Door closer

Abstract

A door closer (1) according to the invention has a body (2) and an internal chamber (18), and the body has an aperture (5) into the internal chamber. The door closer comprises a relief valve placed within the aperture (5) between the internal chamber and outside of the door closer. The relief valve has a gasket groove (7) fitted with a gasket (8). The gasket groove had an outer edge (9) and an inner edge (10). The outer edge (9) of the gasket groove (7) is formed so that when installed in the door closer, a sufficient gap (20) is between the outer edge (9) and the door closer body (2) in order for the gasket to protrude from the groove and / or break due to raising temperature and fluid pressure of a fluid in the internal chamber (18), and allowing the fluid to emerge from the door closer. The relief valve also comprises an external thread part (11). The external thread part (11) comprises a thread cutting slot (12), which forms a channel for the fluid of the internal chamber through the external thread part (11), and the inner edge (10) is arranged so that it forms an extended route (21) for the fluid.

Description

Field of technology

[0001] This invention relates to a door closer, particularly to relief valve constructions for door closer fluid.Prior art

[0002] A pressure medium flowing from one side of the piston to another is used in door closers. The pressure medium is generally oil suitable for the purpose. The door closer has at least one channel through which the oil can flow to the opposite side of the piston. Thus, there is an internal chamber within the door closer that contains suitable fluid.

[0003] In the event of a fire, the pressure of the door closer fluid, in practice oil, rises due to increased temperature, and in the worst case, the oil will uncontrollably burst out of the door closer with high pressure and catch fire, which is not desirable and possibly not allowed in fire tests conducted on door closers.

[0004] The fire side of the door is not a problem because everything will burn anyway when the temperature reaches approximately 1000 degrees Celsius. On the outside, the non-fire side, the temperature of the uninsulated door may rise to some 600 degrees. A door closer installed outside a door is a problem for door closer manufacturers. A door closer is usually installed at the top edge of the door - that is the hottest part of the door in case of fire.

[0005] If there is no exit route for over-pressurized oil, the oil will most often emerge from the door closer shaft neck and may be directed upwards or towards the door with high pressure, which may cause it to catch fire. In the worst case, the door closer body may crack. Therefore, it is known that an exit route for over-pressurized oil be arranged in a door closer. These constructions are also called relief valve constructions.

[0006] The patent publication GB 2349173 presents a prior art relief valve construction in which there is a plugged aperture on the top of the door closer body. The plug will melt due to heat, allowing the oil to emerge from the door closer through the aperture. The top side also contains raised edges that cause the emerged oil to remain on the top surface of the door closer with the intention that it will smoke and evaporate from the heat. The problem with this solution is that the oil may still catch fire on the top surface of the door closer, particularly at higher temperatures. Furthermore, the point in time when the plug melts - that is, the valve opens - depends heavily on external circumstances (such as the structure of the door and wall).

[0007] EP 1700987 discloses a relief valve that comprises gasket situated on a gasket groove. The gasket is arranged to protrude out of the gasket groove in case of a fire. In this solution oil may come out of the door closer too slowly, in which case there is danger that the door closer body may crack.Short description

[0008] The object of the invention is to eliminate the problems said above. The object is achieved in a way described in the independent claims. Dependent claims illustrate different embodiments of the invention.

[0009] A door closer 1 according to the invention has a body 2 and an internal chamber 18, and the body has an aperture 5 into the internal chamber. The door closer comprises a relief valve 6, 6A placed within the aperture 5 in the body 2, between the internal chamber and outside of the door closer. The relief valve 6, 6A has a gasket groove 7 fitted with a gasket 8. The gasket groove had an outer edge 9 and an inner edge 10. The outer edge 9 of the gasket groove 7 is formed so that when installed in the door closer, a sufficient gap 20 is between the outer edge 9 and the door closer body 2 in order for the gasket to protrude from the groove and / or break due to raising temperature and fluid pressure of a fluid in the internal chamber 18, and allowing the fluid to emerge from the door closer.

[0010] The relief valve 6, 6A also comprises an external thread part 11 on an opposite side of the inner edge 10 of the gasket groove than the gasket groove 7. The external thread part 11 comprises a thread cutting slot 12, 17, which forms a channel for the fluid of the internal chamber through the external thread part 11, and the inner edge 10 is arranged so that it forms an extended route 21, 17A for the fluid.List of figures

[0011] In the following, the invention is described in more detail by reference to the enclosed drawings, where Figure 1illustrates an example of a door closer according to the invention, Figure 2illustrates an example of a relief valve, Figure 3illustrates another view from the example of figure 2, Figure 4illustrates another example of the relief valve, Figure 5illustrates the relief valve of figure 2 installed in the door closer, Figure 6illustrates the relief valve of figure 4 installed in the door closer, Figure 7illustrates the relief valve of figure 2 with the oil in the door closer at over-pressure, Figure 8illustrates another figure from the relief valve of figure 4, Figure 9illustrates a cross section view of the relief valve of figure 8, Figure 10illustrates yet another figure from the relief valve of figure 2, and Figure 11illustrates a cross section view of the relief valve of figure 10. Description of the invention

[0012] Figure 1 illustrates an example of a door closer according to the invention. A door closer 1 according to the invention has a body 2 and internal chamber 18, and the body has an aperture 5 into the internal chamber. The internal chamber refers to the interior of the door closer that contains door closer fluid (oil) or may receive the flow of door closer fluid. Thus, the internal chamber includes the volumes on both sides of the door closer piston, as well as the channel or channels between them. Figures 5, 6 and 7 shows partially a door closer body 2 and a very simplified illustration of the internal chamber 18. The example of figure 1 shows also an arm system 3 of the door closer, which is attached to the door closer body 2 at one end. The other end of the arm system is attachable to the fixing accessory, which is for attaching the other end to a door frame or to a door depending on the installation in question.

[0013] The door closer 1 comprises a relief valve 6, 6A placed within the aperture 5 in the body 2, between the internal chamber and outside of the door closer. Figure 2 shows an example of the relief valve 6, and figure 4 shows another example of the relief valve 6A. The relief valve 6, 6A has a gasket groove 7 fitted with a gasket 8. The gasket groove had an outer edge 9 and an inner edge 10. The outer edge 9 of the gasket groove 7 is formed so that when installed in the door closer, a sufficient gap 20 is between the outer edge 9 and the door closer body 2 in order for the gasket to protrude from the groove and / or break due to raising temperature and fluid pressure of a fluid in the internal chamber 18, and allowing the fluid to emerge from the door closer.

[0014] The relief valve 6, 6A also comprises an external thread part 11 on an opposite side of the inner edge 10 of the gasket groove than the gasket groove 7. The external thread part 11 comprises a thread cutting slot 12, 17, which forms a channel for the fluid of the internal chamber through the external thread part 11, and the inner edge 10 is arranged so that it forms an extended route 21, 17A for the fluid.

[0015] The external thread part 11 is for attaching the relief valve to the body 2, more precisely screwing the relief valve into the aperture 5 of the body. A top surface 15 of the relief valve has a cutting 16 (such as a hexagonal socket, a crosshead socket or a torx socket) for an installation tool. See figures 3 and 10. The external thread part 11 keeps the relief valve in its installation position in a reliable manner. However, in the arrangement according to the invention, the external thread part is cut in order to have said cutting slot 17 for forming the channel for the door closer fluid. Even so, the external thread part 11 provides a reliable installation. The external threads are against internal threads in a fitting manner, so there is very little room between the external threads and the internal threads. This room does not give enough space for the door closer fluid to flow outside quickly enough in case of fire. The current manufacturing accuracy is so good that said room between the threads is very small. So, without the cutting slot, the fluid pressure in the internal chamber 18 may raise due to fire so high that the body 2 will break and the fluid will splash out in an uncontrolled way.

[0016] However, the cutting slot is not enough to get the fluid to flow out quickly enough, since the inner edge also forms an obstacle to the fluid flow. Therefore, the inner edge 10 is arranged so that it forms an extended route 21, 17A for the fluid.

[0017] Figure 2 shows an example 6 how the extended route can be formed. In this example the height of the inner edge is not so high than a basic fitting height of the inner edge. The fitting height means that the top of the inner edge is very near the surface of the aperture 5, so the gap between the body and the top is very narrow. Figures 3, 5, 7, 10 and 11 show also this example having lower height, which is called in this context as a second height.

[0018] So, the inner edge 10 has a second height 22A in relation to a bottom 23 of the gasket groove 7. The second height 22A is smaller than a height of a fitting height 22 of the inner edge. As can be seen especially in a cross-section of figure 11, the second height of the inner edge 10 is at a sector of 360 degrees, in other words around the relief valve. So, the basic shape of the relief valve is cylindrical as can be seen also in the other figures. So, the inner edge is arranged to form an inner extended gap 21 between the body 2 and the top 24A of the inner edge, the inner extended gap 21 being the extended route.

[0019] In figure 2 the gasket 8 is on the gasket groove 7. In figure 3 the relief valve 6 is illustrated without the gasket for illustrating better the gasket groove 7. Figure 3 and 10 shows also the cutting 16 for an installation tool on the top surface 15 of the relief valve. The thread cutting slot 12 is conveniently so deep that it cuts the threads away. It may also cut little away from the section 13 between the inner edge 10 and the external thread part 11 as illustrated in figures. However, the thread cutting slot may also be formed another way so that it does not cut anything on the section 13 between the inner edge 10 and the external thread part 11. The height and width of the thread cutting slot may also be different from the slot illustrated in the figures.

[0020] Figure 5 shows the relief valve 6 installed on the body 2 of the door closer, more precisely into the aperture 5 in the body. In this example the aperture has four main sections. The uppermost main section 19C has the widest diameter of the aperture 5, and it may have a bevelled edge at the outer surface 2A of the body 2. The gasket 8 is against the surface of the uppermost section 19C, and the gasket is arranged to so that in normal circumstances it prevents the door closer fluid from leaking out from the internal chamber 18. The outer edge 9 may extend to the top surface 15. The corner between the top surface and the outer edge surface may be bevelled as in the figures.

[0021] The next main aperture section below the uppermost section 19C is an internal thread section 19B having internal threads on its surface. As said above, the external thread part 11 is fitted with the internal threads. The diameter of the internal thread section is smaller than the diameter of the uppermost section. Below the internal thread section there is section 19 without threads. Further, in this embodiment there is a connection section 19A below the section 19 without threads. The diameter of the connection section is smaller than the diameter of the internal thread section 19B or the section 19 without threads. The connection section connects the aperture 5 to the internal chamber 18.

[0022] Further, there is a subsection 19D between the uppermost section 19C and the internal thread section 19B. In the subsection 19D, the diameter of the aperture changes from the diameter of the uppermost section to the diameter of the internal thread section. Even if figure 5, and figures 6 - 7 show only one embodiment of the aperture 5, other embodiments are also possible, like the connection section having a wider diameter.

[0023] Figure 7 shows also the relief valve 6 installed on the body 2 of the door closer, but now a fluid pressure level and temperature in the internal chamber 18 is above the normal condition due to fire. The fluid (like oil) under over-pressure flows via the thread cuttings slot 12 and the inner extended gap 21 towards the gasket 8. The over pressurised fluid forces the gasket 8 out of the groove 7 to the gap 20. The gasket 8 protrudes finally out of the aperture and / or breaks. So, the fluid can flow out th rough the gap 20. A similar situation may occur in the embodiment of figure 6 and in any other potential embodiments of the invention.

[0024] So, the invention allows the fluid to leak out. It is preferred that the fluid emerges gradually, but still quickly enough. If the fluid bursts out suddenly (for example due to cracking of the body) or too rapidly, it will catch fire more easily. Dimensioning can be used to adjust the tripping pressure to suit different types of door closer bodies or installation locations.

[0025] Figure 11 shows the cross section of the relief valve at the bottom 23 of the gasket groove. As said, the fitting height means that the top of the inner edge is very near the surface of the aperture 5 (the surface of the uppermost section 19C). This hight is called as a first height 22 in relation to a bottom 23 of the gasket groove 7. The second height 22A is smaller than a height of a fitting height 22 of the inner edge. The inner extended gap 21 being the extended route is between the surface of the uppermost section 19C of the aperture and the top 24A of the inner edge 10.

[0026] Figure 7, and figures 6, 8, 9 show another embodiment where the inner edge 10A has said first height 22 in relation to a bottom 23 of the gasket groove 7, and the top 24 of the inner edge 10A is fitted in relation to the aperture 5, and the inner edge 10A comprises a sector 25 having an edge cutting slot 17A. The edge cutting slot is the extended route.

[0027] The edge cutting slot 17A and the thread cutting slot 17 may be in line with each other. Therefore, they may be formed together. The height of the edge cutting slot 17A and also the thread cutting slot 17 may be so that it slightly cut the bottom of the section 13 between the inner edge 10A and the external thread part 11. However, the hight may also be different.

[0028] The inner edge 10A may have at least two said sectors. Figure 9 illustrates another similar sector 17B as dashed lines. As can be seen the first height 22 in relation to a bottom 23 of the gasket groove 7 is fitted to the surface of the aperture 5, i.e. to the surface of the uppermost section 19C in this embodiment. So, there is very little room between the top 24 of the inner edge 10A and the surface of the uppermost section 19C (dashed line circle). So, the edge cutting slot 17A or more slots forms said extended route for the fluid of the door closer. As can be seen the height 26 between the bottom of edge cutting slot and the bottom of the gasket groove 7 is smaller than the first hight.

[0029] As can be noted from the embodiments the invention may be made in many ways. The most common embodiment of the valve gasket is an O-ring gasket and a groove intended for an O-ring, although other profiles may be used. The above illustrated relief valve embodiments have the section 13 between the inner edge 10, 10A and the external thread part 11, but it may be possible to have an embodiment without this section 13. Further, the above illustrated embodiments have a bottom section 14 on the other side of the external thread section 11 than said section 13 and the inner section 10, 10A. The bottom section is useful for manufacturing reasons, but the relief valve 6, 6A may also be without the bottom section.

[0030] As can be seen above the gasket prevents oil from leaking out of the internal chamber 18 in the door closer body in normal circumstances. But when the temperature of the fluid and its pressure increase due to fire, and the fluid pressure within the door closer reaches a certain level, the gasket groove allows the gasket 8 to protrude from the groove and / or break, and the fluid is allowed to leak out at a suitable speed. A sufficient level of over-pressure is, for example a fluid pressure level of 100 bar. As said, dimensioning can be used to adjust the tripping pressure to suit different types of door. Therefore, the body of the door closer does not crack, or the outcoming fluid does not catch fire, but instead smoke and evaporate without spreading fire.

[0031] As said, the relief valve is placed between the internal chamber of the door closer and the outside of the door closer, more precisely to aperture 5. The aperture for the relief valve can be placed in the door closer body so that it is in connection with the desired part of the internal chamber. Because the relief valve operation is based on an increase in fluid pressure, it is very predictable. This means that the same inventive embodiment is applicable to many different installations without separate customisation. Applicability to different types of door closers is also good, as a relief valve according to the invention can be placed at the desired position within the desired door closer without any major advance design.

[0032] It is evident from the above that the invention is not limited to the embodiments described in this text but can be implemented in many other different embodiments within the scope of the independent claims.

Examples

Embodiment Construction

[0012]Figure 1 illustrates an example of a door closer according to the invention. A door closer 1 according to the invention has a body 2 and internal chamber 18, and the body has an aperture 5 into the internal chamber. The internal chamber refers to the interior of the door closer that contains door closer fluid (oil) or may receive the flow of door closer fluid. Thus, the internal chamber includes the volumes on both sides of the door closer piston, as well as the channel or channels between them. Figures 5, 6 and 7 shows partially a door closer body 2 and a very simplified illustration of the internal chamber 18. The example of figure 1 shows also an arm system 3 of the door closer, which is attached to the door closer body 2 at one end. The other end of the arm system is attachable to the fixing accessory, which is for attaching the other end to a door frame or to a door depending on the installation in question.

[0013]The door closer 1 comprises a relief valve 6, 6A placed wit...

Field of technology

[0001] This invention relates to a door closer, particularly to relief valve constructions for door closer fluid.Prior art

[0002] A pressure medium flowing from one side of the piston to another is used in door closers. The pressure medium is generally oil suitable for the purpose. The door closer has at least one channel through which the oil can flow to the opposite side of the piston. Thus, there is an internal chamber within the door closer that contains suitable fluid.

[0003] In the event of a fire, the pressure of the door closer fluid, in practice oil, rises due to increased temperature, and in the worst case, the oil will uncontrollably burst out of the door closer with high pressure and catch fire, which is not desirable and possibly not allowed in fire tests conducted on door closers.

[0004] The fire side of the door is not a problem because everything will burn anyway when the temperature reaches approximately 1000 degrees Celsius. On the outside, the non-fire side, the temperature of the uninsulated door may rise to some 600 degrees. A door closer installed outside a door is a problem for door closer manufacturers. A door closer is usually installed at the top edge of the door - that is the hottest part of the door in case of fire.

[0005] If there is no exit route for over-pressurized oil, the oil will most often emerge from the door closer shaft neck and may be directed upwards or towards the door with high pressure, which may cause it to catch fire. In the worst case, the door closer body may crack. Therefore, it is known that an exit route for over-pressurized oil be arranged in a door closer. These constructions are also called relief valve constructions.

[0006] The patent publication GB 2349173 presents a prior art relief valve construction in which there is a plugged aperture on the top of the door closer body. The plug will melt due to heat, allowing the oil to emerge from the door closer through the aperture. The top side also contains raised edges that cause the emerged oil to remain on the top surface of the door closer with the intention that it will smoke and evaporate from the heat. The problem with this solution is that the oil may still catch fire on the top surface of the door closer, particularly at higher temperatures. Furthermore, the point in time when the plug melts - that is, the valve opens - depends heavily on external circumstances (such as the structure of the door and wall).

[0007] EP 1700987 discloses a relief valve that comprises gasket situated on a gasket groove. The gasket is arranged to protrude out of the gasket groove in case of a fire. In this solution oil may come out of the door closer too slowly, in which case there is danger that the door closer body may crack.Short description

[0008] The object of the invention is to eliminate the problems said above. The object is achieved in a way described in the independent claims. Dependent claims illustrate different embodiments of the invention.

[0009] A door closer 1 according to the invention has a body 2 and an internal chamber 18, and the body has an aperture 5 into the internal chamber. The door closer comprises a relief valve 6, 6A placed within the aperture 5 in the body 2, between the internal chamber and outside of the door closer. The relief valve 6, 6A has a gasket groove 7 fitted with a gasket 8. The gasket groove had an outer edge 9 and an inner edge 10. The outer edge 9 of the gasket groove 7 is formed so that when installed in the door closer, a sufficient gap 20 is between the outer edge 9 and the door closer body 2 in order for the gasket to protrude from the groove and / or break due to raising temperature and fluid pressure of a fluid in the internal chamber 18, and allowing the fluid to emerge from the door closer.

[0010] The relief valve 6, 6A also comprises an external thread part 11 on an opposite side of the inner edge 10 of the gasket groove than the gasket groove 7. The external thread part 11 comprises a thread cutting slot 12, 17, which forms a channel for the fluid of the internal chamber through the external thread part 11, and the inner edge 10 is arranged so that it forms an extended route 21, 17A for the fluid.List of figures

[0011] In the following, the invention is described in more detail by reference to the enclosed drawings, where Figure 1illustrates an example of a door closer according to the invention, Figure 2illustrates an example of a relief valve, Figure 3illustrates another view from the example of figure 2, Figure 4illustrates another example of the relief valve, Figure 5illustrates the relief valve of figure 2 installed in the door closer, Figure 6illustrates the relief valve of figure 4 installed in the door closer, Figure 7illustrates the relief valve of figure 2 with the oil in the door closer at over-pressure, Figure 8illustrates another figure from the relief valve of figure 4, Figure 9illustrates a cross section view of the relief valve of figure 8, Figure 10illustrates yet another figure from the relief valve of figure 2, and Figure 11illustrates a cross section view of the relief valve of figure 10. Description of the invention

[0012] Figure 1 illustrates an example of a door closer according to the invention. A door closer 1 according to the invention has a body 2 and internal chamber 18, and the body has an aperture 5 into the internal chamber. The internal chamber refers to the interior of the door closer that contains door closer fluid (oil) or may receive the flow of door closer fluid. Thus, the internal chamber includes the volumes on both sides of the door closer piston, as well as the channel or channels between them. Figures 5, 6 and 7 shows partially a door closer body 2 and a very simplified illustration of the internal chamber 18. The example of figure 1 shows also an arm system 3 of the door closer, which is attached to the door closer body 2 at one end. The other end of the arm system is attachable to the fixing accessory, which is for attaching the other end to a door frame or to a door depending on the installation in question.

[0013] The door closer 1 comprises a relief valve 6, 6A placed within the aperture 5 in the body 2, between the internal chamber and outside of the door closer. Figure 2 shows an example of the relief valve 6, and figure 4 shows another example of the relief valve 6A. The relief valve 6, 6A has a gasket groove 7 fitted with a gasket 8. The gasket groove had an outer edge 9 and an inner edge 10. The outer edge 9 of the gasket groove 7 is formed so that when installed in the door closer, a sufficient gap 20 is between the outer edge 9 and the door closer body 2 in order for the gasket to protrude from the groove and / or break due to raising temperature and fluid pressure of a fluid in the internal chamber 18, and allowing the fluid to emerge from the door closer.

[0014] The relief valve 6, 6A also comprises an external thread part 11 on an opposite side of the inner edge 10 of the gasket groove than the gasket groove 7. The external thread part 11 comprises a thread cutting slot 12, 17, which forms a channel for the fluid of the internal chamber through the external thread part 11, and the inner edge 10 is arranged so that it forms an extended route 21, 17A for the fluid.

[0015] The external thread part 11 is for attaching the relief valve to the body 2, more precisely screwing the relief valve into the aperture 5 of the body. A top surface 15 of the relief valve has a cutting 16 (such as a hexagonal socket, a crosshead socket or a torx socket) for an installation tool. See figures 3 and 10. The external thread part 11 keeps the relief valve in its installation position in a reliable manner. However, in the arrangement according to the invention, the external thread part is cut in order to have said cutting slot 17 for forming the channel for the door closer fluid. Even so, the external thread part 11 provides a reliable installation. The external threads are against internal threads in a fitting manner, so there is very little room between the external threads and the internal threads. This room does not give enough space for the door closer fluid to flow outside quickly enough in case of fire. The current manufacturing accuracy is so good that said room between the threads is very small. So, without the cutting slot, the fluid pressure in the internal chamber 18 may raise due to fire so high that the body 2 will break and the fluid will splash out in an uncontrolled way.

[0016] However, the cutting slot is not enough to get the fluid to flow out quickly enough, since the inner edge also forms an obstacle to the fluid flow. Therefore, the inner edge 10 is arranged so that it forms an extended route 21, 17A for the fluid.

[0017] Figure 2 shows an example 6 how the extended route can be formed. In this example the height of the inner edge is not so high than a basic fitting height of the inner edge. The fitting height means that the top of the inner edge is very near the surface of the aperture 5, so the gap between the body and the top is very narrow. Figures 3, 5, 7, 10 and 11 show also this example having lower height, which is called in this context as a second height.

[0018] So, the inner edge 10 has a second height 22A in relation to a bottom 23 of the gasket groove 7. The second height 22A is smaller than a height of a fitting height 22 of the inner edge. As can be seen especially in a cross-section of figure 11, the second height of the inner edge 10 is at a sector of 360 degrees, in other words around the relief valve. So, the basic shape of the relief valve is cylindrical as can be seen also in the other figures. So, the inner edge is arranged to form an inner extended gap 21 between the body 2 and the top 24A of the inner edge, the inner extended gap 21 being the extended route.

[0019] In figure 2 the gasket 8 is on the gasket groove 7. In figure 3 the relief valve 6 is illustrated without the gasket for illustrating better the gasket groove 7. Figure 3 and 10 shows also the cutting 16 for an installation tool on the top surface 15 of the relief valve. The thread cutting slot 12 is conveniently so deep that it cuts the threads away. It may also cut little away from the section 13 between the inner edge 10 and the external thread part 11 as illustrated in figures. However, the thread cutting slot may also be formed another way so that it does not cut anything on the section 13 between the inner edge 10 and the external thread part 11. The height and width of the thread cutting slot may also be different from the slot illustrated in the figures.

[0020] Figure 5 shows the relief valve 6 installed on the body 2 of the door closer, more precisely into the aperture 5 in the body. In this example the aperture has four main sections. The uppermost main section 19C has the widest diameter of the aperture 5, and it may have a bevelled edge at the outer surface 2A of the body 2. The gasket 8 is against the surface of the uppermost section 19C, and the gasket is arranged to so that in normal circumstances it prevents the door closer fluid from leaking out from the internal chamber 18. The outer edge 9 may extend to the top surface 15. The corner between the top surface and the outer edge surface may be bevelled as in the figures.

[0021] The next main aperture section below the uppermost section 19C is an internal thread section 19B having internal threads on its surface. As said above, the external thread part 11 is fitted with the internal threads. The diameter of the internal thread section is smaller than the diameter of the uppermost section. Below the internal thread section there is section 19 without threads. Further, in this embodiment there is a connection section 19A below the section 19 without threads. The diameter of the connection section is smaller than the diameter of the internal thread section 19B or the section 19 without threads. The connection section connects the aperture 5 to the internal chamber 18.

[0022] Further, there is a subsection 19D between the uppermost section 19C and the internal thread section 19B. In the subsection 19D, the diameter of the aperture changes from the diameter of the uppermost section to the diameter of the internal thread section. Even if figure 5, and figures 6 - 7 show only one embodiment of the aperture 5, other embodiments are also possible, like the connection section having a wider diameter.

[0023] Figure 7 shows also the relief valve 6 installed on the body 2 of the door closer, but now a fluid pressure level and temperature in the internal chamber 18 is above the normal condition due to fire. The fluid (like oil) under over-pressure flows via the thread cuttings slot 12 and the inner extended gap 21 towards the gasket 8. The over pressurised fluid forces the gasket 8 out of the groove 7 to the gap 20. The gasket 8 protrudes finally out of the aperture and / or breaks. So, the fluid can flow out th rough the gap 20. A similar situation may occur in the embodiment of figure 6 and in any other potential embodiments of the invention.

[0024] So, the invention allows the fluid to leak out. It is preferred that the fluid emerges gradually, but still quickly enough. If the fluid bursts out suddenly (for example due to cracking of the body) or too rapidly, it will catch fire more easily. Dimensioning can be used to adjust the tripping pressure to suit different types of door closer bodies or installation locations.

[0025] Figure 11 shows the cross section of the relief valve at the bottom 23 of the gasket groove. As said, the fitting height means that the top of the inner edge is very near the surface of the aperture 5 (the surface of the uppermost section 19C). This hight is called as a first height 22 in relation to a bottom 23 of the gasket groove 7. The second height 22A is smaller than a height of a fitting height 22 of the inner edge. The inner extended gap 21 being the extended route is between the surface of the uppermost section 19C of the aperture and the top 24A of the inner edge 10.

[0026] Figure 7, and figures 6, 8, 9 show another embodiment where the inner edge 10A has said first height 22 in relation to a bottom 23 of the gasket groove 7, and the top 24 of the inner edge 10A is fitted in relation to the aperture 5, and the inner edge 10A comprises a sector 25 having an edge cutting slot 17A. The edge cutting slot is the extended route.

[0027] The edge cutting slot 17A and the thread cutting slot 17 may be in line with each other. Therefore, they may be formed together. The height of the edge cutting slot 17A and also the thread cutting slot 17 may be so that it slightly cut the bottom of the section 13 between the inner edge 10A and the external thread part 11. However, the hight may also be different.

[0028] The inner edge 10A may have at least two said sectors. Figure 9 illustrates another similar sector 17B as dashed lines. As can be seen the first height 22 in relation to a bottom 23 of the gasket groove 7 is fitted to the surface of the aperture 5, i.e. to the surface of the uppermost section 19C in this embodiment. So, there is very little room between the top 24 of the inner edge 10A and the surface of the uppermost section 19C (dashed line circle). So, the edge cutting slot 17A or more slots forms said extended route for the fluid of the door closer. As can be seen the height 26 between the bottom of edge cutting slot and the bottom of the gasket groove 7 is smaller than the first hight.

[0029] As can be noted from the embodiments the invention may be made in many ways. The most common embodiment of the valve gasket is an O-ring gasket and a groove intended for an O-ring, although other profiles may be used. The above illustrated relief valve embodiments have the section 13 between the inner edge 10, 10A and the external thread part 11, but it may be possible to have an embodiment without this section 13. Further, the above illustrated embodiments have a bottom section 14 on the other side of the external thread section 11 than said section 13 and the inner section 10, 10A. The bottom section is useful for manufacturing reasons, but the relief valve 6, 6A may also be without the bottom section.

[0030] As can be seen above the gasket prevents oil from leaking out of the internal chamber 18 in the door closer body in normal circumstances. But when the temperature of the fluid and its pressure increase due to fire, and the fluid pressure within the door closer reaches a certain level, the gasket groove allows the gasket 8 to protrude from the groove and / or break, and the fluid is allowed to leak out at a suitable speed. A sufficient level of over-pressure is, for example a fluid pressure level of 100 bar. As said, dimensioning can be used to adjust the tripping pressure to suit different types of door. Therefore, the body of the door closer does not crack, or the outcoming fluid does not catch fire, but instead smoke and evaporate without spreading fire.

[0031] As said, the relief valve is placed between the internal chamber of the door closer and the outside of the door closer, more precisely to aperture 5. The aperture for the relief valve can be placed in the door closer body so that it is in connection with the desired part of the internal chamber. Because the relief valve operation is based on an increase in fluid pressure, it is very predictable. This means that the same inventive embodiment is applicable to many different installations without separate customisation. Applicability to different types of door closers is also good, as a relief valve according to the invention can be placed at the desired position within the desired door closer without any major advance design.

[0032] It is evident from the above that the invention is not limited to the embodiments described in this text but can be implemented in many other different embodiments within the scope of the independent claims.

Examples

Embodiment Construction

[0012]Figure 1 illustrates an example of a door closer according to the invention. A door closer 1 according to the invention has a body 2 and internal chamber 18, and the body has an aperture 5 into the internal chamber. The internal chamber refers to the interior of the door closer that contains door closer fluid (oil) or may receive the flow of door closer fluid. Thus, the internal chamber includes the volumes on both sides of the door closer piston, as well as the channel or channels between them. Figures 5, 6 and 7 shows partially a door closer body 2 and a very simplified illustration of the internal chamber 18. The example of figure 1 shows also an arm system 3 of the door closer, which is attached to the door closer body 2 at one end. The other end of the arm system is attachable to the fixing accessory, which is for attaching the other end to a door frame or to a door depending on the installation in question.

[0013]The door closer 1 comprises a relief valve 6, 6A placed wit...

Claims

1. A door closer (1) with a body (2) and internal chamber (18), the body having an aperture (5) into the internal chamber, the door closer comprising a relief valve (6, 6A) placed within the aperture (5) in the body (2) between the internal chamber and outside of the door closer, the relief valve (6, 6A) having a gasket groove (7) fitted with a gasket (8), the gasket groove having an outer edge 9 and an inner edge (10), the outer edge (9) of the gasket groove (7) being formed so that when installed in the door closer, a sufficient gap (20) is between the outer edge (9) and the door closer body (2) in order for the gasket to protrude from the groove and / or break due to raising temperature and fluid pressure of a fluid in the internal chamber (18), and allowing the fluid to emerge from the door closer, the relief valve (6, 6A) also comprising an external thread part (11) on an opposite side of the inner edge (10) of the gasket groove than the gasket groove (7), characterised in that the external thread part (11) comprises a thread cutting slot (12, 17), which forms a channel for the fluid of the internal chamber through the external thread part (11), and the inner edge (10) is arranged so that it forms an extended route (21, 17A) for the fluid.

2. An arrangement according to claim 1, characterised in that the inner edge (10A) has a first height (22) in relation to a bottom (23) of the gasket groove (7), and a top (24) of the inner edge (10A) is fitted in relation to the aperture (5), and the inner edge (10A) comprises a sector (25) having an edge cutting slot (17A), which is the extended route.

3. An arrangement according to claim 2, characterised in that the inner edge (10A) has at least two said sector.

4. An arrangement according to claim 2, characterised in that the edge cutting slot (17A) and the thread cutting slot (17) are in line with each other.

5. An arrangement according to claim 1, characterised in that the inner edge (10) has a second height (22A) in relation to a bottom (23) of the gasket groove (7), the second height (22A) being smaller than a fitting height (22) of the inner edge, the second height of the inner edge (10) being at a sector of 360 degrees, and so the inner edge being arranged to form an inner extended gap (21) between the body (2) and a top (24A) of the inner edge, the inner extended gap (21) being the extended route.

Images