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US3720486A - Hydraulic actuators - Google Patents

Hydraulic actuators Download PDF

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Publication number
US3720486A
US3720486A US00074102A US3720486DA US3720486A US 3720486 A US3720486 A US 3720486A US 00074102 A US00074102 A US 00074102A US 3720486D A US3720486D A US 3720486DA US 3720486 A US3720486 A US 3720486A
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United States
Prior art keywords
valve
working chamber
piston
pressure
valve holder
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Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US00074102A
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English (en)
Inventor
P Jousson
M Moret
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
INST DE RECHERCHE WOOG CH
WOOG INST RECH
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WOOG INST RECH
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by WOOG INST RECH filed Critical WOOG INST RECH
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Publication of US3720486A publication Critical patent/US3720486A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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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
    • F15B21/00—Common features of fluid actuator systems; Fluid-pressure actuator systems or details thereof, not covered by any other group of this subclass
    • F15B21/12—Fluid oscillators or pulse generators

Definitions

  • An hydraulic actuator for supplying liquid pressure pulses to a hand appliance for body care comprises a cylinder and reciprocating piston forming a working chamber, an outlet passage connected to the working chamber, an inlet chamber connected to the working chamber through an inlet valve, and pressure regulating means for bypassing a portion of the liquid to the inlet chamber on the pressure stroke of the piston.
  • the pressure regulating means includes a valve holder adjustably mounted in the inlet chamber and movable toward and away from an opening in the working chamber opposite the piston, and the inlet valve is mounted therein inside the annular region of the valve holder which closes the opening. Tapered notches at the front end of the valve holder cooperate with the housing to provide bypass passages of progressively increasing cross-sectional area as the valve holder is moved away from the opening, and are designed to provide a linear reduction in liquid pressure in the outlet passage.
  • the present invention relates to hydraulic actuator units which can be used either as pump units for connection to h'ygiene devices, for example, hydraulic motor driven toothbrushes, water jet devices for eliminating food residues from interdental spaces and gum massaging devices, or hydraulic transmitter devices.
  • an apparatus for body care which includes a pump unit having a liquid reservoir, and an electric motor for driving the pump unit.
  • the pump unit includes a reciprocating piston which is driven by the electric motor.
  • the piston is slidable within a cylindrical part of a working chamber formed in the body of the pump unit and water is admitted to the working chamber from a reservoir and an inlet chamber, through an inlet valve. Movement of the piston in one direction permits water to flow from the inlet chamber, via the inlet valve, into the working chamber. Movement of the piston in the reverse direction causes the inlet valve to close and the water to be delivered under pressure to a supply conduit.
  • the pump unit further includes a pressure regulating device which includes an orifice which permits Water under pressure from the working chamber to return to the inlet chamber.
  • the orifice is controlled by means of a plunger faced with a resilient insert. By moving the plunger in one sense a small by-pass passage is opened and the pump unit therefore delivers water at a lower pressure through the supply conduit.
  • the pump unit supplies liquid pressure pulses to a unitary hand appliance capable of operation either as an hydraulic toothbrush or as a water jet.
  • the hand appliance includes a piston-type hydraulic motor for driving a toothbrush attachment, or other attachments, and a conduit for supplying the pressure pulses to a Water jet attachment.
  • a valve is provided 7 which is actuable to yield either type of operation.
  • Air bubbles can cause diificulties when starting the pump units and may, in fact prevent starting altogether. Sometimes the air bubbles can be dispersed by manipulating the pressure regulating device to bleed or deaerate the pump unit but this is time consuming and not always successful.
  • Air bubbles are particularly troublesome when the hydraulic actuator is used to drive an hydraulic motor in a hand appliance, and an accurate transmission of a displacement is required.
  • a second disadvantage found in both the above described known devices is the difficulty encountered in accurately regulating the pressure of the liquid discharge from the pump units.
  • the means includes a by-pass arrangement, displacement of which, in the body of the actuator, causes a change in the pressure of the liquid discharged from the actuator, the displacement and the change in pressure having a linear relationship.
  • a still further object of the present invention is the provision of an hdraulic actuator, the construction and assembly of which is very simple.
  • the present invention employs a reciprocating piston mounted in a cylinder to form a working chamber, with an outlet passage connected to the working chamber for supplying liquid pressure pulses to a hand appliance for body care.
  • an opening to the working chamber is provided opposite the piston, and the inlet chamber is on the opposite side of the opening from the piston.
  • the pressure regulating means includes a valve holder adjustably mounted in the inlet chamber for movement toward and away from the opening to bypass a portion of the liquid to the inlet chamber on the pressure stroke of the piston.
  • the front of the valve holder has an annular region adapted to abut a corresponding annular region around the opening toprevent liquid flow thereby in the forward position of the valve holder, thereby yielding maximum pressure pulses in the outlet passage.
  • An inlet valve is mounted in the valve holder with the valve head on the working chamber side of the valve holder and cooperates with a valve seat on the front of the valve holder.
  • the valve head and valve seat are inside the annular region of the pressure regulating means.
  • the inlet valve has a valve stem carrying the valve head, and the valve stem is mounted inside the valve holder and movable in the direction of movement of the piston.
  • the forces acting on the valve head and stem are in the direction of movement thereof, so that bending forces are largely avoided, thereby avoiding excessive wear and promoting reliable operation over a long period of time even though plastic materials are used to reduce cost.
  • the front of the valve holder and the adjacent portion of the valve housing have closely-spaced longitudinally extending surfaces with a plurality of tapered notches in one of the surfaces shaped to provide corresponding assages of progressively increasing crosssectional area for fluid flow from the working chamber to the inlet chamber as the valve holder is moved away from the opening to the working chamber, thereby producing a gradual change in pressure of the outlet pulses as the pressure regulating means is adjusted.
  • the cross-sectional area of the tapered notches is predetermined to yield a reduction in outlet pulse pressure which varies linearly with the movement of the valve holder away from the opening. This greatly facilitates adjustment of the pressure to suit the users desires.
  • FIG. 1 is a longitudinal section through a hydraulic actuator according to the present invention
  • FIG. 2 is a partial longitudinal section illustrating a modification of the hydraulic actuator of FIG. 1;
  • FIG. 3 is a transverse cross-section on the line III-III of FIG. 1;
  • FIG. 4 is a transverse cross-section on the line IVIV of FIG. 1;
  • FIG. 5 is a transverse cross-section on the line V-V of FIG. 1;
  • FIG. 6 is a graph showing the progression of the crosssectional area of the by-pass section according to the regulation position.
  • FIG. 7 is a graph which illustrates the variations of pressure according to displacements of the pressure regulator of a known hydraulic actuator and a hydraulic actuator according to the invention.
  • a hydraulic actuator for connection to a hygiene appliance such as a toothbrush, includes a generally tubular body 5 having a through bore and two passageways 13, 14 extending through a side wall of the body 5.
  • Passageway 14 is an inlet passageway and communicates with a liquid reservoir (not shown) and passageway 13 is an outlet passageway and is connected, by means of a conduit 27, to a hygiene appliance (not shown) for example, a hydraulic motor driven toothbrush.
  • the through bore includes a cylindrical working chamber 26 in which reciprocates a piston 1 driven by any known means (not shown).
  • a seal 4 is mounted around the piston 1 in a recess formed at said left hand end, and a guide plate 3 encloses the seal 4 in the recess.
  • the guide plate 3 also centers the piston 1 in the working chamber 26.
  • the body 5 has an inlet chamber 24 which is enlarged to receive an insert 21 having a central threaded hole.
  • the insert 21 seats on a shoulder in the inlet chamber 24 and has an end face flush with the end of the body 5.
  • a retaining clip 22 of resilient material engages over a flange surrounding the opposite end of the body 5, that is, the right hand end of body 5 and engages the end face of the insert 21.
  • the member 19 includes a first part 19a having a central bore, and a knob 20 extending outwardly from the end of the body 5.
  • the knob 20 has flutes 25 to assist in the turning of the member 19.
  • An end portion of the first part 19a carries a second part in the form of a sleeve 23 for movement therewith.
  • the sleeve 23, as seen in FIGS. 1 and 5 is generally cylindrical and is open at the end carried by the first part 19a and formed with an inwardly directed flange at the opposite end.
  • the flange defines a hole and the outer peripheral edge of the flange is formed as a seating 7 for a valve head 6 of a valve member.
  • Arms 10b extend radially inwardly from a part 10 of the sleeve 23 for supporting a bearing part 10a.
  • the valve member has a stem 18 which extends through and is supported by bearing part 10a.
  • Opposed apertures 15 are formed in the side walls of the sleeve 23, which apertures 15 are in general alignment with the inlet passageway 14.
  • a shoulder 17 is rigidly attached to the valve stem 18 and a spring 12 is arranged between the shoulder 17 and an end face of the bearing part 1011 to bias the valve head 6 against the seating 7.
  • a seal 16 is arranged over the end of the sleeve 23 adjacent the insert 21.
  • annular region of the front of sleeve 23 forming part of the valve holder abuts a corresponding annular region of the shoulder 8 of the body 5 which forms part of the pump housing, and hence closes the opening in the wall of the working chamber 26 opposite the piston 1. Thus no liquid can pass thereby.
  • Rotation of the valve holder by knob 20 allows the front of sleeve 23 to be moved away from shoulder 8.
  • the periphery of the front end of sleeve 23 has a longitudinally-extending surface which is closely adjacent a corresponding longitudinally-extending surface of body 5.
  • the logitudinally-extending surface at the front of sleeve 23 has a plurality of tapered notches 9 which increase in cross-section toward the front of sleeve 23.
  • the small ends of the notches are in engagement with the adjacent surface of body 5.
  • the effective cross-sectional area of the notches progressively increases, thereby allowing a progressively increasing liquid flow thereby from the working chamber 26 to the inlet chamber 24 on the pressure strokes of the piston 1.
  • the pressure of the liquid pulses in outlet passage 13 is gradually reduced as the valve holder is moved toward the right.
  • the notches 9 are shaped so that the reduction in pressure in the outlet passage 13 varies linearly with movement of the valve holder sleeve 23 away from the opening in the working chamber 26. This will be explained further in connection with FIGS. 6 and 7.
  • FIG. 1 there is very little dead space in which air bubbles can accumulate. With the pressure regulator closed, as shown, there is an annular space around the valve head 6 in which air bubbles may tend to accumulate. However, with the valve head 6 on the working chamber side of the valve seat 7, the flow of water around the valve head on the suction strokes of the piston tends to wash out air bubbles which may form in this annular space so that excessive accumulation of air in this space is prevented.
  • the piston 1 is reciprocated in the Working chamber 26 such that, when it moves to the left as shown in FIG. 1, liquid is drawn through inlet passageway 14 into the inlet chamber 24 through apertures 15 into the valve holder and then into the working chamber 26. Movement of the piston 1 in the reverse or compression sense, causes the valve head 6 to seat on the seating 7 and the liquid in the working chamber 26 to be discharged under pressure through outlet passageway 13.
  • knob 20 can be turned to adjust the position of member 19 in the body 5. Adjustment of member 19 permits to a greater or lesser extent a by-pass to be formed between the shoulder 8 and the end face of sleeve 23 carried by member 19. By increasing the distance between the shoulder 8 and the end face of the sleeve 23, when the piston is making a compression stroke, some liquid will flow from the working chamber 26 through the space between the shoulder 8 of body 5 and the end face of sleeve 23 and then through notches 9, thereby reducing the pressure of the liquid being discharged through the outlet passageway 13.
  • FIG. 2 illustrates a modification of the piston of the hydraulic actuator, in which the piston 2 consists of a semi-elastic plastics material having a circular lip 28 which is arranged in a liquid tight manner in the working chamber 26.
  • the piston 2 consists of a semi-elastic plastics material having a circular lip 28 which is arranged in a liquid tight manner in the working chamber 26.
  • FIG. 6 is a graph showing the progressive change in the cross-sectional area of the pressure regulating arrangement according to the axial position L of the sleeve 23.
  • the line P designated the closed position of the pres sure regulator and P the fully open position. It can be seen that from the starting (closed) position of the sleeve 23, the area is constant for about of its displacement then the area change becomes practically linear for about of the displacement and then becomes hyperbolic or exponential according to conditions.
  • the number of tapered notches 9 in the end face of the sleeve 23 can vary and some experimentation as to the precise shape of the taper may have to be performed under particular conditions to obtain a linear regulation of the pressure.
  • FIG. 7 is a graph which illustrates the decrease of pressure P in the working chamber 26 according tothe axial position L of the pressure regulator member 19.
  • the straight line a represents the linear function of the regulation obtained according to a pressure regulator of the present invention.
  • Curve line b represents the function obtained by a known pressure regulator. As will be noted, curve b shows a rapid decrease in pressure as the regulator is moved from its closed position, thereby making the adjustment quite ditficult in the higher pressure region. On the other hand, curve a shows a much more gradual change, thereby facilitating the obtaining of a desired mid-range pressure.
  • the hydraulic actuator can be used as a transmitter device, for transmitting linear displacements.
  • An advantage of the present embodiment is that it permits the regulation of liquid under a pressure in a simple linear and reliable manner, this is what is usually required when the actuator is used with hygiene appliances.
  • the hydraulic actuator can be manufactured from plastics material.
  • An hydraulic actuator for supplying liquid pressure pulses to a hand appliance for body care which comprises (a) a housing having a cylinder and a reciprocating piston mounted therein forming a working chamber,
  • manually-operated pressure regulating means comprising a valve holder adjustably mounted in said inlet chamber for progressive adjustment toward and away from said opening and for establishing an dmaintaining a fixed spacing between said valve holder and opening when manually adjusted thereto and thereby bypass a selectable portion of the liquid in said working chamber to said inlet chamber on the pressure stroke of said piston,
  • an inlet valve mounted in said valve holder having a valve head on the working chamber side of the valve holder and a cooperating valve seat on the front of the valve holder,
  • valve head and valve seat being inside said annular region so that liquid flow through the inlet valve on the suction stroke of the piston washes through the region adjacent the front of the valve holder and said opening to prevent accumulation .of air in said region in the closed position of said pressure regulating means
  • An hydraulic actuator for supplying pressure pulses to a hand appliance for body care which comprises (a) a housing having a cylinder and a reciprocating piston mounted therein forming a working chamber,
  • manually-operated pressure regulating means comprising a valve holder threadedly mounted in said inlet chamber for progressive adjustment toward and away from said opening and for establishing and maintaining a fixed spacing between said valve holder and opening when manually adjusted thereto and thereby bypass a selectable portion of the liquid in said working chamber to said inlet chamber on the pressure stroke of said piston,
  • an inlet valve including a valve head and valve stem mounted in said holder with the valve head on the working chamber side of the front of the valve holder and the valve stem inside the valve holder and movable in the direction of movement of said piston
  • valve seat on the front of the valve holder cooperating with said valve head and a spring mounted within the valve holder for biasing the valve head toward the valve seat
  • valve head and valve seat being inside said annular region so that liquid flow through the inlet valve on the suction stroke of the piston washes through the region adjacent the front of the valve holder and said opening to prevent accumulation of air in said region in the closed position of said pressure regulating means.
  • An hydraulic actuator for supplying liquid pressure pulses to a hand appliance for body care which comprises (a) a housing having a cylinder and a reciprocating piston mounted therein forming a working chamber,
  • pressure regulating means comprising a valve holder threadedly mounted in said inlet chamber for movement toward and away from said opening to bypass a portion of the liquid in said working chamber to said inlet chamber on the pressure stroke of said piston,
  • said housing and the front end of said valve holder having closely-spaced longitudinally-extending surfaces with a plurality of tapered notches in one of said surfaces shaped to provide corresponding passages of progressively increasing cross-sectional area for fluid flow from the working chamber to the inlet chamber as the valve holder is moved away from said opening,
  • an inlet valve including a valve head and valve stem mounted in said holder with the valve head on the working chamber side of the front of the valve holder and the valve stem inside the valve holder and movable in the direction of movement of said piston
  • valve head and valve seat being inside said annular region. 4.
  • An hydraulic actuator for supplying liquid pressure pulses to a hand appliance for body care which comprises (a) a housing having a cylinder and a reciprocating piston mounted therein forming a working chamber,
  • pressure regulating means comprising a valve holder adjustably mounted in said inlet chamber for movement toward and away from said opening to bypass a portion of the liquid to the inlet chamber on the pressure stroke of said piston,
  • an inlet valve mounted in said valve holder having a valve head on the working chamber side of the valve holder and a cooperating valve seat on the front of the valve holder,
  • valve head and valve seat being inside said annular region
  • (j) means for resiliently biasing said valve head toward said valve seat.
  • An hydraulic actuator in accordance with claim 5 in which the progressively increasing cross-sectional area of said tapered notches is predetermined to yield a reduction in pressure of the liquid discharged through said outlet passage which varies linearly with the movement of said valve holder away from said opening.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Details Of Reciprocating Pumps (AREA)
  • Reciprocating Pumps (AREA)
US00074102A 1969-09-19 1970-09-21 Hydraulic actuators Expired - Lifetime US3720486A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CH1423969A CH518447A (fr) 1969-09-19 1969-09-19 Générateur de pression hydraulique pour dispositif de soins corporels

Publications (1)

Publication Number Publication Date
US3720486A true US3720486A (en) 1973-03-13

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ID=4399141

Family Applications (1)

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US00074102A Expired - Lifetime US3720486A (en) 1969-09-19 1970-09-21 Hydraulic actuators

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US (1) US3720486A (de)
CA (1) CA924217A (de)
CH (1) CH518447A (de)
DE (1) DE2045997C3 (de)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3966359A (en) * 1974-03-01 1976-06-29 Les Produits Associes, Sa Apparatus for body hygiene
US4445824A (en) * 1981-11-02 1984-05-01 Ball Value Co., Inc. Valve for compressor clearance or by-pass control
US10385835B2 (en) * 2012-02-22 2019-08-20 King Nutronics Corporation Multi-fluid precision calibration pressure source

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2722353C3 (de) * 1977-05-17 1987-01-22 Oberdorfer, Guido, 7919 Bellenberg Hochdruckreinigungsgerät mit einem Ventil zur Einstellung der Abgabemenge
DE2910982A1 (de) * 1979-03-21 1980-10-02 Gimelli & Co Ag Intermittierend arbeitende schubkolbenfluessigkeitspumpe
DE3131995A1 (de) * 1981-08-13 1983-02-24 Petz Electro, 3185 Schmitten Kolbenpumpe, insbesondere fuer mundduschen
DE9313929U1 (de) * 1993-09-15 1994-10-27 Wap Reinigungssysteme Gmbh & Co, 89287 Bellenberg Ventilblock mit Dampfstufe

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3966359A (en) * 1974-03-01 1976-06-29 Les Produits Associes, Sa Apparatus for body hygiene
US4445824A (en) * 1981-11-02 1984-05-01 Ball Value Co., Inc. Valve for compressor clearance or by-pass control
US10385835B2 (en) * 2012-02-22 2019-08-20 King Nutronics Corporation Multi-fluid precision calibration pressure source
US11913439B2 (en) 2012-02-22 2024-02-27 King Nutronics, Llc Multi-fluid precision calibration pressure source

Also Published As

Publication number Publication date
CH518447A (fr) 1972-01-31
DE2045997C3 (de) 1978-03-02
DE2045997A1 (de) 1971-03-25
DE2045997B2 (de) 1977-07-07
CA924217A (en) 1973-04-10

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