EP0000517A1 - Sealing cup - Google Patents
Sealing cup Download PDFInfo
- Publication number
- EP0000517A1 EP0000517A1 EP78100392A EP78100392A EP0000517A1 EP 0000517 A1 EP0000517 A1 EP 0000517A1 EP 78100392 A EP78100392 A EP 78100392A EP 78100392 A EP78100392 A EP 78100392A EP 0000517 A1 EP0000517 A1 EP 0000517A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- cylinder
- cup
- piston
- angle
- sealing
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
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Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16J—PISTONS; CYLINDERS; SEALINGS
- F16J15/00—Sealings
- F16J15/16—Sealings between relatively-moving surfaces
- F16J15/32—Sealings between relatively-moving surfaces with elastic sealings, e.g. O-rings
- F16J15/324—Arrangements for lubrication or cooling of the sealing itself
Definitions
- This invention generally relates to a sealing cup adapted for use in vehicular devices and more particularly to improvements in a sealing cup to be mounted on any piston and cylinder for recaiving the fluid pressure and for fluidtightly sealing the same.
- the brake device of these days has to satisfy the following requirements to provide an improved brake cup; that the brake pedal will be smoothly depressed with little resistance and that the vehicle can, be stopped by a small depression of the brake pedal.
- one of the major drawbacks of the conventional brake cup is, although satisfactory as regards the sealing, that it is obliged to increase the resistance of slide due to shortage of the oil film formed between the slide surfaces. Therefore, a large foot force is necessary to pressurize the brake fluid, causing a poor pressurizing efficiency of brake fluid. In addition, a stable movement of the piston provided with the conventional brake cup will not be secured due to possible vibration like stickslip vibration with the result of unstable brake application.
- a wedge-shaped clearance of a predetermined angle and shape is formed for example betwwen the cylinder and the leading edge of the piston cup upon the fitting thereof between the piston and the cylinder, thereby permitting the oil admission into the wedge-shaped clearance when the piston cup slides in accordance with the piston movement.
- the lubrication of oil is increased and the oil film is formed.on the sliding .surfaces of the cylinder or the piston thereby decreasing the slide resistance.
- an angle ⁇ of the leading edge of the outer peripheral wall of the piston cup with respect to the cylinder axis is made smaller than an angle e of the remaining part of the peripheral wall thereof with respect to the cylinder axis when the piston cup is fitted between the piston and the cylinder, and the angle ⁇ is made 1° ⁇ ⁇ ⁇ 15°.
- the angle ⁇ of the leading edge of the sealing cup is defined as inclination when unmounted toward a wall where the sealing cup is slidably contacted.
- Figs. 1 t6 4 wherein so-called ring cups are illustrated; cups of Figs. 1 and 3 are called S.A.E type while the cups of Figs. 2 and 4 are called Opel type.
- Each of these conventional ring cups comprises an outer lip 1 substantially similar to the frustum of a cone, an inner lip 2, and a base 3.
- S.A.E type cup of Figs. 1 and 3 comprises a tip A at the maximum diameter portion of the outer lip 1 at which the maximum pressure is applied by contact of the cup with a cylinder CY.
- the fluid film may not be formed between the sealing portion of the outer lip 1 and the cylinder CY because there is no provision of a leading edge to provide clearance in the case of the S.A.E type cup as shown in Fig. 3, thereby causing the sealing portion 4 to be brought into direct contact with the cylinder CY and increasing the slide resistance therebetween.
- a piston cup of the invention comprises an outer lip 1 provided with a leading edge 6.
- the angle ⁇ of the leading edge 6 relative to the axis parallel to the cylinder axis is smaller when unmounted than the angle ⁇ of the remaining portion 4 to the said axis 1° ⁇ ⁇ ⁇ 15°.
- the portion A is at a position where the outer diameter of the piston cup is larger than the inner diameter of the cylinder.
- the wedge-shaped clearance is constituted between the leading edge 6 and the cylinder wall to form the oil film therebetween when the piston cup slides on the cylinder wall.
- the slide resistance of the cup will be decreased to realize various advantages such as a stable movement of the piston, improvement in the pressure increasing efficiency, and improvement in the durability of the cup.
- the piston cup of Fig. 7(A) comprises an outer wall 7 of the inner lip 2 which includes a portion smaller in diameter than the outer diameter of the piston and the sealing wall 4 of the outer lip 1 which includes a portion larger in diameter than the inner diameter of the cylinder. Consequently, the piston cup receives bending force at the inner-lip 2 thereof and at the outer lip 1 thereof when installed within the cylinder CY, as shown in Fig. 7(B) wherein the sealing pressure of the cup in contact with the cylinder CY and the piston P is also illustrated.
- Fig. 7(B) shows that the tip B of the outer lip 1 is being apart from the cylinder wall.
- Fig. 8(B) shows that the leading edge is in contact with the cylinder wall when the piston cup is installed and Fig. 8(C) shows that when the inner pressure is applied the tip B of the leading edge is apart from the cylinder wall and the pressure at a portion of the edge is below the inner pressure.
- the fluid wedge operation of the piston cup having the inclination angle ⁇ (Fig. 9(A)) when mounted has been proved effective in the fluid lubrication theory, i.e. the minimum thickness of the fluid film should be a few microns to dozens of microns in order to realize the fluid wedge. operation in the most effective way, so that the inclination angle ⁇ is a few degrees.
- the tip angle ⁇ preferably be designed as 1° ⁇ ⁇ ⁇ 7° from Fig. 9(B). It is to be noted in Fig. 9(B) that the angle ⁇ may be designed as 1° ⁇ ⁇ ⁇ 10° in order to accomplish the fluid wedge effect.
- Fig. 10 shows the test results of slide resistance with the angle ⁇ being different -30°, -10°, and 5° when the length l of the edge 6 is nearly equal to 0.15 x (L:length of the sealing wall 4) and the angle 0 is 15°.
- the angle ⁇ may be varied within the range of 10° ⁇ ⁇ ⁇ 30°.
- the leading edge angle ⁇ may be 1° ⁇ ⁇ ⁇ 15° so as to realize the fluid wedge effect.
- the minimum limit of the angle range should be ⁇ 1° and the decrease of the angle ⁇ (the increars of the absolute value of the angle ⁇ ) will not realize the fluid wedge effect.
- the major factors for accomplishing the fluid wedge operation are the angle, the shape, and the size of the clearance formed between the leading edge of the piston cup and the cylinder (or the piston) when the cup is installed between the cylinder and the piston.
- the shape and the size of the clearance are primarily determined by the angle of the leading edge 6 of the lip and the pressure applied to the inside of cup, and secondarily by the tightening clearance of the cup, and the shape and the elasticity of the portion other than the leading edge thereof.
- Figs. 13 and 14 shows the piston cup of the invention which is being used as secondary cup of the brake device.
- the brake master cylinder will be explained with reference to Fig. 13.
- the tandem master cylinder CY comprises a first piston PI and a second piston P2 each slidably fitted therein.
- the first piston PI is provided with a secondary cup SC and a primary cup PC1.
- the second piston P2 is provided with a primary cup PC2 and floating cups FC1 and FC2.
- a fluid chamber RC of the rear wheel side is pressurized.
- the second piston P2 is also moved left due to pressure in the chamber RC so that the primary cup PC2 closes a compensation hole CH2, fluidically connected to a reservoir tank RT2 thereby pressurizing fluid chamber FC of the front wheel side.
- the secondary cup SC mounted on the first piston P1 serves to seal between the inside of the cylinder CY and" the outside thereof.
- the primary cups PC1 and PC2 of the pistons PI and P2 serve to receive the fluid pressure.
- the floating cups FC1 and FC2 serve to sear betwaen the rear side chamber RC and the front side chamber FC.
- the secondary cup SC comprises an outer lip 11 having an unbroken curve at the outer periphery thereof, and a leading edge 16 at the tip thereof.
- the leading, eage 16 has an inclination of the angle 5° with respect to tne line passing a point A and parallel to the cylinder axis.
- Fig. 15 shows the piston cup of the invention which is used as a primary cup of the brake device.
- the wedge-shaped clearance is similarly formed upon sliding movement of the primary cup so as to decrease the slide resistance.
- the piston cup of the invention may be used as primary cup of the clutch device.
- the piston cup of the invention may be employed in a proportioning valve device which will increase the wheel brake pressure with a reduced ratio relative to the master brake pressure.
- the piston cup used in the proportioning valve device There are two kinds of the piston cup used in the proportioning valve device; in one of which the outer lip of the cup slides with respect to the inner wall of cylinder and in the other of which the inner lip of the cap slides with respect to the outer wall of piston.
- the applicants of the invention have found that the leading edge ingle ⁇ of any cup should be 1 ⁇ ⁇ ⁇ 15° so as to effect the fluid wedge operation in the must effective way. Otherwise, the angle ⁇ of the cup may be 1° ⁇ ⁇ ⁇ 7° in consideration of the inner pressure applied thereto and the tightening clearance thereof.
- Fig. 16 shows a modified embodiment of the present invention in which a further inclined surface 47 is provided on a leading edge 46 of the sealing cup.
- the surface 47 is inclined with respect to a line (L) in the direction opposite to the inclination indicated by ⁇ and such the inclination is designated by ⁇ ' in Fig. 16. It is noted that the surface 47 is inclined in a way that the tip portion thereof is apart from the wall when mounted where the sealing cup is slidably contacted.
- the angle ( ⁇ ') is selected from the range of 0° to 45 0 .
- the preferable range of the angle ( ⁇ ') is 15° to 45°.
Landscapes
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Transmission Of Braking Force In Braking Systems (AREA)
- Sealing With Elastic Sealing Lips (AREA)
Abstract
Description
- This invention generally relates to a sealing cup adapted for use in vehicular devices and more particularly to improvements in a sealing cup to be mounted on any piston and cylinder for recaiving the fluid pressure and for fluidtightly sealing the same.
- In vehicles, lots of devices have been employed for pressurizing the fluid in which a piston fitted within the cylinder and a cup mounted on the piston constitute a cylinder chamber to be pressurized by the relative movement of the piston and the cylinder. In the field of brake devices, too, various improvements have been imparted to.a ssaling or piston cup thereof (hereinafter simply referred to as brake cup) in order to increase the sealing effect from the view point of safety. As a result, the requirement for the sealing effect of the brake cup has been satisfied.
- Nowadays, a new requirement of the vehicle driver is to improve a foot feeling upon depression of the brake pedal. That is to say, the brake device of these days has to satisfy the following requirements to provide an improved brake cup; that the brake pedal will be smoothly depressed with little resistance and that the vehicle can, be stopped by a small depression of the brake pedal.
- More specifically, one of the major drawbacks of the conventional brake cup is, although satisfactory as regards the sealing, that it is obliged to increase the resistance of slide due to shortage of the oil film formed between the slide surfaces. Therefore, a large foot force is necessary to pressurize the brake fluid, causing a poor pressurizing efficiency of brake fluid. In addition, a stable movement of the piston provided with the conventional brake cup will not be secured due to possible vibration like stickslip vibration with the result of unstable brake application.
- Therefore, it is one of the objects of the invention to provide a sealing cup which may obviate the difficulties of the conventional one.
- It is another object of the invention to provide a sealing cup in which the slide resistance thereof to a cylinder or a piston may be decreased to thereby improve the pressurizing efficiency of fluid within the cyl-inder.
- It is a further object of the invention to provide a sealing cup which may secure a stable movement of the piston and increase durability.
- According to the invention, a wedge-shaped clearance of a predetermined angle and shape is formed for example betwwen the cylinder and the leading edge of the piston cup upon the fitting thereof between the piston and the cylinder, thereby permitting the oil admission into the wedge-shaped clearance when the piston cup slides in accordance with the piston movement. Thus, the lubrication of oil is increased and the oil film is formed.on the sliding .surfaces of the cylinder or the piston thereby decreasing the slide resistance. More specifically, an angle α of the leading edge of the outer peripheral wall of the piston cup with respect to the cylinder axis is made smaller than an angle e of the remaining part of the peripheral wall thereof with respect to the cylinder axis when the piston cup is fitted between the piston and the cylinder, and the angle α is made 1°≦ α ≦15°. The angle α of the leading edge of the sealing cup is defined as inclination when unmounted toward a wall where the sealing cup is slidably contacted.
- The above and additional objects and features of the invention will be more fully appreciated to those skilled in the art from a consideration of the following detailed explanation of preferred embodiments of the invention when taken in conjunction with the accompanying drawings.
- In the drawings:
- Figs. 1 and 2 are sectional views of conventional piston cups an upper half of each of which is shewn for simplicity when unmounted;
- Figs. 3 and 4 are views similar to Figs. 1 and 2 but showing the conventional piston cups fitted between the piston and the cylinder;
- Fig. 5 is a sectional view of one embodiment of a piston cup in accordance with the invention an upper half of which is shown for simplicity when unmounted;
- Fig. 6 is a view similar to Fig. 5 but showing the piston cup of the invention when fitted between the piston and the cylinder;
- Figs. 7(A) to 7(C) show explanatory cross sections of the piston cup according-to the invention wherein the leading edge angle thereof to the cylinder axis is 5 0 ;
- Figs. 8(A) to 8(C) are viewssimilar to Figs. 7(A) to 7(C) but wherein the leading edge angle to the cylinder axis is 10°;
- Fig. 9(A) is schematic cross section;
- Fig. 9(B) is a graph showing the range of the leading edge angles of the piston cup. to the cylinder axis;
- Fig. 10 is a graph showing the relationship between the slide resistance and the sliding speed with the leading edge angles of the piston cup to the cylinder being different;
- Fig. 11 is a graph showing the relationship between the fluid pressure and the piston stroke;
- Fig. 12 is a graph showing the relationship between the slide resistance and the piston stroke thereby comprising the piston cup of the invention with the conventional piston cups shown in Figs. 1 and 2;
- Fig. 13 is a cross section of a brake master cylinder in which the piston cups are used;
- Fig. 14 is a cross section of the piston cup of the invention adapted for use as a secondary cup of the brake master cylinder of Fig. 13;
- Fig. 15 is a cross section of the piston cup of the invention adapted for use as a primary cup of the brake master cylinder of Fig. 13;
- Fig. 16 is a sectional view of another embodiment of the invention.
- Referring first to Figs. 1
t6 4 wherein so-called ring cups are illustrated; cups of Figs. 1 and 3 are called S.A.E type while the cups of Figs. 2 and 4 are called Opel type. Each of these conventional ring cups comprises anouter lip 1 substantially similar to the frustum of a cone, aninner lip 2, and abase 3. S.A.E type cup of Figs. 1 and 3 comprises a tip A at the maximum diameter portion of theouter lip 1 at which the maximum pressure is applied by contact of the cup with a cylinder CY. The Opel type cup of Figs. 2 and 4 similarly comprises the maximum pressure portion A at the maximum diameter portion thereof, and a tip B with a gradually decreasingdiameter portion 5 from the portion A, the tip angle to the cylinder axis being around 30°. After fitted to a piston P and the cylinder CY as shown in Figs. 3 and 4, these cups are moved to the direction indicated by the arrow upon movement of the piston P with the slide resistance being produced between asealing portion 4 of theouter lip 1 and the cylinder CY. More specifically, the fluid film may not be formed between the sealing portion of theouter lip 1 and the cylinder CY because there is no provision of a leading edge to provide clearance in the case of the S.A.E type cup as shown in Fig. 3, thereby causing the sealingportion 4 to be brought into direct contact with the cylinder CY and increasing the slide resistance therebetween. - When the sealing cup of Fig. 2 is fitted in the cylinder bore as shown in Fig. 4, the bendable lip portion is deformed under pressure when it comes into contact with the inner wall of the cylinder, so that the leading
edge portion 5 is forced to be inclined and apart from the inner wall of the cylinder at an angle greater than when unmounted. As a result, the wedge effect is not easily obtained. - Referring now to Fig. 5, a piston cup of the invention comprises an
outer lip 1 provided with a leadingedge 6. The angle α of the leadingedge 6 relative to the axis parallel to the cylinder axis is smaller when unmounted than the angle δ of theremaining portion 4 to thesaid axis 1° ≦ α ≦ 15°. Naturally, on thesealing wall 4 the portion A is at a position where the outer diameter of the piston cup is larger than the inner diameter of the cylinder. When the piston cup of Fig. 5 is installed between the piston P and the cylinder CY as seen in Fig. 6, the leadingedge 6 will be inclined in relation to the cylinder wall with a relatively small angle. Accordingly, the wedge-shaped clearance is constituted between the leadingedge 6 and the cylinder wall to form the oil film therebetween when the piston cup slides on the cylinder wall. As a consequence, the slide resistance of the cup will be decreased to realize various advantages such as a stable movement of the piston, improvement in the pressure increasing efficiency, and improvement in the durability of the cup. - The change of the cup shape when the cup is installed in the cylinder due to the change of the angle α of Fig. 5 is analized with the condition of & =15° and α=5° (Figs. 7(A)-7(C)) or α =10° (Figs. 8(A)-8(C)).
- The piston cup of Fig. 7(A) comprises an
outer wall 7 of theinner lip 2 which includes a portion smaller in diameter than the outer diameter of the piston and thesealing wall 4 of theouter lip 1 which includes a portion larger in diameter than the inner diameter of the cylinder. Consequently, the piston cup receives bending force at the inner-lip 2 thereof and at theouter lip 1 thereof when installed within the cylinder CY, as shown in Fig. 7(B) wherein the sealing pressure of the cup in contact with the cylinder CY and the piston P is also illustrated. Fig. 7(B) shows that the tip B of theouter lip 1 is being apart from the cylinder wall. When the inner pressure of 20 kg/cm2 is applied to the inner wall of the cup, it will be clearly apparent from the pressure distribution shown at the upper part of Fig. 7(C) that the leadingedge 6 from the point A to the point B is apart from the cylinder wall CY. - Similarly, Fig. 8(B) shows that the leading edge is in contact with the cylinder wall when the piston cup is installed and Fig. 8(C) shows that when the inner pressure is applied the tip B of the leading edge is apart from the cylinder wall and the pressure at a portion of the edge is below the inner pressure.
- It should be understood in Fig. 9(B) that the angle α be equal to or below 10° so as-to release the tip of the lip from the cylinder-in an effective way.
- The fluid wedge operation of the piston cup having the inclination angle β (Fig. 9(A)) when mounted has been proved effective in the fluid lubrication theory, i.e. the minimum thickness of the fluid film should be a few microns to dozens of microns in order to realize the fluid wedge. operation in the most effective way, so that the inclination angle β is a few degrees. In order to make the inclination angle β a few degrees when the piston cup is fitted in the cylinder, the tip angle α preferably be designed as 1° ≦ α ≦7° from Fig. 9(B). It is to be noted in Fig. 9(B) that the angle α may be designed as 1° < α <10° in order to accomplish the fluid wedge effect.
- Fig. 10 shows the test results of slide resistance with the angle α being different -30°, -10°, and 5° when the length ℓ of the
edge 6 is nearly equal to 0.15 x (L:length of the sealing wall 4) and the angle 0 is 15°. In the case of α = -30° as in the conventional Opel type cup, the fluid wedge operation is little expected because the leading edge is far apert from the cylinder, and the slide resistance is relatively large. In the case of the angle α = 1° or 5°, the resistance is gradually decreased in accordance with the increase of the speed and the fluid wedge operation will be expected in the case of α = 5°. particularly when the angle α is 5° to realize the wedge operation in the most effective way as seen in Fig. 9(B), the slide resistance is smaller than that of the case of the angle α = 1°. - The applicants have found also that the piston sup of the above-mentioned construction is very advantageous for use in the brake master cylinder of automotive vehicles.
- The pressure applied within the piston cup increases in accordance with the piston stroke as seen ir Fig, 11. Fig. 12 shows the slide resistance of the piston oips of the piston cup of the invention (α = 5°) in comparison with the conventional piston cups shown in Figs. 1 and 2, and proves the piston cup of the invention has far superior results.
- Although the above explanation is based on the inclination angle θ = 15°: the angle θ may be varied within the range of 10° ≦ θ ≦ 30°. In consideration of such range of the angle θ, the leading edge angle α may be 1° ≦ α ≦ 15° so as to realize the fluid wedge effect.
-
- The minimum limit of the angle range should be ≧ 1° and the decrease of the angle α (the increars of the absolute value of the angle α) will not realize the fluid wedge effect.
- The major factors for accomplishing the fluid wedge operation are the angle, the shape, and the size of the clearance formed between the leading edge of the piston cup and the cylinder (or the piston) when the cup is installed between the cylinder and the piston. The shape and the size of the clearance are primarily determined by the angle of the
leading edge 6 of the lip and the pressure applied to the inside of cup, and secondarily by the tightening clearance of the cup, and the shape and the elasticity of the portion other than the leading edge thereof. After the tests and the analysis of these factors, the applicants found that the range of 1° ≦ α ≦ 15° is the most effective. - Figs. 13 and 14 shows the piston cup of the invention which is being used as secondary cup of the brake device. At first the brake master cylinder will be explained with reference to Fig. 13.
- The tandem master cylinder CY comprises a first piston PI and a second piston P2 each slidably fitted therein. The first piston PI is provided with a secondary cup SC and a primary cup PC1. Similarly, the second piston P2 is provided with a primary cup PC2 and floating cups FC1 and FC2. When a brake pedal BP is depressed to push a rod PR, the primary cup PC1 is moved left in unison with the first piston PI to close a compensation hole CH1 which is in fluid communication with a reservoir tank RT1.
- Thus, a fluid chamber RC of the rear wheel side is pressurized. The second piston P2 is also moved left due to pressure in the chamber RC so that the primary cup PC2 closes a compensation hole CH2, fluidically connected to a reservoir tank RT2 thereby pressurizing fluid chamber FC of the front wheel side.
- The secondary cup SC mounted on the first piston P1 serves to seal between the inside of the cylinder CY and" the outside thereof. The primary cups PC1 and PC2 of the pistons PI and P2 serve to receive the fluid pressure. The floating cups FC1 and FC2 serve to sear betwaen the rear side chamber RC and the front side chamber FC.
- The secondary cup SC comprises an outer lip 11 having an unbroken curve at the outer periphery thereof, and a leading edge 16 at the tip thereof. The leading, eage 16 has an inclination of the
angle 5° with respect to tne line passing a point A and parallel to the cylinder axis. When the cup is moved the wedge-shaped clearance is formed between the cylinder wall and the edge 16 of the cup so as to admit the fluid therein. Therefore, the slide resistance is decreased due to the oil film produced on the cylinder wall. - Fig. 15 shows the piston cup of the invention which is used as a primary cup of the brake device.
- The primary cup comprises a
leading edge 26 of an outer lip 21 which is formed parallel to the cylinder axis (the leading edge angle α = 10). The wedge-shaped clearance is similarly formed upon sliding movement of the primary cup so as to decrease the slide resistance. - The piston cup of the invention may be used as primary cup of the clutch device.
- It should be noted that modifications of the invention are possible as long as the leading edge angle α of the cup with respect to the cylinder axis is 1° ≦ α ≦ 15°. For instance, the piston cup of the invention may be employed in a proportioning valve device which will increase the wheel brake pressure with a reduced ratio relative to the master brake pressure. There are two kinds of the piston cup used in the proportioning valve device; in one of which the outer lip of the cup slides with respect to the inner wall of cylinder and in the other of which the inner lip of the cap slides with respect to the outer wall of piston. The applicants of the invention have found that the leading edge ingle α of any cup should be 1 ≦ α ≦ 15° so as to effect the fluid wedge operation in the must effective way. Otherwise, the angle α of the cup may be 1° ≦ α ≦ 7° in consideration of the inner pressure applied thereto and the tightening clearance thereof.
- Fig. 16 shows a modified embodiment of the present invention in which a further
inclined surface 47 is provided on aleading edge 46 of the sealing cup. Thesurface 47 is inclined with respect to a line (L) in the direction opposite to the inclination indicated by α and such the inclination is designated by α' in Fig. 16. It is noted that thesurface 47 is inclined in a way that the tip portion thereof is apart from the wall when mounted where the sealing cup is slidably contacted. The angle (α') is selected from the range of 0° to 450. The preferable range of the angle (α') is 15° to 45°. - . By the provision of the angle α', it is possible to avoid the objectionable adhesion of the tip of the piston cup to the cylinder wall which may be caused due to the manufacturing error of the angle α, the expansion or the thermal deformation of the cup during use thereof, and the frictional force on the cup during sliding movement thereof.
- Although the invention has been shown and described with respect to preferred embodiments, it is obvious that equivalent alternations and modification will occur to others skilled in the art upon the reading and understanding of this specification. The present invention includes all such equivalent alternations and modifications, and is limited only by the scope of the claims.
Claims (8)
said angle α of said annular inclined portion is predetermined as follows;
said angle α of said annular inclined portion has a following relation to said angle & of the other part of said annular inner and/or outer sealing surfaces with respect to the axis of said cylinder,
fluid under the predetermined pressure is applied to said inner wall of said cup mounted between a brake master cylinder and a piston and said inclined portion and edge portion are formed on said outer sealing surface. 8. A sealing cup for a hydraulic piston cylinder device in accordanoe with claim 7, characterized in that
the angle α of said annular inclined portion is 5° and the angle α' of said edge portion is -30°.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP95011/77 | 1977-07-15 | ||
JP1977095011U JPS5835892Y2 (en) | 1977-07-15 | 1977-07-15 | piston cup |
Publications (2)
Publication Number | Publication Date |
---|---|
EP0000517A1 true EP0000517A1 (en) | 1979-02-07 |
EP0000517B1 EP0000517B1 (en) | 1981-05-13 |
Family
ID=14126009
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP78100392A Expired EP0000517B1 (en) | 1977-07-15 | 1978-07-13 | Sealing cup |
Country Status (4)
Country | Link |
---|---|
US (1) | US4189160A (en) |
EP (1) | EP0000517B1 (en) |
JP (1) | JPS5835892Y2 (en) |
DE (1) | DE2860697D1 (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5169286A (en) * | 1989-03-09 | 1992-12-08 | Yutaka Yamada | Variable capacity centrifugal water pump with movable pressure chamber formed by impeller |
DE19505012A1 (en) * | 1995-02-15 | 1996-08-22 | Teves Gmbh Alfred | Sealing sleeve for hydraulic systems |
Families Citing this family (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4258927A (en) * | 1978-12-13 | 1981-03-31 | Garlock Inc. | Shaft seal with retractable polytetrafluoroethylene-lined sealing lip |
US4867043A (en) * | 1986-06-30 | 1989-09-19 | Tayco Developments, Inc. | End cap for fluid cylinder |
US5575484A (en) * | 1995-06-30 | 1996-11-19 | Greene, Tweed Of Delaware, Inc. | Fluid pressure activated piston return spring seal |
DE10028672A1 (en) * | 2000-06-09 | 2001-12-13 | Fte Automotive Gmbh | Sealing element for hydraulic piston-cylinder arrangements |
JP4699594B2 (en) * | 2000-10-10 | 2011-06-15 | カヤバ工業株式会社 | Fluid pressure packing |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2815995A (en) * | 1954-06-28 | 1957-12-10 | Acushnet Process Company | Lip type seal for sealing hydraulic and pneumatic pressure systems |
GB944921A (en) * | 1959-01-10 | 1963-12-18 | Girling Ltd | Improvements in seals |
Family Cites Families (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CA529112A (en) * | 1956-08-14 | The Garlock Packing Company Of Canada | Sealing devices | |
US2664952A (en) * | 1948-03-15 | 1954-01-05 | Guiberson Corp | Casing packer cup |
US2686402A (en) * | 1948-12-31 | 1954-08-17 | Charles A Samuel | Hydraulic brake wheel cylinder piston |
US2720924A (en) * | 1950-02-20 | 1955-10-18 | Cicero C Brown | Connecting devices for well tools |
US2884291A (en) * | 1953-10-05 | 1959-04-28 | Kelsey Hayes Co | Sealing cup |
US2867457A (en) * | 1954-07-16 | 1959-01-06 | Gen Motors Corp | Fluid seal |
DE1046966B (en) * | 1956-04-30 | 1958-12-18 | Freudenberg Carl Kg | Lip seal |
GB1019523A (en) * | 1964-01-22 | 1966-02-09 | Angus George Co Ltd | Improvements in and relating to packing rings |
US3527507A (en) * | 1968-02-12 | 1970-09-08 | Garlock Inc | Unitary bearing element with improved,integral scraper-sealing lip |
DE2002082A1 (en) * | 1969-11-26 | 1971-06-03 | Mini U Generaldirektor Der Deu | Lip seal for air couplings |
US3653670A (en) * | 1970-05-11 | 1972-04-04 | Cascade Corp | Spring-loaded seal with symmetrical cross section |
-
1977
- 1977-07-15 JP JP1977095011U patent/JPS5835892Y2/en not_active Expired
-
1978
- 1978-07-13 DE DE7878100392T patent/DE2860697D1/en not_active Expired
- 1978-07-13 EP EP78100392A patent/EP0000517B1/en not_active Expired
- 1978-07-14 US US05/924,837 patent/US4189160A/en not_active Expired - Lifetime
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2815995A (en) * | 1954-06-28 | 1957-12-10 | Acushnet Process Company | Lip type seal for sealing hydraulic and pneumatic pressure systems |
GB944921A (en) * | 1959-01-10 | 1963-12-18 | Girling Ltd | Improvements in seals |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5169286A (en) * | 1989-03-09 | 1992-12-08 | Yutaka Yamada | Variable capacity centrifugal water pump with movable pressure chamber formed by impeller |
DE19505012A1 (en) * | 1995-02-15 | 1996-08-22 | Teves Gmbh Alfred | Sealing sleeve for hydraulic systems |
Also Published As
Publication number | Publication date |
---|---|
JPS5835892Y2 (en) | 1983-08-12 |
DE2860697D1 (en) | 1981-08-20 |
US4189160A (en) | 1980-02-19 |
EP0000517B1 (en) | 1981-05-13 |
JPS5421785U (en) | 1979-02-13 |
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