Patents Assigned to Dynapac Maskin AB
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Patent number: 4609055Abstract: A system is disclosed for minimizing the transmission of vibrations from a vibratory source through a pair of shafts to a handle mounted transversely to the shafts. The handle is mounted to the shafts through resilient, elastomeric, hourglass-shaped shock absorbers. The mass of the handle and the spring stiffness of the shock absorbers are selected to provide the handle with a characteristic frequency (F.sub.c) such that F.sub.s >.sqroot.2 F.sub.c. To limit axial deflection of the shock absorbers when transverse forces are applied to the handle, each of the elastomeric elements is mounted between and inside a respective pair of nested cups having their open ends facing one another, one cup of each pair being connected to the handle and the other cup of each pair being connected to a shaft.Type: GrantFiled: November 15, 1984Date of Patent: September 2, 1986Assignee: Dynapac Maskin ABInventors: Lars M. Grafstrom, Lennart Hallstedt, Per Enochsson
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Patent number: 4546425Abstract: A method is disclosed for providing optimal compaction of various materials by controlling the vibration amplitude of an adjustable amplitude vibratory roller. The vibration amplitude is automatically reduced when excessively high jolting forces are sensed by transducers carried by the roller or its frame. The apparatus for carrying out the method includes a continuously adjustable eccentric element in the vibratory roller, at least two signal transducers mounted on the roller drum or frame and axially separated, to generate signals representing the vibrational movement of the roller. A regulating system responsive to the signals from the signal transducers reset the adjustable eccentric element to vary the vibration amplitude and provide optimal compaction.Type: GrantFiled: March 24, 1983Date of Patent: October 8, 1985Assignee: Dynapac Maskin ABInventor: Claes Breitholtz
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Patent number: 4523486Abstract: A vibratory apparatus in which the amplitude of vibration is continuously adjustable, includes a tubular rotatable shaft journalled in the member to be vibrated, and at least one elongated and flexible eccentric mass element disposed in the tubular shaft. The eccentric mass element is guided along guide surfaces, arranged so that part of the eccentric mass element is urged by centrifugal force away from the axis of the tubular shaft when the shaft is rotating. An adjustment means is coupled to the eccentric element to control the position of the element along the slide surfaces, to thereby vary the vibration amplitude of the vibrating tubular shaft.Type: GrantFiled: February 7, 1983Date of Patent: June 18, 1985Assignee: Dynapac Maskin ABInventor: Alfredo Bueno
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Patent number: 4481835Abstract: A hydraulic adjusting system is provided for the continuous adjustment of the vibration amplitude of a rotating eccentric element. The hydraulic adjusting device includes a piston in a single acting cylinder. A piston connecting rod extends through the cylinder and is rigidly journalled axially inside the piston. One end of the rod is rigidly connected to a drive shaft of the eccentric element and the other end to a power source for rotatably driving the eccentric element. The system provides for continuous adjustment of amplitude vibration and, since the vibration amplitude is directly proportional to the hydraulic pressure acting on the piston, the system also facilitates setting and monitoring of such vibration amplitude.Type: GrantFiled: October 20, 1982Date of Patent: November 13, 1984Assignee: Dynapac Maskin ABInventor: Stig Storm
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Patent number: 4342485Abstract: A cold surface pavement planer, used to scarify and profile concrete and asphaltic pavements, is constructed with a sealed cutter drum. A gear box in the cutter drum, transmitting power to the cutter drum from an engine on the planer chassis, is cooled efficiently by a coolant liquid in the cutter drum in which the gear box is partially immersed.Type: GrantFiled: August 29, 1980Date of Patent: August 3, 1982Assignee: Dynapac Maskin ABInventor: Eskil Tuneblom
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Patent number: 4317314Abstract: A machine for finishing a flat surface, for example a floor made of cement, concrete, or similar hardened material, includes a chassis supported by at least three wheels arranged to carry the weight of the chassis. A grinding tool, preferably a grinding wheel, is mounted to the chassis to rotate about a vertical rotational axis and to rest on the floor when grinding work is in progress. The grinding wheel is mounted to move freely in the vertical direction relative to the chassis such that the weight of the grinding wheel is carried by the floor, and the grinding pressure is readily adjustable for differing applications.Type: GrantFiled: May 13, 1980Date of Patent: March 2, 1982Assignee: Dynapac Maskin ABInventors: Per Carlstrom, Gert Persson
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Patent number: 4266884Abstract: A road roller comprises a frame and a pair of drums, at least one of which is a guide drum, on which the frame is pivotally supported. A steering mechanism is attached to the guide drum for steering the road roller. The supporting mechanism for the guide drum includes a vertical pivot shaft coupled to the guide drum, a vertical anti-friction bearing on the pivot shaft for permitting the guide drum to pivot horizontally relative to the frame, and a flexible support coupled between the bearing and the frame for permitting limited lateral twisting of the guide drum relative to the frame. The flexible support comprises a pair of longitudinally spaced rubber mounts for absorbing longitudinal shocks but for inhibiting longitudinal twisting of the drum relative to the frame.Type: GrantFiled: May 7, 1979Date of Patent: May 12, 1981Assignee: Dynapac Maskin ABInventor: Eskil Tuneblom
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Patent number: 4221499Abstract: An easily adjusted vibratory device useful, for example, on soil compacting vibratory rollers. One or more mass elements are supported eccentrically on a rotating shaft. The mass elements are pivotal about a pivotal axis or shaft perpendicular to the rotating shaft. Pivoting the mass elements during rotation of the shaft moves the center of gravity of the mass elements toward or away from the rotating shaft and thereby continuously alters the magnitude of the centrifugal force acting on the mass elements to cause vibration. The mass elements are formed, with respect to the pivotal shaft, to minimize the force necessary to pivot the elements by maintaining the moment arms from the axis of the pivotal shaft to the centrifugal force resultant at or near zero. In a specific embodiment the rotating shaft is cylindrical, the mass elements and pivotal shaft are supported within the rotating shaft.Type: GrantFiled: April 28, 1978Date of Patent: September 9, 1980Assignee: Dynapac Maskin ABInventors: Claes Breitholz, Rolf Dahlin
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Patent number: 4198178Abstract: A concrete floor finisher for finishing newly-placed concrete. The machine comprises a rotor hub, a plurality of rotor arms on the hub for rotation about an axis, a blade pivotable on each arm, and a motor for driving the rotor hub. The pitch of the blades is adjustable depending upon the condition of the wet concrete, by a piston and cylinder centrally located about the axis of rotation of the rotor, and a stud connected at one end to the blades and at its other end engaging a portion of the piston to adjust the pitch of the blades in response to the axial displacement of the piston.Type: GrantFiled: June 27, 1978Date of Patent: April 15, 1980Assignee: Dynapac Maskin ABInventors: Per Carlstrom, Bo Lundberg, Gert Persson
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Patent number: 4145156Abstract: A plate vibrator for compacting soil, asphalt and similar materials comprises a bottom plate on which is rigidly mounted a vibrating element driven by a power unit that is mounted resiliently on the bottom plate. The vibrating element comprises at least two counterrotating eccentric weights mounted on a shaft, the phase positions of the eccentrics being capable of adjustment in relation to each other by means of an adjusting mechanism so that the direction of the resultant of the centrifugal forces can be arbitrarily selected in relation to the bottom plate. The location of the element and power unit in relation to each other on the bottom plate and the distribution of the masses oscillating with the bottom plate are chosen to minimize structural height and maximize translational motion both forward and in reverse.Type: GrantFiled: August 15, 1977Date of Patent: March 20, 1979Assignee: Dynapac Maskin ABInventor: Gunnar Grane
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Patent number: 4034614Abstract: An apparatus for generating vibrations comprises at least two masses mounted on a rotatable shaft and capable of moving radially against a spring force in relation to the center line of the shaft. Means for locking the masses to each other are provided, and the masses are arranged such that their respective centers of gravity are so distributed about the center line of the rotatable shaft that the resulting eccentric moment of the masses in relation to the center line is low or substantially zero when the shaft is stationary or rotating at low speed.Type: GrantFiled: September 16, 1975Date of Patent: July 12, 1977Assignee: Dynapac Maskin ABInventors: Torsten Fors, Martin Norrman
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Patent number: 4033427Abstract: Steering apparatus for road rollers of the self-propelled type having two drums each of which is journalled to rotate in a frame pivotally mounted on a common chassis. A piston rod, pivotally connected at its ends to the drum frames, is slidably mounted in a steering cylinder pivotally mounted on the chassis. A control system for transmitting and receiving a pressure medium through a pair of lines connected to the steering cylinder responds to a steering device to cause movement of the piston in the cylinder, so that the piston rod causes simultaneous rotation of the drum frames and proper tracking of the road roller drums.Type: GrantFiled: December 10, 1975Date of Patent: July 5, 1977Assignee: Dynapac Maskin ABInventor: Rune Sturesson
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Patent number: D271773Type: GrantFiled: July 17, 1981Date of Patent: December 13, 1983Assignee: Dynapac Maskin ABInventor: Bo Ekelund