Abstract: A magnetic jack comprising a body consisting of a series of slidably telescoped sections expandable along the jack axis, and a pair of electromagnets disposed between each successive pair of sections, each connected to one section, and having confronting poles of like polarity, so that they repel each other when electric current is supplied thereto, in order to extend the sections along the jack axis. The magnet pairs between successive pairs of body sections may be energized selectively, or the energizing current may be variably adjusted, in order to vary the height and force of the lift provided by the jack.

Abstract: An attachment or accessory to a wheeled floor jack of the type that rolls during use is disclosed. The accessory comprises a flat, elongated guard sized to receive and carry the wheels of the jack and to captivate them within it. The accessory provides a flat platform or base on which and within which the jack can roll and over which the weight lifted can be spread and serves to keep the wheels from the ambient surface. The attachment thus overcomes the problem encountered when using such jacks on a soft surface, such as snow, sand, dirt or asphalt, of having the wheels embed and the jack "snow plow," or slip. The attachment is designed to remain attached to the jack after insertion, but to easily receive the jack and be removed from it. The attachment also aids in handling the jack and limits or eliminates undesirable rolling, for example, when the jack is stored in the trunk of an automobile.

Abstract: A lifting jack has its upward and downward traveling distance controlled by means of a limit switch. The lifting jack has a base, an upright outer member rigidly connected to the base and an upright inner member movable coaxially within the outer member. An up stop and an adjustable down stop are rigidly attached to and move with the inner member. An adjustable mount is mounted in a fixed position on the outer member, and the limit switch is mounted in fixed position on the mount. A guide shoe assembly is pivotally connected to the mount and is oriented generally perpendicular to the direction of travel of the inner member. A stop engaging member at one end of the guide is positioned to engage the up stop and the down stop, and an arm guiding portion at the opposite end engages and guides an actuating arm of the limit switch.

Abstract: An extension for a common trolley type service jack that includes an elongate rigid frame with a tunnel extending inwardly from one end thereof to receive the jacking end portion of the trolley type service jack. The rigid frame bears downwardly on the frame of the service jack adjacent the entry to the tunnel and inwardly thereof are supports for the wheels of the trolley jack. A lift platform is attached to the rigid frame by a lever pivotally attached at one end to the lift platform and at the other end to the rigid frame and overly the tunnel. The lever extends beyond the tunnel and on the free outer end is mounted the lift platform, the lever being pivotally movable by the lift portion of the jack to raise the lift platform of the jack extension.

Abstract: A traction mat to aid vehicle wheels for driving out of ice, snow, mud or sand and the like that is an elongated unitary stamped metal structure which is generally rectangular and having a forward inwardly tapered end portion with the mat including a plurality of upwardly extending flanges disposed at 90.degree. with respect to the planer surface and a plurality of downwardly projecting V-shaped gripping lugs. The mat outer side edges are formed with trough shaped ribs for stiffening and the upwardly extending flanges and downwardly shaped gripping lugs are provided with structurally formed ribbing to increase the rigidity for placement and use in a variety of terrains.

Abstract: A bumper structure for a vehicle or the like, having a relatively long extension and retraction travel whereby the bumper may be sufficiently extended when the vehicle is in motion to provide a relatively very large shock or impact absorption, the structure readily being capable of extension for example, of 20 inches or more, and capable of being designed to provide a progressive shock absorbing action of widely varying characteristics. The construction is such that relatively long extension and retraction may be achieved in a structure taking up relatively little if any greater longitudinal space than conventional bumper structures, and even less space than many of the "so-called" shock absorbing bumpers now being introduced, which results are accomplished by the use of chain structures which are rigid in compression but which may be passed around cooperable sprockets whereby unextended portions of the chains may extend transversely to the longitudinal axis of the vehicle.

Abstract: A new invention of an easy pull clawed tool rest for removing nails, brads, tacks, spikes, etc., is disclosed wherein the size measures four inches in base length, 13/4 inches in width, and 11/2 inches in height at its thickest end, said vertical height rounding to meet the 1/8 inch height of the opposite base end in an arc determined by a connecting portion of a 6 inch radius circle. Indents of 3/4 inch width and 1/4 inch depth begin at the 11/2 inch vertical height midway between base and top surface and run parallel to the base toward the 1/8 inch height for a length of 11/4 inches, providing grip depressions for thumb and fingers of user. The rest shall be of molded 75 to 80 durometer neoprene rubber or comparable material which reduces possibility of surface marring to the maximum when the rest is used, while at the same time functioning well in the purpose for which it is intended.

Abstract: A safety device for use with a forklift having an elevatable carriage, a vertical guide for the carriage, and a horizontal cross bar mounted on the guide, the device having a pair of members spaced to provide a slot dimensioned for fitted engagement with the cross bar and a portion projecting from the members for supporting the carriage in elevated relation on the guide when the device is in such fitted engagement with the cross bar.

Abstract: An hydraulic floor jack of the type which rolls on the floor to engage under a vehicle to lift it. This jack is characterized by an articulated frame to operatively and selectively use less floor space, flexible tire wheels to allow the load on the jack to be transmitted directly to the floor by the base of the jack upon flexing of the flexible tires under the load until the best rests on the floor, and by a narrow construction and arrangement of the operative parts to allow engagement in narrow spaces and in particular between the tandem wheels of a truck.

Abstract: A lift with a work platform supported by a scissors linkage on a base includes a single hydraulic cylinder for elevating the linkage. The cylinder is connected between a lower link and a swing arm which is pivotally connected to the linkage. During a first lifting stage the swing arm bears against a cam surface on the uppermost link to cause an initial unfolding action of the upper links. Prior to the arm leaving the cam surface, the arm bears against an abutment on one of the lower links for a second lifting stage to cause unfolding of the linkage from the bottom. This arrangement provides a strong, smooth unfolding of the linkage. The base is provided with outriggers which can be folded against the sides of the base when not in use and which are pivoted to a transverse position for use. Links connecting the outriggers to a guide track enable positive locking of the outriggers in the operative position.

Abstract: A screw jack, for raising the power piston of a diesel engine's control governor until the power piston firmly clamps the gap gage, is provided to maintain the piston in its full load position during the adjustment of the engine fuel pump racks to match the governor piston gage, this adjustment being done when the diesel engine is shut down and the start contactors blocked open or insulated. The screw jack contains a break joint which, in its fully operative clamping position, can be rendered instantly inoperative simply by breaking the joint of the jack manually, a result effected by a single karate-like sweep of the hand.

Abstract: A table top assembly for a vehicle bumper jack including a planar table top, a table support member including a pair of parallel spaced guide members secured to the bottom of the table top and a pair of jaws adapted to grip opposing surfaces of the column of the bumper jack and mounted between said guide members for relative longitudinal movement of said table top over the bumper jack.

Abstract: In the post-stressing of concrete structures, a tendon comprised of a plurality of elongated strands is formed by inserting elongated strands which will eventually form the tendon into a plurality of parking ducts and then withdrawing the plurality of strands simultaneously as a group from the parking ducts and into the duct of the structure to be post-stressed without fouling and jamming. Once in the ducts of the structure, the strands are anchored and post-tensioned as a tendon to develop the desired stress.

Abstract: Device having movable jaws for gripping the shank of a pin or bolt is provided with ridges or grooves on the jaws which mate with corresponding ridges or grooves on the shank. The jaws are mounted to slide toward and away from each other and this sliding movement is induced by linkage pivotally connected to the jaws. An abutment is provided for limiting the movement of one of the jaws so that actuation of the linkage causes movement of said one jaw until it strikes the abutment followed by movement of the other jaw.

Abstract: This invention relates to a method of inserting tension wires in the process of wire assembling for a concrete pole or pile characterized in that forward ends of a required number of tension wires are clamped together by a chuck, and the chuck is inserted from one end of a wire cage to the other end and interiorly thereof, so that a number of tension wires can be inserted into the wire cage at one time.

Abstract: A method and apparatus are disclosed for lifting a manhole cover. The apparatus comprises a means for engaging the manhole cover which cooperates with a means for raising and lowering the manhole cover. A pivot means is also provided which cooperates with the means for raising and lowering the manhole cover. According to the method of the invention the pivot means is positioned adjacent one edge of the manhole cover. A lifting means is engaged with the manhole cover and a bar is placed in engagement with the pivot means and the lifting means. Pressure is applied to one end of the bar and the manhole cover is lifted to a position to allow pivoting the manhole cover to a desired position prior to lowering.

Abstract: A jack structure is provided and includes an elevatable portion spaced centrally between a pair of stationary anchor points relative to which the elevatable portion may be elevated. The elevatable portion includes a lift member elevatable therewith and engageable with, to lift, undersurface portions of a motorcycle frame which passes beneath the engine of the motorcycle. With the front of the motorcycle frame elevated and the rear portion of the motorcycle frame supported by the retractable stand with which most motorcycles are equipped, the front wheel of the motorcycle is spaced above the ground and the jack structure further includes adjustable length bracing rods which may be anchored between the aforementioned anchor points and the handgrip portions of the handle bar of the motorcycle in order to firmly lock the handle bar and front fork assembly of the motorcycle against oscillation relative to the frame while the front wheel of the motorcycle is being spun during a wheel balancing operation.

Abstract: A method of reinforcing structures by means of tensioned steel cables is disclosed. A hollow conduit or duct is positioned in the structure and secured therein and made a part thereof by pouring concrete in a form surrounding the conduit. A specified number of steel strands, wires or cables are inserted and pushed through the conduit one-by-one by a mechanical strand pusher. A nose guide is positioned on the end of each of the strands if required to enable them to pass easily through the conduit. When the required amount of strands are positioned in the conduit and the concrete has set to a predetermined strength, the strands are stressed thereby putting the structure under compression.

Abstract: In a method of lowering and raising loads by means of a jack assembly and lifting element the load is transferred from the lifting element by supporting means disposed on the lifting element and having a cross-section considerably larger than that of the lifting element. The supporting means are alternately carried by preferably dismountable carrying members with holes for the lifting element, which holes are smaller than the cross-section of the supporting means, the carrying members being mounted on relatively movable parts of the jack assembly.