Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
  • B62D—MOTOR VEHICLES; TRAILERS
  • B62D57/00—Vehicles characterised by having other propulsion or other ground- engaging means than wheels or endless track, alone or in addition to wheels or endless track
  • B62D57/02—Vehicles characterised by having other propulsion or other ground- engaging means than wheels or endless track, alone or in addition to wheels or endless track with ground-engaging propulsion means, e.g. walking members
  • B62D57/022—Vehicles characterised by having other propulsion or other ground- engaging means than wheels or endless track, alone or in addition to wheels or endless track with ground-engaging propulsion means, e.g. walking members consisting of members having both rotational and walking movements
• • E—FIXED CONSTRUCTIONS
  • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
  • E02F—DREDGING; SOIL-SHIFTING
  • E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
  • E02F9/02—Travelling-gear, e.g. associated with slewing gears
  • E02F9/04—Walking gears moving the dredger forward step-by-step

Definitions

• the invention relates to a load-bearing swinging arm causing an advance movement of a mobile device by means of its pivoting movement and being pivotally connected to another construction in a pivotal relationship thereto about an axis of rotation, an actuator for effecting said pivoting movement being provided between the arm and the construction at the pivot.
• the swinging arm of aforementioned type forms a leg or a part thereof in a machine that moves supported by arms.
• the problem has been to control the very large force or moment present between the construction and the arm in such a manner that the construction will not be subjected to excess loads which are in the practice quite large and shorten the life of the bearings, keeping further in mind that the structure should not be too complicated.
• high speed and small force are needed.
• the present disposals of actuators can not satisfy these two opposite needs.
• the purpose of the invention is to overcome the above- mentioned drawbacks.
• the points of action acting on the construction by ay of the actuator are provided on both sides of the axis o" rotation. It is now possible to utilize the so-called force couple principle at the pivot. In the situations requiring large turning moment in the pivot both actuators are provided for effecting a moment in the same direction abound the axis of rotation simultaneously. Because the actuators are situated on both sides of the axis of rotation, the senses of action of their forces are opposite, thus compensating mutually the effects of their forces at least partly.
• the placing of the actuators in accordance with the invention makes the control possibilities of the arm more versatile. In a non-critical load situation it is possible to provide only one of the actuators with the supply of energy. It is thereby possible to reach a great speed of movement by means of a small energy supply.
• the actuators can thus serve as a sort of gearing.
• the points of action are situated on the same line that intersects the axis of rotation. If the aim is an ideal force couple in several arm positions by means of a simple system, it can be achieved by placing the points of action at equal distances from the axis of rotation and provide the actuators for causing equal forces at the points of action.
• the swinging arm is also at its other end pivotally connected to another construction in a pivotal relationship thereto about an axis of rotation.
• the actuators acting on the construction and on the other construction can be fixed on the same swinging arm, in which case the control of the whole leg will be facilitated because the actuators are in the same area.
• the actuators are placed inside the swinging arm in a housing-like construction where they are well protected but perform an optimal function.
• the housing-like construction makes the arm lighter, and the arm will, be at the same time strong.
• Fig. 1 shows the principle of the swinging arm in accordance with the invention
• Fig. 2 shows one solution of the pivotal connection in a sectional view at the axis of rotation A
• Figs. 3 and 4 show another solution of the pivotal connection in a sectional view at the axis of rotation and in longitudinal section along the longitudinal direction of the arm, respectively,
• Figs. 5 and 6 illustrate one possibility to accomplish the fixing of the actuator and the supply of pressure medium to the actuator in a side view and sectional view of the actuator
• Fig. 7 shows a leg comprising the arm con ⁇ struction of the invention seen from the side
• Fig. 8 shows the leg of Fig. 7 seen from the front.
• Fig. 1 shows a swinging arm 1 in accordance with the invention as seen in its plane of pivoting, that is, in the direction of the axis of rotation A.
• a construction with respect to which the arm 1 is pivotal is denoted with reference numeral 2.
• At the pivot permitting the pivoting movement there is a pair of actuators which is constituted of two actuators 3.
• One part of an actuator 3 is pivotally connected to the arm 1 so that it is relatively immobile with respect to the latter in the longitudinal direction of the actuator, and the other part that is movable with respect to the former is attached to the construction 2.
• Fig. 1 shows one of such extreme positions with uninterrupted lines and correspondingly the other of such extreme positions with broken lines. Dash-and-dot lines show the path of movement of the points of action between these extreme positions. As shown by Fig.
• the points of action 3a and 3b are further located within the contours of the arm 1 when the arm is looked at in the direction of the axis of rotation A. Also the other parts of the actuator 3, such as the actuator end pivotally connected to the arm 1, are also situated within the contours of the arm.
• the actuator 3 is pivotally fixed on the arm at point 3c using well-known solutions that make the path of movement of the points of action 3a and 3b possible.
• the actuators can be of any type capable of transmitting force and accomplishing the movement between the arm 1 and the construction 2 by influencing the points of action 3a and 3b by means of the actuator.
• variable in length can be chosen devices operated by means of pressure medium, especially hydraulic cylinders.
• the body of the cylinder can be attached to the arm 1 and the end of the piston rod will form a point of action on the construction 2, said rod being mountable at this point using well-known solutions of securing that allow the piston rod and the construction to pivot with respect to each other. It is also possible to accomplish the mounting in a contrary manner, that is, the cylinder body may be pivotally connected to the construction 2 and the piston rod end correspondingly to the arm 1.
• An important advantage in the invention is the fact that the pivotal movement can be accomplished by using only one of the actuators 3, because this will be in certain cases sufficient for effecting the pivotal movement around the axis A, for example when the arm 1 is swung in a position where it is not subjected to the load of the construction supported by the arm.
• the inlet line to the inactive actuator and the outlet line from the same can be coupled together to form a free circulation, or the actuators can also be connected in series in this situation. The volumetric flow supplied to the actuators can be minimized without any harmful effect on the speed of movement of the arm.
• each of the actuators 3 can be used for effecting a moment to either of the directions when desired.
• hydraulic cylinders they are consequently double-acting, that is, when the piston is acted upon it is possible to achieve either a pushing force or a pulling force.
• the points of action 3a and 3b can always be positioned and the actuators can be dimensioned in such a fashion that the points of action effect a force couple at least in one position, for example in a critical one in view of the load.
• each of the points of action is so situated and the force exerted thereon is such that according to the laws of the mechanics the forces have opposite directions and are of equal magnitude.
• Fig. 1 shows how the points of action are placed in this case at equal distances from the axis of rotation A.
• the actuators 3 are provided for effecting always equal forces at the points of action 3a and 3b.
• this can be provided most practically by dimensioning the cylinders equal in size and making the work surface of the piston equal on both sides of the piston.
• the piston rod passes through the whole work space of the cylinder on both sides of the piston, which is schematically shown by broken lines in conjunction with the cylinders 3 of Fig. 1.
• the absolute value of the total moment is always equal at the given position.
• the individual moments influencing through the points 3a and 3b may slightly deviate from each other owing to a sligh ly unsym etrical location of the force lines determined by the actuators 3, but for the purpose of the turning moment causing the movement of the arm this fact has little importance.
• Fig. 1 shows further the fact that when the points 3a and 3b are situated on the same line extending through the axis of rotation A, an ideal force couple cai. act through them at two separate positions, namely at the positions where the force lines are parallel and intersect the path of m. ement of the points having the form of a circle arc.
• p a and p b are the work pressures prevailing in the cylinders
• a a and A b are the corresponding areas on which the aforementioned pressures are acting.
• the formula illustrates the situation at a given time.
• the pressure is a factor that can be constantly varied and this possibility can be utilized during the movement.
• the pressures can also be variable independently of each other.
• the above-described dimensioning formula can be utilized in one direction of movement only, or in both directions of movement.
• a force couple operative in whichever direction can be produced also by means of such cylinders where the work areas on the opposite sides of the piston are different, for example owing to the fact that the piston rod is not passed through the cylinder within both work spaces.
• This provision requires different work pressures in the same cylinder, depending on the direction of movement. It is also possible to alter the force caused by the actuators during the movement, for example in the case of hydraulic cylinders their work pressures can be altered. In this way a greater force can be applied at predetermined points within the range of movement.
• an ideal force couple can be provided only at a predetermined position in case the actuators cause always the same constant force. Also this kind of idea falls within the scope of the invention, even if in the case of Fig. 1 the dimensioning of the actuators and the positioning of the points of action is preferred in the sense that an ideal force couple will prevail at two critical positions regarding the load, either when the movement proceeds in one direction or when it proceeds in either direction. This kind of situation will be present for example when the arm 1 supports the load in such a fashion that the arm forms an angle with the vertical plane.
• Fig. 1 shows further the corresponding arrangement at the opposite end of the arm for providing a relative movement between the other construction 4, such as another swinging arm, and the arm 1.
• the other construction 4 such as another swinging arm
• a pair of actuators attached to the arm at points 5c, the pair comprising two actuators 5 and the corresponding points of action 5a and 5b acting on a construction, as well as an axis of rotation B situated between the points of action.
• the rotation of the arm 1 and the other construction 4 with respect to each other takes place around the axis of rotation. All alternatives mentioned in conjunction with the actuators 3 and the points of action 3a and 3b can be applied in an analogical manner to the actuators 5 and the points of action 5a and 5b.
• Fig. 1 shows further the corresponding arrangement at the opposite end of the arm for providing a relative movement between the other construction 4, such as another swinging arm, and the arm 1.
• a pair of actuators attached to the arm at points 5c, the pair comprising two actuators 5 and the corresponding
• both the actuators 5 and their points of action 5a and 5b lie also in this case within the contours of the arm as the arm is looked at in the direction of the axis of rotation B.
• the Figure illustrates excellently how in this type of arm 1 incorporating the axes of rotation A and B at its both ends the actuators 3 and 5 causing the rotation can be provided in the same arm, that is, all actuators can be centralized to a single unit.
• Fig. 2 shows a cross-section of the pivotal connection to the construction 2 at the axis of rotation A.
• the arm 1 is made pivotal by fixing the ends of the actuators 3 on the construction 2 which in the Figure is formed of a part 2a surrounding the axis of rotation A and fixed on the body of the machine in a non- rotating relationship thereto.
• the part is equipped with bearings of circular shape in the plane perpendicular to the axis of rotation A (in the case of Figure slide bearings 6) , inside which bearings said part 2a is situated and on the outer circumference of which the arm 1 is mounted in pivotal relation thereto.
• the structure of the arm 1 v/ill be described hereinafter more closely. As shown by Fig.
• the bearings 6 are situated in the direction of the axis of rotation A on both sides of the points of action 3a and 3b, that is, on the opposite sides of the plane of the points of action 3a and 3b, whereby a symmetrical structure without any torsional forces can be provided.
• Fig. 2 illustrates further how the fixing points 3a and 3b of the actuators are located in the plane perpendicular to the axis A outside the bearing surfaces 6 in the brackets provided in the part 2a, and situated between the bearings 6 as seen in the direction of axis A.
• Figs. 3 and 4 show another possible structure. Although it depicts the structure at one. end of the arm 1 where the arm 4 pivotal with respect thereto is mounted, it can be also used at the location shown by Fig. 2.
• the parts of the arm 4 are here denoted with reference numeral 4 and the bearings are of the same principle as in Fig. 2.
• the Figure reveals also the housing-like structure of the arm 1, that is, all actuators 3 and 5 and points of action 3a and 3b as well as 5a and 5b are situated well protected inside the housing-like arm, and thus they do not require much space.
• Fig. 3 shows another possible structure. Although it depicts the structure at one. end of the arm 1 where the arm 4 pivotal with respect thereto is mounted, it can be also used at the location shown by Fig. 2.
• the parts of the arm 4 are here denoted with reference numeral 4 and the bearings are of the same principle as in Fig. 2.
• the Figure reveals also the housing-like structure of the arm 1, that is, all actuator
• the points of action namely 5a ard 5b
• the points of action are attached to a part 4b connected to the arm 4 in non-rotating relationship thereto and lying between the bearings 6.
• the part 4b is situated between the extension of the longitudinal side walls of the arm 4.
• the arm 4 can be of a housing-like structure, even if no actuators were placed inside it. A light construction combined with strength will be the advantage in this case.
• Figs. 5 and 6 show an advantageous way to fix a hydraulic cylinder serving as actuator on the arm and to provide the suppl of pressure medium thereto.
• the cylinder is also in this case made pivotal at the pivot point 3c inside the housing like structure.
• the pivotal connection is accomplished by a bearing piece 9 rigidly joined to the body of the cylinder, that is, to the part comprising the work chambers of the cylinder.
• the piece is at its both sides connected pivotally to the arm 1 at the bearing points provided in the opposite side walls of the housing-like construction of the arm.
• Passages 10*, 11' for pressure medium are provided in the bearing piece 9 in such a fashion that the passage 10' extending into one of the cylinder chambers opens on one side of the bearing piece and the passage 11* leading to the chamber on the opposite side of the piston opens on the side located on the opposite side of the pivoting plane of the piece. Because the bearing piece 9 and the body of the cylinder 3 are joined together to a substantially mutually immovable relationship, the construction formed by the piece 9 and the cylinder 3, that is, the construction situated inside the arm 1 does not require any flexible hoses for delivering pressure medium into the cylinder. One passage 10• for pressure medium is led along the bores made inside the bearing piece to a rigid pipe 10" remaining inside the arm and joined to the surface of the bearing piece.
• the passage continues along the pipe into a chamber at one end of the cylinder.
• the other passage ll 1 is led straight along a bore formed at the pivoting axis of the bearing piece into the other chamber, which is situated on the opposite side of the piston with respect to the aforementioned chamber.
• the passages 10' and 11* open on the outer surface of the bearing piece on the opposite sides of the pivoting plane of the arm 1.
• Said points are constituted of holes, which are concentric with respect to the pivoting axis C between the arm 1 and the bearing piece 9 and which are of such structure that the respective conduits 10 and 11 situated outside the arm and serving as inlet and outlet lines of the pressure medium (illustrated schematically by broken lines in Fig. 6) can be fixed thereon by using a rotating or flexible fitting.
• Fig. 5 shows further the possibility that the pivoting point 3c for connecting the actuator 3 to the arm 1 need not necessarily be situated at the opposite end of the actuator in its longitudinal direction as seen from the connecting point between the construction 2 and actuator 3.
• the pivoting point is situated in the cylinder 3 so close to the construction 2 as possible, that is, in the part containing the work chambers of the cylinder at the point where the piston rod emerges from the cylinder.
• Figs. 7 and 8 show a larger construction incorporating the above-described arm 1.
• the Figures show a leg of a machine travelling on a support for advancement. The advancement of the machine takes place through the movement of the leg.
• the construction 2 is in this case a construction through which the arm 1, which can be designated thigh section, is mounted on the body of the machine.
• the construction 4 is another arm mounted at the opposite end of the arm 1, and it can be designated shin section.
• the arms 1 and 4 form the leg which for its part supports the machine body, and this kind of apparatus comprises for example four, preferably six such legs symmetrically divided onto both sides of the longitudinal centre line of the machine.
• a foot section 8 at the free end of the arm 4 serves as point of support against the support for advancement in this kind of leg.
• the pivots at the axes of rotation A and B are subjected to quite large stresses when the leg is situated on the support for advancement, the fact which makes the present invention very applicable in this connection.
• Figs. 7 and 8 show also some paths of movement of the arms 1 and 4, the respective extreme positions being denoted by dash-and-dot lines and by corresponding reference signs.
• the arms 1 and 4 can be moved also sideways within a certain angle on both sides of the vertical plane owing to the fact that the arm 1 is attached to a part 2 which is pivotal with respect to the machine body, said pivoting movement taking place about a horizontal axis D perpendicular to the axes of rotation A and B.
• Fig. C shows further by broken lines an actuator 7 that controls said pivoting movement, the actuator being in this case a hydraulic cylinder.
• the corresponding part of a slightly different structure is illustrated also in Fig. 2 by corresponding reference signs.

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• Engineering & Computer Science (AREA)
• Mining & Mineral Resources (AREA)
• Civil Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Structural Engineering (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Transportation (AREA)
• Mechanical Engineering (AREA)
• Manipulator (AREA)

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• 1990
  • 1990-08-14 FI FI904009A patent/FI87171C/fi not_active IP Right Cessation
• 1991
  • 1991-08-14 AU AU83122/91A patent/AU8312291A/en not_active Abandoned
  • 1991-08-14 WO PCT/FI1991/000251 patent/WO1992003328A1/en unknown
  • 1991-08-14 US US07/969,313 patent/US5353886A/en not_active Expired - Lifetime

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