Showing papers on "Boom published in 1985"

Real and monetary aspects of the 'Dutch disease'

Abstract: When the average rate of growth of an economy is high, considerable changes in the relative sizes of different sectors can often be accommodated without great cost. However, in an environment of sluggish overall growth, such as has characterised most of the world in the past eight years, structural adjustment may be extremely painful, even though it results from a boom elsewhere in the economy. The problems are likely to be particularly acute if the boom takes the form of a rapid and unanticipated expansion of a small number of sectors, as typically follows the exploitation of natural resource discoveries.

Commodity Export Boom and the Real Exchange Rate: the Money-Inflation Link

Abstract: This paper analyzes the relation between exogenous changes in commodity export prices and the real exchange rate in a monetary economy. The traditional Dutch?Disease case is extended, and the monetary consequences of an export boom are explored. It is shown that commodity export booms can generate, in the short run, either an excess demand or an excess supply for money. In a monetary setting the short-run behavior of the real exchange rate can differ significantly from the more traditional Dutch-Disease case without money. The model is tested using data for Colombia.

Folding boom for agricultural sprayers

Abstract: A folding boom for agricultural sprayers comprising a center frame section mounted in the bed of a truck on a trailer. First and second boom assemblies normally extend outwardly from the center section with each of the first and second boom assemblies comprising inner, intermediate and outer boom sections. The inner boom section is connected to the center frame section so that the inner boom section will pivotally move rearwardly if the inner boom section strikes an obstruction. The inner boom section is also connected to the center frame section in such a manner so that the inner boom section may be freely pivotally moved to a transport position. The intermediate boom section is pivotally connected to the outer end of the inner boom section so that the intermediate boom section may pivot rearwardly relative to the inner boom section if the outer or intermediate boom sections strike an obstruction. The outer boom section is pivotally connected, about a horizontal axis, to the outer end of the intermediate boom section so that the outer end of the outer boom section is pivotally moved upwardly if either the intermediate or outer boom sections strike an obstruction. The outer end of the outer boom section is also pivotally moved upwardly if the inner boom section moves downwardly relative to the center frame section. The outer boom section may be folded upwardly over the intermediate section for transport purposes and the intermediate boom section may be folded rearwardly relative to the inner boom section for transport purposes.

Wheel-lift tow truck

Abstract: A tow truck of the wheel-lift type is provided. In a first embodiment, a telescopic boom is supported by parallelogram linkage which is actuated by a hydraulic motor which is slightly inclined to the horizontal, the inner end of the boom, in its travel position being above and somewhat forwardly of the ring gear housing of the rear axle of the tow truck. The parallelogram linkage supports the boom through a boom support structure which permits it to be swung in a substantially horizontal plane, about substantially vertical pinions. The grid, which engages the wheels, includes a movable member which engages a wheel and raises it relative to the boom and grid, without movement of the boom. In a second embodiment, a substantially vertical post supports a parallelogram linkage which in turn supports a substantially horizontal extensible boom having a wheel grid at its outer end.

High temperature oil boom cover blanket

Abstract: A high temperature oil containment boom cover blanket for conventional elongated cylindrical oil containment booms is disclosed. The cover blanket, when installed onto a conventional oil containment boom effectively converts the boom into a high temperature oil containment boom which allows for in situ burning of spilled oil during cleanup operations.

Containment boom system

Abstract: An oil containment boom system of two parallel, spaced-apart booms, with the forward boom designed to permit splashover of oil, a low pressure area between the booms functioning to retain the splashover oil.

Right-of-way tree line trimmer

Abstract: A tree line trimmer which includes a boom assembly with a lower boom and upper boom pivotally connected for movement in a common plane. An elongated cutter head is mounted to the outer boom and includes a plurality of overlapping, rotatable saw blades.

Crane boom having variable angle offset capability

Abstract: A mobile crane having a boom and a boom extension connected thereto with a toggle linkage for connecting the boom extension to the boom to allow the boom extension to be offset from the boom by one of a plurality of predetermined angles. A pair of double links is pivotably attached to the boom extension while a pair of single links is pivotably attached to the upper sheave pin in the boom head. Both the single and double links have a hole in the opposite end. Either the single or double links also have a hole in at least one intermediate position. The link having one hole is then pinned to the other link having two holes, the hole selected in the second link determining the angles of offset when tension is applied to the linkage by pivoting the boom extension about the lower sheave pin after removal of the upper boom foot pins. Biasing devices are provided to cause the linkage, which pivots freely at both ends and in the middle, to toggle upward when tension thereon is released. A storage position is provided for storing the double links and the link connector pins so as to prevent interference with the other apparatus and loss of the connector pins when the linkage is not in use.

Recovery vehicle device

Abstract: The invention relates to a device for a recovery vehicle of the type comprising rear, lowerable supporting stifflegs (5) and a crane boom (1) which turns about a horizontal axis (11) and has a boom foot (2) and a folding boom (3) with an extension (4) thereon. According to the invention the crane boom is placed on a turntable or the like on the vehicle. Means (6) are provided by which to turn the turntable and consequently the crane boom about a vertical axis of rotation. In order that the boom foot, which during transport preferably is arranged between a pair of lowerable rear stifflegs, should be unobstructed by these stifflegs or other obstacles, the crane boom is longitudinally displaceable relative to the turntable, according to a preferred embodiment.

Apparatus for operating working element of excavator

Abstract: A device for the operation of an excavator working element. An arm connected to the working element (3) and a boom (4) for supporting and operating the arm are fabricated each in the shape of a hollow tube whose opposite ends are left unclosed. A boom cylinder (23), an arm cylinder (27), or a work­ing element cylinder is disposed as contained within the boom or the arm. The point of connection of the boom to the arm and the point of connection of the working element cylinder to the arm constitute a joint fulcrum. The point of connection of the boom cylinder to the boom and the point of connection of the arm cylinder to the boom simi­larly constitute a joint fulcrum.

Boom extension storage means and mechanisms

Abstract: A mobile crane comprises a multi-section telescopic main boom and a boom extension pivotally connected to the point end of the main boom. The boom extension can be manually swung horizontally between an in-use position extending axially from the point end of the main boom and a stored position parallel to and alongside the main boom. Front and rear boom extension storage mechanisms releasably secure the boom extension in stored position. The front mechanism comprises two vertically spaced-apart storage pins which are slidable in tubular pin guides mounted on one lateral side of the main boom. The storage pins are slidably movable fore and aft by a swingable lever to which they are pivotally connected. The storage pins move into and out of engagement with a pair of vertically spaced-apart aligned pin-engaging holes in a member attached to a confronting side of the boom extension when the latter is in stored position. The lever is not only pivotable but is axially shiftable into and out of latched position and is biased into latched position to prevent unlatching due to "bounce". The rear storage mechanism comprises a ramp on the side of the main boom which engages and supports a roller on a member attached to a confronting side of the boom extension and a removable pin secures the member to the ramp.

Means to reduce oscillatory deflection of vehicle

Abstract: A rough terrain vehicle comprises a vehicle chassis, resilient terrain-engaging wheel assemblies connected to the chassis and enabling vertical and angular deflection of the chassis relative to the terrain during vehicle movement, a telescopic crane boom carried by the chassis, a pivot pin for connecting the boom to the chassis and enabling limited reciprocable angular deflection of the boom relative to the chassis as the vehicle moves across supporting terrain and a hydraulic boom hoist cylinder to raise and lower the boom. A deflection reduction system is connected between the chassis and the boom to reduce or eliminate vertical and angular deflection (bouncing and porpoising) of the chassis relative to the terrain which tends to occur in response to dynamic loads imposed on the vehicle axles by movement across uneven terrain or by acceleration or deceleration of the vehicle. The deflection reduction system includes a resiliently compressible and expandable spring connected between the chassis and the boom and enables limited angular deflection of the boom relative to the chassis. The deflection reduction system further comprises a damping system connected between the chassis and the boom and to the spring to reduce the speed of spring motion as rapidly as possible to thereby dissipate the dynamic load. Preferably, the deflection reduction system is embodied in the boom hoist cylinder.

Where has the Urban Crisis Gone? How Boston and other Large Cities have Stemmed Economic Decline

Abstract: Two national phenomena, economic transformation and the baby boom's young households, have brought new life to the Boston economy and that of other cities. The transformation has been largely downtown-oriented, however, and few of the benefits have spilled over into the poorer neighborhoods where most of the city's population lives. Substantial public infrastructure investment and the urban renewal write-down of land costs helped stake the private investment boom evident since the mid-1970s. Property values have skyrocketed. The rise in one-and two-person households and nonfamily households also has been accelerating since the mid-1970s and ushering in a return to the cities. The expanding concentration of minority and other poor populations in the cities have lagged behind, real income has eroded, poverty has increased, housing has become scarce, and gentrification holds a threat of displacement. The beneficence of the economic boom has not flowed into the public coffers; Boston, New York, and other larg...

Controller for working machine in power shovel

Abstract: PURPOSE:To prevent the floating of vehicle body by a method in which an inclination angle sensor for the turning direction of the working machine of an upper slewing body of the vehicle body is provided, and when a judgment is made of the floating of the vehicle body to a given degree on the basis of inclined angles, the command value of a boom turning speed is made to be zero CONSTITUTION:The first turning speed arithmetic circuits 16 and 20 for a boom and an arm are provided so that speed vectors on the basis of a speed vector setter for the tip of working machine, a boom angle detector 12, and an arm angle detector 13 are matched with each other An oil-pressure supply flow rate controller for cylinders 4 and 5 on the basis of turning speed commands of the first and second booms and the first arm is also provided The inclined angles of the working machines 1-3 of an upper slewing body 7 of the vehicle body are detected by the detectors, and on the basis of the detected values, the floating of the vehicle body is judged and boom turning speed commands are selected by a switching controller The operability and safety of the working machines can thus be enhanced

Telescopic boom mechanism

Abstract: A telescopic boom for use on an elevating apparatus includes a first boom, a second boom telescopically disposed in the first boom, a third boom telescopically disposed in the second boom, a rolling mechanism disposed between the first and third booms and rollingly movably on wall surfaces of the first and third booms, and a locking lever assembly disposed on each of ends of the second and third booms in the first boom for selectively engaging the rolling mechanism to connect the rolling mechanism to one of the second and third booms at a time.

Series self-leveling valve with single spool for unloading and relief

Abstract: A self-leveling series type hydraulic system including boom and bucket valves which separately control boom and bucket cylinders and a flow divider valve positioned in the exhaust flow path of the rod end of the boom cylinder. The flow divider valve splits the flow sending a portion of it to the cap end of the bucket cylinder so as to maintain the bucket in a level condition during raising of the boom with the remaining flow connected to one of the boom valve motor ports. An improved boom lower circuit which bypasses the flow divider valve as the boom is lowered to achieve a faster boom lower rate and the inclusion of an unloading valve in the bucket circuit which includes the dual function of preventing cavitation and relieving high pressure.

Elevated swinging device for placing slag retention devices in tapping converters

Abstract: A swinging device pivotally suspended from an overhead support adjacent a tapping converter telescopically positions a boom for relative vertical tilting and swinging motion toward and away from said converter on an arcuate path on a vertical plane. The boom supports a boom extension and jaws on the boom extension releaseably hold a slag retaining device so that the same can be moved into the converter and positioned in the tap hole thereof.

Vehicle boom lock

Abstract: A vehicle boom lock is disclosed for holding a boom assembly in a retracted transport position on an implement carrying swing frame. The boom lock includes a slotted coupling joint on the swing frame, and a deflectable cable assembly which extends cantileverably from the boom assembly for automatically interlockingly engaging the slotted coupling joint in response to pivotal movement of the boom assembly to the retracted position. A release mechanism can be manually manipulated from an operator station to conveniently disengage the cable assembly from the slotted coupling joint.

Mechanical digger toy

Abstract: A toy mechanical digger includes a base frame member, a longitudinally-extending base beam pivotally mounted on the base frame for manually-actuated, 360° slewing action relative to the base frame, a seal longitudinally slidably mounted with respect to the base beam; a primary boom having a pivoted end, and intermediate end, and a remote end, the pivoted end being pivotally mounted to the forward end of the base beam, such that the remote end can be raised and lowered, the intermediate end pivotally mounted to the forward end of the seat such that forward and rearward longitudinal sliding movement of the seat is linked to the lowering and raising movements, respectively, of the primary boom; a secondary boom having a pivoted end and a remote end, the pivoted end mounted on the remote end of the primary boom for pivotal movement relative thereto. A bucket is pivotally mounted on the remote end of the secondary boom, whereby the primary boom, the secondary boom and the bucket can be manually actuated to dig and dump. Two separate, manually-actuable, mechanical operators are mechanically connected to the secondary boom and to the bucket. A user, sitting on the seat can by manual operation of the seat and the two operators cause the primary boom to pivot with respect to the base frame, cause the secondary boom to pivot with respect to the primary boom, and cause the bucket to pivot vertically with respect to the secondary boom.

Varible outhaul wishbone boom for board sailor

Abstract: A resiliently flexible wishbone boom comprised of a pair of boom sections attached to the pivotal mast of a sailboard. A sail located between the boom sections is attached by its leading edge to the mast and at one location along its trailing edge to the outer end of the boom. The boom has flexible forward portions which enable the boom sections to be drawn closer together, thereby making the boom longer and applying increased outhaul tension on the sail which changes its overall curvature and aerodynamic efficiency.

Hydraulic circuit for crane

Abstract: A hydraulic circuit for a crane having both lift and boom hoist pumps driven by the same engine with appropriate control valves to independently control the lift hooks and the boom angle. An unloading valve is interposed in the boom hoise circuit and dumps the boom hoise pump directly to reservoir when the pressure in the left pump circuit becomes excessive. A boom limit valve, actuated as the boom reaches both upper and lower limits, also causes the unloading valve to dump the boom hoise pump to reservoir.

Plane excavating and shaping control device of hydraulic shovel

Abstract: PURPOSE:To perform easy and highly precise plane excavation and shaping, by providing a control device comprising a boom rotation speed control part, a bucket position control part, and bucket rotation speed control part, and a bucket angle control part. CONSTITUTION:A control device comprises a boom rotation speed control part 14, a bucket position control part 13, a bucket rotation speed control part 30, and a bucket angle control part 32. The control part 14 computes detecting values, e.g., a signal i2 from an arm control lever 4b, and relative angles between a boom, an arm, and a bucket to control the rotation speed of the boom, and the control part 13 computes various detecting values to control the position of the forward end of the bucket. Further, the control part 30 computes various detecting values to control the rotation speed of the bucket, and the control part 32 computes various detecting values and set values to control a bucket angle. With an arm being controlled, the forward end of the bucket and a bucket angle are controlled to perform easy and highly precise plane excavation and shaping.

Knotless paternoster boom

Abstract: A knotless pasternoster boom 2 for use in holding out a snood 3 from a fishing line 1 comprises a body 6 having an upper end 7 and a lower end 8 and a laterally extending boom member 9 adapted for supporting the snood 3 on the boom member 9 to extend generally axially thereof. The boom 2 has bores 11, 12 extending from respective inlets 13, 14 at the upper and lower ends 7, 8 to an outlet 15 and a prong member 23 associated with the outlet 15. In use of the boom upper and lower loops 26 are taken in the line 1 and fed into the bores 7, 8, through the inlets 13, 14, out of the outlet 15 and around the prong member 23, and the line 1 then pulled taut around the boom 2 thereby to secure the boom 2 in a desired position along the line 1.

Outhaul boom end part for sailboard boom assembly

Abstract: An outhaul boom end part for a sailboard boom assembly is molded integrally from plastic. The outhaul boom end part is generally U-shaped and includes a pair of tubular portions for attachment to the booms and a central portion. The central portion is provided with a pair of jam cleat slots which extend generally parallel to a plane which bisects the U-shaped part, and a sleeve is mounted on the central portion with its excess perpendicular to the plane of the U-shaped part.