Abstract: A novel method for replacing a previously implanted knee joint prosthesis in a patient is disclosed in which the previously implanted femoral component is replaced with a revision femoral component having thicker distal and posterior bearing portions so as to restore the natural anatomic transverse joint plane and collateral ligamentous balance in extension and flexion of the prosthetic joint. Instrumentation for use in this method includes a novel revision cutting jig which is used in the preparation of the distal end of the femur for the implantation of the revision femoral component.

Abstract: An acetabular prosthesis assembly for implantation into a prepared acetabulum has a generally hemispherically-shaped cup. The cup has a substantially hemispherically-shaped inner surface and a substantially hemispherically-shaped outer surface defining a wall therebetween. The wall has a plurality of generally circular apertures therein for receiving a bone screw. The wall surrounding each aperture has a bevelled surface extending toward the outer surface followed by a generally cylindrical surface extending from the bevelled surface to the outer surface of the cup. The generally cylindrical surface of each aperture is threaded with threads of predetermined diameter and pitch. A bone screw has a first screw thread having a pitch and diameter for engagement with the thread of the cylindrical surface on the cup and a second screw thread having a major diameter and a pitch greater than the predetermined diameter and pitch of the cylindrical surface.

Abstract: A modular apparatus for use in the preparation of bone surfaces and the implantation of a modular total knee prosthesis in a patient, which apparatus comprises cutting guides, templates, alignment devices, a distractor and clamping instruments which provide modularity and facilitate bone resection and prosthesis implantation.

Abstract: A water based slurry for use as backup coat on a wax model has colloidal silica and milled zircon as primary ingredients. The slurry is utilized as a backup coat on a wax model used in a lost wax investment casting technique. The slurry comprises of colloidal silica, a latex glue, ammonium alginate, a wetting agent, milled zircon, tabular alumina, glass rock and an anti-foaming agent.

Abstract: A method for preventing adhesion utilizes a viscoelastic gel formed from xanthan gum. The gel is more viscous than blood and is soluble in aqueous solutions. The gel is placed between the tissues by a syringe. The method includes mixing the xanthan gum with either a saline solution or Tyrode's solution to form the gel.

Abstract: A material transporting system is disclosed. The material transport system includes a self-propelled material conveying system which is capable of traversing a surface along an elongated path which has a curvillinear portion. This system also includes a plurality of framework members arranged in tandem on the surface which lies along a portion of the elongated path. Each of the plurality of framework members is connected by connector means on each framework member cooperable with connector means on each adjacent framework member. Each connector means permits universal-type movement between adjacent framework members. The framework members include means for supporting an orbitally movable crawler chain in engagement with the surface. The crawler chain is designed to extend throughout the longitudinal extent of the train. Each of the framework members has means for supporting an orbitally movable conveyor belt above the orbitaly movable crawler chain.

Abstract: Apparatus and a method of protecting the lateral edges of a conveyor belt. A resilient tubular member having a longitudinal slit therein is in resiliently maintained contact with the belt adjacent lateral edges. The resilient member may have portions of its inner surface spaced from the belt edge portions so as to define a number of cushioning air spaces therebetween. The resilient members are preferably of generally circular cross sectional configuration in unexpanded condition and are generally coextensive with the belt. The belt may have recesses for receipt of the slit ends of the tubular resilient member. The method may involve providing an elongated tubular resilient member which is slit longitudinally and circumferentially expanded so as to permit it to receive a lateral edge of the belt. The interengagement may be maintained through resiliently maintained contact alone or by additional means for securing such contact.

Abstract: An improved chain for use as a tension element in conjunction with a resiliently deformable conveyor belt which permits the belt to be prestretched at installation by a predetermined, controlled and limited amount.

Abstract: A maneuverable mining machine is disclosed. The mining machine has a chassis with at least one cutting head mounted on the front of the chassis and adapted to cut into a mine face extending transversely across the front of the machine. The cutting head comprises a cutting drum which is rotatable in a plane parallel to the mine face. The cutting head is mounted on the chassis by way of a support member arranged to effect movement of the cutting drum parallel to the face. A conveying means is mounted on a chassis and is arranged to convey mine material from the front of the chassis to the rear of the chassis.

Abstract: A bit holder for a replaceable bit is disclosed. The bit is of the type having a pointed head portion axially extending from a shaft portion. The bit holder has a holder part for receiving the bit and has a base part for securing to a cutter head. The bit holder part is releaseably secured to the base part for easy replacement. The holder part has at least one reaction surface cooperating with one reaction surface on the base part for counteracting forces arising on the bit while cutting. A bolt extending from the holder part or the base part into a cooperating aperture in the other of the holder part of the base part is utilized to releaseably secure the two pieces together with the reaction surfaces therebetween. The bolt is positioned relative to the reaction surfaces and with respect to the bit so that the gripping force of the bolt counteracts the force of the bending moment created between the bit tip and the reaction surfaces during cutting.

Abstract: A suspension system for an operator's compartment of a mine vehicle. The mine vehicle is of the type having a body wherein the operator's compartment is floatingly supporting on the body adjacent one side thereof for riding on the mine floor as the vehicle moves in the mine. The suspension system includes a vertical guide secured to the body for supporting and guiding rollers which are mounted on the compartment. A chain and sheave arrangement is connected between the vehicle body and the operator's compartment and acts to simultaneously lift both ends of the vehicle compartment in response to vertical forces developed between the mine floor and any point on the operator's compartment. The chain sheave arrangement acts to lift each end of the operator's compartment the same vertical distance with respect to the body thereby keeping the compartment level with respect to the body at all times.

Abstract: A cutter bit holding assembly is disclosed. The cutter bit assembly contains a cutter bit having a shank portion and a cutter bit holder having a socket for receiving the cutter bit shank portion. Also included is a rotary locking element which is associated with the cutter bit holder and a bore adjacent the socket. The bore runs in a direction parallel the direction in which the bit holder cuts. The locking element has an offset locking portion which cooperates with an indented locking surface on the bit shank. The rotary locking element is capable of being rotated completely out of the socket bore and out of engagement with the bit shank locking surface to permit the unencumbered removal or insertion of a bit. An elastomeric element inserted along part of the bore in the cutter bit holder is utilized to prevent rotation of the locking element out of engagement with the bit shank locking surface during operation of the cutting device.

Abstract: A cable tension control device for an electrically powered mine vehicle is disclosed. The vehicle is of the type having an electric trailing cable wound on a cable reel mounted on the vehicle. The cable reel has a motor for rotating the reel in the direction for taking up the cable as the vehicle moves toward a power source and for preventing freespooling of the reel as said cable is unwound as the vehicle moves away from the power source. The device includes a sensor for measuring the amount of electric cable on the reel and utilizes this sensed amount of cable for controlling the drive torque of the motor in direct proportion to the amount of cable sensed on the reel. The same sensed amount of cable is used to control the braking torque developed by the motor when the motor is being driven by the reel as when cable is being pulled off during movement of the vehicle away from the power source.

Abstract: A mining machine is disclosed which has a vehicle body with a first end thereof having a boom pivoted for up and down rotational movement about an axis extending transversely of the vehicle. A cutter head is carried by the boom and a conveyor is mounted on the vehicular body to carry away material cut by the cutter head. A dust collection system is mounted on the boom and vehicle body to convey dust away from the cutting head area. The dust control system has duct work associated therewith which includes a generally rectangularly intake duct section associated with the boom and a generally rectangularly fixed duct section mounted on the vehicle. A transition section connects the intake and the fixed duct sections.

Abstract: A suspension system for an operator's compartment of a mine vehicle is set forth. The mine vehicle is of a type that has a body and operator's compartment positioned adjacent to the body. A guide is attached to the body of the vehicle and a rail is attached to the operator's compartment. This guide and rail arrangement slidably connects the operator's compartment to the body. The guide and rail are arranged to permit the operator's compartment to independently move upward and down in relation to the body. The rail is located in a central portion of the operator's compartment to minimize the angular displacement of the rail with respect to the guide upon rotation of the operator's compartment. This ensures free upward and downward motion of the operator's compartment with respect to the body of the vehicle.

Abstract: Method and apparatus for controlling DC traction motors on opposite sides of a vehicle, particularly a mining machine, by means of an SCR converter. The motors are accelerated while controlling the firing angles of the SCR's such that the current and voltage supplied to the motors increase along ramps until desired normal operating values of voltage and current are reached with the voltage across the series-connected motors being of a substantially greater value than the value it would be if the motors were connected in parallel. In contrast to prior art systems, the traction motors are maintained in a series-connected configuration during normal, essentially steady-state operation; while the voltage across the motors is maintained at said substantially higher value. When one of two drive wheels connected to the traction motors is slipping, the motors are connected in parallel to increase torque with a corresponding decrease and increase in voltage and current, respectively.

Abstract: A method is set forth for controlling the orientation of an articulated boom of the type having a first portion and a second feed arm portion such that the first portion remains parallel to a predetermined position during movement of the articulated boom. The method utilizes a computer which senses the angular position of the various parts of the boom in a total of five directions and computes the required angular position of the feed arm to maintain it parallel to a set position as the boom is moved in any direction. Various hydraulic servovalves are utilized to control the flow of hydraulic fluid in a manner to maintain parallelism within 1/2.degree. with the referenced position.

Abstract: An apparatus for transporting granular materials is disclosed comprising a first conduit having an inlet for introducing the granular material, and transport pump for transporting the material through the first conduit. A nozzle provides a compressible fluid at a relatively high pressure for disaggregating the granular material within the first conduit, the material then proceeds from the first conduit into a second conduit. A relatively low pressure and high volume compressible fluid is supplied to the material to propel the material through the second conduit. There is also provided an adjustment means for changing the position of the nozzle within the first conduit. By adjusting the position of the nozzle, the apparatus can maintain disaggregation when the physical or chemical properties of the granular material are changed thereby preventing clogging of the apparatus due to insufficient disaggregation.

Abstract: A continuous mining machine cutting head structure is set forth. The mining machine is of a type having a support member and an elongated mining head member mounted on the forward end of the support member. The head member is powered for rotation about its longitudinal axis. The head member is of the type having axially extensible and retractable end portions. Included within the head member is a hydraulic piston cylinder arrangement for selectively extending and retracting these end portions. At least one latch element is included within each side of the head member and can be moved into locking engagement with the end portions when it is in an extended position thereby preventing retraction thereof. Also included is a mechanism operatively connected to the piston cylinder arrangement which is capable of moving the latch element out of engagement with the end portion thereby permitting retraction thereof.

Abstract: A mining machine is disclosed comprising a mobile base and a cutting head assembly at a forward end of the mobile base having a cutter drum rotatable about an output shaft disposed along the longitudinal axis of the cutter drum. A drive system for the cutting head assembly comprises at least one motor for driving at least one toothed motor pinion and a generally cylindrical combination gear having generally circular end surfaces. A bevel or face gear is formed in at least one of the end surfaces, having teeth adapted to mate with and be driven by the toothed motor pinion. The combination gear has a worm gear formed in the outside cylindrical surface, which is disposed in driving engagement with the teeth of an output gear integrally and coaxially connected to the output shaft of the cutter drum.