PRESSURE RELIEF VALVE

A pressure relief valve for a height adjustment seat post including a lower housing, a stanchion telescopically supported within the lower housing, and a cartridge including a piston rod driven by a piston to telescopically adjust the stanchion relative to the lower housing includes a pressure relief port in the piston of the height adjustment seat post, a pressure relief valve ball, and a pressure relief valve spring to bias the pressure relief valve ball to a closed position to close the pressure relief port.

BACKGROUND

The present disclosure relates generally to a pressure relief valve and, more specifically, relates to a pressure relief valve for a height adjustment seat post for a saddle of a bicycle.

DETAILED DESCRIPTION

FIGS.1,2,3illustrate an example of a height adjustment seat post10for a saddle of a bicycle in accordance with the present disclosure. In examples, the height adjustment seat post10includes a lower housing12, a stanchion14telescopically supported within the lower housing12, and a cartridge6supported within the lower housing12and the stanchion14to telescopically adjust the stanchion14relative to the lower housing12. In examples, the cartridge6includes a piston16and a piston rod15driven by the piston16to telescopically adjust the stanchion14relative to the lower housing12. In examples, a saddle clamp assembly18is secured to the stanchion14, for example, by a lock ring17, to support a saddle for a bicycle (such as, for example, the saddle20for the bicycle1ofFIG.8). In examples, an end of the cartridge6is retained within the lower housing12by a snap ring11, and an end of the piston rod15is secured to an end of the stanchion14by an upper cap13. In examples, an air cap19covers the end of the height adjustment seat post10.

FIGS.4,5,6,7a,7billustrate an example of a pressure relief valve100for a height adjustment seat post in accordance with the present disclosure, such as, for example, the height adjustment seat post10. In examples, the pressure relief valve100includes a pressure relief port161in a piston160of the height adjustment seat post (e.g., the piston16of the height adjustment seat post10), a pressure relief valve ball120, and a pressure relief valve spring140to bias the pressure relief valve ball120to a closed position to close the pressure relief port161in the piston160. In examples, the pressure relief port161is provided in a center of the piston160.

In examples, the piston160is positioned within a cylinder62of a cartridge60of the height adjustment seat post (e.g., the cartridge6of the height adjustment seat post10), and a piston seal O-ring65provides a seal between the piston160and a cylinder wall63of the cylinder62. In examples, a reservoir64is provided between the cylinder wall63of the cylinder62and a housing61of the cartridge60. In examples, a cylinder cap66caps an end of the cartridge60between the housing61and the cylinder wall63.

In examples, a piston rod150of the height adjustment seat post (e.g., the piston rod15of the height adjustment seat post10) extends from the piston160. In examples, a piston rod coupler170couples the piston rod150with the piston160.

In examples, the pressure relief port161is communicated with the cylinder62of the cartridge60of the height adjustment seat post (e.g., the cartridge6of the height adjustment seat post10) such that increased pressure (fluid pressure) in the cylinder62(Pcylinder>Pcritical) forces the pressure relief valve ball120to an open position (against a bias force of the pressure relief valve spring140) to open the pressure relief port161in the piston160and release the increased pressure. In examples, the increased pressure is released by releasing fluid (oil) in the cylinder62through the pressure relief port161in the piston160to the reservoir64within the cartridge60of the height adjustment seat post (e.g., the cartridge6of the height adjustment seat post10).

In examples, as illustrated in the example ofFIG.4, in a default state, the pressure relief valve100is closed. More specifically, in examples, the pressure relief valve ball120is biased to the closed position by the pressure relief valve spring140to close the pressure relief port161in the piston160.

In examples, as illustrated in the example ofFIG.5, in a pressure relief state, the pressure relief valve100is open. More specifically, in examples, the pressure relief valve ball120is forced to the open position (against the bias force of the pressure relief valve spring140) by increased pressure (fluid pressure) in the cylinder62(Pcylinder>Pcritical) to open the pressure relief port161in the piston160.

In examples, with reference to the example ofFIG.6, with a height adjustment seat post for a saddle of a bicycle in accordance with the present disclosure, such as, for example, the height adjustment seat post10, a column of fluid inside the cylinder62supports the weight of a rider. In examples, pressure of fluid inside the cylinder (Pcyl) will increase as load on the saddle increases. In examples, excessive pressure within the cylinder62could potentially damage components. To help avoid this, in examples, once the pressure of fluid inside the cylinder (Pcyl) reaches a critical pressure (Pcrit), the pressure relief valve100will open, allowing fluid to escape into the reservoir64. In examples, excessive pressure within the cylinder62could result from load spike on the saddle, or due to thermal expansion of fluid inside the cylinder62.

In examples, as illustrated in the example ofFIG.7a, pressure of fluid inside the cylinder (Pcyl) is less than the critical pressure (Pcrit). As such, the pressure relief valve100is in the closed position. More specifically, in examples, the pressure relief valve ball120is biased to the closed position by the pressure relief valve spring140to close the pressure relief port161in the piston160.

In examples, as illustrated in the example ofFIG.7b, pressure of fluid inside the cylinder (Pcyl) is greater than the critical pressure (Pcrit). As such, the pressure relief valve100is in the open position. More specifically, in examples, the pressure relief valve ball120is forced to the open position (against the bias force of the pressure relief valve spring140) to open the pressure relief port161in the piston160. Accordingly, in examples, pressure within the cylinder62is released by releasing fluid (oil) in the cylinder62through the pressure relief port161in the piston160to the reservoir64.

In examples, as illustrated by arrows101and103in the example ofFIG.7b, and with reference to the example ofFIG.7a, pressure within the cylinder62is released by releasing fluid (oil) in the cylinder62to the reservoir64through the pressure relief port161in the piston160, through a seat163for the pressure relief valve ball120in the piston160, around the pressure relief valve ball120, through a seat165for the pressure relief valve spring140in the piston160, through a seat171for the pressure relief valve spring140in the piston rod coupler170, through one or more than one passage173in the piston rod coupler170, through a passage175between the piston rod coupler170and the cylinder wall63, and through one or more than one passage177in the cylinder cap66to the reservoir64.

FIG.8illustrates an example implementation of a pressure relief valve for a height adjustment seat post for a saddle of a bicycle1in accordance with the present disclosure, such as, for example, the height adjustment seat post10for the saddle20. In examples, a control device2may be mounted on a bicycle (e.g., a handlebar of a bicycle), such that operation or actuation of the control device2may be used to apply pull to an actuation or control cable4coupled with a height adjustment seat post for a saddle of a bicycle, such as, for example, the height adjustment seat post10for the saddle20. In examples, the height adjustment seat post includes a pressure relief valve in accordance with the present disclosure, such as, for example, the pressure relief valve100.

A pressure relief valve as disclosed herein, such as, for example, the pressure relief valve100, provides for release (controlled release) of increased pressure within a height adjustment seat post for a saddle of a bicycle, such as, for example, the height adjustment seat post10, to avoid potential damage to components of the height adjustment seat post.