TECHNICAL FIELD

The present invention relates to a device for facilitating the removal of a safety pin of a fire extinguisher according to the preamble of the subsequent claim 1 .

TECHNICAL BACKGROUND

Fire extinguishers in the form of movable units comprise mainly a container for an extinction agent, an outlet opening having an outlet valve, a transport handle and an operating handle for controlling the outlet valve. In order to prevent accidental discharge there is a safety device in the form of a safety pin. The safety pin, which is provided with an eyelet, extends through and locks in openings between the operating handle of the fire extinguisher and the transport handle, which have a common pivot shaft. The safety pin is sealed with a sealing which is broken when the safety pin is drawn out when using the fire extinguisher. In a case of fire, panic might easily break out and people do not always act in a sensible way. Since the fire extinguisher is lifted in the transport handle and the operating handling

simultaneously, the safety pin is jammed. Because the transport handle and the operating handle are pivoted on a common pivot shaft and since the force applied on the operating handle acts on a larger radius to the pivot shaft and since the safety pin sits on a smaller radius to the pivot shaft, there is a gear ratio for the applied force. A comparatively small force on the operating handle will then result in a substantially higher force on the safety pin. Because many people do not know or realize that the safety pin is jammed, this happens time after time and it is a great problem, since most often it is a very urgent task to get the fire extinguisher going. A fire extinguisher, which operates immediately when activated is a critical condition which has to be fulfilled in order to quickly prevent a fire. A number of attempts have been made to prevent these drawbacks caused byf jamming of the safety pin, see for example SE patent 381 816 B, wherein a weakened safety pin is used which is broken when the operating handle is pressed down with a force towards the transport handle. Unfortunately, this might also cause accidental triggering of the extinguishing agent, if someone depresses the handle too hard, when the fire extinguisher is not to be used.

SUMMARY OF THE INVENTION

Accordingly, one object of the invention is to solve the above problem by providing a device according to the present invention, the characterizing features of which are presented in claim 1 .

The device according to the invention relieves the safety pin by mainly comprising a bearing seat and a blocking device journaled therein. The bearing seat with the blocking device are attached on the inside of the transport handle and the operating handle and prevent them from being moved towards each other around there pivot shaft, and accordingly an accidental discharge of the extinction agent is prevented. In relation to its bearing seat, the blocking device has a home position, or blocking start position, and is controlled or its position is controlled indirectly by the safety pin, which is provided between the blocking device and the bearing seat, i.e. such that the pin has a fixed position in the bearing seat, and traverses the trajectory of the blocking device. The bearing seat has a fixed position in relation to the transport handle, so that the blocking device operates in a chosen relationship with the inside part of the operating handle. The geometry between the blocking device in its home position, or blocking start position, and the surface on the inside of the operating handle is so conformed, that the blocking device barely turns away when a force is applied between the operating handle and the transport handle, which results in that only a small torque is created around the pivot shaft of the blocking device, which in turn only results in a small force on the safety pin. Therefore, it is easy to pull out the safety pin, even when a force is applied between the operating handle and the transport handle. When the safety pin is removed, the blocking device can be pivoted away so that the operating handle can move in a direction towards the transport handle and act on the discharge valve of the extinguisher, so that fire extinction can be commenced.

According to one embodiment of the invention, the safety pin might be attached though the ordinary holes for a safety pin in the transport handle and the operating handle, which is also done in connection with conventional handles on fire extinguishers. Common for all embodiments is that the blocking device takes up the main part of the force provided when the operating handle of the fire extinguisher is pressed against the transport handle, and the safety pin only takes up a small part of this force. The blocking device is arranged on the inside of the transport handle of the fire extinguisher and has a fixed pivot shaft in relation to the transport handle and a fixed support in relation to the transport handle or the operating handle. The abutment of the blocking device against the inside of the operating handle of the fire extinguisher is angled, so that the blocking device is always pivoted away when the operating handle is pressed down, after that the safety pin has been pulled out. The geometry is designed in such a way, that the blocking device barely can pivot away around its pivot shaft, which results in that the force on the safety pin will be small in order to maintain the blocking device in its position. When the safety pin is removed, the operating handle can affect the discharge valve of the fire extinguisher so that the extinction can be commenced. Accordingly, the invention can be summarized as a relieving support having a blocking device, which relieves the safety pin of a fire extinguisher and which prevents the operating handle of the fire extinguisher to be pressed towards the transport handle and jam the safety pin, which it is to be pulled out. The relieving support is comprised of two mirror-inverted rims or sides, and between these a pivotal blocking device, which with a fulcrum in its lower part is arranged in the rims, forming a bearing seat for the blocking device. The two mirror-inverted rims are designed with holes for a safety pin. A bushing is provided around the hole on the outside of the rim. The bushing fits on the inside of the hole in the transport handle, which is intended for the safety pin, and with this it will be fixed in position in relation to the transport handle. The blocking device is, on each side in its lower part, integrated with a semicircular pin. The pins of the blocking device are inserted down into a slot on each inside between the two rims. The pins on the blocking device provide a pivot shaft, around which the blocking device is pivoted. The holes in the rims matches a hole or a recess in the blocking device, when it is pivoted upwards. The safety pin is applied through the holes in both the rims and the blocking device, and locks the blocking device and thereby prevents an accidental discharge of the extinction agent in a fire extinguisher. The abutment of the blocking device against the inside of the transport handle is angled so that the blocking device is pivoted away when the operating handle is depressed after the safety pin has been pulled out.

According to a further, advantageous embodiment the relieving support with its bearing seat is provided on the discharge device/valve seat of the fire extinguisher. The abutment of the blocking device against the inside of the operating handle of the fire extinguisher is arranged in such a way that the blocking device is forced to turn/pivot out and down when the operating handle is depressed after the safety pin has been pulled out. When the safety pin is removed the operating handle can affect the discharge valve of the fire extinguisher, which is pressed down so that the extinction can commence.

Common for these two embodiments, described below, is that the safety pin in the conventional way extends between the transport handle and the operating handle though holes therein. A basic condition for this is that the safety pin has a diameter, which is smaller than the diameter of the holes in the transport handle and the operating handle.

SHORT DESCRIPTION OF THE DRAWINGS

The invention will be described more in detail below in connection with a few embodiments with reference to the attached drawings, in which Fig. 1 shows a fire extinguisher of the type for which the invention is relevant, having a safety pin that locks the transport handle and the operating handle to each other,

Fig. 2 shows an exploded view of devices according to the invention in a first embodiment in the form of a relieving support having mirror-inverted rims and blocking device, Fig. 3 shows an exploded view of the device according to fig. 2, supplemented with parts of the fire extinguisher and in another perspective,

Fig. 4 shows an end view of the device according to the first embodiment when assembled, Fig. 5 shows a section through the discharge device of the fire extinguisher along the line B-B in fig. 4, showing when the operating handle is blocked by the relieving support with the safety pin inserted,

Fig. 6 shows a corresponding section through the line B-B in fig. 4, but when the safety pin is removed, and the pressing down of the operating handle just have started, so that the blocking device has pivoted somewhat around its pivot shaft,

Fig. 7 shows a corresponding section through the discharge device of the fire extinguisher through the line B-B in fig. 4, but wherein the blocking device has pivoted completely away around its pivot shaft by the action of the operating handle of the fire extinguisher, when the safety pin has been removed,

Fig. 8 is a perspective view of the relieving support, wherein the operating handle is omitted for clarity reasons,

Fig. 9 is a corresponding perspective view of the relieving support with the operating handle mounted and the safety pin in place, Fig. 10 and 1 1 are exploded views of the device according to a second embodiment, wherein the device with its bearing seat is arranged directly on the discharge device,

Fig. 12 is a perspective view of the device according to the second embodiment in an assembled state and in a secured position,

Fig. 13 is a corresponding perspective view, but wherein the operating handle is omitted for clarity reasons,

Fig. 14 is a side view of the mounted device according to fig. 12,

Fig. 15 is an end view of the device according to fig. 14,

Fig. 16 is a section through the assembled device, showing the comprised blocking device, both in a blocking position as well as a position pivoted to an out of the way. PREFERRED EMBODIMENTS

The device according to the invention in the form of a relieving support for a safety pin of a fire extinguisher is intended to be applied on a type of fire extinguisher 1 , which is shown in fig. 1 with an example of an upper part. The fire extinguisher 1 is provided with a pull-out ring 5 in a safety pin 4, which locks a transport handle 2 provided on a container for extinction agent, and an operating handle 3 to each other in order to prevent accidental discharge of the extinction agent. The safety pin 4 is inserted through holes in the side parts of the transport handle 2 and the operating handle 3, respectively. When the fire extinguisher is to be used, it is gripped by the hand simultaneously over both the transport handle 2 and the operating handle 3, whereby the force which presses them towards each other inadvertently jams the safety pin 4, so that it cannot be pulled out. With reference to figs. 2 - 9 the first embodiment of the device according to the invention will be described.

The device according to the invention is thus designed as a relieving support for the safety pin of a fire extinguisher. Accordingly, fig. 2 shows an exploded view of the relieving support 17, which in this example is comprised of two mirror-inverted rims 6 or end parts, and a blocking device 14. Each of the rims 6 is provided with a hole 7 for a safety pin 4 and a bushing 8 is formed around the hole 7 on the outer side 8 of each of the rim 6. On the inside 19 of each rim 6 there is a slot 9, into which the blocking device 14 is to be inserted. At the lower edge of the rim 6 a supporting piece 1 1 is formed, which rests at the inside of the transport handle, directly underneath the pivot shaft 12. The slot 9, in its lower part, is designed with a round recess 13, which forms a fulcrum for the blocking device 14. On each side the blocking device 14, in its lower part, is integrated with a semicircular pin 16. The pins 16 of the blocking device 14 provide a pivot shaft 12, around which the blocking device 14 turns/pivots. The blocking device 14, in its upper edge, is rounded 21 and at the front edge it is provided with an open semicircular slot 15, intended to accommodate the safety pin 4. Underneath the recess the blocking device has a stop in the form of an abutment edge 35, which cooperates with a stopping surface 36 on each rim 6, which forms an end position, so that the blocking device cannot be turned more anticlockwise, when the safety pin is pulled out. This is in order to prevent self-clinching. At the front edge on each rim 6 there is a resilient flap 10 designed to clamp the rim 6 against the insides of the transport handle 2, when the bushing 8 of the rim 6 is inserted into the hole for the safety pin in the transport handle. Hereby the rims are retained so that the blocking device 14 can be easily mounted. When it is mounted it can be turned forward to its home position around the pivot shaft 12 and holds out the rims against the inner sides of the transport handle 2 with the aid of the side surfaces 60 of the blocking device 14 and surfaces 61 on the inside of the rims. The exploded view according to fig. 3 shows, besides the relieving support, also those parts of the fire extinguisher with which the support cooperates. The above mentioned transport handle 2, 3 is firmly attached at a triggering device/discharge device 23 in the form of a triggering valve/discharge valve 25, placed in a discharge connection at the upper end of the extinction agent container. The operating handle 3 is pivotally connected to the transport handle with the aid of a shaft journal 27 around an axial line 28. The safety pin 4 is intended to be inserted through holes 28, 39 in the transport handle 2 and operating handle 3, respectively, and through the holes 7 in the rims and the recess 15 in the blocking device 14.

The relieving support for the safety pin for fire extinguishers is shown in fig. 5, showing a section along the line B-B in fig. 4 through the trigger/discharge device 23 when the operating handle 3 is blocked by the relieving support 17 with the safety pin 4 inserted. The blocking device 14 is brought down with the pins 16 between the two mirror-inverted rims 6 into the slots 9. The blocking device 14 has been turned up so that the holes in the mirror-inverted rims 6 lie in alignment with the semicircular slot in the blocking device 14, so that the safety pin 5 can be passed through there. The relieving support 17 is fixed in the transport handle 2 of the fire extinguisher in a blocking position, wherein the blocking device is blocked by the safety pin 4 and in its turn blocks the operating handle 3 against pressing down by cooperation

with/abutment against a guide surface 30 on the operating handle, which in the current example is provided by its inside. When a force 20 is exerted on the operating handle 3 and presses against the blocking device 14, this is urged to barely pivot away by the angled guide surface 30 on the inside of the operating handle. The blocking device has, in the current example, a curved sliding surface/contact surface 21 having a touching point 32, viewed in the longitudinal sections according to figs. 5 and 6, against the guide surface 30 of the operating handle 3. According to the invention the guide surface 30 of the operating handle 3 has an extension, viewed in the section according to fig. 5, with an angle V1 to the radius 33 between the touching point 32 and the turning axle 12, which is only a little smaller than a right angle, i.e. 90°. In other words, the operating handle with its guide surface, is angled upwards to a small extent with a small positive angle V2 to an imaginary

tangent/touchline 34, which extends through the touching point 32 perpendicular to the radius 33. The main part of the force 20 will then, with a main force component, run in the direction of the radius 33 through the blocking device down to the rims 6 and further on the inside of the transport handle 2. A very small force component 22, which is created by the operating handle 3, is directed clockwise in the direction of the touching line 34 to the right, viewed in the section in fig. 5, creates a small torque clockwise on the blocking device 14 around its pivot shaft 12. This small torque tries to turn the blocking device, but in the blocking position according to fig. 5 it is taken up by the safety pin 4, which in its inserted position prevents the turning movement of the blocking device. The force which through the blocking device 14 acts/presses against the safety pin 4 becomes a fraction of the force 20 pressing down onto the operating handle 3. This results in that the safety pin 4 without difficulty can be pulled out, whereupon the blocking device 14, on its pivot shaft, is turned away by the operating handle 3, as is evident from the section according to fig. 6. The choice of the angle V2 between the guide surface 30 of the operating handle 3 and the touching line 34, i.e. the angle upwards of the operating handle, is chosen depending on the friction at the contact surface between the blocking device 14 and the guide surface of the operating handle and also in relation to the bearing seat so that the frictional force at the abutting surfaces is overcome. Advantageously, surfaces having a small friction are chosen, i.e. rather smooth and slippery surfaces, which make possible the choice of a small angle V2. One example of an interval for the angle V2 is 3 - 20 degrees. The blocking device 14 is designed in such a way, that after the start of the turning of the blocking device, the small force component resulting in the small torque on the blocking device, increases fast so that the blocking device is quickly turned away. This is achieved by a suitable design of the blocking device and more precise its contact surface 31 against the guide surface 30 of the operating handle 3. In this example, the guide surface is curved, e.g. arc- shaped with a center of curvature which is located outside the turning center 12 of the blocking device, to the right of the radius 33 according to fig. 5. The relieving support for the safety pin for the fire extinguisher is shown in fig. 6, showing a section through the triggering device of the fire extinguisher, where the blocking device 14 has begun to be turned away around its turning axle 12 by the action of the operating handle 3 of the fire extinguisher, when the safety pin is removed. When the blocking device 14 has been turned away the semicircular pins 16 are turned so that they lock the blocking device 14 so that it cannot be removed in this position. In the example shown, the semicircular form of the pins 16 of the blocking device 14 is accomplished in that they are missing part of their cylindrical form along a chord 37, so that the transverse dimension of the pins in the blocking end position of the blocking device is less than the width of the slots 9 in the rims 6 on the inner sides. Hereby the blocking device can be put in place when assembled in its turning position according to fig. 5 and being locked against removal in the other turning positions.

With the operating handle 3 fully depressed as is shown in the section according to fig. 7 the blocking device is accordingly fully turned away and the triggering

valve/discharge valve is depressed as known per se by the inside of the operating handle 3 against the action of a spring mechanism and accordingly open and the extinction can be commenced.

The perspective views according to figs. 8 and 9 further show the relieving support according to the first embodiment in blocking position with the safety pin inserted so that the operating handle cannot be depressed. Here it is also clearly shown that the diameter of the safety pin 4 is less than the diameter of the holes 29, 30 for the pin both in the transport handle 2 and the operating handle 3.

The device according to the invention in the form of the relieving support for the safety pin for a fire extinguisher will now be described in connection with the second embodiment with reference to figs. 10 - 16. The included parts will best be seen in the exploded views according to figs. 10 and 1 1 , where fig. 10 shows the blocking device 45 in raised blocking position, while fig. 1 1 shows the blocking device in a folded down, withdrawn position. Those parts, which fully correspond to the figs. pertaining to the first embodiment have the same reference numerals, i.e. which are parts of a conventional fire extinguisher. In this example the bearing seat for the relieving support 51 is constructed as a basic part 40, which is provided with a through hole 41 , which I view of form and size is adapted to the valve housing 25 of the discharge device 23 and forming an attachment part, which can be attached to a part of the valve housing 25 using press fitting. In this example the hole as well as a part of the valve housing, is cylindrical, while the basic part 40 around the hole has such a width that it goes in between the two attachment legs 42, 43 of the transport handle 22 and has, in this example, two flat side surfaces. From the box-shaped part 44 of the basic part 40 a link part extends, in the end of which the pivot shaft 46 of the blocking device 45 is arranged. The pivot shaft 46 might be constructed as fulcrum pins or as one through pin, which extends on both sides of the blocking device and into holes 47 in two flanges 48, protruding downwards from the blocking device. Alternatively, the link part might have flanges while the blocking device extend downwards between these.

The basic part 40 also has another, smaller through hole 49, which is adapted for passing through of the safety pin 4, which locks the blocking device 45 by

cooperation with a recess 50 in the blocking device, similar to the first example.

Fig. 16 shows with the section along the line F-F according to fig. 15 how the blocking device similar to the first example in the locked blocking position,

cooperates with the inside 30 of the operating handle 3, which is the guide surface, and which results in a very small force impact on the pin, and which, when the safety pin 4 has been pulled out, will be folded into a completely withdrawn position by depressing the operating handle. Both positions are shown in fig. 16, although the operating handle 3 for the sake of clarity is shown only in the locked position.

The invention has been described with reference to a preferred combination and design, and it goes without saying that some exchanges and alterations can be made without leaving the inventive thought. In the embodiment now described, the working point of the blocking device is shown for the fulcrum, resulting in that the force affecting the safety pin is only a fraction of the force used to depress the operating handle. Of course the blocking device might be designed in another way, with working points for the fulcrum and holes, so that the force affecting the safety pin will only be a fraction of the force with which the operating handle is depressed. The fulcrums of the relieving support might be placed in other places and be adapted to different designs of the transport handle and the operating handle, respectively. The relieving support might also be fixed to the operating handle instead of to the transport handle. Therefore, the invention is not to be regarded as restricted to what has been shown and described in the foregoing, but to the contrary similar variations are comprised in the inventive thought, and should be regarded to fall within the scope of the appended claims.

It is also conceivable that the safety pin does not pass through holes in the transport handle and the operating handle, but can function as a safety pin by only being held in place in the bearing seat and in the inserted locking position blocking the blocking device against its turning movement, and thereby also block a mutual movement of the handles. The guide surface on the inside of the operating handle does not have to be straight, but can also be curved, but then having a longer radius of curvature in relation to the radius of the blocking device.