Spanner wrench

A spanner wrench assembly including a base plate having a gripping portion extending from a handle portion and defining an arcuate cavity with an open end. At least one support plate is secured to the gripping portion and substantially matches a configuration of the arcuate cavity. The support plate is of a lesser density material than the base plate. An engagement plate substantially matches the configuration of the arcuate cavity and is secured with respect to the at least one support plate. A cover defines one elongate aperture extending to an open mouth portion formed by an adjacent end of the cover, and another elongate aperture extending to a closed mouth portion dimensioned to accept a connector head which is wider than the elongate apertures.

FIELD OF THE INVENTION

This invention relates generally to a spanner wrench assembly, and more particularly to an adjustable wrench assembly for assembling and disassembling various sizes of components.

BACKGROUND OF THE INVENTION

Industry usage of hydraulic cylinder assemblies utilizing threaded insert cylinder caps is rapidly increasing. These insert caps have external threads which mate with internal threads in the cylinder barrel. When assembled to the cylinder barrel, the insert caps must be tightened to a specified torque. A spanner type wrench is usually used to assemble and disassemble the cap and the barrel, with the wrench having engaging pins to engage slots or holes in the cap. Removal of the cap is usually very difficult due to rusting, corrosion, and denting of the cap and/or cylinder barrel. These problems increase the torque required to remove the cap, and it is very difficult to maintain engagement of the wrench with the cap slots. Installation and removal is even more difficult because the caps are usually cast, resulting in the slots having curved corners and wall surfaces having a draft angle. The use of very large pipe wrenches and chain type wrenches has been only marginally successful due to the width and overall diameter of the caps. Still another problem is that each hydraulic cylinder size requires a separate wrench to fit that particular cylinder cap.

SUMMARY OF THE INVENTION

The present invention relates to an improved spanner wrench assembly for installing and removing components of a structure. The inventive spanner wrench has a base plate with a gripping portion extending from a handle portion and defining an arcuate cavity with an open end. At least one support plate is secured to the gripping portion and has a configuration substantially matching that of the arcuate cavity, the at least one support plate being of a lesser density material than the base plate. An engagement plate is secured with respect to the at least one support plate and substantially matches the configuration of the arcuate cavity. The engagement plate provides locking engagement with the components that need to be disassembled from the main structure. The base plate and the support plate together form a rotation member with the handle portion serving as a lever for rotating the components such as a cap of a hydraulic cylinder.

The spanner wrench assembly may have a pair of the support plates each secured to the base plate and sandwiching the gripping portion therebetween. Each of the support plates may be of a lesser density material than the base plate, thereby reducing the total weight of the spanner wrench assembly. The base plate may be made of steel while the support plates may be made of aluminum.

The inventive configuration permits initial formation of the base plate including the gripping portion and the handle portion as a one-piece plate of a substantially consistent thickness. Such one-piece plate is free of welding or other junction formed between initially-separate gripping and handle portions. The integral one-piece has strengthened connection between the gripping and handle portions. This is in contrast with prior assemblies which have a handle welded to a cylinder to form a member with the lever for rotating the wrench assembly to disassemble a structure, such as to remove a cap of a hydraulic cylinder.

The spanner wrench assembly may have a plurality of engagement blocks, each slidably received within a slot formed in an open face of the engagement plate. The slots may be arranged such that at least one of the slots is positioned with respect to at least one other slot at one of 180°, 120°, 90°, 60° and 30° angles. There may be pairs of the slots with one slot of the pair positioned at a 180° angle with respect to the other slot of the pair. In addition or alternatively, there may be pairs of the slots with one slot of the pair positioned at a 120° angle with respect to the other slot of the pair. In addition or alternatively, there may be pairs of the slots with one slot of the pair positioned at a 90° angle with respect to the other slot of the pair. In addition or alternatively, there may be pairs of the slots with one slot of the pair positioned at a 60° angle with respect to the other slot of the pair. In addition or alternatively, there may be pairs of the slots with one slot of the pair positioned at a 30° angle with respect to the other slot of the pair.

The spanner wrench assembly may further include a locking block secured within each of the slots. The locking block may be adjustable within the slot such that the corresponding one of the engagement blocks may be substantially freely inserted into the slot. Once the engagement block is in the desired position, the locking block may be further adjusted to lock the engagement block in a fixed position within the slot.

In certain embodiments, each of the slots may be a substantially rectangular trough defined by a substantially flat bottom surface with a pair of opposite lateral surfaces extending substantially orthogonally to the bottom surface.

Each of the engagement blocks may have an engagement portion extending from a mounting portion positionable within the slot. The engagement portions of different blocks may be of different sizes to accommodate a variety of engagement cavities in components to be removed.

In certain embodiments, the mounting portion has a pair of lateral surfaces extending from a substantially flat mounting surface positionable against less than the full width of the substantially flat bottom surface of the slot. One of the lateral surfaces of the engagement-block mounting portion is substantially orthogonal to the mounting surface for positioning against one of the lateral surfaces of the slot. The other lateral surface of the engagement block may extend from the mounting surface of the block at a sharp angle.

In some of such embodiments, the locking block has one lateral surface substantially orthogonal to a bottom surface for positioning against the lateral surface of the slot opposite the orthogonal lateral surface of the engagement block. The other lateral surface of the locking block extends at an obtuse angle which substantially equals the subtraction from 180° of the sharp angle of the lateral surface of the mounting portion of the engagement block.

In order to position the engagement block within the slot, the locking block is moved away from the bottom surface of the slot. The locking block may be moved by loosening fasteners securing the locking block to the engagement plate. When the engagement block is in the desired position, the locking block is brought toward the bottom surface of the slot such that the angled lateral surfaces of the locking block and the mounting portion of the engagement block are in tight abutment, thus holding the engagement block in the fixed position within the slot.

In certain embodiments of the spanner wrench, the engagement blocks include pin-retaining blocks each defining a set of cavities with a retaining pin in each cavity. Some of such pin-retaining blocks may have a spring assembly within each cavity which includes a spring depressed by the pin locked within the cavity. When the pin is unlocked, the spring is released and pushes the pin out of the cavity beyond a front face of the pin-retaining block for engagement with the component to be removed from the structure. Alternatively, the pin may be removed from the cavity which stores the pin for positioning into the orthogonal cavity to accommodate engagement with a component that has a configuration requiring such engagement orientation.

The pin may be locked within the cavity by a locking screw which is advanced through a lateral wall of the block into the cavity until engagement with the pin. The pin is unlocked by retrieval of the locking screw from the cavity.

In certain embodiments, the spanner wrench assembly includes a cover plate for closing the open end of the arcuate cavity. In some embodiments, the cover plate defines a pair of spaced apart elongate apertures. Each of the apertures is dimensioned to accept a stem of a corresponding one of a pair of connectors extending from one of the base and support plates. One of the elongate apertures may extend to an open mouth portion formed by an adjacent cover-plate end. Another of the elongate apertures may extend to a closed mouth portion dimensioned to accept a connector head which is wider than the elongate apertures.

For securing the cover plate with respect to the base and support plates to close the arcuate cavity, the cover plate is slid against end surfaces of the base and support plates such that the connector head is at a cover-plate surface opposite a work surface of the cover plate abutting the end surfaces of the base and support plates.

In some versions, both apertures may have a key-hole shape with a wider mouth portion dimensioned to accept the head of the connector and a narrower elongate portion of the aperture dimensioned to accept the stem of the connector, thereby securing the cover plate with respect to the base and support plates

In some embodiments, the narrow elongate portion of the elongate apertures is formed through less than the full thickness of the cover plate with the remaining thickness being formed into an elongate cavity dimensioned to accept the connector head. Such configuration forms a ledge within the elongate aperture with the connector head being recessed within the cover plate against such ledge when the cover plate is secured against end surfaces of the base and support plates to close the arcuate cavity.

Some embodiments of the spanner wrench assembly further include a retainer at the cover-plate work surface. The retainer can be pressed into the cover plate by abutment of the cover-plate work surface and end surfaces of the base and support plates during sliding of the cover plate in and out of engagement with the connectors. The retainer may be a spring-loaded protrusion from the cover-plate work surface. In some of such embodiments, the end surface of one of the base and support plates defines a recess receiving the spring-loaded protrusion.

In some of the embodiments where the spanner wrench assembly has two support plates sandwiching the gripping portion of the base plate, the spanner wrench assembly may include two pairs of spaced apart elongate apertures and two pairs of corresponding connectors extending from one of the base and support plates.

In some examples, the connectors extend from the end surfaces of the support plates and the end surface of the base plate defines the recess for receiving the spring-loaded protrusion from the cover plate.

The spanner wrench assembly may further have a holder which retains the cover plate with respect to the base and support plates when the cover plate is disengaged therefrom. In some embodiments, the holder is a wire rope with one end attached to the cover plate and the other end secured with respect to the arcuate cavity. Such other end may be secured to a side surface of the base plate or the support plate.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

FIGS. 1-11illustrate an exemplary embodiment of an improved spanner wrench assembly10for installing and removing components12of a structure13such as a cap and a hydraulic cylinder.FIGS. 5 and 6best show spanner wrench10having a base plate20with a gripping portion21extending from a handle portion22and defining an arcuate cavity23with an open end24. A pair of support plates26is secured to gripping portion21and has a configuration substantially matching that of arcuate cavity23. Support plates26may be made of material different from the material of base plate20. The support-plate material may be of a lesser density and therefore lighter weight than the material of the base plate, such as aluminum and steel. An engagement plate30is secured to one of support plates26and has substantially matching configuration to that of arcuate cavity23.FIGS. 11, 13 and 14show engagement plate30providing locking engagement with components12. Base plate20and support plate26may be connected with bolts19and/or pins11or otherwise attached together to form a rotation member200with handle portion22serving as a lever for torquing components12. A rectangularly shaped non-metallic plastic plate84is positioned within the middle of arcuate cavity23and is configured to span all three of base plate20and support plates26.

FIGS. 6-9show spanner wrench assembly10having a plurality of engagement blocks40a,40band40c. Each block40is slidably received within a slot32formed in an open face31of engagement plate30.FIGS. 2 and 9best show slots32arranged such that slot321is positioned with respect to slot322at a 180° angle. Slot323is positioned with respect to slots321and322at a 90° angle. And slot324is positioned at a 60° angle with respect to slot321, at a 30° angle with respect to slot323and at a 120° angle with respect to slot322.

FIG. 1shows spanner wrench assembly10including a locking block50secured within each of slots32. As seen inFIGS. 7 and 11, each locking block50is adjustable such that engagement blocks40may be substantially freely inserted into slots32.

FIGS. 1 and 2show each of slots32as a substantially rectangular trough defined by a substantially flat bottom surface33with a pair of opposite lateral surfaces34extending substantially orthogonally to bottom surface33.

Each of engagement blocks40has an engagement portion41extending from a mounting portion43positionable within slot32. Engagement portions41of different blocks40a,40band40cmay be of different sizes to accommodate a variety of engagement cavities in components12ato be removed. Mounting portion43has a pair of lateral surfaces44and45extending from a substantially flat mounting surface46positionable against less than the full width of substantially flat bottom surface33of slot32. Lateral surface44of engagement-block mounting portion43is substantially orthogonal to mounting surface46for positioning against one of lateral surfaces34of slot32. Lateral surface45of engagement block40extends from mounting surface46of block40at a sharp angle.

Locking block50has one lateral surface51substantially orthogonal to a bottom surface53for positioning against lateral surface34of slot32opposite orthogonal lateral surface44of engagement block40. Lateral surface52of locking block50extends at an obtuse angle which substantially equals the subtraction from 180° of the sharp angle of lateral surface45of mounting portion43of engagement block40.

In order to position engagement block40within slot32, locking block50is moved away from bottom surface33of slot32by loosening fasteners54which secure locking block50to engagement plate30. When engagement block40is in desired position, fasteners54are tightened such that angled lateral surface52of locking block50and mounting portion and angled lateral surface45of engagement block40are in tight abutment, thus holding the engagement block in the fixed position within the slot, as seen inFIGS. 7 and 11.

FIGS. 12-14illustrate a type of engagement blocks30which are pin-retaining blocks60, each defining a set of cavities61with a retaining pin62in each cavity61. As seen inFIG. 12, pin-retaining blocks60have a spring assembly within each cavity61. The spring assembly includes a spring64positioned within cavity61between a pad65and a plug66which securely closes one cavity end611. Pin62is positioned at the opposite open end612of cavity against pad65. Spring64is compressed by pin62locked within cavity by a locking screw67which is advanced through a lateral wall68of block60into cavity61until engagement with pin62. Pin62is unlocked by retrieval of locking screw67from cavity61. The force created by the compression of spring64is released by the unlocking pin62and pushes pin62out of cavity61beyond a front face69of pin-retaining block60for engagement with component12bto be removed from structure13, as seen inFIG. 13.FIG. 14shows pin62removed from storage cavity61and positioned onto an orthogonal cavity63to accommodate engagement with a component12cthat has a configuration requiring such engagement orientation.

Spanner wrench assembly10includes a cover plate70for closing open end24of arcuate cavity23.FIGS. 5, 6 and 15-18show cover plate70defining elongate apertures71and72. Each of apertures71and72is dimensioned to accept a stem16of a corresponding one of a pair of connectors15extending from support plates26. Aperture71extends to an open mouth portion74formed by an adjacent cover-plate end73. Elongate apertures72each have a key-hole shape and extend to a closed mouth portion75dimensioned to accept a connector head17which is wider than elongate apertures71and72.

FIGS. 15-18show that in order to close arcuate cavity23and get a secure grip of component12, cover plate70is secured with respect to rotation member200. Cover plate70is slid against end surfaces25and27of base and support plates20and26such that connector head17is at an open cover-plate surface76which is opposite a work surface77abutting end surfaces25and27of rotation member200.

FIGS. 15, 17 and 18show narrow elongate portions78of apertures71and72formed through less than the full thickness of cover plate70such that the remaining thickness defines an elongate cavity79dimensioned to accept connector head17. Such configuration forms a ledge82within elongate cavity79with connector head17being recessed within cover plate70against ledge82when cover plate70closes arcuate cavity23.

FIGS. 5, 6, and 16-18show a retainer80at cover-plate work surface77. During sliding of cover plate70in and out of engagement with connectors15, retainer80can be pressed into cover plate70beyond work surface77by abutment of cover-plate work surface77and end surfaces25and27of base and support plates20and26of rotation member200.FIG. 16shows retainer80as a spring-loaded ball81protruding from cover-plate work surface77.FIG. 15shows end surfaces25of base plate20defining a recess28receiving spring-loaded ball protrusion81to further secure the position of cover plate70closing arcuate cavity23.

When cover plate70is disengaged from rotation member200, a holder18retains cover plate70with respect to base and support plates20and26.FIGS. 2, 11, 13 and 14show holder18as a wire rope with one end attached to cover plate70and the other end secured to a side surface29of base plate20.

FIGS. 11, 13 and 14show spanner wrench assembly10on a piston rod13prior to engagement with the threaded cap member12. Adjustable contact pins141,142and143have been adjusted to center wrench assembly10on rod structure13. Prior to applying a force to handle portion22, contact pins are adjusted to keep the wrench assembly10square with the rod13and to keep the wrench assembly10from “cocking” or twisting. Some embodiments may include a leveling device such as those utilizing a bubble level or some other indicator mechanism that facilitates the centering of wrench assembly10on rod structure13.

While the principles of the invention have been shown and described in connection with specific embodiments, it is to be understood that such embodiments are by way of example and are not limiting.