ES2373150B1 - IMPROVED GAS SPRING - Google Patents

Abstract

Enhanced gas spring. # This document describes a gas spring (1) comprising a rod (2) housed inside a hollow cylindrical body (3) closed at one end, forming an inner chamber prepared for filling with a gas. The fundamental characteristic of this new spring (1) is that it also includes a presence sensor (10) capable of detecting the rod (2) in its resting position, so that an operator can receive information about the condition of the springs ( 1) gas at all times and thus prevent potential problems caused by hooks or seizures that may cause uncontrolled release of the springs (1).

Description

Sions that are reached in the chamber.

Enhanced gas spring.

Object of the invention

The object of the present invention is an improved gas spring with the incorporation of a rod presence detector. Background of the invention

A gas spring is essentially formed by a movable rod along the inner chamber of a hollow cylindrical body. Thanks to the presence of a confined gas inside said chamber, the rod acts as a spring or spring: when, starting from a certain resting position, a force pushes the rod into the chamber, the gas is compressed and opposes a growing force with displacement; when the force on the rod ceases, the pressure of the gas returns the rod to its resting position. Due to the large amount of energy accumulated by the compression of the gas, the expansion of the rod must be carried out in a controlled manner to avoid irreversible damage to the spring.

Gas springs have been used for some time in different industries, such as sheet metal stamping processes, such as elastic force limitation elements. However, sometimes problems occur in the stamping, for example the seizure of a piece, which causes a rod to be compressed, with the danger of being released at an inappropriate time and the dangerous free expansion of the rod occurs. This can cause damage to both the gas spring itself and elements of the stamping machinery.

Currently, there is no system that indicates that a gas spring could be compressed when it should be extended, and that it can help prevent these inconveniences. Description of the invention

The invention describes a gas spring comprising a rod housed inside a hollow cylindrical body closed at one end, forming an inner chamber prepared for filling with a gas, the spring of the invention also comprising a presence sensor capable of detect the stem in its resting position. Thus, through an appropriately configured control panel an operator can receive information about the condition of the gas springs at any time to prevent potential problems.

There are essentially two types of gas springs, the so-called "piston seal" and conventional ones. The "piston-closing" springs have the gas seal fixed to the lower area of the rod. That is, the gas seal moves with the rod, so that when it descends to a retracted position, the free space that is formed in the staggering region of the rod above the seal is free of gas. In this case, it is not necessary for the presence sensor to maintain tightness. On the other hand, conventional springs, which are the most commonly used, have the seal fixed to the upper part of the outer cylindrical body, so that the free space described above is filled with gas when the rod is in the retracted position. In this second type of springs, therefore, they require that the presence sensor installation has a seal capable of ensuring the tightness, and also that the

The presence detector can be located in any way as long as it is able to detect the rod in its resting position. In a preferred embodiment, the sensor is fixed next to the edge of the cylindrical body by means of a connecting piece screwed to said cylindrical body, usually so that it is flush with the edge of the cylindrical body. Thus, when the rod is in the retracted position it is not detected by the sensor, it is only detected when it rises to its resting position.

On the other hand, the presence sensor can be of different types, such as inductive, ultrasonic, infrared, laser, etc., although inductive type sensors are preferably used. Brief description of the fi gures

Figs. 1a and 1b shows perspective sections of a conventional gas spring and a piston closing gas spring.

Fig. 2 shows a perspective of the upper edge of a piston closing gas spring provided with a presence sensor according to the invention.

Figs. 3a and 3b show sections of the rod and the spring presence sensor of Fig. 2 respectively in the rest and compressed position. Preferred Embodiment of the Invention

First, Fig. 1a shows a spring

(100) of conventional gas according to the prior art where it is appreciated how the rod (102) is housed inside the body (103) in a cylindrical shape closed at its lower end and closed at its upper end by a cover (107) integral with the body

(103) and that at the same time allows the sliding of the rod (102), leaving a chamber (105) where the gas is confined. As explained previously, when the rod (102) is subjected to a downward vertical force, the gas confined in the chamber (105) is compressed, offering increasing resistance to the descent of the rod (102). When the force on the rod (102) ceases, the expansion of the compressed gas in the chamber (105) returns the rod (102) to its resting position. The gasket (106), fixed to the cover (107), is the part responsible for sealing the gas in the chamber (105). It is noted that, when the rod (102) passes into its retracted position, a space will be created between said lid (107) and a lower flange of said rod (102), a space that in this spring (100) will be filled with gas. For the installation of a presence sensor to detect the rod (102) in the widening zone it would be necessary in this case to ensure the tightness, in addition to having a sensor capable of withstanding high pressures.

Fig. 1b, on the other hand, represents a spring

(200) of piston seal gas according to the prior art. You can see how in this case the packing

(206) is integral with the rod (202) or piston, so that the space that remains above the broadening of the rod (202) has no gas. In this case, therefore, it is easier to install a sensor that detects the presence or not of said widening, since it is not critical to maintain the tightness.

Fig. 2 shows an example of the invention applied to a piston closure sensor. A perspective view of the upper end of a piston closing gas spring (1) provided with a presence sensor (10) is seen in the figure. The presence sensor (10) is coupled to a connecting piece (11), which a

3 EN 2373150A1 4

in turn it is fixed to the cylindrical body (3) by means of a screw (12), being flush with the edge of said cylindrical body (3).

Figs. 3a and 3b show two sections of the presence sensor (10) when the rod (2) is respectively in the rest position or in a compressed position. Specifically, it is observed in Fig. 3a how the rod (2) is provided with a widening or step which, when the rod (2) is in the rest position, is very close to the detector

(10) at a distance less than its detection range, for example 2 mm. When the rod (2) passes into a compressed position, however, the widening or step away, leaving the detection range of the sensor (10).

It is obvious to think that a stamping team

or of any other type could incorporate this type of gas springs (1) and connect the presence sensors (10) to a control panel, from where an operator would have all the information about the state of each spring (10).

5 EN 2373150A1 6

Claims (5)

1. Improved gas spring (1), comprising a rod (2) housed inside a hollow cylindrical body (3) closed at one end, forming an inner chamber prepared for filling with a gas, characterized in that it also comprises a sensor (10) of presence capable of detecting the rod (2) in its resting position. 2. Improved gas spring (1) according to claim 1, wherein the presence sensor (10) is fixed next to the edge of the cylindrical body (3) by means of a connecting piece (11) screwed to the edge of said cylindrical body (3).

3.

Improved gas spring (1) according to claim 2, wherein the connecting piece (11) is flush with the edge of the cylindrical body (3).

Four.

Enhanced gas spring (1) according to any of the preceding claims, wherein the sensor

(10) Presence is inductive.  ES 2 373 150 A1    ES 2 373 150 A1    ES 2 373 150 A1   SPANISH OFFICE OF THE PATENTS AND BRAND Application no .: 201031091 SPAIN Date of submission of the application: 16.07.2010 Priority Date: REPORT ON THE STATE OF THE TECHNIQUE 51 Int. Cl.: F16F9 / 02 (2006.01) RELEVANT DOCUMENTS

Category

Documents cited Claims Affected

X

US 2003019699 A1 (DOHRMANN WOLFGANG) 01/30/2003, one

paragraphs [0002,0007,0008,0010-0012,0016-0019]; Figure 1.

Y

2-4

Y

ES 1051782 U (ZERTAN S A) 10/01/2002, column 1, line 3; column 3, line 15 - column 4, 2-4

line 16; Figures 1,2,5,6.

Category of the documents cited X: of particular relevance Y: of particular relevance combined with other / s of the same category A: reflects the state of the art O: refers to unwritten disclosure P: published between the priority date and the date of priority submission of the application E: previous document, but published after the date of submission of the application

This report has been produced • for all claims • for claims no: ALL

Date of realization of the report 18.11.2010

Examiner M. Fernández Rodríguez Page 1/4

REPORT OF THE STATE OF THE TECHNIQUE Application number: 201031091 CLASSIFICATION OBJECT OF THE APPLICATION Minimum documentation sought (classification system followed by classification symbols) F16F Electronic databases consulted during the search (name of the database and, if possible, terms of search used) INVENES, EPODOC State of the Art Report Page 2/4  WRITTEN OPINION Application number: 201031091 Date of Written Opinion: Statement

Novelty (Art. 6.1 LP 11/1986)

Claims Claims 2-4 1 IF NOT

Inventive activity (Art. 8.1 LP11 / 1986)

Claims Claims 1-4 IF NOT

The application is considered to comply with the industrial application requirement. This requirement was evaluated during the formal and technical examination phase of the application (Article 31.2 Law 11/1986).  Opinion Base.- This opinion has been made on the basis of the patent application as published. State of the Art Report Page 3/4  WRITTEN OPINION Application number: 201031091 1. Documents considered.- The documents belonging to the state of the art taken into consideration for the realization of this opinion are listed below.

Document

Publication or Identification Number publication date

D01

US 2003019699 A1 (DOHRMANN WOLFGANG) 01/30/2003

D02

ES 1051782 U (ZERTAN S A) 01.10.2002

2. Statement motivated according to articles 29.6 and 29.7 of the Regulations for the execution of Law 11/1986, of March 20, on Patents on novelty and inventive activity; quotes and explanations in support of this statement The object of the invention is an improved gas spring, with sensor. Claim 1 has the following technical characteristics: Improved gas spring (1), such that it comprises a rod (2) housed inside a hollow cylindrical body (3) closed at one end, forming an inner chamber prepared for filling with a gas, also includes a sensor (10) of presence capable of detecting the rod (2) in its resting position. (References in parentheses correspond to the application document). Document D01 anticipates these characteristics by disclosing an improved gas spring, which comprises a rod (2) housed inside a hollow cylindrical body (1) closed at one end, forming an inner chamber prepared for its filling with a gas, also includes a presence sensor (13) capable of detecting the rod (2) in its position of repose. (References in parentheses correspond to document D01). Therefore, the spring described in claim 1 is not new (Art.6 L11 / 86). Claim 2, dependent on R1, adds the following characteristics to the spring: where the presence sensor (10) is fixed next to the edge of the cylindrical body (3), by means of a connecting piece (11) screwed to the edge of said cylindrical body (3). (References in parentheses correspond to the application document). Document D01 discloses the presence of a sensor connected externally to the spring. Therefore, the technical effect to to look for is the incorporation of the sensor in the spring body; and the underlying technical problem consists of integration a piece, in which the sensor is inserted, in the spring, by means of a screwed connection. Document D02 discloses a sensor inserted in a watertight one piece that allows its incorporation by screw connection (ref. 13, 14, D02) to another body where it has to act. It would be obvious to a person skilled in the art to replace the anti-doping sensor in D01 with the sensor disclosed in the document D02 for obtaining the sensor spring defined in claim 2. Therefore, it is considered that the Claim 2 does not imply inventive activity (Art. 8 L11 / 86). Claim 3, dependent on R2, states that it is a spring where the connecting piece (ref.11, application) It is flush with the edge of the cylindrical body (ref. 3, application). It is considered an obvious design option for a person skilled in the art that the joint is flush with the edge of the cylindrical body. Therefore, claim 2 has no inventive activity (Art. 8 L11 / 86). Claim 4, dependent on any of the preceding claims, states that it is a spring wherein the Presence sensor (ref. 10, request) is inductive. Document D02 anticipates disclosing an inductive type sensor. Therefore, claim 4 has no inventive activity (Art. 8 L11 / 86). State of the Art Report Page 4/4