JP4130976B2 - Spring brake actuator release tool - Google Patents

Description

Background of the Invention
This specification describes the brake actuator with little or no movement along the axis relative to the outside of the actuator housing.springRelates to an improved release tool for spring brake actuator.
Spring brake actuators are used in modern large vehicles to activate the brakes when the vehicle is parked or when a part of the vehicle brake system fails. In either situation, the strong spring expands and moves the mechanical rod that operates the brake actuator. This operation may occur when the vehicle is on the road. In that case, the operator of the vehicle needs to put a spring in the cage so that the vehicle can be moved. Maintenance of springs, brakes and actuators, especially (springParking side maintenance is not recommended. Nevertheless, if parking side opening is attempted, the spring must be caged by the mechanical element prior to such opening. When the actuator is removed or installed, or when the vehicle is towed, usuallyspringCan also be put in a cage.
Therefore, the release tool is usually provided on the parking side of the spring brake actuator. Release tools are usuallyspringIt was a bolt that could be received in the piston that holds it. As the bolt rotates, it pulls the spring piston toward the outer end of the housing, holding the spring, or “put it in the cage”. The bolt usually moved out of the housing along the axis as it was turned. Thus, in the prior art spring brake actuator, the release bolt isspringOnce fully enters the cage, it usually extends outwardly from the outer end of the brake actuator housing along the axis.
While this type of release bolt has been found to work well in many applications, there may not be enough space along the axis for the release bolt to extend along the axis from the brake actuator. Therefore,springThere are desirable advantages to providing a release bolt that does not extend along the axis away from the actuator when it is in the cage. In conventional technology,springCould not provide a device to achieve the goal of not requiring an auxiliary clearance along the axis at the outer end of the spring, brake, or actuator chamber, while allowing reliable cage placement .
Summary of invention
In the disclosed embodiment of the present invention, the spring brake actuator includes:springA release tool is provided that extends little or no along its axis beyond its initial position as it enters the cage. In a preferred embodiment of the invention, the release bolt comprises a head that reaches from the outside of the brake actuator housing. The bolt engages with an internally threaded nut. As the bolt head is turned, the nut moves along the axis. The nut engages with the spring piston and moves the spring piston. The spring piston is thus pulled along the axis towards the outer end of the brake housing,springIn a cage. Since the bolt head does not move away from the brake actuator head along the axis during this movement, no space along the auxiliary axis is required on the outer surface of the brake actuator.
In other preferred features, the nut is initially maintained by a spring in any position to align with the initial thread of the bolt. As the operator begins to turn the bolt, the nut is immediately engaged by the thread and begins to retract toward the outer edge of the housing. On the other hand, the nut does not actually engage the thread initially, so if the operator begins to turn the bolt in the wrong direction, the nut will not move away from the outer end of the brake actuator. In this way, the present invention ensures that there is no movement of the nut in a direction that would prevent normal operation of the brake actuator.
In another aspect of the invention, the nut includes an outer peripheral edge that matches the contour of the inner bore in the piston. The nut can slide in this internal bore during normal operation of the brake.
In some embodiments, the spring biases the nut toward the bolt. This spring biases the nut and bolt slightly outward along the axis before the nut contacts the spring piston. The bolt extends a small distance away from the outer portion of the brake actuator housing. An observer who sees this bolt head spaced slightly outward along the axis from the housing will see that the brake actuator is not in the cage. In this embodiment, when the operator begins to turn the bolt, the nut eventually contacts the flange on the spring piston,springBegin to put in the cage and occupy the gap. Initially, after this contact, the spring force that biases the nut outwardsspringFirst, it is overcome so that it can move inward and fully caged before the external position. The observer looking at the bolt head in this positionspringRecognize that is partially or completely in the cage. Most preferably, the snap ring on the bolt contacts the inside of the housing when the bolt is moved outward by spring to its external position. This snap ring defines a restraining device that limits the movement out of the bolt.
In other features, an O-ring is disposed during bolt movement as described above on the outer peripheral surface of the bolt at any location such that it provides an outer housing for the seal. This O-ring combined with a spring at the inner end of the bolt provides a concentrated force to stabilize the bolt and damp vibration effects on the bolt.
In other embodiments, the bolt can be utilized without the use of a small spring. In this embodiment, the bolt does not pop up when not in the cage and the nut is always received on the thread. The other operational aspects of this embodiment are similar to those described above.
In yet another aspect, the present invention comprises a hollow push rod that receives a portion of the total length of the bolt and nut. In this way, the total length of the brake actuator does not increase due to the total length of the release bolt. Rather, part of the total length of the release bolt isspringCan extend into the push rod inward along the axis, reducing the required outer envelope size of the brake actuator.
In other features, the present invention may be utilized with either piston brakes or diaphragm brakes.
According to the present inventionspringIn the method of operating the spring brake actuator to move the cage into the cage, the bolt is received in a threaded nut. The nut is received within a portion of the spring piston so that when the bolt is turned, the nut engages with the spring piston and pulls it toward the outer end of the brake housing head. The method includes rotating the release bolt head, thereby rotating the nut until the nut engages the spring piston. The method further envisages continued rotation of the head so that the nut begins to move the spring piston until the spring is fully caged.
One problem that arises when using the aforementioned release bolts of the present invention is that it is somewhat difficult to determine when the release bolt is fully released. Release boltspringIf the brake is not fully released, the brake cannot extend to its maximum effective stroke. This would not be desirable. Thus, in a further embodiment of the present invention, a structure visible from the outside of the brake is provided that provides an indication of whether the release bolt is fully released.
In one embodiment,springA pop-up indicator is built into the release bolt that extends out of the brake when the is not fully released. The pop-up indicator is preferably made from a light color so that it can be easily seen. An operator looking at the pop-up indicator will know that the brake has not been fully released.
In a further preferred embodiment, the release bolt itself has two threaded portions and the threads extend in opposite directions. The inner threaded portion is received in the nut as described above. The outer threaded portion formed integrally with the inner threaded portion is received within the outer nut. As this release bolt is turned, the outer threaded portion moves within the outer nut, the bolt extends out of the brake and pulls the inner portion and nut outward. At the same time, the inner threaded portion rotates within its release nut, and then the release nut moves upward. Therefore, the release nut is pushed by the threaded part of both the push rod andspringIt is moving relative to. In this way, the outer portion extends to the outside of the brake housing, but only by a relatively small amount. An observer of this brake can determine whether the brake is fully released by seeing if the release bolt moves inward with respect to the outer surface of the brake housing. If it is moving, you know that the brake is fully released.
These and other features of the present invention can be best understood from the following specification and drawings briefly described below.
[Brief description of the drawings]
FIG. 1 is a partial cross-sectional view of a spring brake actuator incorporating the present invention.
FIG. 2 is a cross-sectional view taken along line 2-2 illustrated in FIG.
FIG. 3 is a cross-sectional view of the spring brake actuator moving toward the actuated piston.
FIG. 4 shows the spring brake actuator of FIG. 1 with the spring in the cage.
FIG. 5 shows the release bolt of the second embodiment.
FIG. 6A shows a brake actuator according to a third embodiment.
FIG. 6B shows the embodiment of FIG. 6A moved to another operational position.
FIG. 6C shows the embodiment of FIG. 6A moved to yet another operational position.
FIG. 7 shows another embodiment of the brake in the first state.
FIG. 8 shows the embodiment of FIG. 7 in a subsequent position.
FIG. 9 shows yet another subsequent position.
FIG. 10 shows yet another subsequent position.
FIG. 11 shows yet another embodiment of the release tool of the present invention.
FIG. 12 shows the embodiment of FIG. 11 in the enlarged position.
FIG. 13 shows the embodiment of FIG. 11 in its caged position.
Detailed Description of the Preferred Embodiment
FIG. 1 shows a spring brake actuator 20. Structures of spring brake actuators other than those related to the release tool mechanism are known in the art. Therefore, a detailed description of all components of the brake actuator is not described. As is known, the spring brake actuator includes a central housing body 22. This central housing body 22 is generally called a flange case.OutsideConnected to the brake housing member 24. thisOutsideThe brake housing member 24 is known as the service chamber and is also known as the head with respect to the external brake housing 26. What is in the headspring28.springAs known, 28 engages the brake selectively through the yoke 27 under certain conditions. The chamber 30 is limited to the diaphragm 32. When pressurized air is received in the chamber 30, the diaphragm 32 moves upward,spring28 is compressed. In this state, the push rod 34 connected to the diaphragm 32 also moves upward. In this positionspring28 is not actuated and the push rod 34 is not forced down. Therefore, when the brake actuator is on the parking side, the yoke 27 is moved and the brake is not operated. If the parking brake is engaged or there is something wrong with the system,spring28 expands to force the push rod 34 downward and move the yoke 27 outward.
spring28 is received on the spring piston 36. Release bolt 38 extends through brake housing 24. O-ring seal 39 provides a hermetic seal between bolt 38 and housing portion 24. The threaded bolt portion 40 extends from the bolt head 41. The nut 42 is received on a bolt at the inner end of the housing 24. The nut 42 is received in the bore 44 in the piston 36. The spring 46 biases the nut 42 in an arbitrary position so that the screw in the nut 42 is aligned with the starting thread 48 of the threaded portion 40. The portion 49 below the thread 48 is not threaded. Thus, when the bolt head 41 is turned in the first direction, the thread 48 is engaged on the thread 42 and the nut begins to be pulled upward on the threaded portion 40. On the other hand, when the head 41 is turned in the opposite direction, the nut 42 is not pulled up onto the thread 48 and the nut 42 does not move over the threaded portion 40.
Also, as shown in FIG. 1, a small spring 46 biases the bolt head 41 to an arbitrary position so that there is a slight gap 70 between the bolt head 41 and the housing 44. The snap ring 64 prevents the bolt 38 from moving further out.spring46 biases the nut 42 and thus the bolt 38 outward to this position. The observer of the gap 70springIt will be understood that 28 remains uncaged within the brake actuator 20.
As illustrated in FIG. 2, the bore portion 44 includes an inner peripheral edge that coincides with the outer peripheral edge of the nut 42. Of course, other cross-sections are within the scope of the present invention, but in this view, both the nut and the bore are illustrated as being hexagonal. As also shown, the unthreaded portion 49 of the lower portion of the bolt 38 is received within the bore 52 of the nut 42. The bore 52 is threaded.
As shown in FIG.springWhen 28 is expanded, the piston 36 is moved downward together with the push rod 34. Since the nut 42 slides within the bore 44, this movement does not affect the release tool. That meansspringAs 28 moves from the position shown in FIG. 1 to the position shown in FIG. 3, nut 42 simply slides within bore 44. As shown in FIG. 3, a long gap 70 is maintained during this movement.springCan be designed. The observerspringIt will be understood that 28 remains out of the cage.
In some examples, when the brake actuator is in the extended position, an operator may mechanically engage from outside the brake actuator 20.springIt may be desirable to capture 38 or place it in a cage. Conventional techniques typically move the mechanical members in the housing,springA release bolt that was turned to capture 28 was provided.
As shown in FIG. 4, the tool 60 may begin to turn the head 41 of the bolt 38. When the bolt 38 is initially rotated, the nut 42 is engaged on the thread of the threaded portion 40. As the head 41 continues to rotate, the nut 42 moves upward along the axis along the threaded portion 40.
Eventually, the nut 42 contacts the flange 62 at the outer end of the piston 36. At that point, if the bolt head 41 continues to rotate, the nut 42 moves the piston 36. This movementspring28 is captured or placed in a cage. The first movement that occurs when the nut first contacts the flange 62 is the inward movement of the bolt head 41 toward the housing 24. After the nut contacts the flange 62, the nutspringIt is not biased outward by the force of 46. Rather, as the nut rotates, the nut and bolt move inward, eliminating the gap 70. When further tightened, the nut 42 is connected to the flange 62, the piston 36, and thus thespring28 begins to be pulled into the cage position as illustrated in FIG. In this way, an observer who confirms that the gap 70 no longer exists isspringYou will recognize that is partially or completely in the cage.
FIG. 5 shows another embodiment of an actuator. The actuator 80 has a smallspringThere is no. The spring piston 82 includes a bore 84 as in the previous embodiment. The nut 86 rises along the bolt 88. As the bolt 88 rotates, the nut 86 moves along the axis within the bore 84 as in the previous embodiment. There is a thread 90 along the entire length of the bolt 88 and the nut 86 is always received on the thread 90 in the preferred embodiment. The flange 92 extends inward from the piston 82. As the bolt 88 rotates, the nut 86 moves and eventually contacts the flange 92. If the rotation of the bolt head 88 is continued, as in the previous embodiment,springIs put in a cage.
The brake actuator illustrated in FIGS. 1-5 is provided in a spring chamber.Actuator memberAs a diaphragm. The embodiment 80 illustrated in FIGS. 6A-6B discloses a piston-type brake actuator. Other features of embodiment 80 are also illustrated in FIGS. 6A-6C. It should be understood that the features generally illustrated in the release tool in FIGS. 6A-6C also find advantages in the diaphragm brake. In addition, the release tool shown in FIGS. 1-5 also finds an advantage over the piston brake.
As illustrated in FIG. 6A, the piston brake 80 incorporates a housing member 82 that is connected to the central housing 84 as is the case with a clip 86 or other known connection.spring88 biases the piston 90 against the outside. The piston 90 moves with the push rod 92 and actuates the yoke as in the previous embodiment. The push rod 92 is formed with a bore 94 and the bolt 96 extends downward into the bore 94. The nut 98 is small as in the previous embodiment.spring99 is biased upward. As shown, the bolt 96 is thus spaced from the outer housing 82 by a small amount 97, again to the observer.springGives an indication that is not in the cage. In this embodiment, the bolt 96 extends into the push rod 92 so that the brake actuator 80 may have an outer envelope size along a relatively smaller axis than when the push rod 92 is solid. is there. Thus, a portion of the total bolt length is occupied by extending it into the hollow push rod 92. As shown, push rod 92 extends through opening 100 in central housing 84. In the position shown in FIG. 6A,spring88 is compressed by the air pressure in the chamber below the piston 90.
As illustrated in FIG. 6B,spring88 now expands to move the piston 90 relative to the central housing 84. Push rod 92 extends through opening 100 and the yoke operates in a known manner. As also shown, the nut 98 is slightly spaced from the flange 102 in this position. The gap 97 remains in this position and the dimensions are preferably such that the piston 90 bottoms in the housing 84 before the flange 102 contacts the nut 98,springDimensions are selected to overcome 99 small forces. Therefore, the observerspringIt could also be said that 88 remains uncaged in this position.
As shown in FIG. 6C, the bolt 96, in turn, moves the nut 98, and the piston 90 andspringThe 88 was rotated into the cage. The hollow push rod concept, as mentioned above, is a small returnspringAlthough described in the embodiment ofspringIt should be understood that the embodiment shown in FIG. 5 without this can also be combined with this hollow pushrod embodiment.
In the method of placing a brake actuator in a cage according to the present invention, first the brake actuator need not be moved along the axis away from the housing member.springA threaded release tool is provided that can be rotated to enter the cage.
In a preferred embodiment, the method comprises:springProviding such a release tool that engages with the nut along with a nut that moves along the axis when rotated by the release bolt to enter the cage.
The method further moves the nut,springAlso included is the step of starting to turn the release bolt in order to put it in the cage.
With respect to the release tool, it can be difficult to determine whether the brake is fully released from the outside of the brake. Accordingly, embodiments of the present invention having a display structure visible from the outside of the brake have also been developed.
A first embodiment 110 is illustrated in FIG. The push rod 112 receives the nut 114 as in the previous embodiment. The spring piston 116 is a restraining device for the nut 114 as in the previous embodiment. Cap 118 is received on pop-up indicator rod 120.spring124 reacts away from the release bolt 123 in the shelf portion 122.spring124 pushes the head 126 of the indicator 120 out of the brake housing. The head 126 is preferably made from a light color. An observer looking at the bright head will find that the brake is not fully released. As an example, in FIG. 7 the brake is shown fully in the cage. In this way, the head 126 can move relative to the bolt 123 and the shelf 122.
As shown in FIG. 8, the release nut 114 has moved downward, but is still fullyspringNot released. Therefore,springCannot extend to its full stroke. It would be desirable to provide an indication that the operator has not yet fully released the brakes. As illustrated in this figure,spring124 continues to bias the head 126 to the outside of the brake.
As illustrated in FIG. 9, the release nut 114 has moved further and now has fully released the brake. Release nut 114 now contacts cap 118 and pulls cap 118 inward. As a result, instead of the rod 120 and the head 126,springPulled against the force of 124. As shown, the head 126 no longer extends out of the cap. The observer will see that the brake has been fully released.
As illustrated in FIG. 10, the nut 114 has completely released the brake, sospringCan extend to its full stroke. Again, the head 126 does not extend outside the brake in this state.
FIG. 11 illustrates another embodiment 140 that includes a release bolt 142. Release bolt 142 rotates internal release nut 144, which moves within push rod 146 as described in the previous embodiment. Release bolt 142 also includes an outer nut 148. Release bolt 142 includes two integral threaded portions 150 and 152. The threads on portions 150 and 152 extend in opposite directions. The threads on the portion 150 rotate within the outer nut 148 and the threads on the portion 152 rotate within the inner nut 144.
In the position illustrated in FIG. 11, the release bolt 142 has fully released the brake. Note that the release bolt 142 does not extend at all to the outside of the housing.
In this position, as shown in FIG. 12, the push rod 146 isspringUnder the influence of 154, it can extend to its maximum range. Again, the bolt 142 does not extend out of the housing and the observer will be able to confirm that the brake is fully released.
springRotate the bolt head 142 if you want to place it in the cage. The thread 152 rotates within the nut 144 and the nut 144 advances along the thread 152 as in the previous embodiment. At the same time, however, the thread 150 rotates within the outer nut 148 so that the thread 150 moves out of the housing. As the screw thread 150 moves, the bolt 142 and thus the nut 144 move. Thus, essentially, when the nut 142 is turned, the screw thread 150 causes the bolt 142 to move out of the housing. However, there is an amplitude of the nut 14 cage for the second thread 152. For this reason, the bolt 142 isspringIn order to achieve full cage placement, only a relatively small amount of movement relative to the outside of the housing is required as illustrated in FIG.
While preferred embodiments of the present invention have been disclosed, workers having ordinary skill in the art will recognize that certain changes may occur within the scope of the present invention. For that reason, the following claims must be studied to determine the true scope and content of this invention.

Claims (16)

A central housing;
An external brake housing (24) connected to the central housing, the external brake housing (24) receiving a spring between the central housing and the central housing;
The axially moving spring (28) to move the actuating member (34) axially outward of the central housing member and selectively actuate the brake;
A release structure comprising outer portions (41, 142) exposed to the outside of the external brake housing, wherein the spring does not push the actuating member outward of the central housing (22). The release structure that allows a spring to be captured and operable to capture the spring without axial movement of the outer portion relative to the external brake housing;
A structure (70) visible from the external brake housing to provide an indication of whether the release structure is fully released ;
The release structure includes a threaded bolt, the outer portion (41) is a portion of the bolt projecting from the external brake housing, and the release structure is disposed within the external brake housing. A spring brake actuator having at least one nut (42) capable of meshing with a threaded portion of a bolt and a small spring that presses the nut against the bolt and catching the spring with the nut . The spring brake actuator of claim 1, wherein the spring is received on a spring piston (36) coupled to a diaphragm, and the diaphragm is fixed between the external brake housing and the central housing. The spring brake actuator of claim 1, wherein the spring is received on a piston type actuator member (90) and the piston moves within the external brake housing. The actuating member is a push rod (92) comprising a hollow bore extending over at least a portion of its entire length along its axis, wherein at least a portion of the release structure extends into the hollow bore. Item 2. The spring, brake, and actuator according to Item 1. The spring brake according to claim 1, wherein the outer portion is a portion extending from an external brake housing of the bolt, and the bolt does not move axially relative to the external brake housing when the spring is captured.・ Actuator. 6. The indicator of claim 5 , wherein the release structure comprises an indicator that extends out of the external brake housing when the release structure is not fully released, but is retracted inward when the release structure is released. Spring, brake and actuator. The spring-brake actuator of claim 1, wherein the release structure moves axially such that the display is invisible toward the external brake housing during capture of the spring. The threaded bolt comprises a bolt having two threaded portions, the threads on the two threaded portions extend in opposite directions, and the thread is The spring brake actuator of claim 1 wherein each of said portions is received within a nut. A central housing;
An external brake housing connected to the central housing, the external brake housing receiving a spring between the central housing;
Moving the actuating member (92, 112) axially outwardly of the central housing and selectively moving the spring (88) to actuate the brake;
A release tool structure having a first portion and a second portion, said first portion worth, is exposed from the outer brake housing, outwardly of the spring the actuating member said central housing The first portion is rotated relative to the external brake housing to capture the spring so that the second portion (98) is rotated when the first portion is rotated. A spring brake actuator comprising a release tool wherein the second portion is selectively engaged with the first portion such that the second portion is moved axially to capture the spring. A central housing defining a gap for the passage of the push rod (146);
A push rod that selectively extends through the gap;
An external brake housing connected to the central housing and constituting a spring chamber;
An actuator member (90) capable of engaging and moving the push rod;
A spring (88) for selectively moving the actuator member and the push rod with respect to the outside of the gap;
The push rod to move through the gap selectively or put the spring cage, a release tool for preventing movement of said spring, said release tool is completely cage being movable between entering position and a fully released position, in order to put the spring cage comprises a part member in the spring chain bar, the axially outward of the outer brake housing When the release tool is moved, the resulting of the member in the spring chain bar movement is amplified, it requires the release tool in the spring chain bar moves extensively to the outer of the brake housing A release tool that is larger than the movement of the release tool ,
A spring brake, wherein the release tool comprises a bolt, the bolt is a bolt having a plurality of threaded portions, and a member in the spring chamber is a nut that is received on the threaded portion of the bolt; Actuator. The bolt comprising a first and a portion where the second threaded was cut (150, 152), said first threaded portion (150), threaded in the outer brake housing is turned off external extended in a first direction to be received within the nut (148), a portion where the second threaded was cut (152) is, according to claim 10 comprising a screw thread that extends in a direction different from the first direction Spring brake actuator. 12. The nut of claim 11 , wherein the nut is received in a bore in the push rod and the nut is restrained from rotation relative to the push rod, but freely moves along an axis in the push rod. Spring, brake and actuator. 13. The spring brake actuator according to claim 12 , wherein an outer diameter of the second threaded portion is smaller than that of the first threaded portion. The spring brake actuator of claim 13 , wherein the actuator member comprises a piston. The spring brake actuator according to claim 11 , wherein the second threaded portion has a smaller outer diameter than the first threaded portion. A member (144) in the spring chamber (30) is received in a bore in the push rod and the member (144) in the spring chamber (30) is restrained against rotation relative to the push rod. 11. A spring brake actuator according to claim 10 , wherein the spring brake actuator moves freely along an axis within the push rod.

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