Abstract: This invention relates to a solenoid valve where a volume governor which governs the hydraulic flow is inserted coaxially to the valve closure member into the valve accommodating body of the valve. The volume governor is integrated by way of series connection between the first pressure medium connection, emanating from a pressure medium source, and the valve closure member. A reduction of the valve operating noises is ensured with a smallest-requirement-answering structural size, thus the control noises being prevented from propagating over the entire connected system.

Abstract: The invention is concerned with a slip-controlled brake system, adapted for use in automotive vehicles, provided with a master cylinder connected to wheel brakes through main pressure conduits. The brake system is made up of hydraulic auxiliary pressure pumps, wheel sensors and electronic circuits for determining the wheel rotation pattern and for generating electrical brake pressure control signals which control electromagnetically actuable pressure fluid inlet and outlet valves provided in the pressure fluid conduits for slip control purposes. At least one volume-displacing pressure pulsation snubber cooperating with the pressure column of the two main pressure conduits is being disposed between the wheel brakes and the appertaining inlet valves of two main pressure conduits.

Abstract: Disclosed is a regulator for use in fluid braking systems of motor vehicles, particularly hydraulic braking systems. The regulator includes a housing which is advantageously formed of a main housing piece and a detachable cap piece. A resilient bulb is mounted within the housing, such as between the main piece and cap. The housing includes a bulb cavity in which expandable portions of the resilient bulb arc mounted. The bulb cavity is larger than the resilient bulb so that increased braking pressures applied by the braking system to the interior of the bulb cause the bulb to expand outwardly within the cavity. The space between the interior surfaces of the cavity and the outer surfaces of the bulb define a bulb restraint chamber. The housing is preferably provided with a restraint pressure supply which allows a desired, elevated restraint pressure to be established within the restraint chamber.

Abstract: An accumulator for use in a hydraulic control circuit comprises a check valve for allowing a suction of air into a working fluid pressure chamber from the atmosphere. The check valve includes a valve cylinder integrally formed with a member for defining the working fluid pressure chamber. The check valve includes a check ball movable within a bore of the cylinder, and a ball stopper having an outer peripheral surface formed with mesh-like grooves press fitted into the bore to retain the ball within the bore.

Abstract: The invention is related to a hydraulic unit for hydraulic control and regulation of apparatuses, in particular for brake pressure control apparatuses in anti-lock control systems or for traction slip control systems for automotive vehicles. In order to effectively reduce both the noise level depending on the switching positions of the solenoid valves and its diffusion, the invention is based on the concept that while the outlet solenoid valve is open to limit the volume of pressure agent being taken in from the pressure agent source and flowing to the pressure agent consumer through a slide valve which is integrated into the valve accommodation body, a control edge being active at the slide valve reduces the pressure agent flow due to the lifting stroke motion which is dependent on the pressure differential.

Abstract: An anti-lock-controlled hydraulic brake system is described having a pump (9) and a master brake cylinder (1). An arrangement for controlling the pump pressure is integrated in the master brake cylinder ( 1 ) and consists of the combination of a connection of the pump to the master cylinder and reservoir, and a primary seal (30, 34) cooperating with a compensating hole (36) in the master cylinder wall. The seal (30, 34) consists of an elastic ring (37) lying on the inside and of a slide ring (38) lying on the outside. The necessary communication between the storage reservoir ( 7 ) and the brake circuits, which enables the brake circuits to be resupplied via a non-return valve, is effected via the nonreturn valves (10, 11) of the pump (9). The double seal can be backed by a secondary seal (41) which completely seals the working chamber against leakage flow past the primary ring seal.

Abstract: A damper for use in a hydraulic clutch actuator to attenuate vibrations transmitted from the crankshaft of the engine of the associated vehicle to the clutch pedal. The baffle includes an elongated cylindrical housing positioned in the conduit interconnecting the master and slave cylinders of the actuator coaxial with the axis of the conduit and including a spring biased piston mounted in the bore of the housing. The housing is open at its rear end and closed at its front end by an end wall defining an outlet port for the damper and the piston includes a central through passage defining the inlet port of the damper at the rear end of the through passage. A baffle is provided at the front end of the piston to provide a circuitous path between the central passage of the piston and the outlet port of the damper.

Abstract: A slip-controlled brake system, especially for use with automotive vehicles has a brake pressure generator (1) accommodating a master cylinder (2) connected to the brake pressure generator through master brake conduits (62,63) are the wheel brakes (31 to 34), comprising hydraulic auxiliary pressure pumps (21,26) and wheel sensors (S1 to S4) and electronic circuits capable to control, for slip control purposed, electromagnetically actuable pressure fluid inlet valves (24,25,29,30) and pressure fluid outlet valves (22,23,35,36) provided in the pressure fluid conduits, with pressure pulsation attenuators (27) of a defined volume expansion and flow length being provided for noise reduction purposed during the control operation, between the master cylinder (2) and the wheel brakes (31 through 34).

Abstract: A system and method of controlling pressure in a wheel brake cylinder of a brake. The hydraulic cylinder is connected to an electrically driven pump and a flow control valve is connected between the pump and the wheel cylinder. The system and method operate to control the speed of a motor driven pump to generate a desired pressure in a cylinder of the brake; generate a differential pressure, in the flow control valve, proportional to pump flow and communication same to a spring biased valving element; cause the valving element to move, in response to pressure forces acting on the valving element, generated by the pressure differential, and the force of the bias spring, so as to selectively open and close an associated exhaust port, connected to a drain or sump, such that in the steady state an equilibrium condition is achieved where the pressure forces balance the spring force and the pressure in the hydraulic cylinder is constant.

Abstract: An apparatus for damping pressure fluctuations in hydraulic motor vehicle systems with an anti-skid and/or traction control system, the apparatus comprises a throttle and a pressure limiting valve. The apparatus comprises a sleeve-like housing with a screen-like throttle body received in it along with a prestressed compression spring with which the throttle body is supported on the bottom of the housing. The housing and the throttle body are embodied as molded sheet-metal parts. On its bottom, the housing has an opening, with a valve seat, made by stamping without metal cutting, of a pressure limiting valve, which is engaged by the throttle body, which has a stamped bulge of rounded shape. A throttle opening of the throttle body, located in the bulge, is disposed coaxially with the larger-diameter opening of the housing. The apparatus can be used in hydraulic motor vehicle brake systems with an anti-skid and/or traction control system.

Abstract: Disclosed is a regulator for use in fluid braking systems of motor vehicles, particularly hydraulic braking systems. The regulator includes a housing which is advantageously formed of a main housing piece and a detachable cap piece. A resilient bulb is mounted within the housing, such as between the main piece and cap. The housing includes a bulb cavity in which expandable portions of the resilient bulb are mounted. The bulb cavity is larger than the resilient bulb so that increased braking pressures applied by the braking system to the interior of the bulb cause the bulb to expand outwardly within the cavity. The space between the interior surfaces of the cavity and the outer surfaces of the bulb define a bulb restraint chamber. The housing is preferably provided with a restraint pressure supply which allows a desired, elevated restraint pressure to be established within the restraint chamber.

Abstract: A braking circuit provided with an antilocking apparatus, which prevents the pumping pulsation from transferring onto the master cylinder side during pumping operation time in a reflux system of antilocking apparatus of discharging the operating liquid into the reflux passage from the wheel brake at the antilocking time so as to reflux it onto the master cylinder side by a pump provided on the reflux passage, thereby to effectively restrain the undesired pulsation to be transferred onto the master cylinder side by the equalization of the discharge pressure through the absorption of the discharge pressure.

Abstract: A pressure control device for an anti-lock and/or anti-slip system of a motor vehicle comprises a valve casing (10) in which a damping chamber (36) and an expansion chamber (44) are arranged in a common recess (12, 12'), the two chambers having a common axis. A pump is disposed in an adjacent recess having an axis parallel to the common axis of the chambers whereby substantial space is saved over prior arrangements.

Abstract: A slip-controlled brake system, especially for use with automotive vehicles has a brake pressure generator (1) accommodating a master cylinder (2) connected to the brake pressure generator through master brake conduits (62,63) are the wheel brakes (31 to 34), comprising hydraulic auxiliary pressure pumps (21,26) and wheel sensors (S1 to S4) and electronic circuits capable to control, for slip control purposed, electromagnetically actuable pressure fluid inlet valves (24,25,29,30) and pressure fluid outlet valves (22,23,35,36) provided in the pressure fluid conduits, with pressure pulsation attenuators (27) of a defined volume expansion and flow length being provided for noise reduction purposed during the control operation, between the master cylinder (2) and the wheel brakes (31 through 34).

Abstract: An anti-locking hydraulic brake system is described which includes a pump, the output of which flows through a pressure valve (20), a damping chamber (24), a check valve (28) and a throttle (3I) and is delivered to a pressure connection in communication with the wheel brake conduit. To ensure, in a compact structural design, a noise-minimizing hydraulic pressure source, while avoiding a flow back of pressure fluid from the brake system into the damping device, a check valve (28) is integrated into the damping device. A pressure valve is integrated with the check valve and damping chamber, with an elastomeric elastic member disposed in the damping chamber to absorb pressure pulsations.

Abstract: A braking system for a vehicle which includes a master cylinder, and a wheel cylinder for braking a wheel with a brake fluid pressure supplied from the master cylinder. A pulsating-pressure absorbing apparatus is arranged between the master cylinder and the wheel cylinder. The pulsating-pressure absorbing apparatus includes a main body, an inlet formed in the main body and connected to the master cylinder, an outlet formed in the main body and connected to a side of the wheel cylinder, and a stepped hole formed in communication with the inlet and outlet. A stepped plunger is slidably fitted into the stepped hole, and a check valve is arranged in a path defined within the plunger for permitting brake fluid to flow from the inlet towards the outlet and for inhibiting brake fluid from flowing from the outlet towards the inlet.

Abstract: An adjustable pressure control device for hydraulic brake system which reduces pressure surges during braking to decrease wheel slip at one or more wheels during braking. The device has replaceable internal elements which may be combined to tailor the damping response of the device to a specified application.

Abstract: An anti-lock hydraulic brake system is described having a bypass line to a pump used to evacuate and pressurize the wheel brakes during antilock control. A pressure control valve in the bypass line regulates the pressure in the pressure line to the master cylinder pressure level. A low pressure accumulator absorbs recirculated fluid flow from the bypass line. A pressure operated valve opens only when a difference in pressure between the master cylinder pressure and the pump outlet pressure line pressure develops. The consequence is that a non-return valve a and pressure operated valve in combination bring about isolation of the master cylinder during antilock control to prevent brake pedal reaction to pump pressure developed during a braking pressure control operation. When the accumulator is fully charged, the bypass line is closed by means of a shut-off valve operated by an accumulator piston so that the pump delivers fluid via the pressure valve (18) back into the master cylinder (1).

Abstract: The present invention is directed to providing an accumulator for pulsation absorption on a feeding passage between a hydraulic pressure generating device and hydraulic pressure booster equipment, and to provide a restriction on a section of the feeding passage between the accumulator and the hydraulic pressure generating device. As the result, the pulsation caused by a pump is reduced by the restriction, and the pulsation thus reduced is absorbed by the accumulator. Therefore, pulsation is effectively decreased by the restriction and the accumulator, and the pulsation transmitted to the hydraulic pressure booster equipment is quite small.

Abstract: A hydraulic system having a pressure generator which is protected against destructive overload. The hydraulic system has a pulsating feeding pressure generator, such as a piston pump, which feeds pressure fluid at high pressure into a damper chamber of a housing. A throttle body having a throttle bore is disposed on the outlet side of the damper chamber. For producing the protective effect, the damper chamber is preceded by a rupture disk communicating with the outlet. The throttle body suitably has a thin-walled portion, embodied as a rupture disk, in which the throttle bore is located. The embodiment described is advantageously usable in hydraulic systems in which pressure fluids are pulsatingly fed at high pressures.

Abstract: An adjustable pressure control device for hydraulic brake system which reduces pressure surges during braking to decrease wheel slip at one or more wheels during braking. The device has replaceable internal elements which may be combined to tailor the damping response of the device to a specified application.

Abstract: A hydraulic braking system for an automotive vehicle having a master cylinder communicated with a wheel brake cylinder through a primary passage, and an anti-skid apparatus including a fluid pump which is disposed in a recirculation passage connected to the primary passage. An orifice is disposed in the recirculation passage on a discharge side of said fluid pump. In parallel with the orifice, a relief valve is disposed. The relief valve permits a flow of a brake fluid from the fluid pump to the primary passage when a differential pressure between the pressures on the upstream side and downstream side of the orifice exceeds a predetermined value. Consequently, a discharge pulsation of the fluid pump is effectively reduced.

Abstract: The ABS pump output pulsation dampening device (59) comprises a body (10) having disposed therein a pressure source (12) communicating with an inlet line (14) that transmits pressure to an outlet line (16) via an accumulator or storage chamber (20). The body (10) receives at an open end (13) a spring (38) operated accumulator (30) having an accumulator piston (36) received within said accumulator chamber (20). One end (50) of the accumulator piston (36) includes an interior opening (32) which receives slideably and with clearance a dampening piston (60) and a resilient member (62) which biases the dampening piston (60) into engagement with a seat (15) at the end of the inlet line (14). The dampening piston (60) includes an orifice (64) at an one end (63) adjacent the seat (15) and which communicates with a passage (65) extending through the dampening piston (60).

Abstract: In a hydraulic brake system for feedback-free ABS control for mobile units, motor vehicles, motorcycles and the like, it is proposed that partial hydraulic units be provided in accordance with the number of desired closed and optionally also open brake circuits, and that the actuating piston of each shutoff valve provided in each partial hydraulic unit and interrupting the communication between the master brake cylinder and the associated wheel brake cylinder and simultaneously opening the communication between the wheel brake cylinder and a plunger-piston, with a pressure equalization face, which is acted upon in parallel with the pressure from the master brake cylinder line. As a result, given suitable embodiment and adaptation of the remaining pressure faces of the actuating piston, a pressure equilibrium is obtained in the sense of compensation for the working pressures exerted.

Abstract: This invention relates to release/relief valves, trailer brake release valve, and apparatus for equalizing pressure and absorbing shock, as they pertain to pneumatic brake systems for buses, trucks, and trucks/semi-trailers, singular and in multiple combinations in automotive air brake installations; and more particularly to a differential pressure regulator quick release valve that employs a dilivery channel for directing and centralizing fluid pressure differentials to its base housing and the same delivery channel directing the exhaust of fluid pressure to its quick release ports.

Abstract: Disclosed is a regulator for use in fluid braking systems of motor vehicles, particularly hydraulic braking systems. The regulator includes a housing which is advantageously formed of a main housing piece and a detachable cap piece. A resilient bulb is mounted within the housing, such as between the main piece and cap. The housing includes a bulb cavity in which expandable portions of the resilient bulb are mounted. The bulb cavity is larger than the resilient bulb so that increased braking pressures applied by the braking system to the interior of the bulb cause the bulb to expand outwardly within the cavity. The space between the interior surfaces of the cavity and the outer surfaces of the bulb define a bulb restraint chamber. The housing is preferably provided with a restraint pressure supply which allows a desired, elevated restraint pressure to be established within the restraint chamber.

Abstract: A damper for use with a hydraulic clutch actuator of the type including a master cylinder and a slave cylinder with a conduit interconnecting the outlet of the master cylinder and the inlet of the slave cylinder. The damper is positioned in the conduit between the master cylinder and slave cylinder and includes a diaphragm having a front face constituting a barrier wall of the hydraulic system so that the diaphragm can deflect in response to vibrations transmitted through the hydraulic fluid in the system to effect damping of the vibration and further includes a structure confronting but spaced from the rear face of the central region of the diaphragm which operates to limit the deflection of the central region of the diaphragm to a predetermined maximum magnitude to limit the stress at the center of the diaphragm to an acceptable level and thereby improve the fatigue life of the diaphragm.

Abstract: A pedal-actuated braking pressure generator for a brake system with anti-lock control comprising a vacuum-operated servo unit (1), which serves both for boosting the braking force and for generating an auxiliary energy opposed to the pedal force. The system further comprises a master brake cylinder (2) and a piston arrangement (3) connected upstream of the servo unit (1). The piston arrangement comprises a pedal-side piston (15), a reversing valve (18), a pressure transmission chamber (17) and a push-rod piston (19). By a multi-directional valve (5) it is possible to arrest the pedal-side piston (15) during anti-lock control. By means of the reversing valve (18), a pressure medium path is established from the pressure transmission chamber (17) to the pressure compensation reservoir (6), thereby the push-rod piston (19) is relieved in the direction of release of the brake.

Abstract: The vehicle brake system has a master brake cylinder to generate brake pressure in at least one wheel brake. To avoid wheel locking during braking, a pressure control valve assembly and a pump for drawing pressure fluid out of the wheel brake are disposed between the master brake cylinder and the wheel brake. With its outlet, the pump communicates with the master brake cylinder via a damper chamber and a throttle having a pressure limiting valve disposed to bypass the throttle. The throttle and the pressure limiting valve have a common sleevelike housing, in which a cylindrically embodiment closing element is guided longitudinally movably. This closing element has a hollow collar on its face end that in the closing position fits over an inflow opening for pressure fluid. The collar of the closing element, in order to form the throttle, is provided with at least one aperture open toward this face end.

Abstract: The invention relates to a device for a hydraulic unit, in particular in anti-skid systems for vehicle brake systems, which has a radial piston pump. The eccentric driven by a drive shaft in the pump meets pump pistons also located in the pump, usually in the region of high stroke variation speed. An resultant mechanical and hydraulic vibration, which causes noise and annoying movement at the brake pedal, is counteracted according to the invention in that a resilient intermediate element is disposed between the pump pistons and the eccentric element, and the eccentric is driven via a torsionally elastic coupling.

Abstract: A first control valve which is normally open connects a master cylinder connection to a wheel cylinder connection. A second control valve which is normally closed connects the wheel cylinder connection to a storing chamber for returning brake fluid and to an inlet passage of a return pump when it is in open position. The return pump communicates through an output passage with a damping chamber. The damping chamber is arranged in a valve receptacle for the first control valve, and the storing compartment is arranged in a valve receptacle for the second control valve.

Abstract: The invention relates to an apparatus for pressure regulation in hydraulic systems, in particular in anti-skid systems of vehicle brake systems. According to the invention, a throttle switchover valve that includes a bypass valve and a throttle assembly is disposed in the brake circuit between a damper chamber and the master cylinder. The throttle switchover valve either creates an unhindered passage for the brake fluid or throttles it, depending on the intensity of the brake pressure. This suppresses pulsations transmitted to the foot pedal, yet nevertheless, rapid braking and fast release of the brake of a motor vehicle are assured.

Abstract: A braking system for a vehicle is disclosed which includes a master cylinder, a wheel cylinder for braking a wheel or wheels with the brake fluid pressure supplied from the master cylinder and a pulsating-pressure absorbing apparatus arranged between the master cylinder and the wheel cylinder. The pulsating-pressure absorbing apparatus includes a throttle for limiting the brake fluid flowing from the side of the wheel cylinder towards the master cylinder and a plunger arranged between the inlet and outlet of the main body. The plunger is movable in response to the brake fluid pressure difference between both sdes of the plunger. When the plunger is located at the first side of the outlet, the throttle becomes operative and when the plunger is located at the second side of the inlet, the throttle becomes inoperative.

Abstract: In the sump unit 1 of this invention, the sump unit 1 is installed in the operating fluid passage 4, and the fluid accommodating chamber 1a is formed as a part of the operating fluid passage 4.Therefore, the sump unit 1 does not protrude extensively from the operating fluid passage 4, and the fluid pressure control unit can be designed in more compact form. Because the fluid accommodating chamber 1a of the sump unit 1 is formed as a part of the operating fluid passage 4, the air intermingled with the operating fluid in the fluid accommodating chamber 1a can be easily withdrawn, and this extensively facilitates the air vent of the fluid pressure control unit.

Abstract: A radial piston pump in which an annular coupling device (10), whose axially directed extensions (11) each engage a working piston, has a preset break point (15) in the area of the axial extensions (11).

Abstract: A radial piston pump has diametrically opposed pistons coupled to each other by a coupling ring mounted in circumferential grooves located adjacent the facing ends of the piston. The coupling ring is formed with axially projecting bifurcated arms received in the piston grooves. The arms are of a reversely bent undulating shape which is compressed between opposed walls of the groove to firmly couple the ring to each piston. The ring is thus supported entirely by the pistons. A central opening through the ring is expanded in the direction normal to the piston axis to provide clearance for side to side motion of an eccentric which drives the pistons in reciprocation.

Abstract: To shift the resonant (peak) hydraulic pressure vibration frequency, caused when hydraulic pressure varies by brake unit torque fluctuations due to worn-away brake rotor for instance, away from the brake shimmy generation range (e.g. 10 to 17 Hz), an auxiliary pipe is additionally connected between a first pipe connecting the master cylinder to the right side hydraulic cylinder and a second pipe connecting the master cylinder to the left side hydraulic cylinder in the vicinity of the two hydraulic cylinders.

Abstract: A manually/electrically operated brake system for applying a brake to a wheel of a vehicle, including a master cylinder operated by a brake operating member, to generate a manually controlled braking pressure according to an operation of the brake operating member, a wheel brake cylinder for applying a brake to the wheel, a primary fluid passage for connecting the master cylinder to the wheel brake cylinder, an electrically controlled pressure generating device for generating an electrically controlled braking pressure to produce a required braking effect determined based on at least one of an operating force and an operating stroke of the brake operating member, and a switching device provided in the primary fluid passage, for applying the electrically controlled braking pressure to the wheel brake cylinder while disconnecting the master cylinder from the wheel brake cylinder when the electrically controlled pressure generating device is normally functioning, and for applying the manually controlled braking

Abstract: In a hydraulic motor vehicle brake system with slip control comprising a pressure accumulator (13), a hydraulic pump (23), a non-return valve (2) and a brake power booster (17). The pressure outlet of the pump (23) is connected with the pressure accumulator and with an inlet of the brake power booster (17) via the non-return valve (2). The outlet side of the non-return valve (2) is connected with the inlet of the brake power booster (17) via the pressure accumulator (13) in order to reduce noises caused by pressure pulsations in the fluid flow of the pump (23).

Abstract: Disclosed is an accumulator for use on hydraulic brake systems. The accumulator includes a housing, a pressurization cap which is threadably connected into the housing and a resilient bulb contained within a volume between the housing and pressurization cap. The resilient bulb provides a flexible volume which can expand in response to high pressure surges and shock waves experienced by the braking system. The bulb is contained primarily within an interior cavity formed in the pressurization cap. The resilient bulb is constructed in a size and shape which causes an annular volume between the bulb and pressurization cap to be pre-pressurized when the accumulator is assembled together. The accumulator is also provided with a particularly effective sealing arrangement to prevent leakage of air and hydraulic fluid from around the bulb.

Abstract: A pressure stabilization and equalization device to prevent single wheel lock-up in hydraulic brake systems comprises a housing with openings adapted for connection to a hydraulic line between a power source and a pair of brake actuators. The openings communicate with a fluid receiving first chamber within the housing containing the exposed end face of a freely movable piston axially aligned with a shock absorbing, resiliently yieldable member that extends axially into but does not fill a second chamber formed by the housing. Hydraulic shock waves of increased pressure which occur within the first chamber because of an imbalance reaction from one of the brake actuators as the brakes are applied in a vehicle, are absorbed and damped out by movement of the piston against the resiliently, yieldable member which temporarily deforms within its chamber of the housing.

Abstract: An anti-vibration apparatus for an automotive hydraulic braking system for preventing the brake vibration by means of imparting the function of absorbing the pulsation of the hydraulic braking fluid pressure to any one structural member of the braking system, which is disposed in the hydraulic, braking fluid circuit, with respective proper object, such as a three-way joint, a pressure control valve, a wheel cylinder, etc. This apparatus is constructed in communication with the fluid passage within the respective structural member and comprises a cylinder formed integrally with the structural member body, a plunger slidably and fluid-tightly fitted in the cylinder, one end thereof being under the pressure of the hydraulic braking fluid and the other end thereof being faced to an air chamber, a stopper for restricting the axial sliding of the plunger within a limited range, and a spring for constantly biasing the plunger against the hydraulic braking fluid pressure.

Abstract: Apparatus for equalizing pressure and absorbing shock to prevent single wheel lock-up in a pneumatic braking system including a pneumatic source coupled by air lines to two brake actuators and being subject to the presence of contaminants of the water droplet and particulate type, the apparatus comprising a walled housing including an inner surface forming an elongated cavity having a first port for connection to the pneumatic source and a second port for connection to one of the actuators, the cavity being configured to form a first chamber that communicates with the first and the second port and to form a second chamber, a rigid piston having a first end and an opposed second end, an elongated resiliently yieldable, shock absorbing member disposed within the cavity between the second end and an opposite wall of the cavity, the member having an outer surface and a transverse cross-sectional dimension less than the corresponding transverse cross-sectional dimension of the cavity such that the separated outer