GB1560291A - Vacuumbooster having dust cover retaining device - Google Patents
Vacuumbooster having dust cover retaining device Download PDFInfo
- Publication number
- GB1560291A GB1560291A GB2960576A GB2960576A GB1560291A GB 1560291 A GB1560291 A GB 1560291A GB 2960576 A GB2960576 A GB 2960576A GB 2960576 A GB2960576 A GB 2960576A GB 1560291 A GB1560291 A GB 1560291A
- Authority
- GB
- United Kingdom
- Prior art keywords
- valve body
- retainer
- dust cover
- vacuum booster
- pawls
- 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.)
- Expired
Links
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
- F16J15/50—Sealings between relatively-movable members, by means of a sealing without relatively-moving surfaces, e.g. fluid-tight sealings for transmitting motion through a wall
- F16J15/52—Sealings between relatively-movable members, by means of a sealing without relatively-moving surfaces, e.g. fluid-tight sealings for transmitting motion through a wall by means of sealing bellows or diaphragms
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
- B60T13/00—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems
- B60T13/10—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems with fluid assistance, drive, or release
- B60T13/24—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems with fluid assistance, drive, or release the fluid being gaseous
- B60T13/46—Vacuum systems
- B60T13/52—Vacuum systems indirect, i.e. vacuum booster units
Landscapes
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Transportation (AREA)
- Braking Systems And Boosters (AREA)
- Sealing Devices (AREA)
- Clamps And Clips (AREA)
Description
(54) VACUUM BOOSTER HAVING DUST
COVER RETAINING DEVICE
(71) We TOKICO LTD., a Japanese body corporate, of 6-3 Fujimi l-chome, Kawasaki-ku, Kawasaki-shi, Kanagawaken, Japan, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:
The invention relates to vacuum boosters for use in a vehicle braking device and of the type having a housing, a valve body displaceably mounted in the housing with one end portion of the valve body projecting from the housing, and a generally cylindrical dust cover covering the projecting end portion of the valve body.
In such boosters, it has been conventional practice to include an annular retainer for fixing the dust cover to the free end of said projecting portion of the valve body. The known retainers have, however, had the disadvantage that they have been subject to becoming detached from the valve body in use.
In accordance with the present invention, there is provided a vacuum booster comprising a housing, a valve body displaceably mounted in the housing with one end portion of the valve body projecting from the housing, a generally cylindrical dust cover covering the projecting end portion of the valve body, and an annular retainer which is formed with a plurality of resilient pawls which engage a cylindrical surface of the end portion of the valve housing and which are so inclined relative to said cylindrical surface that they resiliently bend to allow the annular retainer to be slid axially onto the valve body during assembly of the booster but thereafter engage said cylindrical surface such as to resist movement of the annular retainer in the opposite direction relative to the valve body, either the inner periphery or the outer periphery of the annular retainer being secured to the dust cover.
The invention will now be further described, by way of example, with reference to the accompanying drawings, in which:
Figure 1 is a partially cross-sectional schematic view of a vacuum booster according to the present invention incorporating a dust-cover retaining device;
Figure 2 is a front view of a retainer for use in the dust cover retaining device shown in Figure 1;
Figure 3 is a cross-sectional side view of the retainer of Figure 2;
Figure 4 is a cross-sectional view showing a modified form of the dust cover retaining device in Figure 1;
Figure 5 is a front view of a retainer for use in the device of Figure 4;
Figure 6 is a cross-sectional side view of the retainer in Figure 5;
Figure 7 is a front view of a further modified retainer for use in the dust cover retaining device;
Figure 8 is a cross-sectional side view of the retainer of Figure 7;;
Figure 9 is a fragmentary cross-sectional view showing one prior art dust cover retaining device;
Figure 10 is a front view of a retainer used in the device of Figure 9; and
Figure 11 is a cross-sectional side view of the retainer of Figure 10.
Heretofore, a device for retaining a dust cover on a valve body of a vacuum booster has been such as shown in Figures 9 to 11. In Figure 9, which shows a fragmentary cross-sectional view of a vacuum booster, a valve body 52 projecting slidably from a housing (not shown) of a vacuum booster surrounds an input rod 53 and defines an annular space therebetween which space acts as a passage for introducing atmosphere into one side of a dia phragm when the booster is actuated
Filters 56 and 57 are disposed in the passage.An annular retainer 55 Figure 10 is a front view of the retainer and
Figure 11 is a cross-sectional side view thereof) has been fitted on the peripheral wall of the valve body 52 at the open end thereof with a cylindrical retaining portion 55b being force-fitted on the valve body 52, and a radially extending flat portion 55a of the retainer engaging the outer periphery of an end portion 54b of a dust cover 54 surrounding and protecting the valve body 52 from dust or the like.
However, it has been found that the valve body 52 which is usually made of synthetic resin such a phenol resin often suffers shrinkage due to the thermal influence of the vehicle engine or the like, with a resultant loss of tightness between the retaining portion 55b and the valve body 52. Thus, the known retainer tends to slip off the valve body 52 when the booster is actuated. Consequently, the desired dust protecting function will be adversely affected.
Other known valve bodies are not subject to the abovedescribed shrinkage but, in these, other shortcomings have been experienced. Because of the configuration of the retainer 55 is has been difficult to afford a sufficient amount of engagement between the retainer 55 and the valve body 52 and to machine the mating portions of the retainer and the valve body sufficiently accurately.
A vacuum booster shown in Figure 1 is of conventional type and has a diapragm (not shown) partitioning the interior of a housing 1 into two chambers, namely, a vacuum chamber (left hand side in the drawing) and a pressure chamber (right hand side). A valve body 2 controllying the communication between the chambers is disposed in the housing 1 and projects outwardly from the housing 1. The valve body 2 is of a substantially cylindrical shape in the portion projecting from the housing 1, and surrounds an input rod 3 so as to define a passage therebetween for the introduction of atmospheric air. The projecting portion of the valve body 2 is covered by a dust cover 4 which prevents the ingress of dust or the like into the interior of the booster.One end 4a of the dust cover 4 is fitted in an annular groove la formed in the housing
land the other end 4b is connected to a free end 2a of the valve body 2 by a retainer 5. Filters 6, 7 and sound absorbing material 8 are disposed in the air introducing passage.
The retainer 5 is made of a resilient material in the annular shape as shown in
Figure 2 and, as best shown in Figure 3, consists of a flat portion 5a, an axially extending flange portion Sb, an inclined portion Sc and a plurality of pawl positions Sd. The radially inner periphery of the inclined portion Sc of the retainer 5 is adapted to engage in an annular groove 4c formed in the end portion 4b of the dust cover 4, and the flange portion Sb of the retainer 5 is adapted to engage the outer periphery of the end portion 2a of the valve body 2. The pawls Sc resiliently engage the inner periphery of the end portion 2a of the valve body 2.
A diameter L1 defined by the tips of the pawls 5d is somewhat larger than the inner diameter LI of the end portion 2a of the valve body 2, so that when the retainer S is fitted on the valve body 2, the pawls are resiliently deflected and the tip ends of the pawls act to prevent withdrawal of the retainer from the valve body 2. The retainer S shown in Figures 1 to 3 may easily be formed from metal plate by punching and pressing.
Should the valve body 2 suffer shrinkage or contraction due to thermal influence from an engine or the like, the retainer 5 would be maintained in position without slipping off the valve body 2, since the pawls Sd, 5d firmly press against the inner surface of the portion 2a of the valve body 2.
A modified form of the dust cover retaining device 5' is shown in Figures 4, 5 and 6. This embodiment differs from the first embodiment in that the flange portion 5b is omitted and that an annular groove 4'c formed in the inner periphery of an end portion 4'b of a dust cover 4' engages with the outer periphery of a flat portion 5'a of the retainer 5'. The retainer 5' is mounted on the valve body 2' with the pawls 5d' pressing against the inner periphery of the valve body 2'.
A further embodiment of retainer according to the present invention is shown in Figures 7 and 8.
In this embodiment, the retainer 5" has a plurality of pawls S"d, 5"d formed in the axially extending or flange portion 5"b by a three-side punching and bending out technique. The retainer 5" is mounted on a valve body with the pawls S"d pressing
against the outer peripheral surface of the valve body while an end of a dust cover
engages with the inner end of a flat portion
S"a of the retainer 5".
Thus, the dust cover retaining devices all include a plurality of resilient pawls which act, in use, to hold the retainer in
place on the valve body so that the dust
cover is tightly mounted on the valve body.
Since the engagement between the retainer
and the valve body is maintained by the resilience of the pawls, variations in the dimensions of the valve body arising from thermal contraction of the valve body or from machining tolerance of the valve body or the retainer will not act to cause slippingoff of the retainer. Furthermore, the pawls are highly effective to prevent relative axial movement of the retainer and valve body in one direction by virtue of the direction of inclination or deflection, whereby, the retainer is easy to install but difficult to remove.
WHAT WE CLAIM IS:
1. A vacuum booster comprising a housing, a valve body displaceably mounted in the housing with one end portion of the valve body projecting from the housing, a generally cylindrical dust cover covering the projecting end portion of the valve body, and an annular retainer which is formed with a plurality of resilient pawls which engage a cylindrical surface of the end portion of the valve housing and which are so inclined relative to said cylindrical surface that they resiliently bend to allow the annular retainer to be slid axially onto the valve body during assembly of the booster but thereafter engage said cylindrical surface such as to resist movement of the annular retainer in the opposite direction relative to the valve body, either the inner periphery or the outer periphery of the annular retainer being secured to the dust cover.
2. A vacuum booster as claimed in claim 1 wherein said cylindrical surface engaged by the pawls is the inner peripheral surface of said projecting end portion of the valve body.
3. A vacuum booster as claimed in claim 1 wherein said cylindrical surface engaged by the pawls is the outer peripheral surface of said projecting end portion of the valve body.
4. A vacuum booster as claimed in any of claims 1 to 3 wherein each of the pawls is three-sided and is formed by punching and bending out from the body of the retaining device which is formed of metal plate.
S. A vacuum booster having a dust cover retaining device constructed substantially as hereinbefore particularly described with reference to and as illustrated in Figs.
1 to 3 of the accompanying drawings.
6. A vacuum booster having a dust cover retaining device constructed substantially as hereinbefore particularly described with reference to and as illustrated in Figs.
4 to 6 of the accompanying drawings.
7. A vacuum booster having a dust cover retaining device constructed substantially as hereinbefore particularly described with reference to and as illustrated in Figs.
7 and 8 of the accompanying drawings.
**WARNING** end of DESC field may overlap start of CLMS **.
Claims (1)
- **WARNING** start of CLMS field may overlap end of DESC **.dimensions of the valve body arising from thermal contraction of the valve body or from machining tolerance of the valve body or the retainer will not act to cause slippingoff of the retainer. Furthermore, the pawls are highly effective to prevent relative axial movement of the retainer and valve body in one direction by virtue of the direction of inclination or deflection, whereby, the retainer is easy to install but difficult to remove.WHAT WE CLAIM IS:1. A vacuum booster comprising a housing, a valve body displaceably mounted in the housing with one end portion of the valve body projecting from the housing, a generally cylindrical dust cover covering the projecting end portion of the valve body, and an annular retainer which is formed with a plurality of resilient pawls which engage a cylindrical surface of the end portion of the valve housing and which are so inclined relative to said cylindrical surface that they resiliently bend to allow the annular retainer to be slid axially onto the valve body during assembly of the booster but thereafter engage said cylindrical surface such as to resist movement of the annular retainer in the opposite direction relative to the valve body, either the inner periphery or the outer periphery of the annular retainer being secured to the dust cover.2. A vacuum booster as claimed in claim 1 wherein said cylindrical surface engaged by the pawls is the inner peripheral surface of said projecting end portion of the valve body.3. A vacuum booster as claimed in claim 1 wherein said cylindrical surface engaged by the pawls is the outer peripheral surface of said projecting end portion of the valve body.4. A vacuum booster as claimed in any of claims 1 to 3 wherein each of the pawls is three-sided and is formed by punching and bending out from the body of the retaining device which is formed of metal plate.S. A vacuum booster having a dust cover retaining device constructed substantially as hereinbefore particularly described with reference to and as illustrated in Figs.1 to 3 of the accompanying drawings.6. A vacuum booster having a dust cover retaining device constructed substantially as hereinbefore particularly described with reference to and as illustrated in Figs.4 to 6 of the accompanying drawings.7. A vacuum booster having a dust cover retaining device constructed substantially as hereinbefore particularly described with reference to and as illustrated in Figs.7 and 8 of the accompanying drawings.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1975099709U JPS5536293Y2 (en) | 1975-07-18 | 1975-07-18 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB1560291A true GB1560291A (en) | 1980-02-06 |
Family
ID=14254588
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB2960576A Expired GB1560291A (en) | 1975-07-18 | 1976-07-16 | Vacuumbooster having dust cover retaining device |
Country Status (5)
| Country | Link |
|---|---|
| JP (1) | JPS5536293Y2 (en) |
| BR (1) | BR7604644A (en) |
| DE (1) | DE2631458B2 (en) |
| ES (1) | ES449871A1 (en) |
| GB (1) | GB1560291A (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2918734C2 (en) * | 1979-05-09 | 1986-09-04 | Alfred Teves Gmbh, 6000 Frankfurt | Vacuum booster |
| DE9201972U1 (en) * | 1992-02-15 | 1993-06-17 | Hydraulik Techniek, Emmen | Pull cylinder |
| KR0143588B1 (en) * | 1995-12-19 | 1998-08-01 | 정몽원 | Noise decreasing system of booster |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5228072Y2 (en) * | 1973-09-27 | 1977-06-25 |
-
1975
- 1975-07-18 JP JP1975099709U patent/JPS5536293Y2/ja not_active Expired
-
1976
- 1976-07-13 DE DE19762631458 patent/DE2631458B2/en not_active Ceased
- 1976-07-16 ES ES449871A patent/ES449871A1/en not_active Expired
- 1976-07-16 GB GB2960576A patent/GB1560291A/en not_active Expired
- 1976-07-16 BR BR7604644A patent/BR7604644A/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5536293Y2 (en) | 1980-08-26 |
| BR7604644A (en) | 1977-08-02 |
| DE2631458B2 (en) | 1978-06-15 |
| ES449871A1 (en) | 1977-08-16 |
| JPS5213385U (en) | 1977-01-29 |
| DE2631458A1 (en) | 1977-01-20 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PS | Patent sealed | ||
| PCNP | Patent ceased through non-payment of renewal fee |
Effective date: 19930716 |