Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
  • F04B9/00—Piston machines or pumps characterised by the driving or driven means to or from their working members
  • F04B9/08—Piston machines or pumps characterised by the driving or driven means to or from their working members the means being fluid
  • F04B9/12—Piston machines or pumps characterised by the driving or driven means to or from their working members the means being fluid the fluid being elastic, e.g. steam or air
  • F04B9/123—Piston machines or pumps characterised by the driving or driven means to or from their working members the means being fluid the fluid being elastic, e.g. steam or air having only one pumping chamber
  • F04B9/125—Piston machines or pumps characterised by the driving or driven means to or from their working members the means being fluid the fluid being elastic, e.g. steam or air having only one pumping chamber reciprocating movement of the pumping member being obtained by a double-acting elastic-fluid motor
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
  • F04B53/00—Component parts, details or accessories not provided for in, or of interest apart from, groups F04B1/00 - F04B23/00 or F04B39/00 - F04B47/00
  • F04B53/18—Lubricating
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16K—VALVES; TAPS; COCKS; ACTUATING-FLOATS; DEVICES FOR VENTING OR AERATING
  • F16K31/00—Actuating devices; Operating means; Releasing devices
  • F16K31/44—Mechanical actuating means
  • F16K31/56—Mechanical actuating means without stable intermediate position, e.g. with snap action
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16N—LUBRICATING
  • F16N13/00—Lubricating-pumps
  • F16N13/02—Lubricating-pumps with reciprocating piston
  • F16N13/06—Actuation of lubricating-pumps
  • F16N13/16—Actuation of lubricating-pumps with fluid drive

Definitions

• the present invention relates to a pneumatic motor assembly for a lubricant pump, which is used particularly in the field of maintenance and repair of vehicles such as cars, vans, trucks, tractors, et cetera.
• the cooperation between the exchanger means and the elastic means is provided by two levers, which are pivoted between the side walls of the body and the front faces of two bushes slidingly inserted in holes provided laterally in the body.
• the elastic means acts on the rear faces of the bushes and is constituted by two spiral springs. The springs are accommodated in two caps, which are screwed by virtue of one end to the holes formed laterally in the body.
• the exchanger means acts on the diverting means so as to block the intake and outlet, preparing them for the return stroke of the piston.
• the air is introduced through the usual hole, the diverting means and the pipe for connection to the top of the cylinder.
• the air contained in the chamber, whose volume is gradually reduced by the piston is discharged externally through the passage and the diverting means.
• the exchanger means entrained by the stem, again reaches the inversion position from the forward position. From the inversion position it is moved to the retracted position by the intervention of the elastic means.
• the exchanger means acts on the diverting means so as to block the intake and the outlet, preparing them for the new forward stroke of the piston, and so forth.
• the reciprocating movement of the stem aspirates the lubricant, which by rising up the riser becomes available for dosage.
• the main drawback of the above described motor assembly is its performance, which is highly impaired by the fact that the stroke available inside the cylinder is not utilized completely by the piston. In fact, during the return stroke, the piston stops before it reaches the bottom of the cylinder. This is due to the fact that the narrow portion of the stem is necessarily longer than the exchanger means. Therefore, during the forward stroke of the piston, the narrow portion of the stem protrudes partially with respect to the bottom of the cylinder. Accordingly, it is necessary to prevent the variation in diameter that occurs between the narrow portion and the rest of the stem that lies outside the bottom from interfering with the annular gasket arranged so as to wrap around the stem on a guiding and sealing bush associated with the first hole of the cavity that is directed toward the cylinder.
• a second drawback of conventional devices is that they comprise a means, for guiding and sealing the stem toward the riser, constituted by a guiding bush, an annular gasket and a closure flange, packed and inserted in a compartment formed axially in the body, just below the cavity, and retained by an elastic end ring engaged in the compartment.
• the lubricant delivery hole is provided just below the compartment.
• the body of the assembly is in fact obtained from a solid cylindrical block, which is initially provided with an axial bore having different diameters and so forth, accordingly also entailing considerable machining waste.
• Figure 1 is a perspective view of a lubricant pump provided with the assembly according to the invention.
• Figure 4 is a sectional view, taken along the line IV-IV of Figure 2, of another detail of the assembly;
• Figure 8 is a detail sectional view, taken along the line VII-VII of Figure 6, of the assembly in the assembled condition.
• the pump generally designated by the reference numeral 6, is applied vertically to a drum 7 containing liquid or semisolid lubricant.
• the pump 6 is substantially axially elongated and includes, in the following order, a pneumatic cylinder 8, a motor assembly 9, and a riser 10.
• the motor assembly 9 includes a body 15 that is predominantly axially elongated.
• the body 15 forms a cylindrical cavity 16, which lies approximately at right angles to the length of the body 15.
• the cavity 16 is fed with compressed air through a hole provided at the rear (not shown) for connection to the hose 12.
• a first hole 18 and a second hole 19 are provided on the side wall 17 of the cavity 16, along the main axis of the body 15.
• An exchanger means 24 is accommodated inside the cavity 16 and is provided with an axial through hole 25, which slidingly accommodates a narrow intermediate portion 26 of the stem 20.
• An elastic means generally designated by the reference numeral 29, cooperates laterally with the exchanger means 24 by virtue of levers 30 engaged in slots 31 formed on the side wall of the exchanger means 24.
• a diverting means D introduces air from the cavity 16 first into one chamber of the cylinder 8 and then into the other chamber, the chambers being formed by the piston 21, and evacuates externally the air contained alternately in each one of the chambers, whose volume is gradually reduced by the piston 21.
• the diverting means D is associated with a front opening of the cavity 16 and interacts with the exchanger means 24 by virtue of a flat region 32 formed at the front on the exchanger means.
• the axial through hole 25 comprises a wider end portion 33, which is directed toward the end of the stem 20 that supports the piston 21 so as to accommodate a non-narrow part of the stem 20 during the return stroke of the piston 21 , thus delaying the exchange.
• the stem 20 in fact penetrates more deeply into the exchanger means 24.
• the non-narrow part designated by the reference numeral 34, is located directly behind the narrow portion 26 in the direction of the return stroke of the piston 21. Accordingly, the length of the non-narrow part 34 is equal to the depth of the wider end portion 33.
• the limit of the return stroke of the piston 21 is determined by the locator 35, which is formed between the wider end portion 33 and the axial through hole 25, which constitutes an abutment with respect to the corresponding locator 36 formed on the stem 20 so as to straddle the narrow intermediate portion 26 and the non-narrow part 34.
• the above feature allows to use a guiding and sealing bush 37 associated with the first hole 18 which has a limited height, so as to not interfere with the return stroke of the piston 21.
• the narrow intermediate portion 26 is also extended by the same length, so as to restore the proportions between the axial dimensions of the components that interact.
• the assembly 9 includes a guiding and sealing cartridge 40, which is engaged in the second hole 19, protrudes along the stem 20 outside the body 15, and is directed toward the riser 10.
• the cartridge 40 is formed by a first tubular segment 41, which is provided externally with a threaded end part 42, which is engaged in the corresponding second complementarily threaded hole 19, and is provided internally with a likewise threaded intermediate part 43.
• the head of the first segment 41 acts as an abutment for the exchanger means 24 in the retracted position.
• a second shorter tubular segment 44 is arranged coaxially inside the first tubular segment 41 and is externally provided with a threaded end part 45, which engages the corresponding threaded intermediate part 43 of the first tubular segment 41.
• the second tubular segment 44 has, at the threaded end part 45, a hexagonal seat 46, which accommodates a handling tool (not shown) for screwing and, at the opposite end, has an annular gasket 47, which is adapted to form a seal on the portion 23 of the stem 20 against air seepage from the cavity 16 toward the riser 10.
• annular gasket 48 having an inverted U-shaped cross-section, is inserted in the first tubular segment 41 on the side of the riser 10, just below the second tubular segment 44.
• an elastic means generally designated by the reference numeral 130, cooperates laterally with the exchanger means 24 as a replacement of the conventional means shown in the other figures.
• a particularity of the elastid means 130 is that it is arranged between the exchanger means 24 and the side wall 17.
• the elastic means 130 is constituted by two springs 131, shown in Figure 7.
• Each spring 131 includes two legs 132, two arms 133, and a central concavity 134, which in the active condition is directed into the cavity 16.
• Figure 7 shows that, before assembly, the legs 132 are divaricated, whereas after assembly the legs 132 are substantially parallel.
• the legs 132 form an obtuse angle with the arms 133 and in the active condition they form a substantially right angle.
• each spring 131 is inserted in seats 135 and 136 formed respectively in the exchanger means 24 and in the body 15.
• the seats 135 formed in the exchanger means 24 include two holes 137 in which elastic pins 138 are inserted.
• the holes 137 are formed in the sides of the exchanger means 24 in the central area of the flat region 32, symmetrically and at right angles to the longitudinal central axis of the exchanger means 24.
• the seats 136 formed in the body 15 include two holes 139, in which elastic pins 140 are inserted.
• the holes 139 are formed on the margin of the cavity 16, in the central band of the body 15, symmetrically and at right angles to the longitudinal central axis of the body 15.
• the holes 139 include a first portion 141 and a second portion 142.
• the first portion 141 of the holes 139 has a larger diameter than the second portion 142.
• the springs 131 are kept in position by pins 143, inserted in the first portions 141 after the springs 131 have been arranged in the active position.
• the pins 143 are in turn retained within the first portions 141 by the diverting means D, which closes the front opening of the cavity 16.
• the springs 131 are preferably made of a metal wire shaped so as to lie on a plane.
• the operation of the elastic means 130 occurs as follows. Assume that the exchanger means 24 is in one of the two stroke limit positions. Moving from this position, the exchanger means 24 compresses the springs 131 until it reaches the position in which the diverting means D reverses the flow of the circulation of the air. From this position, the springs 131 are released, pushing the exchanger means 24 to the other stroke limit position, and so forth.
• the improved pneumatic motor assembly achieves the intended aim and object, allowing an actual improvement in efficiency owing to the fact that the stroke available in the cylinder is utilized fully by the piston, both during the forward stroke and during the return stroke, and it allows to reduce manufacturing costs and accordingly the final price, and to improve its overall aesthetic appearance.
• the guiding and sealing cartridge external to the body allows a considerable saving of material thereon which is approximately equal to 20%, because the portion of body related to the compartment for accommodating the means for guiding and sealing the stem on the riser side is no longer necessary, and because the lubricant dispensing hole is formed directly below the cavity instead of below the guiding and sealing means.
• first and second holes have the same diameter and are equally threaded.
• the solution adopted to provide the seats helps to reduce costs. Instead of providing very small holes in order to insert the legs of the springs, it is in fact more convenient to provide holes having a larger diameter and then insert therein elastic pins so as to bring the holes to the required diameter.
• the solution chosen for fitting the springs is also relevant, since it proves itself very easy. It is in fact sufficient to place the body at the end of its stroke, take each spring by compressing its legs until they are parallel, and then insert them in the already-provided seats.

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• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Compressor (AREA)

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• 2001
  • 2001-12-28 US US10/451,620 patent/US20040045429A1/en not_active Abandoned
  • 2001-12-28 EP EP01272773A patent/EP1356222A1/de not_active Withdrawn
  • 2001-12-28 WO PCT/IB2001/002714 patent/WO2002053959A1/en not_active Application Discontinuation
  • 2001-12-28 CN CNA018215025A patent/CN1483118A/zh active Pending

Non-Patent Citations (1)

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