Abstract: A cutter head arranged to rotate about an axis of rotation for removing material from a water bed comprises a base ring positioned respect to the axis of rotation; a hub positioned with respect to the axis of rotation; a plurality of arms extending between the base ring and the hub, the arms comprising a plurality of cutting tools; and a plurality of skirts, each skirt extending from one of the plurality of arms to the hub to form a closed surface between the arm and the hub from a distal end of the cutter head toward the base ring and ending with a side configured to be parallel to a backplate, leaving an open channel between the skirt and the backplate.

Abstract: There is disclosed an excavation apparatus (5), such as an underwater excavation apparatus, having means for producing, in use, at least one vortex, spiral or turbulent flow in a laminar flow of fluid, e.g. water. The excavation apparatus (5) comprises a rotor (10) having a rotor rotation axis (A), wherein, in use, flow of fluid past or across the rotor (10) is at a first angle (?) from the axis of rotation (A). The excavation apparatus (5) comprises the rotor (5) and means or an arrangement for dampening reactive torque on the apparatus (5) caused by rotation of the rotor (10), in use. The turbulent flow is provided within, such as within a (transverse) cross-section, of the laminar flow.

Abstract: The invention relates to a cutter head (10) for dredging ground under water, this cutter head being suitable for attachment rotatably around a central axis to the ladder (2) of a cutter suction dredger (1) and for being moved through the ground (9) therewith in a lateral sweeping movement, the cutter head comprising a base ring (13), a hub (14) situated at a distance in the direction of the central axis from the base ring, and a plurality of arms (15) extending from the base ring to the hub, wherein a passage opening (16) is located between arms and wherein the arms are provided with a first series of cutting tools on a leading part (15a) relative to the direction of rotation of the cutter head, and wherein at least one arm is provided with a second series of cutting tools on a part of the arm (15b) facing away from the central axis.

Abstract: Device for dislodging and recovering dredging material of varying nature, comprising a bearing housing (25), a drive shaft (11) mounted therein for rotatingly driving with a determined torque a cutter head (10, 10?) with a support ring (15, 15?), which cutter head is mountable on the drive shaft via a hub (9), and a suction pipe (13) which can be connected to a suction mouth (14, 14?) which is surrounded by a fixed cutter shield (21, 21?) which fills the space between the rotating support ring on the one side and the suction mouth and the bearing housing on the other, wherein a number of cutter heads with a different support ring diameter can be mounted on the drive shaft, wherein the support ring diameter is determined by the torque and the nature of the dredging material to be recovered.

Abstract: A suction tube device having a frame, a tube, a centrifugal pump which cooperates with the tube, and a cutter head at one end of the tube. The tube, centrifugal pump, and cutter head are supported by the frame. The centrifugal pump and the cutter head are each provided with a drive system, the drive systems of the centrifugal pump and of the cutter head each having at least one motor. A motor of the drive system of the cutter head and a motor of the drive system of the centrifugal pump are interchangeable with respect to each other.

Abstract: A cutter head for a cutter suction dredger to be mounted rotatably about a cutter head center axis with respect to a suction device for sucking up material cut loose by the cutter head from the bottom of a body of water, which cutter head includes a base ring, a boss spaced from the base ring in the direction of the center axis, and a plurality of arms which extend from the base ring to the boss and are distributed at regular intervals in the peripheral direction, each arm has a series of teeth located on the radially outermost parts of the arm and directed outwards at an angle with respect to the peripheral direction, the direction of rotation of the cutter head being set such that the teeth perform a cutting movement, with non-return mechanisms, preventing movement of cut material from the center axis to the exterior.

Abstract: A machine for improved excavation of underwater rock that eliminates failures due to over-stressed cutting teeth by positioning each hardened tooth for optimized Kinetic Energy. It has a plurality of blades, each with a hub and a plurality of spokes connecting the hub to a rim. Teeth are mounted on the leading edge of each blade approximately equidistant from the cutter axis of rotation, allowing each tooth to have the proper combination of velocity and cutting force required to shatter massive, hard rock. As a result, all teeth have approximately the same peripheral velocity; have adequate Kinetic Energy to shatter rock upon impact, and are subject to approximately the same maximum stress during rock excavation.

Abstract: A dredge cutterhead has a plurality of helical arms interconnecting a hub and a ring. Each of the arms has a front leading edge for attachment of cutting teeth. In one aspect, each of the arms has a trough portion, and the arm is shaped such that dredged material is directed toward the ring along the center of the trough portion. In another aspect, the ring of the cutterhead defines an annular channel for receiving loosened material.

Abstract: A dredge cutterhead has a plurality of helical arms interconnecting a hub and a ring. Each of the arms has a front leading edge for attachment of cutting teeth. In one aspect, each of the arms has a trough portion, and the arm is shaped such that dredged material is directed toward the ring along the center of the trough portion. In another aspect, the ring of the cutterhead defines an annular channel for receiving loosened material.

Abstract: A pin is laid out so as to pass through a boom laid out between a pair of bosses of the center frame of the upper rotating body, and are attachably, detachably, and pivotably mounted on the boom. A cab is laid out on one side of the pair of bosses, and oil tanks such as a hydraulic oil tank and fuel oil tank are laid out on the other side thereof. The sections of oil tanks that meet the extension line of the center line of the pins are formed as a space section with which the pin does not interfere when the pin is moved along the extension line. In the upper rotating body where the hydraulic oil tank and the fuel oil tank are laid out to keep the relation of the front and rear positions, the space between both oil tanks is positioned nearly on the extension line of the center line of the pins, and a cut section of the oil tank is formed on at least one side of both oil tanks, and besides partly hollowly.

Abstract: A device for creating a localized water jet within a body of water allows for the displacement of material from the floor of the body of water. The device includes two powered screws within a jet pipe. The screws are arranged coaxially and their direction of rotation, pitch, and speed of rotation are arranged such that the torque produced by one of the screws tends to counteract the torque produced by the other, allowing for improved control of the device.

Abstract: A dredge apparatus with an improved cutter includes a hull, a boom extending from the hull, and a cutter element rotatably mounted at the free end of the boom. The cutter element is positioned adjacent a suction line that is supported by the boom. The improved cutter element includes a plurality of rings having large open central portions for transmitting material to the suction. At least a pair of rings are spaced apart, one of the rings being supported using a rotary hub and spokes to a drive shaft. The external periphery of each of the rings carries three circumferentially spaced helical vanes. The helical vanes extend circumferentially and from ring to ring beginning at a front ring and ending at a rear ring which is adjacent the boom. Each of the vanes is "V-shaped" in transverse cross section providing a concave and a convex vane surface. The concave surface of each vane faces the suction line. The convex surface of each vane faces the front of the cutter element.

Abstract: A dredge cutterhead has a plurality of helical arms inter-connecting a hub and a ring. Each of the arms has a front leading edge for attachment of cutting teeth. In one aspect, each of the arms has a trough portion, and the arm is shaped such that dredged material is directed toward the ring along the center of the trough portion. In another aspect, the ring of the cutterhead defines an annular channel for receiving loosened material.