Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
  • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
  • F15B15/00—Fluid-actuated devices for displacing a member from one position to another; Gearing associated therewith
  • F15B15/20—Other details, e.g. assembly with regulating devices
  • F15B15/28—Means for indicating the position, e.g. end of stroke
  • F15B15/2892—Means for indicating the position, e.g. end of stroke characterised by the attachment means

Definitions

• the invention concerns a holding device for a piston position sensor, being displaceably mounted on the outside of a fluid pressure cylinder, particularly for the sensing of a magnetic field generated by at least one permanent magnet being attached to the piston of the fluid pressure cylinder, which holding device comprises an essentially U-shaped yoke, being displaceable along and fastenable to the outside of the cylinder tube by means of fastening elements.
• the aim of the invention is to achieve a holding device which may be used with the latter type of fluid pressure cylinder without external tension rods, yet facilitating safe mounting of the above mentioned type of piston position sensor with a clamping device, being available on the market.
• a holding device having the features stated in claim 1, the holding device thus being characterized in that the essentially U-shaped yoke is displaceable along and fastenable to at least one guide being formed on the outside of and integrally with the cylinder tube, that a holding element is partly insertable into and fastenable within the yoke, said holding element being provided with a protruding holding pin, and that the piston position sensor is provided with a clamping device, by means of which the piston position sensor is clampable onto said protruding holding pin.
• piston position sensors of the previously known type.
• the piston position sensor may easily be detached from the holding pin without detaching the yoke from its fastened position on the guides. This means that the piston position sensor may be dismounted and remounted without altering the adjusted position of the yoke.
• FIG. 1 shows, in a cross-sectional view, a cylinder tube with a holding device mounted thereon, according to a first embodiment
• Fig. 2 shows the holding device according to Fig. 1 and a part of the cylinder tube in longitudinal section;
• Fig. 3 shows, in a cross-sectional view, an upper part of the cylinder tube with a holding device (according to Fig. 1 and 2) and a piston position sensor mounted thereon; and Fig. 4 shows, in a cross-sectional view, a second embodiment of the holding device.
• Fig. 1 and 2 thus illustrate a cylinder tube 1 of a fluid pressure cylinder, the cylinder end plates at the ends of the cylinder tube and a displaceable piston with associated piston rod inside of the cylinder tube not being shown.
• the cylinder tube 1 which is preferably manufactured from an aluminium alloy, has on the one hand, longitudinal beads 2 with through holes 3 therein for fastening screws (not shown) for the end plates and, on the other hand, dovetail shaped longitudinal beads 4 on opposite sides of the cylinder tube 1, with undercut, mutually parallel guide grooves 4a, 4b, formed at their
• This holding device 5 for a piston postion sensor comprises a U- shaped yoke 6, the shanks 7 and 8 of which at their ends are formed with inwardly projecting gripping edges 7a, 8a, engaging the guide grooves 4a and 4b, respectively.
• the yoke 6 may be made of metal but is preferably produced out of a rigid plastic material, rendering the yoke a certain dimensional flexibility as well as good sliding properties relative to the guide grooves 4a, 4b.
• the dimensional flexibility is further increased by longitudinal weakenings 6a, 6b in the web portion 6c of the yoke adjacent to the respective shank.
• the shanks 7, 8 are provided with bevels or recesses 7b, 8b (Fig.
• the yoke 6 is thus displaceable along the whole length of the cylinder tube 1 (for the positioning close to the second end plate, the yoke may be snapped out of the guide grooves 4a, 4b and turned 180°, so that the bevelled corner portions 7b, 8b, abut said second end plate) and may be positioned and fixed in a desired position by means of a transverse fastening screw 9, which, when tightened, presses the shanks 7, 8 of the yoke towards each other in the area of the fastening screw 9, i.e.
• the threaded end portion of the fastening screw 9 (not visible in the figures) is in threaded engagement with a nut, which is non-rotatably guided in a recess in the opposite shank 8.
• a holding body or element 10 with a protruding pin 10b, onto which a piston position sensor 12 (Fig. 3) is fastenable comprises an essentially cylindrical portion 10a (Fig. 2) which is dimensioned to be inserted between the shanks 7, 8 of the yoke with a certain play.
• a second transverse fastening screw 13 may be inserted through a hole in the shank 7 and through a circumferentialgroove 14 in the cylindrical portion 10a of the holding element to an opposing hole in the shank 8, where a nut (not shown) engaging the thread of the fastening screw 13 is non-rotatably arranged in a recess (not shown) in the shank 8.
• the holding element 10 is locked axially inside the yoke 6 while being rotatable around the axis of the cylindrical portion 10a, the circumferential groove 14 making such a rotation possible.
• This rotatability is utilized for the adjustment of the axially protruding holding pin 10b to a desired radial distance from the outside of the cylinder tube 1.
• the holding pin 10b is namely excentrically placed relative to the axis of the cylindrical portion 10a, as best illustrated in Figs. 1 and 3.
• the fastenable piston position sensor 12 may be adjusted in such a way that its sensor element is placed close to the outer surface of the cylinder tube,
• the adjusting operation is facilitated by the free end surface of the holding pin 10b being provided with an internal hexagonal recess 11, so that the whole holding element may be rotated to a desired rotational position by means of a hexagon screw driver.
• the recess 11 may of course be replaced by a slot for an
• the holding element 10 may be locked in the adjusted rotational position by means of a locking screw 15, which is screwed through a threaded through hole in the web portion 6c of the yoke 6c.
• the piston position sensor 12 itself is of a known type, including a sensor element 12a, from which an electric cable 16 with power supply and signal conduits emerges, a fastening screw 12b and a clamping jaw 12c actuated thereby.
• the piston position sensor 12 is fastenable on the holding pin 10b.
• the holding pin 10b may be provided with a scale or markings, so that the piston position sensor 12 may be dismounted and remounted in exactly the same position on the holding pin.
• the U-shaped yoke 6' is turned with its shanks 7', 8' away from the cylinder tube 1', the web portion 6'c of the yoke 6' lying on a longitudinal bead 16' with an inner, undercut, essentially T-shaped guide groove 4' formed on the outside of the cylinder tube 1'.
• a displaceable nut 17' is seated within this groove and is in threaded engagement with a screw 18', the head 18'a of which is countersunk in an inner recess in the web portion 6'c of the yoke 6'.
• the yoke 6' is thus displaceable along the bead 17' and the groove 4' as well as fastenable in a desired position by means of the screw 18'.
• the holding element 10' with its excentrically arranged
• longitudinally protruding holding pin 10'b is in this case directly fastenable between the shanks 7', 8' of the yoke 6' by means of the two fastening screws 9', 13', of which (as in the previous embodiment) one, namely the fastening screw 9', serves as an axial abutment when inserting the cylindrical portion 10'a of the holding element 10' between the shanks 7', 8' and the other, namely the fastening screw 13', locks this portion 10'a axially in the inserted position through cooperation with a circumferential groove 14'.
• the holding element 10' may be fixed by tightening the two fastening screws 9' 13'.

Landscapes

• Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Fluid Mechanics (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Portable Nailing Machines And Staplers (AREA)
• Clamps And Clips (AREA)
• Actuator (AREA)

Priority Applications (2)

Applications Claiming Priority (2)

Publications (1)

Family

ID=20379826

Family Applications (1)

Country Status (4)

Cited By (4)

Citations (1)

• 1990
  • 1990-06-20 SE SE9002201A patent/SE9002201L/ not_active IP Right Cessation
• 1991
  • 1991-05-29 EP EP91911689A patent/EP0535085B1/de not_active Expired - Lifetime
  • 1991-05-29 WO PCT/SE1991/000377 patent/WO1991019907A1/en active IP Right Grant
  • 1991-05-29 DE DE69111812T patent/DE69111812T2/de not_active Expired - Fee Related

Patent Citations (1)

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