Abstract: A secured crank locking device automatically secures a hand crank in its operative position to an input shaft of a gearing mechanism, with the locking device being easily disengaged to move the crank from its operative position to a stored position following rotation of the crank in the operation of the mechanism.

Abstract: “DISPOSITION INTRODUCED TO HYDROPNEUMATIC JACK”, according to description of the report and the annexed illustrations, it is about a new disposition for a hydropneumatic device that is used to lift and support hauler and semi-haulers, whereby the device was designed to offer more operational easiness to the driver through the increase of speed, as well as the durability of the set.

Abstract: The subject invention pertains to a method and apparatus for providing a trailer jack mount. The subject invention also pertains to a method and apparatus for providing a trailer jack mount for use with towable trailers. The subject invention is advantageous for use with trailers, such as utility trailers, which are frequently moved between various locations. The subject apparatus can also enable the mounting of a trailer jack to a trailer such that the trailer jack can quickly transition up or down relative to the trailer. In a specific embodiment, the subject invention includes a first piece mountable to a trailer and a second piece to which a trailer jack can be secured. In this embodiment, the subject apparatus also includes means for securely attaching the second piece to the first piece and allowing the second piece to pivot relative to the first piece. Advantageously, the subject invention can either be retrofitted to an existing trailer with jack, or installed at original manufacture.

Abstract: The present invention is directed toward an apparatus for quickly configuring a jack to raise a load from its rest position. In particular, the present invention provides a jacking mechanism that telescopes from a locked, elevated position to a locked, lowered position in order to situate the jacking mechanism for raising a load. Correspondingly, the present invention provides a jacking mechanism that telescopes from its locked, lowered position to its locked, elevated position for stowing the mechanism between uses.

Abstract: A device for removing a clip pin from a jack utilizing a lever having a first portion, a second portion, and a fulcrum therebetween. The arm is linked to the fulcrum of the lever and extends outwardly to bear on the housing of the jack. A fastener holds the lever first portion to the clip pin of the jack such that movement of the second portion of the lever about the fulcrum removes the clip pin.

Abstract: A lift mechanism for a fifth wheel trailer tube and foot pad that is both functional and accessible. A tee handle is made with curved ends and a smooth finish, making it comfortable to grip when lowering or raising the foot pad assembly. A telescoping tube is hollow, allowing a cable to be guided through it and around a pully to an eye bolt that is attached to the foot pad. A cover is provided over the pully to keep the cable securly in the pully groove and direct it to the foot pad using the slotted cutouts in the cover. A main “L” shaped bracket allows the telescoping tube to be mounted at an angle, making it easier for operator reach.

Abstract: A mechanical arm includes a base that mount on a selected support. A proximal arm member has a proximal end portion pivotally secured to the base and a distal end portion pivotally secured to a distal arm member. The base has a first fixed gear element disposed thereon, and a second fixed gear element is disposed on the distal arm member. A drive shaft is rotatably disposed on the proximal arm member and includes a first end portion provided with a first drive gear engaging the first fixed gear element and a second drive gear provided with a second drive gear engaging the second fixed gear element such that rotation of the drive shaft acts to pivot the arm members. A drive acts to rotate the drive shaft.

Abstract: A trailer tongue jack includes a grease (or zerk) fitting for providing grease to internal parts The jack includes an outer tube and an inner telescoping tube. A threaded insert (or nut) is fixedly attached inside an upper end of the inner telescoping tube. A screw shaft threadedly cooperates with the insert to extend or retract the inner telescoping tube from a lower end of the outer tube. A crank is provided to turn the screw shaft either directly or through gears, and a thrust bearing carries a vertical load between the screw shaft and the outer tube. The grease fitting allows the internal parts, and the thrust bearing in particular, to be easily lubricated.

Abstract: Disclosed herein is a mechanical screw jack comprising: a housing; a mechanical jack stroke limiting nut connected to the housing, the nut having a nut wall, the wall defining an interior female threaded surface and an interior screw travel limiting surface located adjacent to the interior female threaded surface; and a mechanical jack screw having an externally threaded male surface for threadably engaging the interior female threaded surface of the mechanical jack stroke limiting nut and a disruption; wherein the unthreaded screw travel limiting surface is capable of interferingly engaging at least a portion of the disruption to prevent over travel of the threaded screw. A method of limiting screw travel in a mechanical screw jack is also disclosed. Advantageously, screw travel is limited such that a user can over torque the screw, such that the screw can travel with respect to the nut without damaging the threaded portion of the nut.

Abstract: A trailer tongue arrangement is provided having a power jack. The power jack is removably engaged with the tongue and includes a circular level unit thereon which indicates a level condition in the front-to-back and side-to-side directions.

Abstract: The present invention is directed to a mounting member for a jack. The mounting member includes a single die cast member having a jack engaging portion. The jack engaging portion is capable of being mounted to a jack tube having either a square or circular cross-section. The mounting member also includes a connecting portion integrally formed with the jack engaging portion. The connecting portion is capable of pivotal connection to an object to be supported with the jack.

Abstract: An apparatus for assisting in the operation of a conventional trailer jack. The jack assistance apparatus is attached to a conventional trailer jack having telescoping tubes with a coarse adjustment and a fine adjustment. The apparatus includes a lever arm that engages a locking pin handle on the jack, and a guide tube that contains a chain or other flexible member with one end attached to the jack base and the other attached to a handle. The lever arm and handle are located for convenient access by an operator for coarse vertical adjustment of the jack.

Abstract: The present invention relates generally to a jack stand and methods of making and using same. In particular, but not by way of limitation, the present invention relates to a jack stand having (1) a targeting assembly for use in aligning the jack stand when attached to a trailer with an operating vehicle; and (2) means for automatically moving the foot assembly of the jack stand from a ground engaging configuration to an upright stored configuration.

Abstract: A towed rotary cutter includes a self-leveling hitch equipped with a parking stand mounted in a centered position beneath the hitch. Through the operation of the leveling links, the hydraulic lift cylinder that is used for raising and lowering the ground wheels of the cutter relative to the cutter frame is also used to manipulate the hitch, once the parking stand is placed in its park position, so as to remove the weight of the hitch from the tractor drawbar when unhitching the tractor from the rotary cutter, or to place the hitch clevis at the correct height for connecting it to the tractor drawbar when hitching the cutter to the tractor. In a first embodiment, the parking stand is constructed for use with a hitch having a feature for automatically maintaining the clevis in a horizontal attitude.

Abstract: Disclosed herein is a mechanical screw jack comprising: a housing; a mechanical jack stroke limiting nut connected to the housing, the nut having a nut wall, the wall defining an interior female threaded surface and an interior screw travel limiting surface located adjacent to the interior female threaded surface; and a mechanical jack screw having an externally threaded male surface for threadably engaging the interior female threaded surface of the mechanical jack stroke limiting nut and a disruption; wherein the unthreaded screw travel limiting surface is capable of interferingly engaging at least a portion of the disruption to prevent over travel of the threaded screw. A method of limiting screw travel in a mechanical screw jack is also disclosed. Advantageously, screw travel is limited such that a user can over torque the screw, such that the screw can travel with respect to the nut without damaging the threaded portion of the nut.

Abstract: A portable drive system for automating the rotation of drive systems designed to use hand cranks. The portable drive system includes an housing designed for being held in position by a human using two hands, a drive motor positioned substantially within the housing and used to provide a rotational force for activating a drive shaft conventionally activated by a hand crank, and a drive shaft which is operationally coupled to the drive motor and extends from the housing through an aperture in the front wall of the housing.

Abstract: A detachable jack assembly for attaching to a hitch, including a leg having a first member movably connected to a foot member; a crank assembly disposed on the first member and having a rotatable arm, the crank assembly operably connecting the first member to move the foot member relative to the first member when the arm is rotated; an attachment member disposed on the first member and having a pin hole formed therein; a pin configured to fit in the pin hole; and a lock-out assembly disposed on the attachment member, including a bar member biased to a first position and movable to a second position, wherein the rotation of the rotatable arm is limited by the bar member when the bar member is in the first position, and the rotatable arm moves freely when the bar member is in the second position, wherein, when the pin is disposed in the pin hole, and the bar member is in the second position, the pin maintains the bar member in the second position.

Abstract: A trailer tongue arrangement is provided having a power jack. The power jack is removably engaged with the tongue and includes a circular level unit thereon which indicates a level condition in the front-to-back and side-to-side directions.

Abstract: A combination trailer crank and locking mechanism. The device includes a crank portion having a handle portion separated from a coupler portion by a generally S-shaped body portion. When the coupler portion of the device is coupled with a rotatable shaft of a retractable leg assembly of a trailer, the crank portion facilitates the raising and lowering of the trailer's legs. The device also includes a locking portion which is connected to the crank portion in a transverse orientation. When the device is connected to the rotatable shaft of the trailer by the locking portion, the crank portion will abut an underneath side of the trailer and prevent rotation of the rotatable shaft, thereby preventing a person from being able to raise and lower the retractable legs of the trailer.

Abstract: An inner leg telescopically fits within an outer leg and includes a motor coaxially mounted to an end remote from the outer leg. A drive screw is coupled to the motor shaft and extends through a drive nut in an axially extending drive nut riser. As the motor rotates the drive screw, the inner leg extends and retracts from the outer leg. In a preferred embodiment of the invention, the drive nut riser is a hollow cylindrical tube extending substantially the length of the outer tube to position the drive nut near the intersection between the inner and outer legs when fully extended. Such an arrangement allows a motor to be coaxially mounted within the inner leg and, therefore, concealed and provides the desired extension and retraction of the legs for adjustment to different operative positions.

Abstract: A trailer tongue jack system which in an exemplary embodiment has separable upper and lower housings which must be coupled together to form a complete operable system, and a driveshaft with a recessed non-standard coupling which must be coupled in order to allow the housings to be coupled.

Abstract: A motor-driven trailer swivel jack is described that includes a detachable steering assembly. The steering assembly is fastened to the jack by both electrical and mechanical fasteners. The mechanical fastener allows the steering assembly to freely pivot in the vertical direction, which allows the user to maintain a grip on the steering as the jack moves over rough terrain. The mechanical fastener provides a rigid connection in the horizontal direction, which allows steering forces to be transferred to the jack without loss. The electrical connector is mounted between the motor and its power source. All the wiring necessary to connect the motor to the power source and the switch to control the motor is located in, or attached to, the removable steering assembly. When the steering assembly is removed, the de-energized motor effectively brakes the wheel of the jack, which complements the absence of a steering mechanism to make the jack difficult to accidentally move or tamper with.

Abstract: Trailer jack attachment assemblies which do not extend below the lowermost frame member of the trailer body so as to avoid increasing obstruction from roads and rough terrain. Attachment is made to the trailer frame without destroying its structural integrity. Cross-braces between laterally opposite attachments minimize localized twisting of individual frame members.

Abstract: A trailer tongue includes a support and a support leg slidingly and pivotally engaged with the support. When the support leg is raised or lowered the trailer tongue moves in a substantially vertical direction. In a preferred embodiment, the trailer tongue includes a rigid strut having first and second ends and a mechanism for extending and retracting the support leg pivotally connect to the support and the support leg. The first end of the rigid strut is pivotally connected to the support leg and the second end is pivotally connected to the support.

Abstract: A vehicle trailer is provided having an adapter apparatus for providing a temporary spare tire. Typically, the trailer will be equipped with removable brackets by which the adapter apparatus can be connected to the trailer frame. If a spare tire is needed, the adapter apparatus is positioned at a bracket adjacent the failed wheel. The adapter apparatus itself includes a rotatable wheel mounted at the distal end of an elongate jack. Actuation of the jack causes the failed wheel to be lifted from the ground. The operator can then proceed to the desired destination on the wheel of the adapter apparatus without requiring the failed wheel to be removed. In exemplary embodiments, the adapter apparatus can be used as a tongue lift when a spare tire is not required.

Abstract: A trailer tongue includes a support and a support leg slidingly and pivotally engaged with the support. When the support leg is raised or lowered the trailer tongue moves in a substantially vertical direction. In a preferred embodiment, the trailer tongue includes a rigid strut having first and second ends and a mechanism for extending and retracting the support leg pivotally connect to the support and the support leg. The first end of the rigid strut is pivotally connected to the support leg and the second end is pivotally connected to the support.

Abstract: A mobile vehicle service trailer provides a portable maintenance facility for motor vehicles (passenger cars, pickup trucks and sport utility vehicles, etc.) without need to transport the vehicle to a maintenance facility at a fixed location. The present trailer has rearwardly disposed wheels and laterally extendible ramps, enabling the trailer to be positioned laterally at the front or rear of the vehicle needing service and the vehicle to be positioned laterally across the trailer. This configuration provides for ease of loading and unloading the vehicle to and from the trailer in cramped parking situations, such as parking lots and garages, etc. The rear wheels of the trailer are pivotally mounted, allowing the trailer body to be lowered to the underlying surface for placement of a vehicle thereon.

Abstract: A vehicular jack system is provided including a mounting bracket fixedly coupled to a frame of a vehicle. Also included is a jack assembly connected to the mounting bracket for elevating the vehicle. A jack arm is provided for manually elevating the vehicle via the jack assembly by way of a reciprocating motion.

Abstract: A trailer with expandable sides and retractable wheels used for performing on site vehicle maintenance and repair services. The trailer has a rectangular frame mounted on wheels with a conventional trailer coupler for attachment to a towing vehicle. The wheels are pivotally mounted to the frame, the wheels being locked in a ground engaging position for towing the trailer, and being unlocked so that the frame may be lowered into a ground engaging position by a plurality of hydraulic cylinders for the servicing of vehicles. The frame includes a plurality of crossbeams. A pair of side extenders telescope into the front, rear and center crossbeams so that the width of the trailer may be extended by hydraulic cylinders with the frame in a ground engaging position. The trailer includes a two-post hydraulic vehicle lift for raising the vehicle to be serviced.

Abstract: Small boats being trailer launched from steep ramps are in danger of spilling water over the transom if the bow is held high by the trailer. The invention is for a two component jack screw mechanism that can lower the trailer tongue below the trailer hitch without disconnecting it from the towing vehicle. One component coupled to the trailer tongue has a vertical tower that fits within a second tower attached to the second component that is coupled to the trailer hitch. A manually operated crank attached to a jack screw within the two towers lowers the tongue and the bow of the boat so that the boat may float from the trailer.

Abstract: A landing gear crank handle for raising and lowering vehicle landing gear is provided that includes a first hand hold that is horizontal when the handle is in a full extended position, a second hand hold connected to the first hand hold by a central portion, and an arm connected to the first hand hold; and a jaw connector attached to the arm and adapted to connect the crank handle to a landing gear crank mechanism and adapted to allow the crank handle to lock into a collapsed position, a partially extended position, and a full extended position.

Abstract: A load frame which mounts on a trailer between the trailer hitch connection and the trailer frame front cross member. The load frame is a wishbone-shaped structural unit which mounts to the trailer frame front cross member with a pivoting saddle on the two rear legs of the wishbone. The load frame includes a spindle mount connected to a wheel assembly and a retracting arm for engaging a retracting apparatus to adjust the relationship between the wheel assembly and the trailer frame. The spindle mount includes a suspension mechanism and a pivoting connection for the wheel assembly. The wheel assembly includes a spindle member which is slidably and rotatably attached to the spindle mount. A tire is rotatably attached to the wheel assembly. The tire extends downwardly from the spindle mount to roll along the ground and support a portion of the tongue weight of the trailer.

Abstract: Disclosed is a trailer jack leveling adapter for improving a fifth wheel trailer jack stand having a pair of downwardly telescoping leg assemblies whereby one of the leg assemblies may be adjusted to compensate for an uneven supporting surface for leveling the trailer. The trailer jack leveling adapter comprises a connector fixedly attached to a lower end of a leg assembly. An elongated leg extension is longitudinally adjustably engaged with the connector. The leg extension is also pivotally connected at a lower end thereof to a leg assembly foot pad such that the leg extension and foot pad may be moved relative the leg assembly for leveling the trailer.

Abstract: A jack of the type having inner and outer legs and a screw for extending and retracting the inner leg relative to the outer leg. The screw is mounted on a base fixed to the outer leg for rotating and limited endwise movement between the upper and lower positions relative to the base such that the screw and inner leg can move downwardly to the lower position when the inner leg is out of ground engagement and the inner leg moves the screw toward the upper position when the leg engages the ground. A rotary drive member is mounted for rotation relative to the base about the axis of the screw and a transmission mechanism responsive to rotation of the drive member drives the screw at a high speed ratio when the screw is in the lower position and at a low speed ratio when the screw is in the upper position.

Abstract: An improved trailer tongue jack including an outer tube and an inner tube which is slidable within the outer tube. The lower end of the inner tube carries a terrain engaging member, such as a caster wheel or sand shoe. A nut is mounted within the inner tube and is threaded on a screw and the upper end of the screw carries a bevel gear which meshes with a second bevel gear mounted on a handle. The bevel gears are supported within a polymeric cup mounted in the upper end of the outer tube and the cup also serves to rotatably support the handle as well as the upper end of the screw and further functions, along with a thrust washer, as a thrust bearing for the screw. The jack also includes an improved locking mechanism for locking the jack in either a vertical or horizontal position. A U-shaped swivel bracket is secured to the outer surface of the outer tube and the lower end portion of a locking member is mounted for movement within aligned openings in flanges of the swivel bracket.

Abstract: For carrying out a method to displace an object from a resting position to to a working position or vice verse, a device (1) is arranged comprising a screw (3) with two threads (7, 9) with different pitches and a body (2, 4) with internal threads matching the threads of screw (3). The body is shaped in two parts (2) and (4), which are arranged to be able to be displaced relative to one another in the axial direction of the screw (3), whereby a changing from one thread to another thread can be done by changing the distance between said parts (2, 4) of the body. The screw (3) is arranged to a first object and the body (2, 4) to a second object.

Abstract: A quick release trailer jack comprises a vertical support mast extending through a jack body. Pinion and worm gears housed in the body couple a crank to a rack gear on the mast for vertically raising and lowering the mast relative to the trailer. A plunger coaxial with the pinion gear permits an operator to axially translate the pinion gear lateral the mast axis, thereby decoupling the crank from the rack gear. The pinion gear slides into a cylindrical cavity containing a biasing spring which returns the pinion gear into its normal position, re-coupling the crank and the rack, when the operator releases the plunger.

Abstract: The present invention provides a slidable support assembly which is affixed to an extensible jack leg of a typically heavily loaded commercial trailer and is used to support the front end of the trailer when not connected to a towing truck. The support assembly is able to slide laterally for the purpose of properly aligning the trailer hitching and towing vehicle mechanisms without injury to the operator.

Abstract: A trailer jack mounting assembly which is rotatable has an outer support member which has a cylindrical bore and is mounted to a trailer frame adjacent to its hitch end with the outer support member receiving a horizontally disposed rectangular cross-section sleeve member rotatably fitted and restrained within the outer support member. A slidable latch member in the form of a U-shaped plate having a handle portion at its top fits within a track in the outer support member and is movable between open and closed positions whereby the rotation of the inner support carrying the jack can be placed in either an upright position or a horizontal position.

Abstract: A screw jack incorporating a quick retract mechanism to permit movement of the jack into engagement with the ground such that only limited rotation of the screw is necessary for elevating the tongue of a trailer for disengaging a coupler on the trailer from a trailer hitch. The screw-type jack incorporates an improved handle which is rotatable about a horizontal axis between an active position for rotating the screw about a vehicle axis and a stowed position wherein the handle engages the body of the jack to prevent rotation of the screw. A support for the screw jack which incorporates improved versatility such that it can be interchangeably used on other jacks and can be used in applications involving uneven and/or non-level surface conditions.

Abstract: A combination, retractable jack and support apparatus for trailer tongues. The jack is pivotally connected to counterbalance which is used to raise or lower the support apparatus. The design provides a sturdy horizontal support for trailers in port, disconnected from towing vehicles; and a means to facilitate mechanical retraction of the support apparatus when coupling to a towing vehicle for road travel.

Abstract: A jack is mounted on a trailer tongue by a swivel connection to pivot between a vertically disposed active position and a horizontally disposed stowed position. The swivel connection includes a spacer sandwiched between a bracket on the tongue of the trailer and a bracket on the housing of the jack and rotatably received in a hole in the tongue bracket. The spacer serves to hold the two brackets out of contact with one another. A bolt extends through the housing bracket and the spacer with a non-rotatable fit and causes the housing bracket and the spacer to turn in unison relative to the tongue bracket. A nut and washer on the inner end of the bolt clamp the brackets together while allowing the housing bracket to pivot relative to the tongue bracket. The tongue bracket may either be clamped to the tongue by bolts or may be bolted to still another bracket which is welded to the tongue.

Abstract: A hand-operated hydraulic jack rotatably mounted on a trailer to assist in removably attaching the trailer to the hitching mechanism of a towing vehicle. The jack can be rotated to a vertical position and hydraulically actuated with a hand-operated pump to lift or lower the trailer tongue relative to the hitching mechanism. Once the trailer is attached to the hitching mechanism or is otherwise being adequately supported, the jack can be retracted by opening a thumbscrew valve on the hydraulic circuiting body to allow the hydraulic fluid to move through the return circuit back to the hydraulic fluid reservoir in the jack. The jacks's actuator is retracted by means of springs at the sides of the jack. With the tongue of the trailer supported and the jack retracted, the jack may then be rotated to its horizontal position to provide maximum ground clearance.

Abstract: A trailer hitch device comprises a jack shaft receiving socket mounted on a ground engaging support and slideable on a very low friction surface thus enabling the jack shaft to be shifted to perfect alignment of the components of a trailer hitch.

Abstract: The invention apparatus provides a winching mechanism which is detachably secured to the forward end of the tongue of a trailer. In a first embodiment, a slip nut on a crank operated vertical threaded drive shaft is attached to one end of a cable the opposite end of which is fitted with a snap hook which can be secured to a ball mount. The cable passes around a pulley at the base of a tubular housing in which the threaded shaft and slip nut are mounted. The pulley is located below the tongue. The cable is provided with a hook which is connected to a ball mount and when the drive shaft is driven by the crank causes the front of the trailer to be lifted and drawn to the towing vehicle for connection of the ball socket to the ball on the ball mount. In a second embodiment, the cable is wound on a crank operated drum and is fed to a pulley located below the tongue in a tubular housing of shorter length than employed in the first embodiment.

Abstract: A quick-release rack and pinion safety jack assembly for mounting upon the tongue of a conventional trailer. The jack assembly comprises a vertical support stanchion extending upwardly from a rotatable caster, a rigid rack, and a weatherproof box-like gear housing penetrated by the stanchion. A rotatable hand crank is rotated to move the stanchion relative to the gear housing, to elevate or lower the trailer. The internal gear assembly comprises a worm gear driven by the hand crank and a drive gear driven by the worm which selectively meshes or unmeshes with the rack. The drive gear is mounted for rotation upon a rigid axle which penetrates elongated follower slots defined in opposite walls of the gear housing. The drive gear axle is coupled at its ends by rigid links rotatably anchored in a pivotal safety lever. The safety lever is manually deflectable along an arcuate path between a first lock position and a second released position.

Abstract: Disclosed is a utility trailer having one or more stabilizers attached thto. The stabilizer is comprised of a pair of flat arms pivoted to the trailer and extending away therefrom, the arms defining holes disposed one above the other. A stanchion is vertically translatable through the holes in the arms and a spring in tension is stretched between the free end of the arms, whereby the free ends are biased toward each other and the edges of the arm holes bind against the stanchion to hold it in position. The arms may be pivoted away from each other to free the stanchion from the edges of the arm holes so as to allow the stanchion to be vertically translated to a new position relative to the trailer. A ground engaging foot is connected to the lower end of the stanchion.

Abstract: A parking stand for supporting the tongue of a parked trailer. The parking stand has a coupling ball at its upper end for engagement in the socket of a coupling part on the front end of the trailer tongue and a castor wheel or fixed base at its lower end for supporting the stand on the ground. A clamp on the upper end of the stand acts against the trailer coupling part to secure the stand against swivel movement relative to the trailer tongue.

Abstract: A tongue mounted rack and pinion jack for a trailer wherein a pair of die-cast gear box segments are bolted together for supporting a handle driven worm gear and a pinion gear in self-contained bearing surfaces formed in the gear box segments. When the gear box segments are secured together a gear box, a rack receiving passage and a leg receiving passage are formed therein. A common wall formed in the molded gear box segments separates the gear box from the rack receiving passage and has a window formed therein through which teeth on a pinion gear extend into the rack receiving passage and engage teeth on a rack extending longitudinally through the rack receiving passage and secured to a leg extending through the leg receiving passage.

Abstract: The present invention provides a three-piece telescoping jack that is capable of rapid coarse adjustments in height. The invention comprises first, second and third elongated tubular members that are somewhat nested in a telescoping relationship. The invention further comprises fine adjustment means for holding and adjusting the position of the second member in relation to the first and coarse adjustment means for holding and adjusting the position of the third member in relation to the second. The coarse adjustment means further allow the position of the third member to be rapidly adjusted, either retracted or extended, in relation to the second member. In a preferred embodiment, the fine adjustment means are a threaded nut and bolt. Also in a preferred embodiment, the coarse adjustment means are a pin and a series of holes in the second and third members.