Abstract: A deliquification pump for deliquifying a well comprises a fluid end pump adapted to pump a fluid from a wellbore. In addition, the deliquification pump comprises a hydraulic pump adapted to drive the fluid end pump. The hydraulic pump includes a first internal pump chamber and a first pump assembly disposed in the first chamber. The first pump assembly includes a piston having a first end, a second end, and a throughbore extending between the first end and the second end. In addition, the first pump assembly includes a first wobble plate including a planar end face axially adjacent the second end of the piston and a slot extending axially through the first wobble plate. The first wobble plate is adapted to rotate about the central axis relative to the housing to axially reciprocate the piston and cyclically place the throughbore of the piston in fluid communication with the slot.

Abstract: Gas injection control devices are provided, particularly for deployment in a well-bore to control injection of a gas into a tube or pipe to lift a liquid up the tube, such as crude oil for example. A gas control device is described which comprises a housing, and at least two control valve arrangements within the housing. Each arrangement has an inlet for receiving gas from a pressurized supply, an outlet for supplying pressurized gas for injection into the tube, an inlet valve in a fluid path between the inlet and outlet, and an actuator associated with the inlet valve. Each actuator is independently controllable to switch the respective inlet valve between its open and closed configurations. This allows the gas injection to be switched on and off, and facilitates control of the injection gas flow rate.

Abstract: A seal assembly between a wellhead housing having a bore and a casing hanger, has an inner seal leg for sealing against a hanger and an outer seal leg for sealing against the housing. A bellows style portion is formed on a nose ring carried by the seal assembly to increase lockdown capacity. The bellows style portion has an inner surface that faces an outer profile of the hanger, and an outer surface that faces the bore of the housing. Inner and outer lock rings are disposed on the bellows style portion. When the bellows style portion is axially collapsed, it radially expands into the bore of the housing and the outer profile of the hanger, and urges the inner and outer lock rings into engagement with the outer profile of the hanger and the bore of the housing.

Abstract: An integral tank frame for an emergency response vehicle is provided. The integral tank frame includes a tank mounted within an envelope of space of a ladder frame. The ladder frame has side rails that support the tank on either side thereof. The tank can be mounted to the side rails such that it extends across the top of the side rails, interior to the side rails, or a combination thereof.

Abstract: A low pressure, extended coverage, fire protection sprinkler, e.g., of the upright type, suitable for use in protection of at least extra hazard and high piled storage occupancies, in accordance with the 1999 Edition of NFPA 13, has a body with an internal passageway extending between an inlet end and an opposite outlet end, and a deflector mounted to the body by at least one support arm and disposed in alignment with the axis and generally spaced from the outlet end of the internal passageway. The sprinkler has a predetermined K-factor, e.g., of greater than about 16.0. The sprinkler is configured and arranged to deflect flow of water generally radially outwardly and downwardly of the sprinkler in a predetermined spray pattern. Preferably, the predetermined spray pattern has a generally polygonal shape, e.g., a rectangular shape, when viewed at a predetermined distance below the deflector.

Abstract: A scalable cargo-fire-suppression agent distribution system and method is disclosed. A supply source unit subset of a set of fire-suppression agent supply source units is selected based on an operation condition to provide a selected supply source unit subset, and a fire-suppression agent from the selected supply source unit subset is distributed during the operation condition.

Abstract: An aerator with coring depth adjustment includes a coring depth adjust rod centrally positioned between a left side and a right side of the coring head. A portion of the coring depth adjust rod is threaded to a frame member of the coring head, and a base of the rod abuts a stop on a frame member of the aerator. The coring depth adjust rod rotates to raise and lower the coring head relative to the aerator frame to vary the coring depth.

Abstract: A fastener installation tool including a guide that guides a fastener into a side of a work piece at an angle, while optionally restraining the fastener from wobbling due to rotation, even upon initial entry into the work piece. The guide can define an angled bore including a fastener entrance opening and a fastener exit opening which is adapted to be positioned immediately adjacent the work piece. The guide can include a material ejection port between the openings, through which material bored from the work piece can be evacuated from the angled bore to prevent binding of the material with the fastener. The tool can include a clamp assembly that clamps opposing sides of the work piece to precisely align and steadily hold the angled bore as a fastener is being installed in a side surface. Related methods of using the tool to install fasteners also are provided.

Abstract: An oil pulse tool includes a motor, an oil pulse unit, an output shaft on which a front end tool is attached, a torque detecting sensor for detecting generation of an impact torque, and an operating portion configured to detect a time period between a first impact torque detected by the torque detecting sensor and a second impact torque detected by the torque detecting sensor. The second impact torque is smaller than the first impact torque. The operating portion carries out a notification when the time period between the first impact torque and the second impact torque is less than a predetermined evaluation value for the time period between the first impact torque and the second impact torque.

Abstract: An angle impact tool includes a handle assembly extending along a first axis, a prime mover in the handle, an output shaft rotatable about the first axis, and a work attachment connected to the handle assembly. An output drive is supported in the work attachment for rotation about an output axis perpendicular to the first axis. A gear assembly including a spur gear is positioned within the work attachment to transfer torque from the prime mover about the first axis to the output drive about the output axis. An impact mechanism is positioned within the work attachment and includes a hammer and an anvil. The hammer rotates under the influence of the prime mover and is operable to periodically deliver an impact load to the anvil. The output drive rotates about the output axis under the influence of the impact load being transmitted to the output drive by the anvil.

Abstract: A triple activity drilling ship may be provided with two separate drilling centers, each including drilling apparatus. In addition, a trolley that is capable of supporting tubulars may be positioned between a first position within one of said drilling centers and a second position outside that drilling center. As a result, the trolley may be used to hold assembled tubulars while other activities are ongoing in one or more of the drilling centers.

Abstract: A system and method for controlling an oscillatory penetration apparatus. An embodiment is a system and method for controlling a sonic drill having a displacement and an operating range and operating at a phase difference, said sonic drill comprising a push-pull piston and eccentrics, said method comprising: operating the push-pull piston at an initial push-pull force while the eccentrics are operated at a plurality of different operating frequencies within the operating range of the sonic drill and measuring the displacement at each operating frequency; determining an efficient operating frequency for the material being drilled and operating the eccentrics at said efficient operating frequency; determining the phase difference at which the sonic drill is operating; and if the phase difference is not substantially equal to minus ninety degrees, operating the push-pull piston at another push-pull force.

Abstract: A system to harvest mechanical energy in a wellbore, wherein the mechanical energy comes from motion. The system uses mechanical energy coming from at least one of: motion of a drill bit, motion of a drill string, motion of flowing air or drilling mud down the drill string to the drill bit and up an annulus between the drill string and the wellbore, motion of a bottom hole assembly connected to the drill string. The system can include a plurality of piezoelectric stand bundles, wherein each individual piezoelectric strand can vibrate as the pressure housing moves in the wellbore, thereby producing electricity.

Abstract: A slide-type core retainer for a sample collector including a sampler tube driven into a sea floor. The slide-type core retainer includes a catcher holder detachably coupled to a tip end of the sampler tube; a catcher installed on an inner peripheral surface of a tip end of the catcher holder and configured to allow sediment introduction into the sampler tube and preventing sediment from being lost using resiliency. A control member slidably installed inside the catcher holder controls opening and closing of the catcher. The control member is coupled to the catcher before sample collection so that the catcher remains opened. The control member slides into an inner side of the catcher holder while being separated from the catcher by the resistance of the solid sediment such that the catcher is closed, when resistance is generated by solid sediment after the sampler tube is driven into the sediment.

Abstract: A system and method for hydraulic drilling is provided. A whipstock having a bore can be sealingly engaged at a distal end of a workstring. A drilling apparatus having drill tubing and a flow through device for routing drilling fluid into the drill tubing can be connected to the end of a connection string and inserted down into the work string so that the drill tubing extends through the bore in the whipstock device. Pressurized drilling fluid can then be inserted into the annulus formed between the work string and the connection string so that the pressurized drilling fluid passes through the flow through device into the drilling tube and is discharged out the distal end of the drilling tube as a cutting jet.

Abstract: In one aspect, a drilling apparatus is provided, where the drilling apparatus includes a fluid pump disposed in a main wellbore, a lateral well in fluid communication with the fluid pump and a drilling assembly disposed in the lateral well, wherein the drilling assembly is configured to receive a fluid from the fluid pump to power the drilling assembly and to transport cuttings from the drilling assembly to the main wellbore. The drilling apparatus further includes a sealing mechanism disposed in the main wellbore, the sealing mechanism being configured to direct the cuttings in the fluid downhole of the sealing mechanism.

Abstract: A method and system are provided for injecting high pressure abrasive fluid into an abrasive jet tool. The method and system comprise a slurry tank connected to an abrasive hopper and a low pressure abrasive pump for circulating abrasive slurry and transferring the slurry to a high pressure vessel. The method and system also contain a high pressure non-abrasive pump connected to a high pressure valve for pressurizing the high pressure vessel prior to injecting abrasive fluid into the abrasive jet tool.

Abstract: A fixed-cutter earth-boring tool includes a first blade carrying a first plurality of cutting elements and having a first stiffness and a second blade configured to have a second stiffness different from the first stiffness. A method of forming an earth-boring tool includes forming a bit body having a plurality of blades, and providing at least one cutting element on at least one of the plurality of blades. At least one blade of the plurality has a stiffness different from a stiffness of another blade of the plurality. A fixed-cutter earth-boring drill bit includes a first blade having a first aggressiveness, and at least one additional blade having a second aggressiveness.

Abstract: In an embodiment, a polycrystalline diamond compacts (“PDC”) includes a substrate and a polycrystalline diamond (“PCD”) table bonded to the substrate. The PCD table defines an upper surface and at least one peripheral surface. The PCD table includes a plurality of bonded diamond grains. The PCD table includes a first region adjacent to the substrate that includes a metallic constituent disposed interstitially between the bonded diamond grains thereof, and a leached second region extending inwardly from the upper surface and the at least one peripheral surface that is depleted of the metallic constituent. The leached second region exhibits a leach depth profile having a maximum leach depth that is measured from the upper surface. A leach depth of the leach depth profile decreases with lateral distance from a central axis of the PCD table and toward the at least one peripheral surface.

Abstract: Diamond bonded construction comprise a diamond body attached to a support. In one embodiment, an initial substrate used to sinter the body is interposed between the body and support, and is thinned to less than 5 times the body thickness, or to less than the body thickness, prior to attachment to the support to relieve stress in the body. In another embodiment, the substrate is removed after sintering, and the body is attached to the support. The support has a material construction different from that of the initial substrate, wherein the initial substrate is selected for infiltration and the support for end use properties. The substrate and support include a hard material with a volume content that may be the same or different. Interfaces between the body, substrate, and/or support may be nonplanar. The body may be thermally stable, and may include a replacement material disposed therein.

Abstract: A transporter for transporting a load over a surface. The transporter includes a support platform for supporting the load. The support platform is characterized by a fore-aft axis, a lateral axis, and an orientation with respect to the surface, the orientation referred to as an attitude. At least one ground-contacting element is flexibly coupled to the support platform in such a manner that the attitude of the support platform is capable of variation. One or more ground-contacting elements are driven by a motorized drive arrangement. A sensor module generates a signal characterizing the attitude of the support platform. Based on the attitude, a controller commands the motorized drive arrangement.

Abstract: The present invention discloses a drill rig relocation system. Lift frames are provided at opposite ends of a base box of a drill rig substructure. A lift cylinder and bearing mat assembly are rotatably connected beneath the lift frame. The bearing mat assemblies may be rotated to the desired direction for moving the drill rig. The lift cylinders are then expanded, placing the bearing mat assemblies onto the ground and lifting the base boxes and drill rig off the ground. The drill rig is supported on linear sleeve bearings slideably mounted in the bearing mat assemblies. Translation cylinders on the bearing mats expanded to move the rig by translating the linear sleeve bearings along the shafts. After the lift cylinder expands to place the bearing mat on the ground, the translation cylinders are retracted, providing the linear bearing with the full length of the shaft for the next movement.

Abstract: An electric utility vehicle with a frame, at least one drive motor mounted to the frame through a suspension assembly, a wheel mounted to the motor, and a steering assembly for steering the vehicle, wherein the steering assembly may be interchangeably reconfigured into a side driver configuration and a center driver configuration. The drive motor may be mounted at any one of four wheel positions. The suspension assembly may be interchangeably reconfigured as an independent A-arm suspension assembly and a trailing arm suspension assembly. The vehicle may include a controller coupled to the motor for independently supplying electrical power to each of two drive motors, such that during a turn an outside motor is supplied with more power than an inside motor. The controller may supply electrical power the drive motor according to a selected acceleration profile of at least two acceleration profiles.

Abstract: A power generation system is disclosed. The power generation system includes an electrical converting device and a repowered portion connected to the electrical converting device. The repowered portion includes a reciprocating internal combustion engine and a gearbox. The reciprocating internal combustion engine is connected to the gearbox by a first connecting structure. The gearbox is connected to the electrical converting device by a second connecting structure.

Abstract: Wheel drive motors (8) constituted of electric motors for driving rear wheels (7) are provided on a vehicle body (2) of a dump truck (1). Each wheel drive motor (8) is connected to a main power generator (12) through a bidirectional converter (20) and the like and driven by power supplied from the main power generator (12). A resistor (21) that consumes regenerative power from each wheel drive motor (8) is connected to the bidirectional converter (20). Cooling air is supplied to the resistor (21) from a blower (24). Operations of a switch (23) of the resistor (21) and the blower (24) are controlled by a controller (28). A mode selecting switch (29) for selecting a heating mode (A), a blowing mode (B), and a heating and blowing mode (C) is connected to the controller (28).

Abstract: An in-wheel driving device disposed in a car wheel includes a motor including a stator and a rotor; a transmission unit disposed adjacent to the motor, having an opening therein, and configured to receive rotation power from the rotor and rotate the car wheel; and a rigid shaft inserted into the opening to fix the motor to a car body.

Abstract: An upper revolving structure is provided with a revolving frame, a floor member, and a cab box. On this, an indoor unit for an air conditioner is provided on the floor member, and an outdoor air inlet port is provided by being opened to the outside of the cab box. An outdoor air duct is provided for supplying outdoor air introduced through the outdoor air inlet port toward the indoor unit. In this duct, an intermediate portion is arranged at a high position on the side of an operator's seat, and on this intermediate portion, a filter accommodating portion is provided by being opened into the cab box. In the filter accommodating portion, an outdoor air filter for trapping dusts in the outdoor air flowing through the outdoor air duct is accommodated capable of being attached and removed.

Abstract: A front panel opening/closing system includes a hydraulic cylinder, a tilt cylinder, a tilt pump, and a valve. The hydraulic cylinder is connected to a front panel of a cap to perform an operation of opening/closing the front panel. The tilt cylinder is connected to the cap to perform an operation of tilting the cap. The tilt pump is connected to the hydraulic cylinder and the tilt cylinder through a hydraulic line to provide oil pressure. The valve is disposed at the hydraulic line of the tilt pump and the tilt cylinder. When the valve is positioned at a first position, the oil pressure is supplied from a hydraulic pump to the hydraulic cylinder and the tilt cylinder through the hydraulic line. When the valve is positioned at a second position, the oil pressure is supplied from the hydraulic pump only to the tilt cylinder through the hydraulic line.

Abstract: An apparatus for controlling the propulsion and direction of an air cushion vehicle including a housing and a first vane pivotally coupled to the housing and pivotable about a first axis. A second vane assembly including at least one second vane is disposed within the first vane. The second vane assembly is pivotally coupled to the first vane and pivotal about a second axis. The second axis is orthogonal to the first axis. A first actuator is operably coupled to the first vane and a second actuator is operably coupled to the second vane assembly. The first actuator pivots the first vane and the second vane assembly about the first axis. The second actuator pivots the second vane assembly relative to the first vane and about the second axis to control the flow of air through the housing.

Abstract: A flywheel module has a closed housing with an opening, and an output which is formed by an output shaft that extends outward through the opening. A sealing ring is present between the output shaft and the boundary wall of the opening. A flywheel is accommodated in the housing, which flywheel is connected via a clutch to a first gear of a transmission whose other gear is connected to a first portion of a centrifugal disengaging clutch of which the other portion is connected to the output shaft. With this it be avoided that the flywheel starts to run at too high a speed, which guarantees the safety of the flywheel module.

Abstract: A fall-proof and anti-collision vacuum cleaner is disclosed in the present application, which comprises a main body, a driving device, a collision baffle and an elastic element. The collision baffle comprises a left side portion, a right portion and a middle portion for connecting the left portion and the right portion, at least one sensor is disposed on the outer edges of the left side, right side and middle portions respectively, the at least one sensor is electrically connected to the driving means, a plurality of shading parts are disposed on the main body corresponding to the positions of the sensors for sheltering the sensors, each of the sensors has three working positions, in the first working position, the sensors receive the feedback signals from the support below the main body, in the second working position, the sensors are sheltered by the shading parts, and in the third working position, the sensors fail to receive any signals within the sensing range thereof.

Abstract: A power assisting device for a bicycle generally including an electric generator, an electric motor and a rheostat. The rheostat includes a mount having a first insert and a second insert. Both inserts include upper and lower apertures. Each upper aperture includes a contact, where in a first position the contacts are in contact with one another, and in a second position the contacts are not. The first insert is attached to the brake lever. Applying the front brakes with the braking lever causes the first insert to move from the first position to the second position. The generator is electrically connected to the upper aperture of the first insert, and the motor is electrically connected to the upper aperture of the second insert. When the braking system is not applied, the inserts are in the first position and the contacts are in contact causing an electrical connection between the rheostat, the generator and the motor.

Abstract: A motorcycle safety belt device secures a rider onto a motorcycle. The device includes a motorcycle having a main seat. A first strap has a first end and a second end. The first end of the first strap is coupled to the motorcycle proximate the main seat. The second end of the first strap is coupled to the motorcycle proximate the main seat such that the first strap is selectively positionable to extend over the main seat of the motorcycle. A buckle selectively couples a first section of the first strap to a second section of the first strap.

Abstract: A vehicle includes a pair of front wheels, at least a pair of rear wheels, a frame portion supported by the pair of front wheels and the pair of rear wheels, a roll-over protection cage supported by the frame portion, a cargo bed supported by the frame portion pivotably behind the roll-over protection cage, an engine supported by the frame portion below the cargo bed, an output adjuster disposed below the cargo bed to adjust an output of the engine, and a protective member disposed between the cargo bed and the output adjuster. The protective member overlaps at least a portion of the output adjuster but does not overlap at least a portion of the engine in a plan view.

Abstract: An integrated steering control system includes a primary, automatic and rear control valves. A steering wheel operates the primary steering control valve and is of a type which includes a leakage characteristic. Steering wheel movement is sensed and a signal is sent which results in the automatic steering control valve being operated for adding fluid that supplied to a steering cylinder by the primary steering control valve in order to compensate for leakage, the amount of added fluid being a function of vehicle ground speed. An electric actuator with position feedback is used for ground speed control. Whenever the actuator position shows that the ground speed is set to zero and a switch in the hydro-handle slot shows that the handle is in the Park position, the automatic steering control valve is activated to move the steering cylinder to a neutral, straight ahead position, as determined by a sensor in a mechanical linkage of the steering control.

Abstract: A preload adjusting plug is inserted through a communication hole extending through center portions of a Z1 gear, a Z4 gear, and an inner ring of a nutation gear. A male thread portion is formed at an outer periphery of one end of the preload adjusting plug, and is screwed to a female thread portion formed at an inner periphery of the Z1 gear. A disc-shaped flange portion extending radially outward is formed at the other end of the preload adjusting plug, and axially presses a back face of the Z4 gear through a bearing. The preload adjusting plug applies predetermined preloads to meshing portions in the nutation gear mechanism.

Abstract: A canalphone system may include a high audio driver carried by a canalphone housing, and a low audio driver carried by the canalphone housing adjacent to the high audio driver. The system may also include an acoustical-timer to phase correct a high audio signal from the high audio driver directed to the outside of the canalphone housing with delivery of a low audio signal from the low audio driver directed to the outside of the canalphone housing.

Abstract: The present disclosure provides a compound membrane and an acoustic device including such a compound membrane. The compound membrane includes a polyetherimide film, and a thermoplastic polyurethance elastomer attached to one surface of the polyetherimide film.

Abstract: Speaker performance can be improved by routing sound from a rear side of speaker through a circuitous port formed between inner and outer surfaces of a wall of the speaker enclosure. An audio speaker enclosure comprises an enclosure housing defining an internal volume with a speaker opening at a first end thereof, the speaker opening being configured to receive a speaker therein, the enclosure housing having an inner surface facing the internal volume and an outer surface, the enclosure further defining at least one port communicating between the internal volume and the outer surface, the at least one port extending between the inner and outer surfaces along a port length that is greater than a maximum housing thickness between the inner and outer surfaces. The speaker enclosure can be made by arranging an inner speaker enclosure shell within an outer speaker enclosure shell such that the port is defined therebetween.

Abstract: An acoustical panel for forming a monolithic ceiling or wall, the panel extending across a rectangular area, and having a core made primarily of gypsum, the core being essentially coextensive with the panel area such that it has two opposed sides, each of an area substantially equal to the area of the panel, the core having a multitude of perforations extending generally between its sides, the perforations being distributed substantially uniformly across the full area of the core and being open at both sides of the core, the face side of the core being covered by a porous layer, the perforations being optionally restricted at a rear side of the core, the porous layer at the face side of the core being suitable for adherence of drywall joint compound and a water-based non-blocking paint.

Abstract: A noise structure having a barrier made of a generally sound redirecting material defining a surface of the barrier, and a plurality of sound absorbing boxes connected to this surface, each box comprising a rear wall and an extensively perforated front wall, the walls defining a longitudinal channel at least partially occupied by a filling made of a sound absorbing material, in which the rear wall is a substantially flat plane wall assembled parallel to and spaced apart from the surface of the barrier and is in its turn extensively perforated.

Abstract: A fall restraint system includes a cable for attachment to a fall restraint harness assembly of a worker. The cable can be attached to a boom arm cantilevered on a mast carried from the ground or can be stretched between two points on opposed walls. A shock absorber is provided for absorbing at least part of the shock forces so as to reduce the loading applied to the support system. This comprises an elongate member with a movable member or sleeve mounted on it for longitudinal movement. The movement is resisted by a friction brake or a compressible material contained within a tube so that the sleeve moves along the tube in response to loads exceeding the normal load to reduce the loading on the cable while compressing the material in the tube.

Abstract: A rappelling apparatus and method are provided, for controlling the rate of movement of a person along a safety line away from an anchored end of the safety line, through use of a control bar having an attachment at one end thereof for a harness safety belt, or the like connected to the person, an operating handle at an opposite end thereof, and provisions between the opposite ends of the control bar for passage of the safety line through the control bar in serpentine pattern. The operating handle is pivoted away from the safety line to reduce the severity of the serpentine pattern and allow controlled movement of the safety line through the control bar. Some forms of the control bar include a one-way clutching arrangement. Some forms of the control bar also include a hand-actuated braking arrangement.

Abstract: A ultra-light, concealable toilet or chair apparatus (10) configured to be suspended from an object to suspend the apparatus above ground is provided. The apparatus comprises of a suspension system (12) configured to be coupled to the object to suspend the apparatus above the ground. The suspension system includes at least one securing device (12) (14) coupled through the primary tensile support member (20) which extends downwardly and sub-divides into left linear side (20a) and right linear side (20b) portion that transitions into a concaved seat when human sits there on, provided, adjustable interlocking latch (22a) is coupled to corresponding ridged interlocking latch (30e), and adjustable interlocking latch (22b) is coupled to corresponding ridged interlocking latch (30f), forming a pair of loops that will surround left and right legs of the human operator, completing structural support.

Abstract: An apparatus and method for a children's convertible dual mode step stool that includes both a single-step mode and a double-step mode. A moveable housing, coupled to a base housing, selectively and lockably maintains either of two different ninety degree orientations to present a desired one of either a single-step mode or a double-step mode.

Abstract: A utility holding device is suitable for carrying tools and materials at a construction site. The utility holding device is especially useful for carrying tools and materials for an electrician or a plumber. The wheels provide mobility. The ladder attachment permits a utility holding device to be safely used with a ladder. The scaffold attachment permits a utility holding device to be safely used with a scaffold.

Abstract: The present invention features a ladder shelf system for adding a generally planar rectangular shelf close to the top of a step ladder. The system has the generally planar rectangular shelf that is rigid with a step engagement member located on a shelf top surface. The step engagement member is adapted to fit inside an interior cavity of a top step of a step ladder. The system has a generally planar rectangular non-slip pad centrally located on the shelf top surface. The system has a locking lever located close to the shelf posterior end. In a first unlocked position, a first clamping member and a second clamping member lie on a plane perpendicular to the shelf top surface. In a second locked position, the first clamping member and the second clamping member lie on a plane parallel with the shelf top surface.

Abstract: A shelf apparatus for use with a ladder or scaffold structure is provided. The shelf apparatus includes a substantially planar shelf structure having a plurality of holes positioned on a first side, wherein at least one of the plurality of holes is formed about a first axis positioned substantially perpendicular to the shelf structure. A cross-member engagement support is positioned on a second side of the shelf structure, the second side of the shelf structure opposite the first side, wherein the cross-member engagement support is formed about a second axis running from a first edge to a second edge of the shelf structure, and wherein the second axis intersects the first axis. A ladder-attachment structure is affixed to the shelf structure.

Abstract: A collapsible staircase is provided with a set of flat parts, with each of the parts intended to function as steps. Each flat part can be moved between a first position and a second position. All of the flat parts are substantially coplanar when the parts are in the first position, and the parts are disposed above each other and at a distance from each other when the parts are in the second position. A retractable holding handle is also provided and driven together with the flat parts.

Abstract: A self-retracting lifeline is provided. In one embodiment, the self-retracting lifeline includes a housing, a drum, an activation assembly, a lifeline and a connector, the drum is received in the housing. The activation assembly is received in the housing. Moreover, the activation assembly is operationally coupled to the drum to selectively rotate the drum. The connector is coupled proximate an end of the lifeline. The connector has a connector passage. The connector passage is configured and arranged to selectively couple the lifeline to the drum.