Abstract: A preservation container for food and the like comprising a sealable container main body (2), to which a lid (3) is attached, an opening (5) connecting the inside and the outside is provided on the lid (3), and a gas non-permeable sheet (6) having a vent hole (7) at a position offset to the opening (5) is arranged to cover the opening (5). When the pressure inside the container is reduced, the sheet (6) is curved toward the inside at a part corresponding to the opening (5) and is adhered and retained on the outer surface of the lid (3).

Abstract: A vacuum apparatus for easily forming a vacuum in any bottle, container or the like and for providing a stable sealing. A lower cylindrical member together with a disc member forms a space portion in which a vacuum or an atmospheric pressure is applied, and the lower portion of an upper cylindrical member is inserted in the space portion and divides the space portion into upper and lower spaces. With a downward movement of the upper cylindrical member, the upper space expands and draws air inside of a bottle, and with an upward movement thereof, the air introduced into the upper space is vented outside. At this time, a check valve is selectively opened and closed and is operated by a pressure difference applied thereon. By repetitive reciprocating movement of the upper cylindrical member, a high vacuum is formed in the bottle and is sealed by the check valve. The apparatus is adaptable in a vacuum bottle, a medical suction instrument or the like.

Abstract: A vacuum pack food container is closed by releasable and reclosable sheet metal closure having a center portion defining an annular recess around an upwardly projecting integral vacuum release button with an undercut wall partially surrounded by a score line smaller than the button. The sealant material is confined within the button and has an outwardly projecting flange releasably bonded to the closure under the score line. Depressing the button peels the sealant flange from the closure to define a vacuum release passage which closes and seals when the pressure on the button is released. A peripheral skirt portion on the closure has inwardly projecting bosses which cooperate with cam surfaces on the bottom of a curled rim portion of a sheet metal container to provide a twist-on twist-off closure.

Abstract: A food container, of the type having a quantity of food vacuum-packed within a body of the container with a closure affixed on an open end of the body of the container, is provided with a low cost improvement for facilitating removal of the closure from the body of the container in the form of a vent opening extending through a wall of the closure overlying the open end of the container and a flexible film strip, a portion of which is sealed to said wall around an area overlying said vent opening. A portion of the film strip which overlies the vent opening is designed to be released from closure wall for equalizing the pressure within the container with that external thereto by pulling up on an unsecured end portion of the film strip. Furthermore, after releasing of the vacuum in the container, the film strip is able to be re-adhered over the vent opening.

Abstract: A sealing cap fastened to a vacuum seal container and controlled to extract air out of vacuum seal container, the sealing cap including a cap body unit fastened to the vacuum seal container, and an extracting unit mounted in the cap body and controlled to extract air out of the vacuum seal container by reciprocating a control cap of the extracting unit with the hand, the air passage being automatically sealed by a flap, which is forced into the close position by atmospheric pressure, the vacuum status of the vacuum seal container being released when a control cap of the air extracting unit is turned in one direction and pressed down, the cap body having a bottom side covered with a rubber disk which fits different spout sizes and shapes, the rubber disk being secured to the cap body by a T-cap and a sponge between the T-cap and the rubber disk, the rubber disk having a convex flange of V-shaped cross section around the periphery, which prohibits the rubber disk from being forced to curve inwards and to escape

Abstract: A vacuum pack food container is closed by releasable and reclosable sheet metal closure having a center portion defining an annular recess around an upwardly projecting integral vacuum release button with an undercut wall partially surrounded by a score line smaller than the button. The sealant material is confined within the button and has an outwardly projecting flange releasably bonded to the closure under the score line. Depressing the button peels the sealant flange from the closure to define a vacuum release passage which closes and seals when the pressure on the button is released. A peripheral skirt portion on the closure has inwardly projecting bosses which cooperate with cam surfaces on the bottom of a curled rim portion of a sheet metal container to provide a twist-on twist-off closure.

Abstract: A sealing plug cap includes a plug cap body fastened to the mouth of a sealing container to seal the passage of the mouth by a deformatable peripheral flap thereof, an air buffer device fastened to the bottom end of the plug cap body inside the sealing container to buffer the speed of air passing through a center air hole on the plug cap body, a socket mounted inside the plug cap body, and a sealing and relief control unit mounted in the socket, the sealing and relief control unit being forced by atmospheric pressure to close the air hole on the plug cap body when a suction pump is used to draw air out of the sealing container, the sealing and relief control unit being forced to open the air hole on the plug cap body when depressed.

Abstract: An evacuation actuating closure includes a lower cap member with a valve seat plate defining a plurality of angularly displaced venting holes at a central area. An annular guiding wall has upper and lower annular portions above and below the valve seat plate. The lower annular portion can be sealingly engaged with an annular upper wall of a container body. An elastomeric disc member includes an elastomeric central portion fixed on the valve seat plate, and a peripheral brim portion to block resiliently the venting holes. The venting holes are unblocked when the pressure below the venting holes is higher than that above the venting holes. An upper cap member includes a transverse depressing portion and an annular skirt portion sleeved on and slidably retained on the annular guiding wall so as to confine an air transit chamber above the valve seat plate. An elastomeric ring-shaped check valve member is disposed between the annular skirt portion and the annular guiding wall.

Abstract: A food container, of the type having a quantity of food vacuum-packed within a body of the container with a closure affixed on an open end of the body of the container, is provided with a low cost improvement for facilitating removal of the closure from the body of the container in the form of a vent opening extending through a wall of the closure overlying the open end of the container and a flexible film strip, a portion of which is sealed to the wall around an area overlying the vent opening. A portion of the film strip which overlies the vent opening is designed to be released from closure wall for equalizing the pressure within the container with that external thereto by pulling up on an unsecured end portion of the film strip. Furthermore, after releasing of the vacuum in the container, the film strip is able to be re-adhered over the vent opening.

Abstract: A hermetic cap for a container containing product packed in said container under vacuum. The cap has an orifice through it and a first frangible seal hermetically sealing the orifice on one surface of the cap and a second frangible seal hermetically sealing the orifice on an opposite surface of the cap.

Abstract: A container includes a container body, a cap member, a disk member and an evacuating unit. The cap member is mounted on a top open end of the container body and is rotatable about a vertical axis. The disk member is provided beneath and inside the cap member to sealingly close the top open end. The disk member has a downward hollow mounting portion in fluid communication with the top open end. The evacuating unit is operable by the cap member for evacuating air from the container body, and is coupled with the disk member. The evacuating unit has a piston mounted on the downward hollow mounting portion. The piston is movable upward and downward in the downward hollow mounting portion via rotation of the cap member so as to suck out air from the container body.

Abstract: The present invention comprises a metal lid constituted by a circular panel, endowed with downward short turned rim or skirt and provided in its inner peripheral circumference a circular groove containing a sealing gasket and having a circular concave depression disposed preferably in a central portion of the panel, wherein there is formed a central hole and wherein in a lateral portion or sector of this circular depressed area is applied a film of high-adherence varnish, being furthermore filled up with an adherent thermoplastic and melting material-former of the seal that penetrates in the hole, forming a short vertical rod, which does not extravasate the hole and remains with its end close and at the same plane of the internal and inferior surface of the panel of the lid without forcing any portion or residue of the material in the inferior part of the hole and further wherein, the film of high-adherence varnish, applied in a lateral part or sector of the circular depression, allows the partial retention o

Abstract: The lid consists of two unitary parts both of which are molded from a soft rubbery substance. The body of the lid butts against the mouth of a container and includes a vacuum release valve and a check valve through which air may be evacuated from the container. The second part is a bellows pump that sealingly engages the body of the lid. As the bellows pump is worked manually, air is drawn from the container into the pump through the check valve on the body of the lid and the air is then discharged into the atmosphere through a second check valve that is an integral portion of the removable bellows pump. Because of its simplicity and lack of small parts, the lid is easy to clean effectively, and reuse is contemplated. The actuators for the pump and for the vacuum release valve extend to the periphery of the lid thereby making it easy for use by handicapped persons.

Abstract: A container includes a cover engaged on an open top. A channel and an opening are formed in the cover. A knob is slidably engaged in the channel and includes a tube having a pair of shoulders. A plug has a pair of hooks engaged into the tube and engaged with the shoulders so as to secure the plug to the tube. A spring is biased between the knob and the plug for biasing the knob partially outward of the cover and for forcing the plug against the cover to enclose the orifice. The plug can be made of plastic material instead of metal material.

Abstract: This invention relates to a container with a self-contained evacuation lid. The container is provided for preserving food and is closed on the top by the evacuation lid. The lid includes a piston rod to be reciprorated up and down such that air inside the container is pumped out. An elastic element is fitted under the piston rod to bias a depressed part of the lid upward for an upward stroke when the depressed part is released after the downward movement. A valve rod is pulled to release the vacuum of the container for removal of the lid.

Abstract: A vacuum container has a vessel and an installed air extraction device covering the vessel. The installed air extraction device has a cap, an air extraction device disposed in the cap, and an air inlet valve passing through a center of the cap. The cap has an inner cover, an outer cover, and a hollow interior defined between the inner cover and the outer cover. An inner sleeve extends downward from the center portion of the outer cover. A spring encloses the middle portion of the air inlet valve. Another spring encloses the inner sleeve.

Abstract: A vacuum seal container comprises a cylindrical container body having a peripheral seal extending therearound and a lid including an outer skirt for engaging the seal. The skirt defines an access port for communication with a vacuum-generating source. The lid further includes seating nodes which seat the lid in a raised position to form an interior air passageway for air evacuation. At reaching a threshold pressure difference between the inside and outside of the container, the seating nodes and the sidewall deform to lower the lid which blocks the interior air passageway to form a vacuum seal.

Abstract: A sealing cap for coupling with an upper edge of a container includes a base disc, a spiral spring, a sucking plate and a soft cap body combined together. The soft cap body is able to be pressed down manually and pushed up by the spring and the sucking plate, to force air from the container to flow out of a hole in the outer circumference of the base disc. The air in the container flows through a stop valve, formed in the bottom center of the base disc, into the space between the base disc and the soft cap body. The air is stopped by a leak valve fixed in the outer circumference of the base disc. A repeated pressing action on the soft cap body is capable of displacing sufficient air from the container to create a partial vacuum therein.

Abstract: A bottle cap with an air removing device consists of a cap unit and an air stopper combined together. The cap unit includes an upper cap portion, a lower cylindrical portion and a valve formed in an interior of both the upper cap portion and the lower cylindrical portion and having a capsule-shaped cavity for a stopper of the air stopper to fit and move up and down therein to stop an air hole in a bottom of the valve so that the air in a bottle fitted with this cap may be pumped out by an extra air pump fitted in an open cavity of the upper cap portion. After the air in the bottle is pumped out, then the air stopper is pushed down by the air pump again, keeping the cap firmly fixed on the mouth of the bottle in an almost vacuum condition, wherein the food therein may not deteriorate for a long time.

Abstract: A vacuum cap for liquor bottles comprising a lower cap body combined on a cylindrical body fixed around a top end of a bottle, an air valve disposed in an annular upper recess of the lower cap body and blocking air holes in the recess and having two upwardly and outwardly extending projections protruding through two slots in an upper cap body fitted in the recess and located over the air valve, an independent air pump being placed on the lower cap body for pumping out the air in the bottle through the air holes and a gap between the air valve and the recess and through the two slots in the upper cap body so as to establish a vacuum in the bottle for preserving liquor contained in the bottle.

Abstract: A sealed can possible to be pumped vacuum comprising a can body, a cap unit and a vacuum pump, the cap unit being capped on the can body, the vacuum pump being placed on the cap unit to pump out the air in the can body so that the can body becomes vacuum and sealed tightly by the can unit to preserve food kept therein good and fresh for a long period time.

Abstract: In accordance with the present invention, an irreversible tamper evident system for a button closure is provided. The irreversible tamper evident system is provided by a color change system carried by the flexible button portion of the closure. The color change system comprises an indicator coating over a dark colored substrate coating. The indicator coat is preferably colored with a light colored transparent colorant such as an orange colored fluorescent dye. The indicator coat is preferably a liquid material which can be cured by evaporation, heat, UV irradiation or the like, to form a solid layer. When the substrate layer and indicator layer are in intimate contact, a first color is observed. Depending upon the relative colors used for this substrate and indicator layers, this first color can be a combination of the colors of the two layer or can be primarily the color of the substrate layer.

Abstract: This relates to the provision of a vacuum actuated button type closure with a tamper indicating arrangement which will visually indicate when a container has been opened or more particularly when the vacuum within a vacuum packed container has been lost. The deflectable button of the closure is utilized to squeeze a dye from a sponge like member into a layer of absorbent material so as to color the absorbent material. The absorbent material, in turn, is provided with non-absorbent areas which define indicia to indicate that an associated container has been opened.

Abstract: A suction device suitable to create a vacuum in containers particularly for the preservation of food in a vacuum, consisting of a casing formed by two coupled halves (4, 5) that contain an electric motor (7) that actuates a suction pump formed by a cylinder-piston unit (14, 15), by means of a reducer group formed by a pinion (17) force-fit onto the shaft (16) of the motor (7) and by a crown gear (19) having an eccentric (37) which actuates a connecting rod (23) connected to the piston (15). The device has at one end a holed tip (34) which can be pluged directly in the seating of the valve (3) that is provided on the container, so that it can be used with one hand only.

Abstract: A closure assembly for a container which includes an air-impervious diaphragm which when subjected to differential pressure will expand to retain articles in place within a container. The diaphragm is retained in position by a ring member that secures the marginal portions of the diaphragm in position. the diaphragm may be secured to a container filled in a vacuum chamber so that atmospheric pressure will extend the diaphragm into the desired position or it may be subject to high pressure air to extend the diaphragm. Means for exhausting the high pressure air or for admitting atmospheric air into the interior of the container for facilitating removal of the closure assembly from the container are also described.

Abstract: The hermatic seal unit is for a container having a lower portion and an upper portion of a slightly greater diameter. There is a shoulder portion at the junction of the upper and lower end portions. The device includes a cover conforming in shape to the upper portion of the element. Spreader elements are pivotally positioned in the cover. The hermetic seal element is positioned on a lower portion of the cover and the spreaders are in contact with the inner surface of the hermetic seal element. The hermetic seal element is in intermittent contact with the top portion and shoulder of the container in order to intermittently define the hermetic seal.

Abstract: This invention relates to a vacuum seasoning device, which is compact in size and simple in structure, and comprises a main body casing which contains a vacuum pump mechanism consisting of a piston, cylinder, and the like arranged horizontally; and said main body is so rotatably supported by a support column that it can transpose itself from a horizontal position to a position where its front portion is slightly raised; and when it is positioned horizontally the base plate of the same hermetically contacts the upper opening edge of the pressure container placed below it, and sucks the air out of the container by means of the horizontal reciprocating movement of the piston, and vent through suction port arranged on the base plate, suction channel of aforementioned vacuum pump mechanism, and then through communicating section thereof.

Abstract: This relates to a closure unit of the type including a closure member lockable in place having secured thereto a lever for effecting unlocking of the closure member. The closure unit has a tamper indicating feature in the form of a rivet projecting from the closure member and being received in a ring member releasably integrally formed with the lever. The rivet has been modified to have a blind hole opening through the underside of the closure member for presentation to the interior of an associated container whereby, should the rivet be severed from the closure member, the blind hole will open to the atmosphere and permit a venting under high pressure of the interior of the container.

Abstract: A closure for a canning glass container with a glass cover and a rubber ring therebetween has an upper rim which is formed in the container and provided with a sealing lip with a wedge having a tip with a radius of curvature between 1 mm and 3 mm, a supporting rim formed in the glass cover and having a circular depression located opposite to the wedge and having a radius of curvature exceeding the radius of curvature of the wedge with the wedge and the circular depression extending over an angle of approximately 110.degree.-70.degree., and a projection formed in the glass cover at its side facing toward the canning glass container and provided with a circular outer edge arranged so that it laterally limits the supporting rim of the canning glass container, centers and holds the rubber ring and centers the glass cover in an inner edge of the canning glass container so that relative displacement of the glass cover and the canning glass container which can hinder closing of the latter, is excluded.

Abstract: A bottle closure cap stampable from sheet metal as a shallow cylindrical inverted dish having a rounded juncture forming a fillet between its crown and its cylindrical wall; a layer of elastomeric material being disposed in the fillet and engageable with the axial end of the bottle when the cap is attached. A generally radially extending rip tab is integral with the cylindrical wall at the bottom edge thereof and is adapted to tear through the cylindrical wall by a generally circumferential pull of the user to gain access to the container. A rip line is provided commencing at a corner defined by the bottom edge of the cylindrical wall where it meets the rip tab. At least one groove is formed in the rip tab extending in the inner surface of the side wall. The rip line extends at a shallow angle across the cylindrical wall, without crossing the groove, continuing to a level which is spaced below the crown, continuing parallel to the crown circumferentially about half-way around the closure cap.

Abstract: This relates to a closure cap for containers wherein the end wall of the closure cap and more particularly an end panel thereof may be subjected to a vacuum which will determine the condition within the container. The closure cap involved is of a small diameter and is specifically intended for use in conjunction with neck finishes having diameters ranging from 27 mm to 43 mm. The end panel of the closure cap is of a specific configuration so that a small diameter central portion in the form of a button will evert under the existing vacuum conditions so as to present a substantially plain end panel when the vacuum condition exists within the container and which will show a popped up button when the vacuum has been relieved. The button will be indicative of product condition or possible tampering.

Abstract: A self-venting waterproof container includes upper and lower waterproof body portions along with a sealing mechanism to effect a seal therebetween. A pressure relief valve provides venting communication between the interior of the container and the environment in which the container is used when there is a differential in environmental pressure and the pressure in the interior of the container. A vacuum relief valve eliminates, when opened, any vacuum existing in the interior of the container. Deformable material used for the body portions allows the container to collapse around the equipment therein under environmental pressure.

Abstract: A closure with internal security for bottles and the like is described, which allows the contents to be immediately and freely poured from the bottle as soon as it is taken from a refrigerator, and therefore has a partial vacuum within it. This closure includes a body which is fixed to the mouth of the bottle and defines a fluid passage, a cap which can be screwed onto the body to close the passage, at least one valve shutter movable along the passage in the body to engage a valve seat in the passage, engagement means between the shutter and the cap for turning of the shutter by the cap as it is unscrewed, a cusp-shaped projection on the body facing the shutter, and a corresponding projection on the shutter for engaging and riding over the cusp-shaped projection upon unscrewing of the cap, to raise the shutter from the valve seat.

Abstract: This relates to the provision of a vacuum indicator in a container wherein a product is vacuum packaged. Most specifically, an end unit for a conventional container is provided with a vent opening through which air rushes into the container when opened. There is secured to the underside of the end unit a whistle device in communication with the opening so that the inwardly rushing air actuates the whistle device and causes the whistle device to emit a whistling sound in accordance with the vacuum present within the container and thereby gives an audible indication of the freshness of the product.

Abstract: A closure particularly intended for sealing containers having products packed therein under high vacuum wherein the vacuum retains the closure in place and a very high lifting or prying force is required to unseat the closure from the container to effect the removal thereof. The closure is provided with a supporting band which is interlocked with the shall of the closure and which supporting band has integrally formed as a part thereof a lever which is engageable with a shoulder on an associated container to effect the necessary lifting or prying action. The lever and associated supporting band are preferably injection molded of plastic material and may either be mechanically interlocked with the closure shell or molded in situ relative thereto. There are also suitable tamper indicating means.

Abstract: This disclosure relates to a closure assembly for containers, particularly glassware containers, wherein the closures may be readily removed even when the product is vacuum packed by the deformation of the cup-shaped body of the closure and the sealing ring through the application of a diametrically opposite squeezing pressure. Normally the deformation of the closure body is prevented by a removable tamper indicating ring which interlocks with the skirt of the closure body and which must be ruptured to effect the removal thereof. The closure may assume various configurations depending upon whether the container is to be reclosed and whether there is an internal vacuum. The closure construction permits a modified sealing surface finish on the glassware container.

Abstract: This disclosure relates to a tamper-indicating band which is utilized in conjunction with a closure for normally preventing the distortion of the closure as would be required to effect the removal of the closure. A tamper-indicating ring includes a continuous band which must be ruptured in order to remove the tamper-indicating ring. When the processing of the container assembly requires the introduction of heat, the tamper-indicating ring is heated and the band expands and then shrinks. Difficulties encountered with this first expansion and later shrinkage have been solved by forming the band in a plurality of sections connected together by expansion segments.

Abstract: This disclosure relates to a closure for containers primarily of the tumbler and carafe types and wherein the containers are formed of glass or glass-like materials. The closure is particularly identifiable by a downward and radial extension of the normal sealing ring to define a lug structure which interlocks with the exterior finish of the container and serves to retain the closure in place, both initially and upon reclosing. If desired, a shrink band or tape may add to the initial holding of the closure in place. Advantageously only the gasket material of the sealing ring is engaged with the finish of the container. The closure is distortable by diametrically squeezing the skirt thereof so as to break the initial seal in the event the product is vacuum packed.

Abstract: The neck of a bottle is closed and sealed by a one-piece cap having a cylrical portion which surrounds the neck, a deformable end wall which extends across the open end of the neck, and a flexible hose which is integral with the end wall. The inner side of the end wall has an annular bead which sealingly engages the inner surface of the neck when the pressure in the interior of the bottle is reduced below atmospheric pressure. An annular groove at the inner side of the end wall surrounds the bead and communicates with the atmosphere by way of at least one channel in the cylindrical portion. The groove communicates with the atmosphere during expulsion of air from the bottle, for example, in response to heating, but is sealed from the interior of the bottle when the end wall bulges inwardly and maintains the bead in sealing engagement with the neck.

Abstract: A closure for food containers embodying an open-ended resilient tubular elastomeric nipple adapted for connection to a source of vacuum so that air within the container may be evacuated prior to storage of the container and its contents. The nipple is provided with an inner frusto-conical wall of small slant angle which constitutes a valve seat. A spherical ball loosely disposed within the nipple is forcefully drawn against the seat incident to differential air pressure on opposite sides of the ball. Unseating of the ball to equalize the air pressure inside and outside the container is accomplished by pinching the nipple immediately below the ball. An obstruction near the upper rim of the nipple prevents escape of the ball during evacuation of the container or during handling of the closure.

Abstract: A cap for a bottle, having a top wall provided with an annular projected part, a skirt portion suspending downward from the peripheral edge of the top wall, a tab suspending downward from a part of the lower edge of the skirt portion, a pair of first separating lines extending toward the top wall from the vicinity of the intersection of the peripheral edge of the tap and the lower edge of the skirt portion, and a pair of second separating lines extending to the vicinity of the upper end of the skirt portion from the lower edge thereof, wherein the distance between the upper ends of the first separating lines is designed such that the terminal ends of the tearing of the first separating lines themselves, or of the tearing effected beyond the lines, are positioned on the tangent line of the internal peripheral circle of the annular projected part.

Abstract: A cap has a top wall and a skirt depending from the top wall. The skirt has two tabs depending therefrom. One tab may be employed to fracture the skirt along a circumferentially weakened first score of which the angle may be from 180.degree. to 250.degree. of the encircling expanse of the skirt. The other tab may be used to tear a portion of the skirt along a pair of radially weakened second scores and to bend the skirt at the inner end portions of those scores, and to introduce air into the container.

Abstract: A home use seal container for food vacuum storage, comprising a vessel and a lid superimposable thereon through the interposition of a resilient gasket, the lid having fast therewith two valves through one of which it is possible to remove air from the container by means of a suction pump and respectively through the other of which it is possible to introduce air into the same container.

Abstract: This invention relates to a canning jar sealer lid provided with a mechanically activated valve and a means for operating the valve manually.In one embodiment, a sectional sealer lid designed for use with screw bands and other holders is constructed in two parts containing apertures and gaskets so arranged that when they are fitted together and held to a canning jar lip by a holder, they unite to form a sealer lid and a relief valve. In use on a jar, the valve formed by the sections of this lid working conjointly will activate according to internal jar pressure applied vacuum sealing the jar or releasing said pressure, and there is a means supplied to manually open the valve externally.A modified embodiment is a single thickness canning jar sealer lid designed for use with screw bands and other holders which has a pressure relief means installed directly through the lid section.

Abstract: A canning jar sealing system has a reusable flat transparent glass lid with bosses of unequal diameter raised from its opposite sides. A peripheral flange portion of the lid is supported on the upper edge of a jar rim so that one boss extends into the mouth of the jar. A thin, flat, reusable, elastomeric sealing ring snugly encircles such boss and extends between the lid flange and the jar rim to form an airtight seal when a partial vacuum is created within the jar during the canning process. Each boss has one or more broad indentations along its peripheral edge which become filled by the sealing ring to indicate that the jar is sealed when the partial vacuum develops. A removable spring clip grips a bead or threads on the outside of the jar rim and exerts a downward force against the center of the lid to secure it to the rim of the jar until a seal is created by the partial vacuum.