US 2002/0158508 A1Published application

Pneumatic booster

AssigneeTokico Ltd.

InventorShuzo Watanabe

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Abstract

A tandem pneumatic booster includes a front shell having a relatively long cylindrical portion and a rear shell having a relatively short cylindrical portion. The cylindrical portions of the front and rear shells are joined together to form a shell body. An opening edge of a cylindrical portion of a center shell is disposed in the joint between the front and rear shells, together with an outer peripheral bead of a diaphragm of a rear power piston. The cylindrical portion of each of the front, rear and center shells has a frusto-conical shape gradually increasing in diameter toward the opening edge thereof. Thus, when front shells, rear shells and center shells are stacked on one another, respectively, as constituent parts before assembly, the depth of fitting between each pair of adjacent shell elements is increased sufficiently to maintain the stacked conditions of the shell elements stably.

Claims17

Dependent claims

A pneumatic booster comprising:

a front shell element having a bottom portion and an outer cylindrical portion extending from an outer edge of said bottom portion, said front shell element further having an inner cylindrical portion projecting from said bottom portion in a same direction as a direction of extension of said outer cylindrical portion to receive a master cylinder;
a rear shell element engaging with said outer cylindrical portion of said front shell element to close an opening edge of said outer cylindrical portion to form a shell body;
a valve body provided to extend through said rear shell element, said valve body having a valve mechanism therein;
and
at least one power piston engaged with said valve body to divide an interior of said shell body into a plurality of chambers;
wherein said outer cylindrical portion of said front shell element has at least one reduced-diameter portion smaller in diameter than said opening edge, and said inner cylindrical portion of said front shell element has at least one reduced-diameter portion smaller in diameter than a proximal end edge of said inner cylindrical portion at said bottom portion, so that when a plurality of said front shell elements as constituent parts before assembly are stacked on one another, both the outer cylindrical portions and the inner cylindrical portions of adjacent front shell elements are fitted In each other, respectively.

3 more elements

A pneumatic booster comprising:

a front shell element to which a master cylinder is to be mounted;
a rear shell element having a bottom portion and an outer cylindrical portion extending from an outer edge of said bottom portion, said rear shell element further having an inner cylindrical portion projecting from said bottom portion in a direction opposite to a direction of extension of said outer cylindrical portion;
a valve body provided to extend through said inner cylindrical portion of said rear shell element, said valve body having a valve mechanism therein;
and
at least one power piston engaged with said valve body to divide Into a plurality of chambers an interior of a shell body which is formed by said front shell element and said rear shell element,
wherein said outer cylindrical portion of said rear shell element has at least one reduced-diameter portion smaller In diameter than an opening edge of said outer cylindrical portion, and said inner cylindrical portion of said rear shell element has at least one reduced-diameter portion smaller in diameter than a proximal end edge of said inner cylindrical portion at said bottom portion, so that when a plurality of said rear shell elements as constituent parts before assembly are stacked on one another, both the outer cylindrical portions and the inner cylindrical portions of adjacent rear shell elements are fitted in each other, respectively.

3 more elements

Dependencies are inferred from the claim text.