve body 126 (see for example FIGS. 5A and 5B).

[0056] As mentioned above, the pawls 120 can be pivotably coupled to the sprocket body 115. In the illustrated example, the pawls 120 are received in recesses 116 in the sprocket body 115. The pawls 120 and the recesses 116 are correspondingly shaped to allow the pawls to pivot within the recesses 116 in response to rotation of the drive sprocket 114. Correspondingly, the pawls 120 can be retained within the recesses by one or more retainers. For example, as shown in FIG. 5, the first plurality of pawls 128 are retained within respective recesses 116 by a first retainer 129 (e g., a washer) and the second plurality of pawls are retained within the respective recesses 116 by a second retainer 131. In other examples, the pawls 120 can be secured to the sprocket body 115 differently, for example, via a pinned connection, a hinge, etc. In some cases, the first retainer 129 can be shaped to key to the camshaft 112 and / or to allow the camshaft 112 to key with the opening 133 defined in the sprocket body 115. e.g., at the first axial end of the sprocket 114 (see FIG. 4). In the illustratedQB\97854476.2 7Attorney Docket No. 660114.0132976237- 1001 -WOOl example, the first retainer 129 and the opening 133 are D-shaped to receive a correspondingly shaped end of the camshaft 112 so that the drive sprocket is rotationally coupled to rotate with the camshaft 112.

[0057] As shown in FIGS. 5-6, the valve body 126 may rotate around a pin or a valve rotational axis. In some examples, the valve body 126 loosely defines a cylindrical geometry7. For example, a cross-sectional shape of the valve body 126 taken radially relative to the valve rotational axis can generally be circular. Referring specifically to FIGS. 5-6, the valve body 126 may include a first valve body section 126a and a second valve body section 126b. The first valve body section 126a can extend axially from the second valve body section 126b.

[0058] In the illustrated example of FIG. 5 A, the first valve body section 126a can include the first drive member 122 that is configured to engage the first row of pawls 128. In some examples, a cross-sectional shape of the first valve body section 126a taken radially relative to the valve rotational axis can generally be circular defining a circular perimeter. However, the first valve body section 126a can include a first recess 127a that extends into the first valve body section 126a from a perimeter thereof. The first recess 127a can be wedge shaped, such that the first valve body section 126a resembles a pac-man (or a sector shape) having rounded comers or edges. The first drive member 122 can extend along a surface of the first recess 127a. In some examples, the first recess 127a extending into the first valve body section 126a may reduce a footprint of the valve body 126. For example, the first drive member 122 may be formed along a solid side of the first recess 127 a, instead of along a projection of the first valve body section 126a, thus decreasing a width or diameter of the first valve body section 126a. Furthermore, in such examples, no component of the first valve body section 126a may extend beyond the circular perimeter defined by the first valve body section 126a.

[0059] In the illustrated example, the second valve body section 126b can include the second member 124 that is configured to engage the second row of pawls 130. In some examples, a cross-sectional shape of the second valve body section 126b taken radially relative to the valve rotational axis can generally be circular defining a circular perimeter. However, the second valve body section 126b can include a second recess 127b and a third recess 127c that each extend into the second valve body section 126b from a perimeter thereof. The second recess 127b can be arc shaped. More specifically, the second recess 127b can be a curvilinear quadratic shape (e.g., a shape having first opposing curved sides that are connected at either end by second opposing sides, which may be curved or straight - in the present example, the first curved sides can be substantially parallel to one another and can be convex relative to theQB\97854476.2 8Attorney Docket No. 660114.0132976237- 1001 -WOOl valve rotational axis). In some examples, the second drive member 124 can be formed along a solid side of the second recess 127b.

[0060] The third recess 127c can also be a curvilinear quadratic shape (e.g.. a shape having first opposing curved sides that are connected at either end by second opposing sides, which may be curved or straight - in the present example, the first curved sides can be substantially parallel to one another and can be convex relative to the valve rotational axis). In some examples, as described further below, a stop member 152 can be formed along a solid side of the third recess 127c.

[0061] In such examples, the second recess 127b and the third recess 127c may form a projection 127d therebetween. For example, the projection 127d can extend from a center of the second valve body section 126b toward the circular perimeter thereof between the second and third recesses 127b, 127c. In some examples, the second drive member 124 and the stop member 152 can be formed on opposing surfaces of the projection 127d.

[0062] In some examples, the projection 127d may be radially aligned with the first recess 127a relative to the valve rotational axis. In such examples, a line extending parallel to the valve rotational axis and through the projection 127d may pass through the first recess 127a. In such examples, the members 122, 124, 152 may be only slightly circumferentially offset from one another about the valve rotational axis, potentially reducing an amount of the valve body 126 need rotate about the valve rotational axis during regular operation.

[0063] In some examples, the second and third recesses 127b, 127c extending into the second valve body section 126b to form the projection 127d can reduce a footprint of the valve body 126. For example, the members 124, 152 being formed along solid sides of the recesses 127b, 127c, instead of along a projection of the second valve body section 126b, can decrease a width or diameter of the second valve body section 126b. In such examples, no component of the second valve body section 126b, including the projection 127d, may extend beyond the circular perimeter defined by the second valve body section 126b.

[0064] In some examples, the valve body 126 may define a diameter that is less than a diameter of the thrust bearing 138. In such examples, each of the first and second valve body sections 126a, 126b may define a define a diameter that is less than the diameter of the thrust bearing 138.

[0065] As described above, the specific geometry of the valve body 126 has been optimized to reduce the overall volume and diameter of the valve body 126 and reduce the footprint of the valve body 126 so that the valve body 126 can be seated closer to the drive sprocket 114 toQB\97854476.2 9Attorney Docket No. 660114.0132976237- 1001 -WOOl reduce the overall dimensions of the valve subsystem 106 compared to some conventional rotary’ valves.

[0066] As shown in FIG. 3, the valve assembly 100 can include a thrust bearing 138 and a thrust washer 140 disposed between the valve body 126 and the pump housing 102. As shown, a footprint of the valve body 126 (i.e., the perimeter of the valve body that faces the thrust bearing 138) is smaller than the area of the thrust bearing 138 facing the valve body 126. Furthermore, the thrust bearing 138 and the thrust washer 140 partially overlap an opening of the pump housing 102 through which camshaft 112 extends.

[0067] Further shown in FIG. 3, the valve assembly 100 can include a sprocket bearing 134. In the illustrated example, the sprocket bearing 134 is configured as flange bushing, however, other bearings can be used. In general, the sprocket bearing 134 can be used to support an axial end of the drive sprocket 1 14 within the manifold 104 opposite the camshaft 112. In the illustrated example, the sprocket bearing 134 supports the drive sprocket 114 and does not directly support or contact the camshaft 112. Here, the sprocket bearing 134 also functions as the second retainer 131 (see FIG. 5). For example, the sprocket bearing 134 can include a flange that functions as the second retainer 131. In other examples the sprocket bearing 134 and the second retainer 131 can be different components.

[0068] FIGS. 5 and 6 show the valve subsystem 106 in a pressure holding position and a pressure dump position, respectively. In the pressure holding position of FIG. 5, a metallic face seal is formed between a high pressure line 144 and the valve body 126 via the sealing disc 146. In the pressure dump position of FIG. 6, the high pressure line 144 is open to the atmosphere. Thus, the two positions of FIGS. 5 and 6 correspond to the two positions of the valve assembly 100.

[0069] In general, the valve assembly 100 can be used to hold pressure in a system (e.g., a hydraulic tool) to perform work and to release pressure when desired or at the end of the work performed. As noted above, as the sprocket 114 rotates, the pawls 120 move outward due to centrifugal force (e.g., as illustrated in FIGS. 5-6). Based on the direction of rotation of the sprocket, a pawl 120 can engage with the valve body 126 to rotate the valve body 126. This rotation of the valve body 126 can align a pressure line with the metallic face seal 146 holding the pressure, or can align the pressure line with a cross hole 148 of the valve body 126 to dump the pressure to the atmosphere.

[0070] FIG. 7 show s the valve body 126, including the first and second drive members 122, 124, the cross hole 148, and an axis opening 150. The axis opening 150 extends along the valveQB\97854476.2 10Attorney Docket No. 660114.0132976237- 1001 -WOOl rotational axis for the valve body 126 and is configured to receive a rotary valve pin (see FIGS. 5 and 6). Each of the first and second drive members 122, 124 includes a comer portion where the valve body 126 is configured to engage a pawl 120. Furthermore, the valve body 126 can include a stop member 152 configured to engage a stopper 154 of the manifold 104 (see FIG. 8).

[0071] As shown in FIG. 8, the stopper 154 is configured to engage the stop member 152 of the valve body 126 to limit the rotation of the valve body 126. The stopper 154 can be integrally formed with the manifold 104. The stop member 152 where the valve body 126 contacts the stopper 154 of the manifold 104 can be disposed on the valve body 126 on the projection 127d opposite the second drive member 122. The projection 127d can be formed as a peninsula-shaped body in some cases. For example, the projection 127d of the valve body 126 includes the second drive member 124 on one lateral side and the stop member 152 on the other lateral side. Also as shown in FIGS. 7 and 8, the projection 127d of the valve body 126 is generally cantilevered relative to a base of the valve body 126 where the first drive member 122 is disposed.

[0072] As described above, the valve subsystem 106 can be smaller than traditional valve systems utilized in conventional tools. In such examples, the valve subsystem 106 may be incorporated into tools of smaller sizes, or other subsystems of a tool may be increased in size to provide other benefits to the tool. Referring to FIG. 5A, in some examples, a largest dimension 155 of the valve subsystem 106 measured perpendicular relative to the valve rotation axis 126 can be about 29 mm. In other examples, the largest dimension of the valve subsystem 106 may be less than about 30 mm, or less than about 32 mm, or less than about 35 mm.

[0073] In some examples, a largest sprocket diameter 156 of the sprocket body 115 maybe about 13.5 mm. In other examples, the largest sprocket diameter 156 of the sprocket body 115 may be less than about 14 mm, or less than about 15 mm, or less than about 16 mm.

[0074] In some examples, a largest valve diameter 157 of the valve body 126 may be about 14 mm. In other examples, the largest valve diameter 157 of the valve body 126 may be less than about 14.5 mm, or less than about 15 mm, or less than about 16 mm.

[0075] In such examples, a maximum combined diameter of the sprocket body 115 and the valve body 126 can be less than about 27 mm, or less than about 28 mm, or less than about 29 mm.

[0076] FIG. 9 illustrates an exemplary geometry of the valve subsystem 106. As shown, a distance 155 across the valve subsystem 106 is approximately 29 millimeters. However, inQB\97854476.2 11Attorney Docket No. 660114.0132976237- 1001 -WO01 other examples, it may be between approximately 25 and 34 millimeters. This length represents the diameter of the hole through which the camshaft 112 extends in the pump housing 102 plus the diameter of the thrust bearing 138 minus the overlap between the hole and the thrust bearing 138. In some conventional valves, there is no overlap between a washer or bearing (e.g., a thrust washer) and the opening in the housing through which the camshaft extends, which can increase the overall length and size of the valve subsystem.

[0077] FIGS. 10-12 illustrate another example of the valve assembly 100. In general, like reference numbers will be used to describe the same or similar components of the valve assembly in FIGS. 10-12 as were used to describe the valve assembly 100 above with reference to FIGS. 1-9. The valve subsystem 106 of FIGS. 10-12 is similar to the valve subsystem 106 described above with reference to FIGS. 1-9 with at least one distinction being the coupling of the camshaft 112 to the drive sprocket 114. The valve assembly 100 of FIGS. 10-12 includes a pin 162 that extends from one end of the drive sprocket 114 toward another end of the drive sprocket 114 and into a distal end of the camshaft 112 (see FIG. 12). In this way the pin 162 can help to secure the sprocket bearing 134, which in turn holds the drive sprocket 114 on the camshaft 112. Correspondingly, the opening 133 in the sprocket body 115 is a through opening to allow the pin 162 to extend entirely through the drive sprocket 114 to engage the camshaft 112 (e.g., from the opening at the second axial end of the sprocket 114 to the opening 133 at the first axial end of the sprocket 114).

[0078] The pin 162 may be press-fit into the distal end of the camshaft 112. However, in other examples, other connections are possible, such as adhesion, threads, welding, etc. Similar to the camshaft 112 connection described above with reference to FIGS. 1-9, the pin 162 connection allows the camshaft 112 to extend only part way into the body of the drive sprocket 114 and does not require additional bearings or support within the manifold 104 beyond the connection to the drive sprocket 114 via the pin 162.

[0079] With reference back to FIG. 10, the valve assembly 100 as shown includes a bearing 164 configured as a bushing. The bearing 164 defines a smaller diameter than the thrust bearing 138 (see, e.g., FIGS. 3-6). The bearing 164 is coaxial with the valve body 126 and can be seated within the manifold 104. As shown in FIG. 12, the bearing 164 does not extend over (e.g., overlap with) the opening in the pump housing 102 through which the camshaft 1 12 extends. This can streamline an assembly process by providing a pump subassembly 170 and a manifold subassembly 172 that can be efficiently married by aligning two parallel axes of the drive sprocket 114 and the valve body 126.QB\97854476.2 12Attorney Docket No. 660114.0132976237- 1001 -WO01

[0080] In particular, during an assembly process, the valve body 126 and bearing 164 can be installed in the manifold 104 to form the manifold subassembly 172 and the drive sprocket 114 can be secured to the camshaft 112 and the pump housing 102 to form the pump subassembly 170. In some conventional valves, installation is often more complex because, for example, first a valve body is inserted in to a manifold or other housing, then the sprocket into the housing, then a bearing associated with the valve body, and then coupling of the camshaft to the drive sprocket, which can be difficult given the bulk of the camshaft and pump housing subassembly.

[0081] Thus, it is advantageous to have a bearing, such as the bearing 164, that does not overlap with the hole in the pump housing 102 through which the camshaft 112 extends so that the valve body 126 and bearing 164 can be installed in the manifold 104 independent of the drive sprocket 114. Furthermore, it can be advantageous to secure the drive sprocket 114 to the pump housing 102 to form a pump subassembly 170 that can be assembled to the manifold subassembly 172 by aligning first and second axes of the drive sprocket 114 and the valve body 126, respectively.

[0082] FIGS. 13-15 illustrate another example of the valve assembly 100. The valve assembly 100 of FIGS. 13-15 is similar to the valve assemblies discussed above, and like reference numbers to describe the same or similar parts will be used where applicable. The valve assembly 100 of FIGS. 13-15 can include a pump subassembly 170 and a manifold subassembly 172.

[0083] As shown in FIG. 15, in the illustrated example, the drive sprocket 114 is coupled to the camshaft 112 via a press fit. More particularly, the drive sprocket 114 is received by the camshaft 112. Similar to the example shown in FIGS. 10-12, the attachment of the drive sprocket 114 to the camshaft 112 can advantageously provide a pump subassembly 170 that can be coupled to the manifold subassembly 172 by advantageously only aligning tw o axes to form a poka-yoke-type connection. Furthermore, like the examples described above, the camshaft 112 shown in FIGS. 13-15 does not extend through the entirety of the drive sprocket 114. More particularly, the camshaft 112, as shown in FIG. 15, does not extend into the drive sprocket 114 at all. Advantageously, the camshaft 112 does not require any bearings or support within the manifold 104 beyond the coupling to the drive sprocket 114. Furthermore, as shown in FIG. 10, the drive sprocket 114 can be supported in the manifold 104 via the sprocket bearing 134.QB\97854476.2 13Attorney Docket No. 660114.0132976237- 1001 -WOOl

[0084] In some examples, pawls 120 can be retained within the sprocket 114 by the retainers 129, 131. In the present example, the retainers 129, 131 can be snap rings. However, in other examples, the retainers 129. 131 may be other applicable retainers.

[0085] In general, it should be appreciated that the various examples of valve assemblies 100 described herein are by way of example, and that components show n in one example may be used in other examples described herein and otherwise. For example, the bushing 164 may be used in addition to or in place of the thrust bearing 138 and the thrust washer 140.

[0086] Other Examples

[0087] Example 1. A power tool, comprising: a manifold; a pump housing coupled to the manifold; a camshaft that is supported by the pump housing, the camshaft having a distal end; a drive sprocket positioned in the manifold, the drive sprocket having a first end that is coupled to the distal end of the camshaft, the drive sprocket including a plurality of pawls; a sprocket bearing coupled between a second end of the drive sprocket and the manifold; and a valve body having a first drive member and a second drive member, the valve body rotating in a first direction when the plurality of pawls engages the first drive member and the valve body rotating in a second direction when the plurality of pawls engages the second drive member.

[0088] Example 2. The power tool of Example 1, wherein the plurality of pawls includes a first set of pawls that engage the first drive member and a second set of pawls that engage the second drive member, the first set of pawls being axially spaced from the second set of pawls.

[0089] Example 3. The power tool of Example 1 or 2, further comprising a valve assembly, wherein the valve assembly defines a first pin that is received in a first bore defined in the pump housing, and wherein the valve assembly defines a second pin that is received in a second bore defined in the manifold.

[0090] Example 4. The power tool of Example 3, wherein the valve body includes a shaft, wherein the second pin is coupled to the shaft of the valve body and the first pin is formed as a unitary component with the shaft.

[0091] Example 5. The power tool of any one of Examples 1-4, wherein the valve body includes a bushing positioned between the first drive member and the pump housing.

[0092] Example 6. The power tool of any one of Examples 1-5, wherein the second drive member includes an orifice that is aligned with a seal in a first rotational position and that is unaligned from the seal in a second rotational position, the seal received in a cavity' defined in the manifold.QB\97854476.2 14Attorney Docket No. 660114.0132976237- 1001 -WOOl

[0093] Example 7. The power tool of any one of Examples 1-6, wherein the second end of the drive sprocket defines a pin that is received in the sprocket bearing.

[0094] Example 8. The power tool of Example 7. further comprising a fastener that is inserted through a bore in the drive sprocket to engage the camshaft, the drive sprocket trapped between a head of the fastener and the camshaft.

[0095] Example 9. The power tool of Example 8, wherein the fastener is a pin that forms a press fit connection with the camshaft.

[0096] Example 10. The power tool of Example 8 or 9, wherein the first end of the drive sprocket defines a recess that receives the camshaft.

[0097] Example 11. The power tool of any one of Examples 8-10, wherein the plurality' of pawls includes a first set of pawls that are retained in the drive sprocket by the sprocket bearing, and a second set of pawls that are retained in the drive sprocket by a washer that is positioned between a body of the drive sprocket and the camshaft.

[0098] Example 12. The power tool of Example 7, wherein the camshaft defines a recess that receives the first end of the drive sprocket.

[0099] Example 13. The power tool of Example 12, wherein the plurality of pawls includes a first set of pawls that are retained in the drive sprocket by a first retainer that is positioned between the sprocket bearing and a body of the drive sprocket, and a second set of pawls that are retained by a second retainer that is positioned between the body of the drive sprocket and the camshaft.

[0100] Example 14. The power tool of Example 13, wherein the first retainer is a snap ring and the second retainer is a snap ring.

[0101] Example 15. The power tool of any one of Examples 1-14, wherein the second drive member defines a peninsula-shaped portion defining a drive portion on one lateral side and a stop portion on an opposite lateral side, the stop portion configured to engage a stopper of the manifold to prevent rotation of the valve body.

[0102] Example 16. A method of assembling a power tool, the method comprising: coupling a first end of a drive sprocket to a camshaft that is rotatably coupled to a pump housing; inserting a valve body into a recess defined in a manifold; and coupling the pump housing with the drive sprocket to the manifold so that the drive sprocket is received in the recess.QB\97854476.2 15Attorney Docket No. 660114.0132976237- 1001 -WO01

[0103] Example 17. The method of Example 16, further comprising coupling a sprocket bearing to a second end of the drive sprocket, the sprocket bearing retaining a first set of pawls in a body of the drive sprocket.

[0104] Example 18. The method of Example 16 or 17, further comprising inserting a pin through a bore defined in the drive sprocket, the pin engaging the camshaft with a press-fit connection.

[0105] Example 19. The method of any one of Examples 16-18, further comprising coupling a retainer to the first end of the drive sprocket, the retainer retaining a second set of pawls in the body of the drive sprocket, the second set of pawls being axially spaced from the first set of pawls.

[0106] Example 20. The method of Example 19, wherein the retainer is a washer that is received on the camshaft.

[0107] Thus, examples of the disclosed invention can provide a system and method for advancing and retracting a piston of a hydraulic tool via a rotary shear seal valve. The previous description of the disclosed examples is provided to enable any person skilled in the art to make or use the invention. Various modifications to these examples will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other examples without departing from the spirit or scope of the invention. Thus, the invention is not intended to be limited to the examples shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.QB\97854476.2 16

Claims

Attorney Docket No. 660114.0132976237- 1001 -WOOlCLAIMSWhat is claimed is:

1. A power tool, comprising: a manifold; a pump housing coupled to the manifold; a camshaft that is supported by the pump housing; a drive sprocket positioned in the manifold, the drive sprocket having a first end that is coupled to the distal end of the camshaft, the drive sprocket including a plurality of pawls; a sprocket bearing coupled between a second end of the drive sprocket and the manifold; and a valve body having a first drive member and a second drive member, the valve body rotating in a first direction when the plurality of pawls engages the first drive member and the valve body rotating in a second direction when the plurality of pawls engages the second drive member.

2. The power tool of claim 1 , wh erein the plurality of pawls includes a first set of pawls that engage the first drive member and a second set of pawls that engage the second drive member, the first set of pawls being axially spaced from the second set of pawls.

3. The power tool of claim 2, wherein the valve assembly defines a first pin that is received in a first bore defined in the pump housing, and wherein the valve assembly defines a second pin that is received in a second bore defined in the manifold.

4. The power tool of claim 3, wherein the second pin is coupled to a shaft of the valve body and the first pin formed as a unitary component with the shaft.

5. The power tool of claim 2, wherein a valve body includes a bushing positioned between the first drive member and the pump housing.QB\97854476.2 17Attorney Docket No. 660114.0132976237- 1001 -WOOl6. The power tool of claim 1 , wherein the second drive member includes an orifice that is aligned with a seal in a first rotational position and that is unaligned from the seal in a second rotational position, the seal received in a cavity defined in the manifold.

7. The power tool of claim 1, wherein the second end of the drive sprocket defines a pin that is received in the sprocket bearing.

8. The power tool of claim 7, wherein a fastener is inserted through a bore in the drive sprocket to engage the camshaft, the drive sprocket trapped between a head of the fastener and the camshaft.

9. The power tool of claim 8, wherein the fastener is a pin that forms a press fit connection with the camshaft.

10. The power tool of claim 8, wherein the first end of the drive sprocket defines a recess that receives the camshaft.

11. The power tool of claim 8, wherein the plurality of pawls includes a first set of pawls that are retained in the drive sprocket by the sprocket bearing, and a second set of pawls that are retained in the drive sprocket by a washer that is positioned between a body of the drive sprocket and the camshaft.

12. The power tool of claim 7, wherein the camshaft defines a recess that receives the first end of the drive sprocket.

13. The power tool of claim 12, wherein the plurality of pawls includes a first set of pawls that are retained in the drive sprocket by a first retainer that is positioned between the sprocket bearing and a body of the drive sprocket, and a second set of pawls that are retained by a second retainer that is positioned between the body of the drive sprocket and the camshaft.

14. The power tool of claim 13, wherein the first retainer is a snap ring and the second retainer is a snap ring.QB\97854476.2 18Attorney Docket No. 660114.0132976237- 1001 -WOOl15. The valve assembly of claim 1, wherein second drive member defines a peninsula-shaped portion defining a drive portion on one lateral side and a stop portion on an opposite lateral side, the stop portion configured to engage a stopper of the manifold to prevent rotation of the valve body.

16. A method of assembling a power tool, the method comprising: coupling a first end of a drive sprocket to camshaft that is rotatably coupled to a pump housing; inserting a valve body into a recess defined in a manifold; and coupling the pump housing with the drive sprocket to the manifold so that the drive sprocket is received in the recess.

17. The method of claim 16, further comprising coupling a sprocket bearing to a second end of the drive sprocket, the sprocket bearing retaining a first set of pawls in a body of the drive sprocket.

18. The method of claim 17, further comprising inserting a pin through a bore defined in the drive sprocket, the pin engaging the camshaft with a press-fit connection.

19. The method of claim 17, further comprising coupling a retainer to the first end of the drive sprocket, the retainer retaining a second set of pawls in the body of the drive sprocket, the second set of pawls being axially spaced from the first set of pawls.

20. The method of claim 19, wherein the retainer is a washer that is received on the camshaft.QB\97854476.2 19

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