Abstract: A safety slide clamp to prevent free flow when tubing is disconnected from an I.V. administration device comprises a blade formed with a tear-drop shaped aperture through which the tubing is positioned. The aperture includes an enlarged portion and a narrow portion which is tapered to form a slot that is engageable with the tubing to prevent flow therethrough. A base formed with a well is attached to the pump and is adapted to slidably receive the blade of the slide clamp. Retaining means formed on the base are spaced to support the blade and retain the tubing in a recess between the fingers and the base. Placement of the tubing into the recess and subsequent insertion of the blade into the well permits operational fluid flow through the tube. Subsequent retraction of the blade urges the tubing into the slot to prevent free flow from the tube upon its removal from the device.

Abstract: An intravenous drip rate control device includes a trough in the rear face of the housing for receiving intravenous tubing. The intravenous tubing is placed within the trough between and in functional communication with a pair of resilient bands. A cam driven by a reversible DC motor moves a lever between a first and second position. In the first position, a blade extending upwardly from the lever is capable of contacting and engaging the tubing and restricting the tubing opening. A tubing door is pivotable about the rear face of the housing between an open and closed position. In the closed position, a plastic material layer extending downwardly from the tubing door contacts and engages the tubing to restrict the tube opening and also provides support for the tubing when the blade applies an upward force on the tubing. The resilient bands ensure minimal "plastic flow" of the tubing and constantly resist the tendency of the side walls of the tubing to extend out and thus the tubing to flatten out.

Abstract: The invention relates to a dosing device for fluids used in infusion or transfusion systems comprising a flexible fluid line transversing a housing to compress the fluid line. The device comprises a housing and an elastomeric tubular element having leading and trailing sections which traverses said housing to interconnect respective ends of said fluid line. The tubular element comprises a thicker portion between the leading and trailing sections whereby the thicker portion protects against longitudinal displacement of the housing. A pressing element engages the tubular element outside the region of the thicker portion.

Abstract: A liquid filling machine has a plurality of discharge nozzles for simultaneously filling a plurality of containers. Each nozzle is connected to a manifold and has a restriction. A discreet pressure sensor is connected to each nozzle upstream from its restriction, and a solenoid valve is provided for each nozzle. A programmable device is connected to each pressure sensor and each valve for calculating a number indicative of fill time and closing each valve when the number is reached.

Abstract: A mechanically actuated pinch valve having a longitudinally extending flexible valve body with an inlet and an outlet and frame members extending along either side of the valve. Side plates are pivotally attached at each side frame. A lower pinch bar or roller extends between the side plates at the lower side of the valve body. A pair of arms are pivotally attached to the side plates and carry an upper pinch bar. The valve is actuated by means of a lever attached to the arms which simultaneously cause the pivot plates to rotate while bringing the upper pinch bar into compressing engagement with the valve body. In other embodiments the actuator mechanism may include a compound linkage or a lead screw for improved control and better mechanical advantage.

Abstract: A rehydrator which dispenses precise amounts of liquid to each row of wells in a titration tray where the dispensing of the liquid is performed through valving means in timed relation to indexing of the platform to present a row of wells beneath the dispensing orifices. The indexing of the tray and the valving means are accomplished by the same drive means to obtain the timed relation.

Abstract: A disposable pinch valve assembly for parenteral solution delivery systems comprises a two-piece tubing receptor housing hingedly connected and with an irreversible snap connection which will not permit removal of the device from parenteral tubing after assembly. A back section has an integral movable pressure plate attached to the housing by integral flexible web connectors. When the movable plate is actuated toward the stationary press surface, tubing is pinched therebetween and the cross-section area of the flow passage through the tubing is reduced. The movable pressure plate is designed to engage a actuator connector which engages the device with a motor-driven actuator in an axially sliding engagement.

Abstract: An elastomechanical sphincter comprising a prosthetic device for implantation about a patient's lumen such as the urethra for closing and opening the lumen. The prosthetic sphincter includes a body of flexible polymeric material configured to define an articulating structure having an elongated occlusion orifice arranged to embrace the patient's urethra with minimal ischemic interruption of circulatory blood flow. An integrally formed manually manipulable pressure relief cuff extends from a peripheral portion of the articulating structure in such a manner that physical pulling on the pressure relief cuff in a direction transverse to the elongation of the occlusion orifice will open the orifice which thereby opens the lumen. The natural elasticity of the device results in a closing of the lumen upon releasing of the pressure relief cuff. In one embodiment, by way of example, the pressure relief cuff may be positioned within the folds of the loose skin of the posterior scrotum.

Abstract: A high performance pinch tube valve for accurate, reliable, high speed and precise control of relatively low viscosity fluids. The valve is particularly adapted for use in apparatus for controlled pattern dyeing of textile material, such as carpet, with liquid dye streams. The valve includes a valve block having a bore receiving a flexible tube, and a passageway communicating with and disposed generally transversely to the bore, the intersection of the bore and the passageway defining a pinch chamber. A tube pinch off member is selectively reciprocal within the passageway into the bore for forcing the flexible tube closed. The tube pinch off member comprises a piston rod and a freely-floating ball disposed between the end of the rod and the flexible tube. The pinch chamber has a flattened wall portion formed in the bore opposite the communicating passageway. Additionally, the communicating passageway has a larger diameter than the bore.

Abstract: A novel improved pinch valve for controlling the flow of fluids in an unrestricted manner in, at least, two flexible tubes, including a housing for holding a solenoid coil between its outer wall and inner cylindrical core member. The solenoid armature is a truncated cone shape which coacts with a similarly shaped opening at the end of the inner cylindrical core member to optimize the flux path of the solenoid and thus its efficiency. A tube retention member includes openings for holding the flexible tubes. A further opening in the tube retention member holds a plunger member which is captured by a retaining pin. The plunger member is secured to the solenoid armature prior to assembly of the tube retention member to the solenoid housing. The plunger member moves with the armature as the solenoid is energized and deenergized. When the solenoid is unenergized, one of the flexible tubes is compressed between a knife like edge on the plunger member and a body portion of other tube retention member.

Abstract: A deformable sleeve for a pinch valve includes an inner tubular body of elastically deformable material which is provided with flanges at its axial ends, and a mesh element having a tubular portion which surrounds the tubular body between the flanges and prevents the same from bulging out under the influence of internal pressure. The mesh element further has anchoring portions which are anchored to the flanges. The anchoring portions can either be connected to the faces of the flanges which face one another, or embedded in the material of the flanges, either directly, or by being connected, such as clamped between or welded to, anchoring rings which are embedded in the material of the flanges. The anchoring rings may be polygonal, especially rectangular or L-shaped in radial section, or circular or similarly curved in radial section. The mesh element may advantageously be of stainless steel mesh.

Abstract: A valve for controlling flow of abrasive media from a blast tank to a nozzle, utilizes rollers for constricting a straight-through tube. In this way the valve meters the flow of the abrasive media into a blast hose through which air is directed under pressure as a carrier for the media. Contact with the media within the valve is limited to a radially constrictable tube adapted for ready replacement as the only component subject to the destructive characteristics of media such as mineral grit, sand, or the like. In association with the pinch tube housing, means is provided permitting ready interchange of manual and automatic tube-constricting assemblies. In the automatic configuration, the size of the valve orifice through which the media passes can be accurately and swiftly regulated by varying the pressure on a diaphragm.

Abstract: A valve having no friction producing components includes a flexible and resilient tube for carrying a fluid, an electrically energizable coil for producing an electromagnetic force when energized, a magnetically attractable element, and an elongate leaf spring attached near one end to the coil and looped outwardly, upwardly and back toward the coil, with the magnetically attractable element attached to the leaf spring near the other end. The leaf spring normally holds the magnetically attractable element out of contact with the coil, but when the coil is energized, the element is attracted towards the coil. The one end of the leaf spring attached to the coil is also formed to extend upwardly and over the magnetically attractable element to act as an anvil, and the other end of the leaf spring attached to the element extends upwardly towards the anvil to form a pinching tab.

Abstract: A pinch valve assembly includes a valve body in which a plunger is spring loaded against a portion of a flexible tube which passes through the valve body. The plunger causes the flexible tube to collapse preventing flow through the tube. Energization of a solenoid which is mounted on the valve body causes the plunger to release the tube, permitting flow. In an alternative embodiment, energization of the solenoid causes the plunger to bear on the flexible tube thereby providing a normally open valve arrangement.In another alternative embodiment the plunger bears on a plurality of flexible tubes thereby facilitating simultaneous control of different fluids.

Abstract: An intravenous drip rate control device includes a control valve having horizontally oriented valve members each provided with valve elements arranged in interdigitating relation with respect to each other. A drip rate sensor senses each intravenous drip and produces an electrical signal in response to each drip. A microprocessor unit compares the sensed drip rate to a preset drip rate and controls operation of an actuating unit which causes one of the valve members to shift toward and away from the other valve member. When one of the valve members is shifted toward the other valve member, a horizontal portion of the drip tube is progressively stretched to narrow the opening through the stretched portion of the tube and thereby reduce the drip rate. When the valve member is shifted away from the other valve member, the tension on the stretched portion of the tube will be progressively released, thereby increasing the opening in the tube and increasing the drip rate.

Abstract: A prophylactic apparatus for cleaning teeth with a flow of air containing powder particles and a flow of water characterized by a first air line extending from a source of pressurized air through at least one filter to a mixing device, a first control device arranged in the first air line for controlling the flow therethrough, the mixing device having a chamber for receiving powder to be fluidized and mixed with air to form an air laden with powder particles, a nozzle connected to the first air line disposed above the level of the particles, a discharge opening disposed above the level of the particles in the chamber connected to a second air line extending to a second nozzle opening, a second control arrangement for controlling the flow of air laden with powder particles in the second air line and an arrangement for unclogging each filter by creating a backflow from at least the chamber of the mixing device and a portion of the first line.

Abstract: A miniature electromagnetic valve having a valve mechanism with three spaced parallel rods, a pair of generally semi-circular, resilient conductor tubes extending between the rods and a linear solenoid for selectively shifting the intermediate rod for selectively and individually pinching the tubes closed.

Abstract: Spaced apart and covered Petri dishes are moved continuously toward a pair of spaced feed nozzles while the covers engage a ramp and are tilted upward away from the dishes to provide a space for reception of the feed nozzles. A photoelectric cell detects the passage of the dishes beneath the feed nozzles and controls the feeding of bacterial culture growth medium alternately from the nozzles into the dishes as the latter move continuously past the nozzles. The covers are replaced over the dishes after filling.

Abstract: A portable device, capable of being hand carried to a selective location along the length of a fire hose at the scene of a fire, is adapted to be swiftly and easily opened by reason of a hinged relationship of its basic parts, to receive the hose. When swung to a closed position about the hose, the clamping device automatically latches and locks in the closed position, to locate stationary and movable jaws at diametrically opposite points on the hose. Then, by operation of a hydraulic means incorporated directly in the device, the movable jaw is forced toward the stationary jaw, to clamp off the hose. The jaws have a particular configuration adapting the same to tightly clamp the hose against any leakage of water therethrough.

Abstract: A combination load and latch mechanism for fluid flow control apparatus, wherein a latch mounted for pivotal movement may be manually opened to disengage an electromechanical manipulating device to permit loading or unloading a feeding tube, the latch automatically closing and the device re-engaging upon release of the latch. The latch includes a slotted side wall that defines a retaining surface for capturing the tube relative to the manipulating device, and a cam surface upon which the tube acts during loading to cam the latch open. Means are included for sensing movement of the latch prior to any disengagement of the manipulating device.

Abstract: A valve for a cigaret gas lighter is comprised of a flexible gas conduit extending between a nozzle and a gas tank. The flexible gas conduit is pinched or bent to close the conduit. An operating member pinches or bends the gas conduit to close the conduit by a spring. A manually operable lever is provided to open the conduit by removing the operating member overcoming the spring force. In a preferred embodiment of the invention, the conduit is positively opened in addition to removal of the operating member when the gas lighter is to be ignited.

Abstract: A pinch valve module comprising a housing, a cylindrical cavity formed in the housing, plural passageways leading from the cavity to the exterior of the housing and spaced about the cavity and a coaxial rotor rotatable within said cavity. The rotor has a diameter less than the diameter of the cavity defining a chamber between its outer wall and the inner cavity wall. Plural spaced pins are located within the chamber and are spaced about the rotor periphery. The rotor has unitary outwardly extending radial protrusions in the form of lobes extending into the chamber. Generally cylindrical tubular rollers or rings are loosely seated about selected ones of said pins within the chamber. Flexible conduits are threaded through said passageways and are disposed along arcuate sections of the chamber walls between the pins and the chamber wall.

Abstract: The valve can be slid over a tube for feeding intravenous fluids to a patient and is manually operable with one hand to control the flow through the tube. A rotatable spindle moves a wedge-shaped draw bar to force a platten with protuberances against the tube to reduce the cross-sectional areas of the tube at multiple points for sensitive metering action.

Abstract: An extended vertical and parallel squeezing device for plastic pipe in a plastic pipe distribution system for fluent materials such as gas and water. According to the invention, height adjustable valve boxes are provided at predetermined squeeze-off points. The plastic pipe squeeze device comprises a pair of squeeze bars which are rotated about a common axis from above the ground via the valve box. A hollow circular shaft and a second shaft internally therein have pipe engaging members at the lower ends thereof, respectively, and a drive means is provided at the opposite ends of the vertical shaft for relatively rotating same so that the pipe engaging members rotate towards each other to squeeze the plastic pipe therebetween. Stop means are provided to limit the amount of squeeze and avoid damage to the plastic pipe and a spacer, offset from the point of engagement of the pipe engaging members provide space for distortion of the pipe from round to oval as it is squeezed.

Abstract: A pinch valve assembly is described for location between the manifold assembly and the flow adjustment valves of a dental handpiece system. The pinch valve assembly of the present invention comprises a housing having a plurality of passageways extending therethrough for receiving a plurality of resilient tubes therein. A plurality of transverse slots extending from each of the passageways to the bottom of the housing are provided and are adapted to receive a plurality of slide elements in each of the slots such that the slide elements can move reciprocally within the slots. The housing is supported on a base and a flexible diaphragm is located between the housing and the base. A rigid disc rests on the diaphragm and supports the slide elements in the slots. A chamber is provided in the base beneath the diaphragm and connected to a source of pressurized fluid.

Abstract: There is disclosed herein a dual flow control clamp for use in continuous ambulatory peritoneal dialysis wherein a patient is connected to the source of dialysis solution through a branched flow path. One branch controls flow to the patient and the other branch controls flow from the patient. The clamp provides for selectively controlling flow in one or both flow paths, while never permitting flow simultaneously in both flow paths.

Abstract: A slide clamp for flexible medical tubing is disclosed that includes a slot having receiving and crimping portions. A stabilizer projects into the receiving portion so that the slide clamp may be kept at any selected elevation along the tubing length when the tubing is in the receiving portion of the slide clamp. In the preferred embodiment, the slide clamp includes a channel extending from a first end of the clamp through the stabilizer, thereby forming stabilizer halves, each being capable of flexure toward and away from each other when the tubing is disposed within the receiving portion.

Abstract: A duck bill valve used to control fluid flow is contained in a sleeve whose wall is apertured to permit the application to the flaps of the valve of radial pressure to open the valve and permit fluid flow. A button located on the sleeve is provided to enable a user to apply the radial pressure when the valve is to be opened.

Abstract: A flow control system, for example for blood plasma or other medical fluids, comprises a plurality of flexible, collapsible flow conduits for the selective and aseptic transfer of fluids between various locations through said conduits. Switching means are provided for selectively collapsing a plurality of separate sections of the conduit to block fluid flow therethrough, to selectively define specific and variable fluid flow paths in the flow conduit. In accordance with this invention, the switching means defines a cam plate, which in turn defines a generally flat face positioned adjacent portions of the flow conduit. Pivot means are provided causing the cam plate to be rotatable about an axis normal to the flat face. Also, a cam connecting system is disclosed, to adapt it to pass through an openable door.

Abstract: An improved apparatus for dispensing flowable material having a pinch valve, an operating lever, a support plate, and a resilient tube located between the lever and the support plate. Movement of an end portion of the lever operates the pinch valve which serves to sequentially isolate a measured quantity of flowable material delivered from a supply and release such measured quantity of material for discharge from the apparatus.

Abstract: Method and apparatus 10 permits material immersed in a body of fluid to move under the influence of gravity across inclined surfaces 14 and 24 having an angle of incline below the horizontal approximately equivalent to that of the repose angles .alpha. and .beta. of the fluid-immersed material. Such materials are moved under the influence of gravity rather than fluid forces to winnowing channels 25 comprising closed regions of finite length through which an upwelling flow of fluid at relatively high velocity passes into the fluid body in which the material is immersed. Undesired materials pass upward, borne on the upwelling flow through the fluid body while desired materials 36 move through winnowing channels 25 counter to the upwelling flow, passing along surface 251 at the repose angle .beta. of such material within the region of relatively high fluid velocity in accord with the material's fluid settling characteristics.

Abstract: An IV chamber flow controller includes a plug integrally connected to the chamber and a flexible tube extending through the plug. A plunger rod is moved by a skirt which is rotatably mounted on the chamber and pinches off the tube to stop flow from the chamber. The skirt includes a crescent shaped groove for controlling movement of the plunger rod. A flow path from the IV chamber to an IV tube is straight and uninterrupted so that leakage and sterility problems are reduced.

Abstract: A pinch valve sleeve for reducing the pressure of fluid flowing therethrough with or without actuation of the valve's pinching mechanism. The valve sleeve features an elongated hollow flexible resilient elastomeric sleeve body having an inner surface circumferentially bounding a flow-through passage and peripheral flanges at both ends suitable for attachment to a section of a pipeline or conduit system. The sleeve body has an ingress section adjacent to the inlet opening of the valve sleeve, an egress section at the outlet opening which permits fluid egress, and a pinchable intermediate section situated between the ingress and egress sections. The inner surface of the sleeve body has thereon a plurality of radially-extending, inwardly-directed protrusions operative for impeding fluid flow through the flow-through passage of the sleeve, thus reducing the pressure so that the pressure of the fluid which exits through the outlet opening is lower than the pressure of the fluid entering the inlet opening.

Abstract: A syringe is provided which is particularly useful in dental work, but which has general utility. The syringe includes pinch valves, and it is constructed to be simple and inexpensive, requiring a minimum of components, and yet to be highly reliable. The syringe is capable of emitting, for example, a stream of air and water, or other fluids or particulate matter, each of which is independently controlled, and neither of which has any tendency to be emitted when only the other is required.

Abstract: In a squeezed tube valve which comprises a valve block with a longitudinal groove to guide a flexible tube and a transverse groove for an electromagnetically actuated clamping bolt to shut off the tube, the crossing between the longitudinal and the transverse groove is rounded off at its edges, and the clamping force exerted by the bolt rises from zero according to an asymptotic rise function over the duration of the shutting action.

Abstract: An actuator device comprising a housing in which there is arranged a permanent magnet extending at 90.degree. from an axially supported member, said member being attached to a driving pawl via a springy leaf, the movement of said magnet being limited by two stop members attached to the bottom plate of the housing, a ratchet wheel with a plurality of teeth pointing downwards and adapted to be engaged by said pawl, another pawl attached to a springy member rigidly attached to said housing, the pawl being adapted to stop a reverse movement of the ratchet wheel, the arrangement being such that application of a magnetic field of adequate strength from a certain distance results in the movement of the magnet and the pawl attached thereto within the range defined by the stop members, each such movement resulting in the stepwise advance of the ratchet wheel by one tooth.

Abstract: Improvements are disclosed in liquid level sensing apparatus having a liquid replenishment line so that as liquid is expended more may be added to keep the liquid at a desired predetermined level. The apparatus is contemplated for use in the humidification of gases, particularly for the administration of oxygen and the like to a patient.

Abstract: Apparatus for control of multiple liquid dispensing providing accurate metering, close spacing of the fluids dispensed and rapid cycling. One embodiment contemplates transferring liquids from a multiplicity of containers to a corresponding multiplicity of wells in a microtitration test tray, and includes a multiplicity of resilient conduits extending from the containers into a common pinch type valve that clamps the ends of the conduits closed or permits them to open for liquid discharge.

Abstract: High performance apparatus for pattern dyeing of textile material by means of a plurality of controlled liquid dye streams. The textile material is conveyed in web form beneath one or more applicators each including a plurality of closely spaced nozzle tubes extending across the textile web. A dye source supplies dye under pressure through flexible tube portions to the nozzle tubes, the flexible tube portions permitting pinching for selective control of dye flow. For rapid and precise control of liquid dye streams, pinch tube valve assemblies are provided for each flexible tube portion for which control of dye flow is desired. A superior and effective pinch tube valve assembly is of the type generally including a valve block portion with a bore in the valve block portion receiving the corresponding dye delivery tube flexible portion.

Abstract: An improved clamp for regulating the flow of fluid through a length of flexible tubing comprising a clamp body for supporting the tubing, having opposing walls extending from the surface of the clamp body so as to present a passage for the flexible tubing. A platen is mounted between the walls for contacting the tubing. Guide surfaces are arranged in the walls with a roller positioned within the guide surfaces. The platen is movably positioned between the roller and the flexible tubing so as to present a compression surface against the tubing along the path of travel of the roller. The combination of the platen and the roller exerts a compressive force against the tubing and distributes the force over a wide area of the tubing so as to prevent permanent deformation of the tubing. This compressive force constricts the tubing and thereby regulates flow of liquid therethrough.

Abstract: A positive opening device for pinch type valves having an elastomeric body consisting of a generally cylindrical sleeve portion forming a material flow passage, with flange portions at the ends for attachment into material flow lines. Under low pressure conditions of operation, or where the sleeve portion has taken a set, being deformed or in partially closed position, it is desireable to improve the function of restoring the sleeve to a full open condition, whether of a full round type or of a pre-pinched type. The sleeve consists of an elastomeric inner layer surrounded by multiple plies of fabric reinforcement, embedded in elastomeric material in the valve body finalized form, and the fabric reinforcement extends through the sleeve and into the flanged ends. End reinforcements extending partially through the sleeve and up into the flanges are added to the body structure.

Abstract: A separable integral donor connector with an improved clamping mechanism for use with flexible blood collection tubing is disclosed. The device is positioned in line with the blood tubing between a phlebotomy needle and the collection bag. Separation of the device is accomplished by manipulation and breaking of a thin frangible ring area and drawing the sections of the device apart. This separation exposes an internally-mounted needle that may be used for penetration of sample collection tube closures and subsequent collection of blood samples. The present embodiment of this invention includes improved manually-operated clamping jaws that are flexibly biased away from the blood tubing. Clamping jaws of differing lengths are disclosed which, when engaged, overlap and cause an area of tubing to be collapsed into a distinctive, S-shaped configuration which crimps and more effectively seals the tubing against blood flow.

Abstract: A double acting pinch valve with floating pinch mechanism. Two opposed rectilinear rigid members extend transversely to a flexible deformable resilient sleeve and on opposite sides of the sleeve; the flow of fluid to be controlled is through the sleeve from one end to the other. A floating piston is provided in a container, i.e. in a cylinder, which container or cylinder also has a floating mounting and suspension. The piston rod is rigidly connected to one of the rigid members, and the floating container is rigidly connected to the other rigid member. The two rigid members and the container with integral piston all have, as a feature of the invention, a floating mounting and suspension on a frame on which the sleeve is mounted, so that these elements are freely displaceable relative to the frame and towards or away from the sleeve.

Abstract: A one-way slide clamp is provided having a slot member with a one-way passageway intermediate a tube receiving section and a tube crimping section to restrain the tubing in the crimping section thereby permanently sealing the fluid passageway.

Abstract: A urine receptor comprising, a receptacle having a chamber to receive urine, and a valve assembly attached to a lower portion of the receptacle. The valve assembly is normally closed, and permits passage of urine through the valve assembly when a valve element of the assembly is pressed.

Abstract: A pinch valve for throttling or terminating the flow of a fluid through a pipe or the like. The valve features two cam bodies within an extension of the valve body. An inner cam body is cammed into non-rotational translational movement in a direction towards and away from the flexible and resilient sleeve of the pinch valve by the cam surface of an outer cam body of circular cross-section which is at least partially rotatable by displacement of a turn handle. The handle may be partially turned about the axis of the outer cam body, to partially constrict or throttle fluid flow, or further turned to completely pinch the sleeve shut and totally terminate fluid flow.

Abstract: A water control valve particularly suited for use with poultry watering apparatus having a deformable rubber sleeve lining the interior of the valve housing. A pair of piston members are arranged to pinch the sleeve and thus cut off the flow through the valve in response to a cross member attached to a control lever alternately urging each of the pistons into the housing.

Abstract: A valve for controlling gravity flow of a fluent product such as milk from a flexible bag of the product through an opening in the bag formed by severing a corner off the bag. The valve includes a pair of spring loaded jaws which engage the bag on opposite sides just above the opening formed by the removal of the corner. Cooperating cam surfaces on the jaws and on movable frames cause the jaws to move toward and away from each other as the frames are moved with respect to each other. Movement of the jaws away from each other causes the edges of the bag at the opening to become taut and restrict flow through the opening, while movement of the jaws towards each other relaxes the bag material adjacent the opening to enhance flow through the opening. The frames also carry resilient sealing bars which engage opposite sides of the bag just above the opening and seal the opening when the jaws are moved away from each other.

Abstract: An improved clamp for regulating the flow of fluid through a length of flexible tubing comprises a clamp body for supporting the tubing, having opposing walls extending from the surface of the clamp body so as to present a passage for the flexible tubing. A platen is mounted between the walls for contacting the tubing. Guide surfaces are arranged in the walls with a roller positioned within the guide surfaces. The platen is movably positioned between the roller and the flexible tubing so as to present a compression surface against the tubing along the path of travel of the roller. The combination of the platen and the roller exerts a compressive force against the tubing and distributes the force over a wide area of the tubing so as to prevent permanent deformation of the tubing. This compressive force constricts the tubing and thereby regulates flow of liquid therethrough.

Abstract: The rate of flow of a fluid through plastic tubing is varied by clamping a portion of a circumferential section of the tube wall with sufficient force to fully close that part of the passage between the clamped wall portions, permitting fluid flow only through the resulting, remaining open cross-sectional area. Cold flow of the plastic material of the clamped portion of the tubing wall, such as might otherwise effect a change in the remaining cross-sectional flow area, is prevented or minimized by rigidly confining the clamped section. To adjustably vary the flow rate, the operative, passage-defining wall section of the tubing is varied by uniformly varying the ratio of the section of clamped tubing, and the remaining, operative wall portion of the tubing, or by deforming the operative wall portion.