US 6,681,682 B2 · Hydraulic cylinder

Abstract

A single-acting type hydraulic cylinder which is operated to be expanded and contracted by supply and discharge of liquid pressure from a so-called bottom side, in which the desired operation is permanently secured without bringing forth abrasion of a bushing or damage of a dust seal caused by rust or scratching in the outer circumference of a rod body. A hydraulic cylinder which is operated to be expanded and contracted by supply and discharge of liquid pressure P to a liquid chamber R partitioned on the bottom side within a cylinder body 1, characterized in that a head member 4 forming an open end of the cylinder body 1 is provided with a lubrication means 7 in sliding contact with the outer circumference of a rod body 3 and an oil seal 8 in series between a bushing 5 and a dust seal 6.

Drawings

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Drawings

Claims5

Dependent claims

A hydraulic cylinder comprising:

a cylinder body;
a head member mounted to an end portion of said cylinder body, said head member having an inner circumference;
a dust seal mounted at an axial end of said head member;
a bushing, said bushing and said dust seal being provided in series arranged on said inner circumference of said head member with said bushing disposed axially inwardly of said dust seal;
a piston in said cylinder body;
a rod body slidably inserted into said cylinder body and through said bushing and through said dust seal with an end connected to said piston, said piston partitioning the inside of said cylinder body into an air spring chamber on a rod side and a liquid chamber on a counterrod side, said rod body extending from said cylinder toward an expanded position upon a supply of liquid pressure to the liquid chamber and returning to a contracted position upon a cancellation of liquid pressure, said head member having a first inner circumferential groove and a second inner circumferential groove in series along an axial direction of said inner circumference of said head member and between said bushing and said dust seal;
lubricating material stored in said first inner circumferential groove adjacent to said bushing and between said bushing and said dust seal;
and
an oil seal provided in said second inner circumferential groove adjacent to said dust seal.

6 more elements

Dependencies are inferred from the claim text.

Description2,804 words

Summary1,123 words

#The present invention relates to a hydraulic cylinder, and particularly to an improvement in a single-acting type hydraulic cylinder suitable for use with a forklift.

#In the past, a single-acting type hydraulic cylinder for a forklift is operated to be extended, for example, as shown in FIG. 2, when liquid pressure P is supplied from the outside to a liquid chamber R which is a chamber on the counter rod side partitioned by a piston 2 slidably inserted into a cylinder body 1.

#Further, the hydraulic cylinder is operated to be contracted when a supply of liquid pressure P to the liquid chamber R is released whereas a rod body 3 having a proximal end connected to the piston 2 gets into the cylinder body 1 due to own weight or load exerting on the extreme end to contract the liquid chamber R through the piston 2.

Brief description of the drawings2 figures

#The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its uses, reference is made to the accompanying drawings and descriptive matter in which a preferred embodiment of the invention is illustrated.

#In the drawings:

#FIG. 1 is a partly cutaway cross sectional view of a hydraulic cylinder according to one embodiment of the present invention; and

Detailed description1,579 words

#Referring to the drawings in particular, the present invention will be described on the basis of an embodiment shown in the figure. As shown in FIG. 1, the hydraulic cylinder according to the present invention is also constituted fundamentally similar to the aforementioned conventional hydraulic cylinder, which is set to a single-acting hydraulic cylinder operated to be expanded and contracted by a supply and discharge of liquid pressure P from so-called bottom side.

#Therefore, in the following description, with respect to the constitution similar to that of the prior art shown in FIG. 2, parts thereof are designated by the same reference numerals in the figure except those as necessary, details of which are omitted.

#That is, in the hydraulic cylinder according to the present invention, a bushing 5 is provided in the inner circumference inside a cylinder body 1 in a head member 4, and a dust seal 6 is provided in the inner circumference of an open end in the head member 4. A lubrication means 7 and an oil seal 8 are provided in series between the bushing 5 and the dust seal 6, that is, in series in an axial direction of a rod body 3.

Facts

Application

09/901,872Filed 9 Jul 2001

Published

US 2001/0047719 A16 Dec 2001

Granted

27 Jan 2004

Term ended

9 Jul 2021

Estimated · how

20 years from earliest known nonprovisional domestic filing plus recorded patent term adjustment. Maintenance-fee lapses, terminal disclaimers and statutory extensions have not been checked. The continuity chain may be incomplete; this is not an enforceability determination.

Classification2 codes

F15B 15/1433
Component parts; Constructional details: end caps
F15B
Systems acting by means of fluids in general

Timeline

9 Jul 2001Application filedUS 09/901,872
9 Jul 2001Assigned to Kayaba Kogyo Kabushiki Kaishaassignment of assignor's interest
6 Dec 2001PublishedUS 2001/0047719 A1
27 Jan 2004GrantedUS 6,681,682 B2
21 Dec 2015Assigned to Kyb Corporationchange of name
9 Jul 2021Term endedEstimated

Hydraulic cylinder

Life of this patent

Hydraulic cylinder

Life of this patent

Life of this patent

Abstract

Drawings

Drawings

Claims5

Description2,804 words

Drawings

Classification2 codes

Life of this patent

Description2,804 words