Compensation system for gas spring

Abstract

The invention relates to a compensation system (100) for a gas spring (10) equipped with a fixed cylinder (1) adapted to contain a gas and a movable rod (2) configured to slide relative to the cylinder (1) to move the spring (10) from an extended configuration to a compressed configuration; the compensation system (100) is adapted to be housed inside the spring (10) and comprises:-a compensation chamber (11, 21) closed by a sliding wall inside the chamber (11, 21) such that, in an extended configuration, the gas housed in the cylinder (1) is located outside the chamber (11, 21) and, in a compressed configuration, the gas housed in the cylinder (1) occupies the first chamber (11, 21). The invention further relates to a gas spring comprising the compensation system.

Description

Technical Field

[0001] The present invention relates to a compensation system for a gas spring.

[0002] The present invention belongs to the technical field of industrial springs, particularly to the technical field of gas springs. Background Art

[0003] Generally, a gas spring includes a fixed outer body (referred to as a cylinder or a sheath) and a movable body (also referred to as a rod).

[0004] More specifically, the gas spring is configured to allow the rod to slide into the fixed outer body through a suitable opening and passage (Figures 1A, 1B, 2A, 2B).

[0005] In addition, the gas spring includes one or more sealing elements, a guiding device for the rod, and a component for injecting gas (also referred to as a filling valve or a loading valve).

[0006] According to the prior art, gas springs can change their configuration from an extended configuration to a compressed configuration. In the extended configuration, the rod moves away from the fixed outer body to reach the maximum stroke of the rod (Figures 1A, 2A), and in the compressed configuration, the rod is fully received in the fixed body (Figures 1B, 2B).

[0007] Gas springs on the market can also reach very high initial pressure values.

[0008] However, once compressed, the spring generates an internal force proportional to the initial force and the compression ratio. In other words: the pressure inside the spring increases, increasing the risk of accidents.

[0009] In fact, nowadays, one of the most important aspects in this field is the aspect related to the safety of these devices.

[0010] For example, defects that cannot be detected by visual inspection do not allow the user to identify a defective gas spring, and thus do not allow preventive measures to be implemented, such as replacing damaged components or the entire spring.

[0011] Specifically, when the gas spring is in the extended configuration, the gas spring has an initial pressure, and when the spring itself is in the compressed configuration, the spring has a final pressure.

[0012] For simplicity, assuming an isothermal transformation, when the spring is in the compressed configuration and thus the volume available for the internal gas is small, the spring will have a higher internal pressure.

[0013] If this value reaches a very high value, it will pose an additional risk to the user and increase the wear sources of the gas spring, particularly increasing the wear sources of the sealing system.

[0014] All these problems are usually the cause of accidents and sudden incidents, and for these incidents, the staff and operators near the spring face considerable risks.

[0015] In addition, the increase in pressure involves an increase in the force required to compress the spring by the machine applying the spring, resulting in an increase in energy consumption and a significant increase in cost.

[0016] Due to the difficulty in evaluating the evolution of these phenomena, the industry strongly believes that it is necessary to ensure sufficient safety conditions regardless of the technology available to the operators in this industry.

[0017] In particular, one of the most obvious needs is to reduce the compression ratio ρ of the gas spring to obtain a safe but at the same time high-quality spring.

[0018] More specifically, the compression ratio ρ is given by the ratio between the initial volume occupied by the gas when the spring is in the extended configuration and the final volume occupied by the gas when the spring is in the compressed configuration.

[0019] There is an external compensation system that provides the connection of a series of springs in order to balance the pressure inside them and reduce the compression ratio.

[0020] However, this solution involves high costs and a significant increase in the overall size of the system, and the consequences are obvious. Summary of the Invention

[0021] Therefore, the object of the present invention is to provide a compensation system for a gas spring that can solve the above-mentioned drawbacks and key problems.

[0022] In particular, the object of the present invention is to create a gas spring that has a reduced compression ratio ρ inside compared to traditional springs.

[0023] Another object of the present invention is to create a gas spring with a reduced compression ratio that is easy and economical to produce and install.

[0024] Finally, the ultimate object of the present invention is to provide a gas spring with increased use safety and effective applicability.

[0025] These objects and other objects are achieved by a compensation system for a gas spring according to the independent claims attached.

[0026] Accordingly, the object of the present invention is a compensation system for a gas spring, which is equipped with a cylinder and a rod. The cylinder includes a fixed body that is hollow and adapted to contain the gas, and the rod includes a hollow movable body that is configured to slide along the cylinder to allow the spring to move from an extended configuration to a compressed configuration. The compensation system is adapted to be housed inside a spring of this type and includes a first sliding wall adapted to define a first compensation chamber such that, in the extended configuration, the gas contained in the cylinder is outside the first chamber, and in the compressed configuration, the gas contained in the cylinder occupies the internal volume of the first chamber.

[0027] In particular, the compensation system includes a second compensation chamber that is closed by a second wall that slides along the second chamber itself such that, in the extended configuration, the gas contained in the cylinder is outside the first compensation chamber and the second compensation chamber, and in the compressed configuration, the gas contained in the cylinder occupies the respective internal volumes of the first compensation chamber and the second compensation chamber.

[0028] This advantageously allows increasing the efficiency of the spring while maintaining a relatively low compression ratio.

[0029] Preferably, the first chamber has a first volume, and the second chamber has a second volume that is greater than the first volume, and when the spring is in the compressed configuration, the first compensation chamber slides into the second compensation chamber to be completely housed within the second chamber.

[0030] In another embodiment of the compensation system, the first chamber coincides with the rod.

[0031] This involves a significant optimization of the space inside the spring.

[0032] Preferably, the compensation system includes a first piston that can be attached inside the spring and is configured to slide the first sliding wall along the first chamber.

[0033] Furthermore, the first piston is attached inside the spring by means of a floating constraint to allow the spring to maintain substantially the same degree of stiffness as a spring without a compensation system.

[0034] For example, the floating constraint can be a hinge that can be attached to the base of the spring.

[0035] In another embodiment, the compensation system includes a second piston that can be attached inside the spring and is configured to slide the second sliding wall along the second chamber, and the first chamber is formed inside the second piston.

[0036] Advantageously, in this way, the space of the spring can be utilized to the maximum extent.

[0037] Optionally, some sealing elements are inserted between the piston and the chamber to hold the piston in place.

[0038] Always optionally, the sealing element is inserted between the chamber and the cylinder block to hold the gas inside the spring and prevent the gas from occupying the chamber in the extended configuration.

[0039] Preferably, the sealing element is inserted between the first sliding wall and the inner wall of the chamber to prevent the gas from occupying the chamber in the extended configuration.

[0040] Furthermore, the object of the present invention also lies in a gas spring including such a compensation system.

[0041] Further detailed technical features are reported in the appended dependent claims. Description of the Drawings

[0042] Now, the present invention will be described by way of non-limiting example with reference to the accompanying drawings, in which:

[0043] - Figures 1A and 1B respectively show a gas spring in an extended configuration and a compressed configuration according to the prior art;

[0044] - Figures 2A and 2B respectively show another embodiment of a gas spring in an extended configuration and a compressed configuration according to the prior art;

[0045] - Figure 3A and Figure 3B respectively show a first embodiment of a gas spring in an extended configuration and a compressed configuration with an integrated compensation system according to the present invention;

[0046] - Figure 4A and Figure 4B respectively show a second embodiment of a gas spring in an extended configuration and a compressed configuration with an integrated compensation system according to the present invention;

[0047] - Figure 5A and Figure 5B respectively show a third embodiment of a gas spring in an extended configuration and a compressed configuration with an integrated compensation system according to the present invention.

[0048] Referring to the mentioned drawings, a preferred embodiment of the compensation system for a gas spring according to the present invention is shown. Detailed Description of the Invention

[0049] Referring to the drawings shown above, the compensation system for a gas spring, which is the object of the present invention, is denoted by the reference numeral 100, and the spring into which the compensation system is inserted is denoted by the reference numeral 10.

[0050] In a first embodiment, according to the present invention, the spring 10 comprises a fixed hollow body 1 or cylinder and a movable hollow body 2 or rod, the movable hollow body or rod having a recess opposite the cylinder 1.

[0051] The rod 2 is configured to slide into the cylinder 1, transitioning from an extended configuration or open configuration ( Figure 3A , Figure 4A , Figure 5A ) to a compressed configuration or closed configuration ( Figure 3B , Figure 4B , Figure 5B ).

[0052] Advantageously, the cylinder 1 and the rod 2 include respective inner lateral surfaces and respective inner base surfaces or bottoms, as will be better explained below.

[0053] In particular, the cylinder 1 includes a lateral surface and a base surface 61 or bottom denoted by reference numeral 51; the rod 2 includes corresponding lateral surface 52 and base surface 62 or bottom.

[0054] Advantageously, on the aforementioned lateral surfaces 51, 52 and on the base surfaces 61, 62, sealing elements, washers and / or other devices suitable for improving the performance of the spring 10 can be attached or connected.

[0055] More specifically, the lateral surfaces 51 and 52 laterally delimit the respective cylinder 1 and the respective rod 2.

[0056] Similarly, the base surfaces 61 and 62 are adapted to delimit the lower boundaries at the bottom of the respective cylinder 1 and the respective rod 2, acting as bases.

[0057] In addition, the cylinder 1 and the rod 2 have another corresponding open surface opposite the surfaces 61, 62 (depending on whether it is the cylinder 1 or the rod 2) to allow gas passage and communication between the cylinder 1 and the rod 2.

[0058] The cylinder 1 and the rod 2 are made in such a way that the rod 2 can be inserted into the cylinder 1 and can slide into the cylinder while maintaining contact between the outer part of the lateral surface 52 of the rod 2 and the inner part of the lateral surface 51 of the cylinder 1.

[0059] In addition, the cylinder 1 and the rod 2 include one or more chambers for accommodating gas inside the spring 10.

[0060] In particular, the lateral surface 51, the base surface 61 and the open surface delimit one or more chambers for accommodating gas inside the cylinder 1.

[0061] Even more specifically, the lateral surface 52, the base surface 62 and the open surface delimit one or more chambers for accommodating gas inside the rod 2.

[0062] Advantageously, the chamber for containing the gas includes one or more openings to allow the gas itself to pass through.

[0063] Also advantageously, in all embodiments of the spring, the spring 10 includes a plurality of washers 4 which are placed in suitable seats or housings in contact with the cylinder body 1 and the rod 2, thus ensuring that the rod 2 slides properly into the cylinder body 1 and preventing gas from leaking from inside the spring 10.

[0064] In particular, the washer 4 or the sealing element is designed to prevent the internal gas of the spring 10 from escaping when in its static condition and during the transition of the spring from the compressed configuration to the extended configuration, and vice versa.

[0065] Advantageously, in the first embodiment, as visible in Figure 3A and Figure 3B the plurality of washers 4 are arranged substantially corresponding to the open surface of the cylinder body 1.

[0066] In the second and third embodiments of the spring 10, as visible in Figure 4A , Figure 4B and Figure 5A , Figure 5B the plurality of washers are placed substantially corresponding to the respective seats in the open surface of the rod 2.

[0067] Also advantageously, the spring 10 includes a stroke end system or element 3 capable of preventing the rod 2 from sliding into the cylinder body 1.

[0068] More specifically, when the cylinder body 1 reaches its maximum stroke or maximum extension ( Figure 3A , Figure 4A , Figure 5A ), such a stroke end system or element 3 does not allow the rod 2 to separate from the cylinder body.

[0069] The present invention allows the compression ratio ρ to be reduced without changing the inherent and manufacturing parameters of the spring, such as the initial height and initial diameter, while ensuring an appropriate spring force.

[0070] Advantageously, in order to reduce the compression ratio ρ described later in this patent, a compensation system 100 is inserted inside the spring 10.

[0071] In particular, the compensation system 100 reduces the initial volume V1 available for the gas in the extended configuration, thus reducing the compensation ratio.

[0072] More specifically, such a compensation system 100 includes a sliding wall 101 which encloses the chamber 11 formed inside the rod 2.

[0073] In this particular embodiment, the sliding wall 101 is attached inside the spring by means of the piston 12, which in turn is attached internally to the cylinder 1.

[0074] In particular, the piston 12 has a "T" shape and, at its lower end (the stem of the "T"), the piston is attached to the base surface 61 of the cylinder 1, while at the opposite end (formed by the sliding wall 101), i.e., at the end with the greater extension or piston head, the piston is placed corresponding to the chamber 11 in order to seal against the inner wall of the aforementioned chamber 11.

[0075] Preferably, the lower end of the piston 12 is attached to the base 61 by means of a floating constraint 5 (such as a hinge or a connecting rod). This advantageously allows it to maintain substantially the same degree of stiffness as a spring without the compensation system 100 of the present invention.

[0076] Of course, the sliding wall can be attached inside the spring in various ways; the sliding wall seals along the inner wall (such as the inner wall of the rod) and is able to slide along this inner wall.

[0077] In an embodiment not shown, the sliding wall can be constrained to the spring base by a helical spring.

[0078] In a further embodiment not shown, the compensation system 100 can include a sliding wall 100 that is slidably constrained to other walls, which can be fastened to the base of the spring itself, for example, by screwing.

[0079] Advantageously, in order to hold the piston 12 in place, a sealing element is inserted between the piston 12 and the wall of the chamber 11.

[0080] Also advantageously, a sealing element is also arranged between the chamber 11 and the cylinder 1 to hold the gas inside the spring and prevent the gas from occupying the chamber 11 in the extended configuration.

[0081] Furthermore, always in order to prevent the gas from occupying the chamber 11 in the extended configuration, a sealing element can be inserted between the first sliding wall and the inner wall of the chamber 11.

[0082] In the embodiment under study, the chamber 11 is housed inside the rod 2 and can completely (first embodiment, Figure 3A and Figure 3B ) or partially (second and third embodiments, Figure 4A 、 Figure 4B and Figure 5A 、 Figure 5B ) occupy the internal volume of the rod 2.

[0083] Advantageously, in the second and third embodiments, the chamber 11 is made separately from the rod 2 and the chamber is integral with the rod.

[0084] Preferably, in these cases, the chamber 11 is also attached to the rod 2 by means of a floating restraint 5.

[0085] In operation, when the spring 10 moves from the extended configuration to the compressed configuration, the rod 2 slides along the cylinder 1 and the chamber 11 moves integrally with the rod 2.

[0086] When the spring 10 reaches the compressed configuration, the chamber 11 is fully inserted into the cylinder 1 and the internal volume of the chamber is completely occupied by the gas.

[0087] In particular, in the compressed configuration, the first sliding wall 101 contacts the bottom of the chamber 11.

[0088] In a second embodiment of the spring 10, as can be seen in Figure 4A and Figure 4B , different from the first embodiment, the cylinder 1 includes a second sliding wall 102 defining a second compensation chamber 21 to increase the initial volume that cannot be occupied by the gas when the spring 10 is in the extended configuration ( Figure 4A ).

[0089] Specifically, in the embodiment shown in Figure 4A and Figure 4B , the second chamber 21 has a larger size than the chamber 11 and is configured to accommodate the chamber 11 itself when the spring is in the compressed configuration ( Figure 4B ).

[0090] Advantageously, again in the foregoing embodiment, the compression ratio ρ is further reduced.

[0091] In a third embodiment ( Figure 5A and Figure 5B ), the spring 10 has the same characteristics as the first embodiment, except that the chamber 11 only occupies the central part of the internal volume of the rod 2 instead of the entire internal volume.

[0092] Advantageously, the device 100 occupies a very small volume of the final volume V2 of the spring 10, while the device reduces the initial volume V1 occupied by the gas by a significant value.

[0093] This allows the compression ratio ρ to be significantly reduced, possibly reaching a value of, for example, approximately 1.2 - 1.3, depending on the embodiment of the spring 10.

[0094] Also advantageously, the gas spring 10 ensures an important initial force, even including the compensation system 100.

[0095] In operation, when the spring 10 is in the fully extended configuration ( Figure 3A , Figure 4A , Figure 5A) When the rod 2 reaches its maximum stroke, and the spring 10 reaches its maximum height.

[0096] In the most common case during the working phase, the internal volume of the spring 10 reaches its maximum value, and thus the corresponding internal pressure will be at its minimum value.

[0097] Conversely, when the spring 10 is in the compressed configuration ( Figure 3B , 4B , 5B), that is, when the rod 2 is fully inserted into the cylinder 1, the internal volume is minimum, and the corresponding pressure reaches its maximum value.

[0098] In particular, the spring 10 is considered a closed system in which an isothermal transformation occurs, that is, in which the product between the volume and the pressure remains constant.

[0099] For this field, a fundamental and important parameter and characteristic is the compression ratio ρ, that is, the value given by the ratio between the initial internal volume V1 (extended configuration) and the final internal volume V2 (compressed configuration) of the spring 10.

[0100] More specifically, the initial internal volume V1 and the final internal volume V2 are respectively given by the internal volumes of the chambers of the cylinder 1 and the rod 2 in the extended configuration and in the compressed configuration.

[0101] This compression ratio ρ is an important parameter and also helps to understand the forces and risks characterizing the spring being analyzed.

[0102] More specifically, the higher the compression ratio ρ, the greater the pressure generated inside the compressed spring 10, and the higher the risk due to the release of the rod 2 in the case of breakage of the spring 10 itself.

[0103] In addition, such a high ratio ρ involves a greater energy consumption for compressing the spring 10.

[0104] More specifically, for example, a gas spring according to the prior art has a total height of 145 mm and a diameter of 75 mm in the extended configuration. This spring guarantees an initial force of 2385 daN at a pressure of 150 bar. The compression ratio ρ between the initial volume V1 and the final volume V2 of the aforementioned spring is 1.69, and in the compressed configuration, the final force is approximately 4030 daN.

[0105] The present invention is capable of achieving a better compression ratio than the springs on the market; in fact, the introduction of the new compensation system 100 enables a further reduced compression ratio compared to the existing solutions.

[0106] In particular, compared with the spring mentioned above with an initial height of 145 mm, a diameter of 75 mm, and a compression ratio ρ of 1.69, the system 100 can achieve a compression ratio ρ of 1.26.

[0107] For example, a conventional spring with a compression ratio ρ of 1.66, an initial force of 2494 daN, and a final force of 4139 daN, as shown in FIGS. 2A and 2B, can achieve a compression ratio ρ of 1.38 and initial and final forces of 2502 daN and 3452 daN, respectively, by means of the embodiment having the chamber 11 as shown Figure 5A Even in this case, although a smaller force is obtained, the advantage obtained from achieving a compensation ratio ρ of 1.38 is indeed significant.

[0108] Advantageously, in the embodiment having two chambers 11 and 21 as shown Figure 4A 、 Figure 4B the same spring 10 in the above situation achieves a compression ratio ρ of even 1.2, only slightly reducing the values of the initial and final forces of the spring 10 itself, and thus obtaining an even more satisfactory result.

[0109] From the above description, the features and advantages of the compensation system 100 for a gas spring, which is the object of the present invention, are clear.

[0110] Finally, it is clear that many other variations can be made to the device discussed without departing from the principle of novelty inherent in the idea of the present invention, since it is clear that in the actual implementation of the present invention, the materials, shapes, and dimensions of the details shown can be arbitrary according to needs, and they can be replaced by other equivalents.

[0111] In the case where reference numerals follow the features and techniques mentioned in any claim, the sole purpose of including such reference numerals is to increase the intelligibility of the claim, and thus, such reference numerals have no limiting effect on the interpretation of each element identified by these reference numerals by way of example.

Claims

1. A compensation system (100) for a gas spring (10), the gas spring being equipped with - a cylinder (1) comprising a fixed hollow body, the fixed hollow body being equipped with a first recess and adapted to contain the gas; - a rod (2) comprising a hollow movable body having a second recess opposite the first recess and configured to slide along the cylinder (1) to move the spring (10) from an extended configuration to a compressed configuration; The compensation system (100) is adapted to be received inside the spring (10) and comprises: - a first sliding wall (101) adapted to define a first compensation chamber (11, 21) inside the spring (10), such that in the extended configuration, the gas contained in the cylinder (1) is outside the first chamber (11, 21), and in the compressed configuration, the gas contained in the cylinder (1) occupies the first chamber (11, 21) The compensation system (100) is characterized in that the compensation system includes a second sliding wall (102) adapted to define a second compensation chamber (21), such that in the extended configuration, the gas contained in the cylinder (1) is outside the first compensation chamber (11) and the second compensation chamber (21), and in the compressed configuration, the gas contained in the cylinder (1) occupies the first compensation chamber (11) and the second compensation chamber (21), and the first compensation chamber (11) has a first volume, and the second compensation chamber (21) has a second volume greater than the first volume, and the first compensation chamber (11) slides into the second compensation chamber (21) so as to be completely received in the second chamber (21) when the spring (10) is in the compressed configuration.

2. The compensation system (100) according to claim 1, characterized in that, The first chamber (11) coincides with the rod (2).

3. The compensation system (100) according to claim 1 or claim 2, characterized in that, The compensation system includes a first piston (12) that can be attached inside the spring (10) and is configured to slide the first sliding wall (101) along the first chamber (11, 21).

4. The compensation system (100) according to claim 3, characterized in that, The first piston (12) is attached inside the spring (10) by means of a floating restraint (5) to allow the spring to substantially maintain the same degree of stiffness as a spring without the compensation system (100).

5. The compensation system (100) according to any one of claims 1 to 4, characterized in that, The compensation system includes a second piston that can be attached inside the spring (10) and is configured to slide the second sliding wall (102) along the second chamber (21), and the first chamber (11) is formed inside the second piston.

6. The compensation system (100) according to any one of claims 1 to 5, characterized in that, The compensation system includes a sealing element inserted between the first sliding wall (101) and the chamber (11) to hold the first sliding wall (101) in place.

7. The compensation system (100) according to claim 7, characterized in that, The sealing element is inserted between the chamber (11) and the cylinder body (1) so as to retain the gas inside the spring (10) and prevent the gas from occupying the chamber (11) in the extended configuration of the gas spring (10).

8. A gas spring (10) comprising a compensation system (100) according to any one of claims 1 to 7.

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