AU718408B1 - Jack - Google Patents

Description

S F Ref: 441869

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

ORIGINAL

Name and Address of Applicant: Actual Inventor(s): Address for Service: Invention Title: Trimax Associates Chan Yeh Co., Ltd.

22, Industries 2nd Road Shing Nan Tsun, Min Shyong Shing Chia-Yi Hsien

TAIWAN

Min-Yuan Kuan Spruson Ferguson, Patent Attorneys Level 33 St Martins Tower, 31 Market Street Sydney, New South Wales, 2000, Australia Jack The following statement is a full description of this invention, including the best method of performing it known to me/us:- 5845

JACK

BACKGROUND OF THE INVENTION Nowadays a wide variety of jacks are used, including air pressure ones, and oil pressure ones. A common disadvantage of traditional jacks is their low speed in lowering down, after having been raised.

Referring to Figs. 6, 7 and 8, a jack includes a main body 12, a valve 18 and a pump 17. The jack can be applied in a pipe bender as shown in Figs. 7and 8. A shaping member 13 is connected to the jack.

A set of rollers 15 are disposed above the jack with a pipe 14 in between. When the pump 17 is operated to raise the jack 12, the shaping member 13 is forced to bend the pipe 14 disposed there -above.

When the valve 18 is operated to lower down the jack, the bent pipe can be replaced with a straight pipe for another bending action.

However, the speed of lowering down the jack is generally too low to meet manufacturer's demand. That is to say, there is a need for a jack having higher lowering down speed in order to increase the efficiency in processing or manufacturing.

It is the object of the present invention to substantially overcome or at least ameliorate one or more of the prior art disadvantages.

Summary of the Invention There is disclosed herein a jack comprising: a base member; a housing connected to said base member; an inner tubular housing disposed within said housing, with oil held between said inner tubular housing and an inner wall of said housing; a piston rod disposed within said inner tubular housing; a spring having a first end connected to a screw which is screwed into said piston rod, and a second end connected to a connecting rod fixed to said base member under said inner tubular housing to provide a downward pulling force to said piston rod; wherein said base member is associated with a pump and a valve such that oil can be pumped into said inner tubular housing to raise said piston rod by said pump, and let out of said inner tubular housing to lower down said piston rod by said valve; and said downward pulling force of said spring accelerates the lowering down of said piston rod.

When the pump is operated, the piston rod is raised by the oil pumped into the inner tubular housing. When the valve is operated, oil is let out of the tubular housing for permitting the piston to be lowered down, the spring accelerating the lowering of the piston rod. Thus, efficiency can be increased in using the jack in processing or manufacturing.

Brief Description of the Drawings Preferred forms of the present invention will now be described by way of examples only, with reference to the accompanying drawings, wherein: Fig. 1 is a perspective view of a jack of a preferred embodiment of the present invention with partially sectional view; Fig. 2 is a sectional view of a jack of the preferred embodiment; Fig. 3 is a sectional view of a jack of the preferred embodiment under upward movement of the piston rod; Fig. 4 is a view showing a jack of the preferred embodiment applied as pipe bender; Fig. 5 is a perspective view of a prior art jack as described in the background; Fig. 6 is a sectional view of a prior art jack as described in the background; Fig. 7 is a view showing a prior art jack applied as a pipe bender; and Fig. 8 is a view showing a prior art jack applied as a pipe bender under upward movement of the piston rod.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A jack of the present invention, referring to Figs. 1 and 2, comprises a housing 25, an inner tubular housing 22, a piston rod 2, a spring 3, a base member 23, a connecting rod 4, a valve 26, and a pump 24 as main parts.

The housing 25 is fixedly connected to the base member 23, and holds the inner tubular housing 22 therein with oil held within a room between inner wall of the housing 25, and the inner tubular housing 22.

The piston rod 2 is disposed within the inner tubular housing 22, and is connected to the spring 3 by a screw 21; the screw 21 connects an upper end of the spring 3, and is screwed into a threaded hole not numbered of the piston rod2.

The connecting rod 4 is fixed to the base member 23 under the inner tubular housing 22 such that a lower end of the spring 3 can be connected thereto. Thus, the spring 3 gives the piston rod 2 a downward pulling force.

The pump 24 is associated with the base member 23 such that it can be operated to pump oil from the housing 25 through a passage of the base member 23 into the inner tubular housing 22. The oil passage of the base member 23 is not a subject of the present invention so it is not detailed here.

The valve 26 is associated with the base member 23 such that it can be operated to permit the oil pumped into the inner tubular housing 22 to flow back into the housing In using the jack of the present invention, the pump 24 is operated as a prior art jack disclosed in the Background in order to raise the piston rod 2 by pumping oil into the inner tubular housing 22. When the valve 26 is operated to lower down the raised piston rod 2, the spring 3 will speed up the lowering down of the piston rod 2 by the pulling force upon the piston rod 2.

Referring to Fig. 4, the jack of the present invention is applied to bend a pipe; it can be easily known that more pipes can be bent per unit of time than a prior art jack can by reason that time consumed for the piston rod 2 to be lowered down is shortened.

From the above description, it can be understood that the jack of the present invention has following advantages.

1. The piston rod 2 can be easily and quickly moved to the original position after oil is released from the inner tubular housing 22 by the valve 26 even the jack is displaced horizontally because of the provision of the spring 3.

2. The jack of the present invention is more efficient in processing products, e.g. bending pipes, because time consumed for the piston rod 2 to be lowed down is shortened.

3. If the Valve 26 is adjusted such that small amount of oil is let out per unit of time, the spring 3 can make the piston rod 2 retreat slowly. That is to say, provision of springs can provide the jack with various retreating speed according to the user's demand.

Claims (1)

1. 2. A jack substantially as hereinbefore described with reference to Figs. 1 to 4 of the accompanying drawings. Dated 8 February, 2000 Trimax Associates Chan Yeh Co., Ltd. Patent Attorneys for the Applicant/Nominated Person SPRUSON FERGUSON [R:\LIBLL09197.doc:vjp