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
  • F15B15/08—Characterised by the construction of the motor unit
  • F15B15/14—Characterised by the construction of the motor unit of the straight-cylinder type
  • F15B15/1423—Component parts; Constructional details
  • F15B15/1457—Piston rods
  • F15B15/1461—Piston rod sealings

Definitions

• the present invention relates to a scraper for cleaning the guide element of a sliding member, or of a stem or of a piston of a piston cylinder unit, and an assembly comprising said scraper.
• the present invention sets out to overcome the drawbacks related to the prior art, in particular by setting out to provide a scraper suitable for preserving the surface condition of the guide elements or of the pistons, and doing so at virtually nil cost thanks to the air used.
• the use of the scraper may even go so far as to effectively prevent the formation of surface deposits at each movement of the linear actuator of a component (such as a slide or sliding member) on its relative guide element .
• FIG. 1 shows an assembly which the present invention relates to according to a possible embodiment, in which the scraper illustrated is partially in cross-section at the first aperture;
• FIG. 2a to 2g show guide elements, stems or pistons suitable for using in the aforesaid assembly
• FIG. 6a, 6b shows an assembly which the present invention relates to according to a further embodiment, in which the scraper of figure 6a is partially in cross- section at the first and the second aperture, the scraper in figure 6a being shown with separated parts.
• reference numeral 1 globally denotes a scraping assembly comprising a guide element 4a-4c for a sliding member (not shown) having a main extension axis Y, or a linear actuator 2 having a main working axis X, and a scraper 10, 12, 14, 16', 16", preferably pneumatic, acting on the linear actuator 2 or on the guide element according to the manner described below.
• the linear actuator 2 comprises a stem 4d-4g which delimits an outer surface 6 and which, according to an embodiment variation, further comprises an external body or cylinder 38 which houses said stem at least partially and so as to slide.
• the stem 4d-4g is part of a piston sliding inside said cylinder 38.
• the guide element comprises a rail or shaped guide (for example extruded or metallic) extending along the main extension axis Y.
• stem and “piston” will be used substantially interchangeably, such terms referring to the component of the linear actuator 2 movable along the main working axis X, or fixed but suitable for moving the external body/cylinder.
• the guide element described may have the same characteristics as the stem.
• the linear actuator 2 is a cylinder-piston group, for example of the hydraulic or pneumatic type.
• a movement fluid such as oil or air
• the linear actuator is of the mechanical type, and in such circumstance the stem defines a cochlea or worm to perform a roto-translat ion .
• a first embodiment provides for a piston which translates only, and a further embodiment a piston roto-translating in relation to the outer body or to the cylinder 38.
• the guide element may thus be configured to cause a roto-translation of a component or of a slide sliding thereon, or a mere translation parallel to the main extension axis Y.
• the scraper 10 (and in particular the relative scraper body 8) is directly constrained to the outer body or to the cylinder 38, in the absence of further support elements or components.
• the scraper 10 is provided with one or more attachment seats 50 to the cylinder 38.
• such seats comprise through holes or slots, engaged by complementary threaded means 52.
• the scraper 12, 14, 16', 16" may be connected to a support component 40, 42, 44 separate from the external body or from the cylinder 38 of the linear actuator 2, or separate from the guide element 4a-4c.
• one variant provides that such scraper 12 is connected to a side bracket 40 connected to a not shown support surface.
• threaded attachment means 52 acting between the bracket 40 and the scraper body 20 may be provided.
• such means 52 cross at least one portion of the side bracket 40 completely and the scraper body 20 partially.
• the side bracket may be "L” or "T” shaped.
• the support component 42, 44 may comprise an attachment plate which acts as the base 14 for one or more scrapers 16', 16".
• the attachment plate 44 presents a first 16' and a second 16" scraper joined to opposite support surfaces 54, 56 which define it.
• support surfaces 54, 56 lie on orthogonal planes in relation to the main axis X, and advantageously define the thickness of such plate 44.
• the support component may be a portion of the component or of the slide sliding along the guide element, in a direction parallel to the main extension axis Y.
• the scraper 10, 12, 14, 16", 16" thus comprises the scraper body 8, 18, 20 mentioned above, which defines at least a first aperture 22 suitable for being connected to a compressed air source or to a suction source (not shown) .
• the scraper which the present invention relates to thus functions with compressed air while, according to a further embodiment, the present scraper functions with aspirated air. Consequently, such variants differ mainly in the directions of transit (indicated by letters "T" or "A” in the drawings) of the flow of air respectively used, as well as by the characteristics of the relative generation means .
• T has been used to denote the direction of transit of the compressed air inside the scraper body 8, 18, 20.
• the letter A instead indicates the direction of an aspiration flow coming out of such body. This should not however be understood as a limitation of such or other embodiments, in that any of the scrapers described or illustrated is suitable for functioning both with compressed air and aspirated air.
• the scraper body 8, 18, 20 further defines a through chamber 24, 26 for the partial and sliding housing of the element/stem 4a-4g parallel to the main axis X, Y, and delimits at least partially one or more second apertures 28, 30, 68; such latter apertures 28, 30, 68 are supplied through the first aperture 22 and are configured to place the through chamber 24, 26 in fluidic communication with the outside environment.
• This way, the flow of air generated by the source is suitable for shifting or removing deposits, residues, impurities or the like from the outer surface 6.
• the second aperture 28, 30, 68 communicates with the outside environment; consequently the pneumatic scraping circuit is an open system.
• the second aperture 28, 30 is oriented to direct a jet or plurality of jets towards the outer surface 6 of the piston and/or element so as to shift or remove deposits, residues or the like.
• the first aperture 22 is engaged by a connector 58 which, by means of a feed pipe (not shown) , connects such aperture 22 to a compressed air source or to a suction source.
• the second apertures 28, 30, 68 flow into (for example directly) the through chamber 24, 26.
• the aspirated air enters the second aperture 68 from the outside environment, transits inside the through chamber 24, 26 and flows out through the first aperture 22.
• the second aperture 68 is made in the scraper body 8, 18, 20, and in particular is made in the form of a duct which crosses the (entire) thickness.
• the second aperture , 68 may be engaged by a filtering member 70, in particular a strainer, to retain any impurities entering the through chamber 24, 26 through such aperture.
• a filtering member 70 in particular a strainer
• such duct houses at least partially the filtering member (as shown for example in schematic manner in figure 6a) .
• the calibrated interstice 36 may act as the second aperture so that, during the actuation of the aspiration source, the flow of aspirated air transits in the through chamber through the space identified between the outer surface 6 of the piston 4d-4g (or of the guide element 4a- 4c) and the scraper body 8, 18, 20.
• the scraper body 8, 18, 20 only partially defines a second aperture, namely in the form of a calibrated interstice 36.
• the calibrated interstice 36 is defined between the free end 60 of the scraper body 8, 18, 20 closer to the element/piston and the aforesaid outer surface 6.
• the free end 60 axially defines the through chamber 24, 26 in particular forming an annular lip facing inwards radially.
• the annular lip has a substantially wedge-shaped cross- section.
• a pair of such free ends 60 may be provided, positioned at both axial ends of the scraper body 20 (to such purpose refer for example to figure 3a ) .
• the scraper body 8, 18, 20 defines at least one body seat 64 for housing at least one fluidic sealing element 62, for example a gasket or O-ring.
• a fluidic sealing element 62 for example a gasket or O-ring.
• seat 64 is positioned at the axial end opposite the through chamber 24, 26 in relation to the calibrated interstice 36, where provided.
• at least a portion of such element/piston 4a-4f forms a prismatic torque with the body of the scraper 18.
• the piston or guide element 4g is housed in a ( roto- ) translatable manner in the through chamber 24.
• Such variant refers, for example to the element /piston indicated by reference numeral 4g in figure 2 or to the cochlea or worm discussed earlier.
• the scraper body 8, 18, 20 extends in a perimetral direction of the element /piston 4a- 4g to house at least a portion thereof.
• the shape of such body may be ( semi- ) annular or angular.
• the chamber defined by the scraper body 18 has a polygonal cross-section (for example, generally trapezoidal), preferably so as to partially house the longitudinal rib 66.
• the latter in fact extends substantially parallel to the main extension axis Y (or to the main working axis X in some variants) .
• the "at least partial" housing refers to an axial direction and/or to a circumferential direction of such piston.
• the body seats 64 have a profile corresponding to the outer perimeter of the element /piston 4a- 4g, and in particular trace in undercut the cross-section of the respective through chamber 24, 26.
• a plurality of second apertures distributed around the element/piston for example at constant intervals, is provided.
• the second aperture 28, 30 is in the form of a continuous groove or furrow which extends along, the scraper body 8, 18, 20, in particular on a plane orthogonal to the main axis X, Y.
• the second aperture 28, 30, or optionally the continuous furrow has a flared cross-section towards the outer surface 6 of the element/piston 4a-4g.
• a pair of continuous furrows 28, 30 axially alongside each other, and separated by at least one intermediate cordon 32 which prevents at least partially the merging of the respective jets air, is provided .
• a calibrated interstice 36 is preferably provided for each furrow, such furrows being suitably facing in opposite directions.
• the body may also be without the body seat 64 and fluidic sealing element 62 contained therein.
• the scraper body 8, 18, 20 may further comprise at least one channelling element 34 of the flow of air towards each continuous furrow 28, 30.
• the channelling element 34 is tapered in the direction of the first aperture 22.
• the intermediate cordon 32 forms the channelling element 34 at the first aperture 22.
• the present invention also relates to a compressed air scraper 10, 12, 14, 16', 16" of the outer surface 6 of a guide element 4a-4c having a main extension axis Y, or of a stem 4d-4g of a linear actuator 2 having a main working axis X.
• Said scraper 10, 12, 14, 16', 16" comprises a scraper body 8, 18, 20 which defines at least one entrance aperture 22 suitable for being connected to a compressed air source, a through chamber 24, 26 for the partial and sliding housing of the guide element 4a-4c or of the stem 4d-4g parallel to said main axis X, Y, and one or more exit apertures 28, 30 of jets of compressed air from" the scraper body 8, 18, 20, supplied through ' the entrance aperture 22 and oriented to direct the jet or plurality of jets towards the outer surface 6 so as to shift or remove deposits, residues or the like from said surface 6.
• the scraper which the present invention relates acts without touching the outer surface, directing flows of air (preferably pressurised) onto it without preventing the movement of the piston (or of the component sliding along the guide element), and in such a way as to preserve satisfactory surface conditions for the entire relative period of actuation/movement.
• the system described does not require forced/scheduled stops to perform maintenance operations but rather permits the progressive removal of the aforesaid deposits or residues to prevent the formation or ' build-up of consistent surface deposits.
• the source suitable for connecting to the entrance aperture may be the same, or a ramification thereof, as that used to cause the extraction of the piston or stem from the relative cylinder. Consequently, the scraper described can be implemented in any existing pneumatic system without any significant initial investment.
• the scraper which the present invention relates to proves particularly suitable for specific applications, and in particular in conditions in' which the deposits, residues, impurities or the like not only need to be removed from the outer surface but also accumulated in confined spaces.
• the aforesaid scraper be used in aseptic environments which must remain so (for example operating theatres, white rooms etc.) it is fundamental that the dirt does not circulate in the outside environment but that it is conducted to dedicated accumulation areas.
• the scraper which the present invention relates to being predisposed to create a depression at the outer surface it is configured to prevent this from negatively influencing the speed and /or accuracy of the movement of the piston or guide element .
• the scraper which the present invention relates to is suitable for shifting or removing impurities coming from the linear actuator itself.
• the impure air and oil where present which leak out externally to the cylinder are directly aspirated by the present scraper, which is preferably located near the cylinder, thereby preventing any risk of contamination of the surrounding environment.

Landscapes

• Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Fluid Mechanics (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Cleaning In General (AREA)
• Preliminary Treatment Of Fibers (AREA)
• Actuator (AREA)

Applications Claiming Priority (2)

Publications (2)

Family

ID=47471903

Family Applications (1)

Country Status (3)

Family Cites Families (3)

• 2012
  • 2012-11-09 IT IT000160A patent/ITBS20120160A1/it unknown
• 2013
  • 2013-04-24 WO PCT/IB2013/053241 patent/WO2014072841A1/en active Application Filing
  • 2013-04-24 EP EP13728525.0A patent/EP2917593B1/de not_active Not-in-force

Non-Patent Citations (1)

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