Limited clearance tool

Abstract

A limited clearance hydraulic tool that provides torque to an associated threaded fastener assembly. A limited clearance hydraulic tool includes a piston and a ratchet. The limited clearance hydraulic tool also includes a drive plate and a piston rod extending between the drive plate and the piston. The limited clearance hydraulic tool also includes a connecting pin that defines a first contact point between the piston rod and the drive plate and continuously connects the piston rod and the drive plate together to always drive and retract the drive plate. Further, the limited clearance hydraulic tool includes a push plate defining a second contact point between the piston rod and the drive plate. The push plate is separate and distinct from the first contact point. The push plate selectively connects the piston rod and the drive plate together to drive the drive plate.

Description

Background Art

[0001] Hydraulically driven ratchet torque tools generate precise bolt loads by rotating the fastener. Standard hydraulic torque tools sometimes use a reaction arm fixed to the tool housing. This arm provides a means of abutment, allowing the tool to apply tightening force to the fastener rather than simply rotating around the fastener's axis. Alternatively, a reaction washer can be used to provide a means of abutment for the tool, where the reaction washer is a component of the threaded fastener assembly. Specifically, the reaction washer is placed directly below the nut or bolt head that will be subjected to the expected tightening force. In addition, the reaction washer is connected to the tool housing.

[0002] However, known tools are inefficient to operate and require extensive maintenance to maintain operability. Furthermore, they can be heavy and awkward to operate. Given these difficulties, a better tool is needed. Summary of the Invention

[0003] In view of the foregoing, a limited clearance hydraulic tool provides torque to an associated threaded fastener assembly. The limited clearance hydraulic tool includes a housing that receives hydraulic fluid and defines a piston cylinder that defines a cylinder axis. The limited clearance hydraulic tool also includes: a piston that is slidably disposed within the piston cylinder of the housing, the piston outputting force and traveling between a retracted position and an extended position; and a ratchet that is rotatably received within the housing, the ratchet defining a ratchet axis and being configured to engage an associated threaded fastener assembly. The limited clearance hydraulic tool also includes: a drive plate that is disposed within the housing so as to at least partially radially surround the ratchet; and a piston rod that extends between the drive plate and the piston.

[0004] The limited clearance hydraulic tool further includes a connecting pin defining a first contact point between the piston rod and the drive plate. The connecting pin continuously connects the piston rod and the drive plate to constantly drive and retract the drive plate by transmitting force from the piston to the drive plate. Furthermore, the limited clearance hydraulic tool includes a push plate defining a second contact point between the piston rod and the drive plate, the push plate being separate and distinct from the first contact point, and selectively connecting the piston rod and the drive plate to drive the drive plate. BRIEF DESCRIPTION OF THE DRAWINGS

[0005] Figure 1 A perspective view of a limited clearance hydraulic tool and threaded fastener assembly.

[0006] Figure 2 It is an exploded perspective view of a limited clearance hydraulic tool.

[0007] Figure 3 is a front cross-sectional view of a limited clearance hydraulic tool, wherein the piston of the limited clearance hydraulic tool is fully extended under no-load conditions.

[0008] Figure 4 is a front cross-sectional view of a limited clearance hydraulic tool, wherein the piston of the limited clearance hydraulic tool is partially extended under load.

[0009] Figure 5 is a front cross-sectional view of a limited clearance hydraulic tool with the piston of the limited clearance hydraulic tool fully retracted.

[0010] Figure 6 is a front cross-sectional view of a limited clearance hydraulic tool, illustrating some of the fluid passages of the limited clearance hydraulic tool.

[0011] Figure 7 is a front cross-sectional view of a limited clearance hydraulic tool showing additional fluid passages of the limited clearance hydraulic tool.

[0012] Figure 8 is a front perspective view of a limited clearance hydraulic tool with a reaction pad of the limited clearance hydraulic tool removed therefrom. DETAILED DESCRIPTION

[0013] Of course, it should be understood that the description and drawings herein are illustrative only and that various modifications and changes may be made to the disclosed structures without departing from the present disclosure. Referring now to the drawings, wherein like reference numerals represent like parts throughout the several views, Figures 1-6 A limited clearance hydraulic tool 10 according to the present disclosure is schematically depicted.

[0014] The limited clearance hydraulic tool 10 provides torque to the associated threaded fastener assembly 12 ( Figure 1 ). The limited clearance hydraulic tool 10 can be used to tighten or loosen an associated threaded fastener assembly 12. As will be described in more detail below, the limited clearance hydraulic tool 10 may include: a housing 14, the housing 14 defining a passage 14a; a piston 16; a ratchet 18, the ratchet 18 defining a ratchet axis 22; a magnetic ring 24; a drive plate 26; a pawl 28; a piston rod 32; a connecting pin 34; a pawl spring 36; a push plate 38; a first cover 40a; a second cover 40b; and a rotary head 42. In addition, the limited clearance hydraulic tool 10 can be fluidly connected to an associated first main line 44 and an associated second main line 46. Further, the limited clearance hydraulic tool 10 can include: a rotating body 48, a shield 50, and a reaction pad 60. In addition, the rotating head 42 can define a pivot head axis 52 and a pivot body axis 54.

[0015] First, it is helpful to review the components of the associated threaded fastener assembly 12 that the limited clearance hydraulic tool 10 engages to perform its work. Figure 1As shown, the associated threaded fastener assembly 12 may include: a threaded portion 56 having a free end 56a; a reaction washer 58 defining an inner diameter 58a and an outer diameter 58b and including an engagement surface 58c; and a nut 62. The threaded portion 56 may be part of a bolt or stud that is threadedly engaged with the nut 62. The reaction washer 58 is disposed on the threaded portion 56 such that the nut 62 is positioned between the reaction washer 58 and the free end 56a of the threaded portion 56 along the ratchet axis 22 to engage the limited clearance hydraulic tool 10, as will be described in more detail below.

[0016] When the limited clearance hydraulic tool 10 is engaged with the associated threaded fastener assembly 12, the reaction washer 58 slidably and coaxially receives the threaded portion 56 along the ratchet axis 22, and the nut 62 threadably and coaxially receives the threaded portion 56 along the ratchet axis 22. As previously described, the limited clearance hydraulic tool 10 can be used to tighten or loosen the associated threaded fastener assembly 12. As will be understood, this means that when the associated threaded fastener assembly 12 is loosened, the nut 62 will travel along the threaded portion 56 toward the free end 56a of the threaded portion 56, allowing the nut 62 to be removed from the threaded portion 56; when the associated threaded portion 56 is tightened, the nut 62 will travel along the threaded portion 56 away from the free end 56a of the threaded portion 56, making it impossible to remove the nut 62 from the threaded portion 56. Although not shown, it will be understood that an object stationary relative to the nut 62 (such as a machine housing) is received or attached to the threaded portion 56 distal to the free end 56a to provide a surface against which the reaction washer 58 and nut 62 can be tightened (i.e., to prevent linear movement of the reaction washer 58 and nut 62 along the ratchet axis 22 away from the free end 56a).

[0017] Furthermore, it is worth noting that the reaction washer 58 can be configured in various ways to prevent it from rotating relative to the object about the threaded portion 56. These configurations may include, for example, protrusions, raised patterns, or serrations to provide a high-friction element on the engagement surface 58 c of the reaction washer 58, which faces the object and away from the free end 56 a. Thus, this high-friction element of the engagement surface 58 c of the reaction washer 58 engages the object to help prevent the reaction washer 58 from rotating relative to the threaded portion 56 or the nut 62. As will be described in greater detail below, the limited clearance hydraulic tool 10 engages the reaction washer 58, causing the housing 14 of the limited clearance hydraulic tool 10 to remain stationary relative to the reaction washer 58 and, therefore, the object.

[0018] refer to Figure 3-Figure 5The housing 14 of the limited-clearance hydraulic tool 10 defines a piston cylinder 64 and receives hydraulic fluid. The hydraulic fluid is transmitted to / from the limited-clearance hydraulic tool 10 via an associated first main line 44 and an associated second main line 46. Furthermore, the piston cylinder 64 may define a cylinder axis 66. The end cap 20 a of the end cap assembly 20 may be disposed on the cylinder axis 66.

[0019] The housing 14 can at least partially house the piston 16, the ratchet 18, the drive plate 26, and the piston rod 32. The housing 14 can be a single-piece structure that includes an integral receiving member 68 configured to engage an associated reaction washer 58 of an associated threaded fastener assembly 12, as described in more detail below. The integral receiving member 68 can include a pair of hoop rings 68a, 68a. The hoop rings 68a, 68a can be at least partially spaced apart from each other to receive the ratchet 18. In addition, each hoop ring 68a, 68a can define a hoop inner diameter 68b, 68b. As shown, the hoop inner diameters 68b, 68b are splined for engagement with a castle spline hub 30, as described in more detail below. As will be appreciated, due to the symmetrical layout of the limited clearance hydraulic tool 10 (i.e., about the plane formed by the pivot head axis 52 and the pivot body axis 54), the limited clearance hydraulic tool 10 can engage the reaction washer 58 and the nut 62 from either side of the plane formed by the pivot head axis 52 and the pivot body axis 54 to change the rotational direction of the ratchet 18 (i.e., tighten or loosen the nut 62).

[0020] These improvements allow the limited clearance hydraulic tool 10 to be lighter than conventional tools and also have an improved profile for use in confined spaces. Furthermore, as shown, the limited clearance hydraulic tool 10 may further include an end cap assembly 20 attached to the housing 14. The end cap assembly 20 may include a variety of separate or integral components that cooperate to seal the housing 14. For example, the end cap assembly 20 may include an end cap 20a. The end cap 20a is removably attached to the housing 14 and provides a smooth design surface for the limited clearance hydraulic tool 10. Furthermore, the end cap 20a helps prevent accidental entry into the limited clearance hydraulic tool 10. Furthermore, the end cap assembly 20 may be removable from the housing 14.

[0021] As previously mentioned, the limited clearance hydraulic tool 10 may include a first cover 40a and a second cover 40b. Figure 1As shown, the first cover 40a and the second cover 40b are removably attached to the housing 14. The first cover 40a and the second cover 40b can be attached to the housing 14 by various methods and can be made of the same or different materials as the housing 14. The limited clearance hydraulic tool 10 can also include a shroud 50. The shroud 50 can be removably attached to the housing 14 on the side of the limited clearance hydraulic tool 10 opposite the end cap 20a. The shroud 50 can provide a smooth design surface for the limited clearance hydraulic tool 10. In addition, the shroud 50 helps prevent accidental entry into the limited clearance hydraulic tool 10.

[0022] This rotation of the ratchet 18 then causes the nut 62 to rotate. However, because the integral receiving member 68 engages the stationary reaction washer 58, the limited clearance hydraulic tool 10 is prevented from rotating about the nut 62. Instead, the nut 62 rotates about the ratchet axis 22 of the limited clearance hydraulic tool 10. Therefore, when the nut 62 is rotated, the housing 14 of the limited clearance hydraulic tool 10 remains stationary. Figure 2 As shown, the limited clearance hydraulic tool 10 may further include a pair of castellated spline hubs 30. The pair of castellated spline hubs 30 are coaxially disposed along the ratchet axis 22 such that the ratchet 18 is disposed therebetween.

[0023] Each castellated spline hub 30 can define an inner diameter 30a for engaging the outer diameter 58b of the reaction washer 58, and an outer diameter 30b for engaging the hoop inner diameter 68b of a corresponding hoop 68a of the integral receiving member 68. Notably, each inner diameter 30a of the splined hub 30 can be castellated for selective engagement with the outer diameter 58b of the reaction washer 58, and each outer diameter 30b of the splined hub 30 can be splined for engagement with the inner diameter 68b of the corresponding hoop 68a. As will be appreciated, when the integral receiving member 68 engages the reaction washer 58 via one of the splined hubs 30, rotation between the reaction washer 58 and the limited clearance hydraulic tool 10 is prevented.

[0024] The ratchet 18 of the limited clearance hydraulic tool 10 is configured to receive the nut 62 of the threaded fastener assembly 12 so as to at least partially radially surround the nut 62. In addition, the integral receiving member 68 engages the outer diameter 58b of the reaction washer 58 via one inner diameter 30a of the castellated spline hub 30. Then, as will be described in more detail below, when hydraulic fluid is supplied to the limited clearance hydraulic tool 10, the ratchet 18 will rotate.

[0025] refer to Figure 3-Figure 5, the housing 14 may define a first housing line 74 in fluid communication with the piston cylinder 64 via a first port 76 and a second housing line 78 in fluid communication with the piston cylinder 64 via a second port 82. Furthermore, the first port 76 and the second port 82 are fluidically isolated from each other by the piston 16. In addition, the first housing line 74 and the second housing line 78 may include a first housing portion 124 and a second housing portion 126, respectively, which are neither parallel nor perpendicular to the cylinder axis 66. Figure 6-Figure 7 , illustrates more fluid pathways for transferring fluid from the rotary head 42 to the housing 14. It is noteworthy that Figure 6 The high pressure fluid path 70 is shown. Figure 7 A low pressure fluid path 80 is illustrated. Because of the above described arrangement, the rotary head 42 and rotary body 48 can be used, thereby providing improved operational flexibility of the intermittent hydraulic tool 10.

[0026] As previously mentioned, the limited clearance hydraulic tool 10 may include a piston 16. The piston 16 may be cylindrical and made of any number of materials that provide sufficient strength and rigidity for proper operation of the piston 16. The piston 16 is slidably disposed within the piston cylinder 64 of the housing 14 and outputs a force to cause subsequent movement of the ratchet 18. The piston 16 may be in an extended position ( Figure 3-Figure 4 ) and retracted position ( Figure 5 ) between. This movement of the piston 16 causes subsequent rotation of the ratchet 18 and thus tightens or loosens the nut 62.

[0027] As shown, the connecting pin 34 may have a circular cross-section. Figure 2 As shown, the connecting pin 34 can be generally cylindrical in shape. It will be appreciated that the connecting pin 34 can define various grooves, recesses, or other structural features without departing from the scope of the present disclosure. Once the connecting pin 34 is installed within the housing 14, the connecting pin 34 can remain stationary relative to the housing 14 during operation of the limited clearance hydraulic tool 10.

[0028] refer to Figure 2-Figure 5 The limited clearance hydraulic tool 10 further includes a drive plate 26. The drive plate 26 is disposed within the housing 14 so as to at least partially radially surround the ratchet 18. The drive plate 26 includes a contact surface 94 that defines a convex shape in a cross-sectional plane orthogonal to the ratchet axis 22.

[0029] Furthermore, the drive plate 26 may define a pin hole 96 for receiving the connecting pin 34 and include a contact surface 94 spaced apart from the pin hole 96. In addition, the drive plate 26 defines a wheel cavity 102 for receiving the ratchet wheel 18 and a pawl cavity 104 for receiving the pawl 28. The pawl cavity 104 and the wheel cavity 102 are in fluid communication with each other.

[0030] The drive plate 26 may further include a first ear portion 106 and a second ear portion 112 spaced apart from each other. The first ear portion 106 and the second ear portion 112 may have the same size and shape. The first ear portion 106 may define a first ear hole 108, and the second ear portion 112 may define a second ear hole 114. The second ear hole 114 and the first ear hole 108 may align with and cooperate with each other to define the pin hole 96 that receives the connecting pin 34 for connecting the piston rod 32 and the drive plate 26 together to define a first contact point.

[0031] Continuing with the figures, the limited clearance hydraulic tool 10 also includes a push plate 38. The push plate 38 may include a contact surface 122 that defines a concave shape in a cross-sectional plane orthogonal to the ratchet axis 22. Furthermore, the contact surface 122 of the push plate 38 may be complementary to the contact surface 94 of the drive plate 26, such that the contact surface 122 of the push plate 38 may at least partially accommodate the contact surface 94 of the drive plate 26. The push plate 38 may be separate from or integrally formed with the piston rod 32 without departing from the scope of the present disclosure.

[0032] like Figure 3-Figure 5 As shown, the piston rod 32 extends between the drive plate 26 and the piston 16 to connect the components together. The piston rod 32 includes a head end 116 and a tail end 118 disposed at opposite ends along the cylinder axis 66. Furthermore, the head end 116 of the piston rod 32 is received between the first ear 106 and the second ear 112 of the drive plate 26 along the cylinder axis 66. Thus, the head end 116 receives the connecting pin 34 to connect the drive plate 26 and the piston rod 32 together, while the tail end 118 connects the piston 16 and the piston rod 32 together. Furthermore, the push plate 38 is disposed between the head end 116 and the tail end 118.

[0033] It is worth noting that when the piston 16 is in the extended position ( Figure 3-Figure 4 ) and retracted position ( Figure 5 ) between the piston rod 32 can be selectively deviated from the cylinder axis 66. However, the deviation is limited by the engagement between the contact surface 122 of the push plate 38 and the contact surface 94 of the drive plate 26. It is worth noting that when Figure 3 and Figure 4 This deviation can be observed when compared with each other.

[0034] Figure 3 The limited clearance hydraulic tool 10 is illustrated in an unloaded state. Specifically, the unloaded state refers to a situation where the limited clearance hydraulic tool 10 is not subjected to a resistive rotational force from the nut 62. Alternatively, the loaded state refers to a situation where the limited clearance hydraulic tool 10 is subjected to a resistive rotational force from the nut 62. The above-described deviation can provide improved operating efficiency of the limited clearance hydraulic tool 10 by properly directing the force from the piston 16 to the drive plate 26 (and therefore to the ratchet 18).

[0035] refer to Figure 1-Figure 5 The ratchet 18 is rotatably received in the housing 14 and is configured to engage and rotate the associated threaded fastener assembly 12 as previously described. The ratchet 18 defines an inner radial surface 84 configured to contact the associated threaded fastener assembly 12 and an outer radial surface 86 including teeth 88 for engaging the pawl 28.

[0036] The inner radial surface 84 can define a hexagonal shape for fully engaging the nut 62. However, it will be understood that the inner radial surface 84 can have a different shape to engage nuts or fasteners of other shapes without departing from the scope of the present disclosure. The outer radial surface 86 can define a groove-like or tooth-like shape for engaging the pawl 28. The ratchet 18 can be configured to rotate only in a single rotational direction.

[0037] like Figure 1-Figure 2 As shown, the limited clearance hydraulic tool 10 may further include a magnetic ring 24. The magnetic ring 24 may have a circular cross-section and a nominal thickness. However, other shapes and thicknesses are possible and contemplated. Furthermore, the magnetic ring 24 may be made from a variety of materials that provide magnetic strength. The magnetic ring 24 may be positioned along the ratchet axis 22 so as to face outward from the ratchet 18. Furthermore, the magnetic ring 24 may include a stop surface 92 facing away from the ratchet 18.

[0038] The stop surface 92 can be sized to contact the associated reaction washer 58 of the associated threaded fastener assembly 12 and prevent over-insertion of the associated threaded fastener assembly 12 into the limited clearance hydraulic tool 10 along the ratchet axis 22. As will be appreciated, the magnetic properties of the magnetic ring 24 facilitate operation of the limited clearance hydraulic tool 10 for improved engagement with the nut 62 of the associated threaded fastener assembly 12. Furthermore, the stop surface 92 can improve operation of the limited clearance hydraulic tool 10 by providing a uniform surface for proper engagement with the associated threaded fastener assembly 12.

[0039] The limited clearance hydraulic tool 10 also includes a pawl 28. The pawl 28 contacts both the drive plate 26 and the ratchet 18. The pawl 28 is slidably received in the pawl cavity 104 of the drive plate 26 to selectively engage the ratchet 18 and limit the rotation of the ratchet 18 about the ratchet axis 22 to a single rotational direction. Figure 3-Figure 5 As shown, a pawl spring 36 can bias the pawl 28 away from the connecting pin 34. This biasing promotes engagement between the pawl 28 and the ratchet wheel to limit the rotation of the ratchet wheel 18 to a single rotational direction.

[0040] The limited clearance hydraulic tool 10 is configured to provide a first torque output for rotating an associated threaded fastener assembly 12 in a first mode, and a second torque output for rotating an associated threaded fastener assembly 12 in a second mode. The second torque output is greater than the first torque output. As previously described, the connecting pin 34 may define a first contact point between the piston rod 32 and the drive plate 26.

[0041] like Figure 3-Figure 5 As shown, the connecting pin 34 continuously connects the piston rod 32 and the drive plate 26 together to always drive and retract the drive plate 26 by transferring force from the piston 16 to the drive plate 26. In addition, the connecting pin 34 contacts the piston rod 32 and the drive plate 26 during both the first mode and the second mode. However, the connecting pin 34 is configured to deflect along the cylinder axis 66 in a direction away from the piston 16 in the second mode to allow the push plate 38 to contact the drive plate 26.

[0042] Continue to refer Figure 3-Figure 5 , the push plate 38 can define a second point of contact between the piston rod 32 and the drive plate 26. The contact surface 122 of the push plate 38 and the contact surface 94 of the drive plate 26 can cooperate to define a second point of contact that selectively occurs to transfer motion from the piston 16 to the drive plate 26.

[0043] As will be appreciated, the ability of the limited-clearance hydraulic tool 10 to operate in both the first and second modes without requiring the installation / removal of components provides numerous advantages. For example, when the limited-clearance hydraulic tool 10 is operated in the first mode, the components of the limited-clearance hydraulic tool 10 experience less wear and tear. Furthermore, when the limited-clearance hydraulic tool 10 is operated in the second mode, more torque is output to the nut 62, improving the operating efficiency of the limited-clearance hydraulic tool 10. Furthermore, because force is transmitted through the first and second contact points in the second mode, components experience less force, thereby reducing maintenance requirements for the limited-clearance hydraulic tool 10.

[0044] Notably, during the first mode, push plate 38 is continuously spaced apart from drive plate 26. However, during the second mode, push plate 38 contacts drive plate 26. Furthermore, contact surface 122 is always spaced apart from connecting pin 34. When push plate 38 contacts and drives drive plate 26, connecting pin 34 transfers the majority of the force output from piston 16 to drive plate 26, while push plate 38 transfers a smaller portion of the force output from piston 16 to drive plate 26. However, when push plate 38 is not driving drive plate 26, connecting pin 34 transfers all of the force output from piston 16 to drive plate 26, while push plate 38 does not transfer any force output from piston 16 to drive plate 26. Furthermore, push plate 38 is separate and distinct from the first contact point mentioned above.

[0045] Thus, the push plate 38 selectively connects the piston rod 32 and the drive plate 26 together to drive the drive plate 26 based on the deflection of the connecting pin 34. Specifically, when a relatively low torque is applied to the ratchet 18, the connecting pin 34 does not deflect (i.e., remains perfectly straight and parallel to the ratchet axis 22 in all planes) and the push plate 38 is spaced apart from the drive plate 26 ( Figure 3 ).

[0046] Conversely, when a higher torque is applied to the ratchet 18, the connecting pin 34 deflects (i.e., all points of the connecting pin 34 are not evenly spaced from the piston 16), causing the push plate 38 to directly contact the drive plate 26 ( Figure 4 ). It will be appreciated that this deflection of the connecting pin 34 (ie, away from the piston 16) is minimal. However, the deflection results in the above-mentioned direct contact, thereby distributing the force from the piston 16 to the drive plate 26.

[0047] It should also be noted that the first and second contact points share a common concentric center to hold the piston rod 32 in place as the drive plate 26 moves. As shown, at least a portion of the pawl 28 shares a vertical axis with the second contact point. In addition, the push plate 38 can be made of a first material defining a first hardness level, and the connecting pin 34 can be made of a second material defining a second hardness level. The first material and the second material are different from each other, and the first hardness level is greater than the second hardness level. It will be understood that the hardness level can be adjusted by various methods, such as heat treatment.

[0048] Return Reference Figure 1 , shows a rotary head 42 configured to be connected to an associated first main line 44 and an associated second main line 46 that are fluidly isolated from each other. The associated first main line 44 is in fluid communication with a first housing line 74, and the associated second main line 46 is in fluid communication with a second housing line 78. It will be understood that the associated first main line 44 and the associated second main line 46 will be provided in a variety of industrial and commercial environments.

[0049] like Figure 3-Figure 5 As shown, the swivel 48 is connected to the swivel head 42. The swivel head 42 is configured to rotate about the swivel 48 so as to define a pivot head axis 52 that is orthogonal to the cylinder axis 66. In addition, the housing 14 defines a swivel opening 72 for receiving the swivel 48. The swivel 48 is configured to rotate at least partially about the housing 14 so as to define a pivot head axis 54 that is generally parallel to the cylinder axis 66. Because the swivel 48 is integral with the housing 14, the swivel 48 is more resistant to damage than conventional top-mounted swivel designs. In addition, due to this layout, a more compact footprint can be provided. Further, this arrangement allows for the addition of additional axes for further rotational degrees of freedom.

[0050] As previously mentioned, the housing 14 may define a passage 14a. Figure 8 As shown, the housing 14 also includes a lug 14b that allows the reaction pad 60 to be slidably received by the housing 14. The reaction pad 60 may include a first end 60a and a second end 60b. The first end 60a and the second end 60b are configured to be located at opposite ends of the reaction pad 60. Figure 3-Figure 8 As shown, the channel 14a of the housing 14 can be disposed on a side of the housing 14 opposite the rotating head 42 along the pivot head axis 52. Furthermore, the channel 14a can define a generally rectangular shape extending primarily in a direction parallel to the cylinder axis 66. Notably, the channel 14a removably receives the reaction pad 60.

[0051] like Figure 2 As shown, the reaction pad 60 may have a generally rectangular shape. This shape may be complementary to the channel 14a. As shown, the reaction pad 60 is removably attached to the housing 14. Notably, the lug 14b of the housing 14 may retain the reaction pad 60 at least partially within the channel 14a. When the limited clearance hydraulic tool 10 is used to provide torque to a nut without a reaction washer, the reaction pad 60 may act as a reaction arm to prevent the limited clearance hydraulic tool 10 from rotating about the ratchet axis 22. Thus, the reaction pad 60 acts as a contact point between the limited clearance hydraulic tool 10 and the surrounding structure, preventing the limited clearance hydraulic tool 10 (more specifically, the housing 14) from rotating relative to the ratchet axis 22. It will be understood that the surrounding structure may include, for example, a nut and threaded portion or flange or other nearby components that are not engaged by the ratchet 18. Furthermore, the reaction pad 60 transfers the forces received from contact with the surrounding structure into the housing 14 without unnecessarily increasing the overall weight of the limited clearance hydraulic tool 10.

[0052] As shown, reaction pad 60 defines a length (i.e., in a direction parallel to cylinder axis 66) that is greater than the length (i.e., in a direction parallel to cylinder axis 66) of passage 14a of housing 14. This difference in length between reaction pad 60 and passage 14a results in first end 60a of reaction pad 60 being located a greater distance from pivot head axis 52 than end cap 14a is from pivot head axis 52. This length of reaction pad 60 allows for improved engagement with surrounding structure.

[0053] It will be appreciated that the reaction pad 60 may have a different length without departing from the scope of the present disclosure. For example, the reaction pad 60 may define a length equal to the length of the passage 14a of the housing 14. This arrangement would result in the first end 60a of the reaction pad 60 (and therefore the reaction pad 60) protruding from the passage 14a (and therefore the housing 14). Alternatively, the reaction pad 60 may define a length greater than that shown, thereby causing the first end 60a of the reaction pad 60 to protrude further than shown. Finally, the reaction pad 60 may be made from a variety of materials without departing from the scope of the present disclosure.

[0054] The above description of a limited clearance hydraulic tool has been described in detail. Modifications and alterations will occur to those who read and understand the above detailed description. However, the present invention is not limited to the above embodiments. Rather, the present invention is broadly defined by the following claims and their equivalents.

Claims

1. A limited clearance hydraulic tool for providing torque to an associated threaded fastener assembly, the limited clearance hydraulic tool comprising: a housing receiving the hydraulic fluid and defining a piston cylinder defining a cylinder axis; a piston slidably disposed within the piston cylinder of the housing, the piston outputting a force and traveling between a retracted position and an extended position; a ratchet rotatably received in the housing, the ratchet defining a ratchet axis and configured to engage the associated threaded fastener assembly; a drive plate disposed within the housing to at least partially radially surround the ratchet; a piston rod extending between the drive plate and the piston; a connecting pin defining a first contact point between the piston rod and the drive plate, the connecting pin continuously connecting the piston rod and the drive plate together to always drive and retract the drive plate by transferring force from the piston to the drive plate; as well as A push plate defines a second contact point between the piston rod and the drive plate, the push plate being separate and distinct from the first contact point, wherein the push plate selectively connects the piston rod and the drive plate together to drive the drive plate.

2. The limited clearance hydraulic tool according to claim 1, wherein: When the push plate contacts and drives the drive plate, the connecting pin transfers most of the force output from the piston to the drive plate, and the push plate transfers a small part of the force output from the piston to the drive plate; and wherein, when the push plate does not drive the drive plate, the connecting pin transfers all of the force output from the piston to the drive plate, and the push plate does not transfer any force output from the piston to the drive plate.

3. The limited clearance hydraulic tool according to claim 1, wherein: The push plate includes a contact surface that defines a concave shape in a cross-sectional plane orthogonal to the ratchet axis; the drive plate includes a contact surface that defines a convex shape in the cross-sectional plane orthogonal to the ratchet axis; wherein the piston rod selectively deviates from the cylinder axis when the piston travels between the retracted position and the extended position; and wherein the deviation is limited by engagement between the contact surface of the push plate and the contact surface of the drive plate.

4. The limited clearance hydraulic tool according to claim 1, wherein: The first contact point and the second contact point share a common concentric center to hold the piston rod in place as the drive plate moves.

5. The limited clearance hydraulic tool according to claim 1, wherein: The drive plate defines a pin hole for receiving the connecting pin and includes a contact surface spaced apart from the pin hole; wherein the push plate includes a contact surface spaced apart from the connecting pin, the contact surface of the push plate and the contact surface of the drive plate cooperate to define a second contact point that occurs selectively to transmit motion from the piston to the drive plate.

6. The limited clearance hydraulic tool according to claim 5, wherein: The contact surface of the push plate is complementary to the contact surface of the drive plate such that the contact surface of the push plate can at least partially accommodate the contact surface of the drive plate.

7. The limited clearance hydraulic tool according to claim 1, further comprising a pawl, the pawl contacting the drive plate and the ratchet simultaneously; wherein The drive plate defines a pawl cavity for receiving the pawl and a wheel cavity for receiving the ratchet; wherein the pawl cavity and the wheel cavity are in fluid communication with each other; and wherein the ratchet defines an inner radial surface configured to contact the associated threaded fastener assembly and an outer radial surface including teeth for engaging the pawl, at least a portion of the pawl sharing a vertical axis with the second contact point.

8. The limited clearance hydraulic tool according to claim 7, further comprising a pawl spring that biases the pawl away from the connecting pin; wherein The pawl is slidingly received in the pawl cavity of the drive plate to selectively engage the ratchet and restrict rotation of the ratchet about the ratchet axis to a single rotational direction.

9. The limited clearance hydraulic tool according to claim 1, wherein: The piston rod includes a head end and a tail end that are arranged to be located at relatively distal ends along the cylinder axis; wherein the head end receives the connecting pin to combine the drive plate and the piston rod together, and the tail end combines the piston and the piston rod together; and wherein the push plate is arranged between the head end and the tail end.

10. The limited clearance hydraulic tool according to claim 9, wherein: The drive plate includes a first ear portion and a second ear portion spaced apart from each other to receive the head end of the piston rod along the cylinder axis; And wherein the first ear portion defines a first ear hole, the second ear portion defines a second ear hole aligned with the first ear hole, and the second ear hole cooperates with the first ear hole to define a pin hole for receiving the connecting pin, which is used to connect the piston rod and the drive plate together to define the first contact point.

11. The limited clearance hydraulic tool according to claim 9, wherein: The push plate is made of a first material defining a first hardness level, and the connecting pin is made of a second material defining a second hardness level; wherein the first material and the second material are different from each other, and the first hardness level is greater than the second hardness level.

12. The limited clearance hydraulic tool according to claim 1, wherein: The limited clearance hydraulic tool is configured to provide a first torque output for rotating the associated threaded fastener assembly in a first mode and to provide a second torque output for rotating the associated threaded fastener assembly in a second mode, the second torque output being greater than the first torque output; And wherein the push plate is continuously spaced apart from the drive plate during the first mode, and the push plate contacts the drive plate during the second mode.

13. The limited clearance hydraulic tool according to claim 12, wherein: The connecting pin contacts the piston rod and the drive plate during both the first mode and the second mode.

14. The limited clearance hydraulic tool according to claim 12, wherein: The connecting pin is configured to deflect along the cylinder axis in a direction away from the piston in the second mode to allow the push plate to contact the drive plate.

15. The limited clearance hydraulic tool according to claim 1, wherein: The housing is a monolithic housing including an integral receiving member configured to engage an associated reaction washer of the associated threaded fastener assembly.

16. The limited clearance hydraulic tool according to claim 15, wherein: It also includes a pair of castellated spline hubs, which are coaxially arranged along the ratchet axis so that the ratchet is arranged between the pair of castellated spline hubs.

17. The limited clearance hydraulic tool according to claim 16, wherein: The integral receiving member includes a pair of hoops at least partially spaced apart from one another to receive the ratchet therebetween; And wherein each of the hoop rings defines a hoop inner diameter that selectively engages a corresponding castellated spline hub to prevent relative rotation between the associated reaction washer and the limited clearance hydraulic tool.

18. The limited clearance hydraulic tool according to claim 1, wherein: Also included is a magnetic ring disposed along the ratchet axis to face outward from the ratchet; wherein the magnetic ring includes a stop surface facing away from the ratchet, the stop surface being sized to contact an associated reaction washer of the associated threaded fastener assembly and prevent over-insertion of the associated threaded fastener assembly into the limited clearance hydraulic tool.

19. The limited clearance hydraulic tool according to claim 1, wherein: The piston, the ratchet, the drive plate and the piston rod are all disposed in the housing.

20. The limited clearance hydraulic tool according to claim 1, wherein: The housing defines a first housing line in fluid communication with the piston cylinder through a first port and a second housing line in fluid communication with the piston cylinder through a second port; wherein the first port and the second port are fluidically isolated from each other by the piston.

21. The limited clearance hydraulic tool according to claim 20, wherein: The first case line and the second case line each include a portion that is non-parallel and non-perpendicular to the cylinder axis.

22. The limited clearance hydraulic tool of claim 20, further comprising: a swivel head configured to be connected to an associated first main line and an associated second main line that are fluidly isolated from each other, wherein the associated first main line is in fluid communication with the first shell line and the associated second main line is in fluid communication with the second shell line; and a rotating body connected to the rotating head, wherein the rotating head is configured to rotate about the rotating body to define a pivot head axis orthogonal to the cylinder axis; wherein the housing defines a rotating body opening for receiving the rotating body, and the rotating body is configured to rotate at least partially about the housing to define a pivot body axis substantially parallel to the cylinder axis.

23. The limited clearance hydraulic tool of claim 1 , further comprising a reaction pad having a first end and a second end, the first end and the second end being located at opposite ends of the reaction pad; wherein The housing defines a channel that at least partially receives the reaction pad.

24. The limited clearance hydraulic tool according to claim 23, wherein: A distance between the first end and the second end defines a length of the reaction pad, the channel defines a channel length; and wherein the channel slidably receives the reaction pad such that the length of the reaction pad is greater than the channel length.

25. The limited clearance hydraulic tool of claim 23, further comprising: a swivel head configured to be connected to an associated first main line and an associated second main line that are fluidly isolated from each other; a rotating body connected to the rotating head, wherein the rotating head is configured to rotate about the rotating body to define a pivot head axis orthogonal to the cylinder axis; and A removable end cap is received by the housing to be disposed on the cylinder axis; wherein a distance between the first end of the reaction pad and the pivot head axis is greater than a distance between the end cap and the pivot head axis.

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