APPARATUS WITH A RODLESS FLUID ACTUATED CYLINDER

Abstract: Apparatus in pressurized fluid cylinders where the piston is provided with a dog (2) extending through a slit in the cylinder wall, the slit being closed off with the aid of a sealing strip. The invention is distinguished in that a support part (4) which is fixed along the cylinder (1) has two free opposing surfaces (7) disposed at the side of the dog (2) and parallel to its path of movement and in that the dog (2) is provided with a portion (8) with two surfaces each of which is in slideable engagement with one of the surfaces (7) of the support part (4).

Description: The present invention relates to an apparatus with a rodless fluid actuated cylinder, wherein the piston is provided with a dog extending through a slot in the cylinder wall, said slot being closed by means of a sealing strip; with a guiding arrangement in the form of a support part extending along the cylinder, rigidly attached to said cylinder and having two free opposing surfaces disposed parallel to the path of movement of the dog; and the dog being provided with a slide with two surfaces each in slidable engagement with one of said opposing surfaces of the support part. Such an apparatus is already proposed by the EP-A-0294350. The rigidity of the support part can become a problem, if the path of movement of the piston is long and the moving speed is high, because the support part must be constructed with very strong and rigid members to avoid vibrations along the cylinder and along the support part. Such a heavy construction for the support part is very expensive and therefore a disadvantage and shall be avoided by the invention. The inventional apparatus is characterized in that the cylinder is provided on its outside with at least two T-slots extending along the cylinder and parallel to its axis; in that the support,part is provided with a first profiled rail disposed in the T-slot nearest the dog; in that an elongated portion is arranged parallel to the support part and on the opposite side thereof to the dog, said elongated portion being provided with a second profiled rail disposed in a second T-slot; and in that the support part and said elongated portion are urged towards each other for thus fastening the support part to the cylinder. With the invention the support part is constructed with two portions, said support part and said elongated portion. These two portions are urged towards each other, e.g. with the aid of screws, disposed along said support part and said portion. Therefore each of the two portions of the entire support part can be manufactured much cheaper and nevertheless an entire support part for the cylinder can be built with a high rigidity. The invention will now be described in more detail in the form of examples and with reference to the drawing, where Fig. 1 is a half section through a schematically indicated cylinder provided with the inventive apparatus, Fig. 2 is a schematic, partial side view (with the end portions also excluded) of the arrangement in Fig. 1, and Fig. 3 is a modified form of the invention schematically illustrated in section. The numeral 1 denotes the very schematical configuration of the cylinder not having a piston rod (the cylinder bore, slot, pistion and its parts are not drawn in, since they can be regarded as being a part of the prior art). The numeral 2 denotes the part of the dog which is outside the cylinder. The illustrated cylinder has a nearly square section with rounded corners and arcuate sides, with pairs of T-slots 3 made on three of the sides. The shape of the slots 3 in the illustrated example will be clearly seen in the enlarged detail of Fig. 3. A support part 4 is provided with a first profiled rail 5 integral with it and having a configuration complementary to that of the T-slot 3. The side from which the profiled rail 5 extends, and which is facing towards the cylinder shell has a configuration complementary to that of the shell. The support part 4 has a principally rectangularly shaped flange 6, the parallel sides of which form two opposing surfaces 7 extending along the entire movement range of the dog 2. The dog 2 is also provided with a yoke 8 surrounding the flange 6 and having two surfaces in slidable engagement with the surfaces 7 of the flange 6. An elongated portion 9 is provided, as with the support part 4, with a second profiled rail 10 having a cross-sectional shape corresponding to that of the T-slot 3. The side facing towards the cylinder shell carrying the second profiled rail 10 has a configuration complementary to that of the cylinder shell. The support part 4 is attached to the cylinder by its being inserted axially with the first profiled rail 5 in the slot 3. The elongated portion 9 with its second profiled rail 10 is inserted axially in the other T-slot 3 in the same way. When the support part 4 and the elongated portion 9 are in place, these parts are urged towards each other with the aid of screws 11 and disposed at an even pitch along the parts. The (not illustrated) screws pass through bores in the elongated portion 9 and coact with threaded holes in the support part 4. Irrespective of the radial movements of the cylinder shell in the region of the slot, due to interior excess pressure, the dog 2 will always be able to be supported against the support flange 6, which is capable of taking up load movements with force components deviating from the purely axial direction. Torques acting on the dog at right angles to its direction of movement are also taken up via the yoke 8 by the flange 6. Within the scope of the invention it is of course possible to vary components and details therein, e.g. the edges facing towards each other of the part 4 and the profile 9 can be provided with tongues 12 and grooves 13 for taking up, together with the screws 11, any bending movements which can occur during assembly and for extreme loads on the dog 2, see Fig. 3. In the latter figure there is also illustrated a possible, modified embodiment, where the support part 4 has two rails or one "yoke portion" and the dog 2 has a flange, slidingly coacting with the inner surfaces of the rails or yoke portion. Fig. 3 also shows the first and second profiled rails 5 and 10 configurated as hooks in cross section, these hooks engaging the T-slot 3. This implementation can facilitate assembly of the support part 4 and elongated portion 9.

Claims: Apparatus with a rodless fluid actuated cylinder (1), wherein the piston is provided with a dog (2) extending through a slot in the cylinder wall, said slot being closed by means of a sealing strip; with a guiding arrangement in the form of a support part (4) extending along the cylinder (1), rigidly attached to said cylinder (1) and having two free opposing surfaces (7) disposed parallel to the path of movement of the dog (2); and the dog (2) being provided with a slide (8, 8′) with two surfaces each in slidable engagement with one of said opposing surfaces (7) of the support part (4), characterized in that the cylinder (1) is provided on its outside with at least two T-slots (3) extending along the cylinder and parallel to its axis; in that the support part (4) is provided with a first profiled rail (5) disposed in the T-slot (3) nearest the dog (2); in that an elongated portion (9) is arranged parallel to the support part (4) and on the opposite side thereof to the dog (2), said elongated portion (9) being provided with a second profiled rail (10) disposed in a second T-slot (3); and in that the support part (4) and said elongated portion (9) are urged towards each other for thus fastening the support part (4) to the cylinder (1). Apparatus as claimed in claim 1, characterized in that the two opposing surfaces (7) of the support part (4) are the two outside faces of a bar (6) and in turn the slide (8) has a U-cross-sectional area, riding on the bar (Fig. 1). Apparatus as claimed in claim 1, characterized in that the two opposing surfaces (7) of the support part (4) are the two inside faces of a U-cross-sectional area and in turn the slide (8′) has the form of a bar (6′) extending inside the U-area (Fig. 3). Apparatus as claimed in claim 1, characterized in that the support part (4) and said elongated portion (9) are urged towards each other with the aid of screws (11), disposed along said part (4) and said portion (9). Apparatus as claimed in claim 1, characterized in that said support part (4) and said elongated portion (9) are provided with tongues (12) and grooves (13) being urged towards each other for taking up bending movements. Apparatus as claimed in claim 1, characterized in that said first and second profiled rails (5, 10) are provided with a T-profile and/or an L-profile.

Inventors: GRANBOM, BO
Applicants: HYGRAMA AG
Application year: 1989
Main classification: F15B15
IPC codes: F15B15