HOSE COUPLING FOR COMPRESSED AIR

Abstract: The invention refers to a hose coupling for compressed air, which has a safety locking device. The safety locking consists in that when the male member (1) is disconnected, the male member (1) is not entirely disengaged but is caught by the locking balls (4) in the female member (2) until the overpressure in the hose and the tool has disappeared. Then the male member (1) is released. In this way the unpleasant bang that otherwise arises, and the effect that the hose together with the male member (1) moves backwards with enormous power, are prevented in a controlled way.

Description: HOSE COUPLING FOR COMPRESSED AIR It is well-known that by the use of pneumatic tools it frequently occurs that one has to remove the tool or perhaps to change to any other tool. The hose coupling which then connects the pneumatic tool with a hose from the pneumatic system is then released. By the release arises then a very high bang and the hose together with the hose coupling nipple move backwards with a very big power. This happens due to the overpressure in the hose leading to the tool is discharged unrestrictedly. It is experienced by many people as tremendous unpleasant that the hose with its nipple rushes away vigorously and uncontrolled with a big bang. Primarily within the in- dustry, where the tools really have a high working pressure and where changes of tools often occur. Unlike other safety systems against this unpleasant effect this construction is designed so, that the existing standardized series of equipment can be used, and to meet the requirement that only one-hand grip shall be needed for quick and uncomplicated changes. The purpose of the construction is thus to prevent the unpleasant bang that is created at changes of tools and to lock the nipple inside the coupling during the time the overpressure in the hose disappears. It is also important that the construction is adapted to already existing standardized series of equipment. The change of the potential tool shall also be just as fast and easy as at already existing standardized series. The invention will be described hereinafter with reference to the enclosed figures wherein Fig 1 shows the hose coupling totally disconnected. Fig 2 shows the hose coupling during connection. Fig 3 shows the hose coupling totally connected. Fig 4 shows the hose coupling during disconnection. The male member (1) is inserted into the coupling (2). Then the front cam (3) on the male member (1) engages the ball (4) and pushes the ball away due to the fact that there is space downwards (5, the spline). After the male member cam (3) has passed the ball, the so called locking pawl's front cam (7) will be forced upwards, at the same time as the rear cam (8) is pressed downwards. A so called seesaw-effect has arisen. The rear cam (8) then grips an axially resilient ring (9). When the male member (1) now is pressed inwards, the entire nonreturn valve (10) at the same time is pressed backwards, but the axially resilient ring (9) is still kept fixed by the locking pawls. The more the male member is pushed in, the higher resilient pressure is built up in the ring (9), which is retained by the rear cam (8) on the locking pawl. When the ring (9) now has an axial resilient pressure backwards, it strives to press the rear cam (8) upwards and the front cam (7) downwards. This can not happen before the male member is far enough inside, so that the front cam (7) can fall down into the spline (11) in the male member. At the same time as the front cam falls down in the spline, the resilient ring (9) is pushed backwards and urges the rear cam (8) upwards. The locking is now completed. See fig. 3. The front cam (7) now lies in the spline (11) and retains the male member (1). The male member is now locked and strives backwards due to the nonreturn valve (10), which now is open and spring-loaded (12) and presses the male member backwards. The locking pawl (6) is now subjected to an inverted seesaw- effect. The front cam (7) is now pressed upwards and the rear cam (8) is pressed downwards. But as shown in fig. 3 we can see that the resilient ring (9) lies in such a position that the cams of the locking pawl can not move in any direction. The male member is locked. In order now to free the male member (see fig 4) from the pneumatic system, the sleeve (13) that surrounds the coupling now must be pulled backwards. The sleeve (13) has a resilient resistance when it is pressed backwards. When the sleeve (13) now is pulled backwards, the turned out spline (5) also will move backwards. The spline (5) will b right in front of the upper stud (15) on the locking pawl. Th result of this now will be that the tendency of the front ca (7) to strive upwards is made possible due to the spline (5 in the sleeve being just in front of the upper stud (15), whe the sleeve is pulled backwards. At the same time as the sleev is pulled backwards, the ball (4) is locked in the male membe spline (11). Looking at fig 3 and imagining that the sleeve i pulled backwards, the space (the spline, 5) for the bal disappears at the same time as it presses the ball somewhat u into the male member spline (11). Soon afterwards the turne out spline (5) will be right in front of the upper stud (15) thereby enabling disconnection of the grip on the male member See fig 4. At the disconnection the male member moves backward at very big force and the nonreturn valve (10) closes. The mal member stops moving when the ball has reached the bottom of it spline. The male member can not move further out. Note! Th sleeve is now kept in a pulled-back position. The male membe is also disconnected from the sealing 0-ring (16). In thi stage the overpressure left in the hose and tool may leak out silently and at controlled rate. When the overpressure ha disappeared, the sleeve (13), that springs, is again allowe to move forward. When the sleeve lies in its front position also the turned out spline (5) lies over the ball and the bal releases its grip on the male member.

Claims: CLAIMS 1. Hose coupling consisting of a male member (1) and female member (2), where the female member (2) has an axiall displaceable slide (10) and is enclosed by an axially dis placeable sleeve (13), which is arranged to turn off the flo through the coupling in one position and to open the flow b an axial displacement caused by the inserting of the mal member ( 1 ) into the female member ( 2 ) , c h a r a c t e r i z e d i n, that the female member (2) further is provided with at leas one locking pawl (6), designed as a two-branched lever, tha balances onto a nib (17) in the female member (2), and th front cam (7) of which has a locking function onto the mal member and the rear cam (8) of which has an interacting lockin function with the spring-loaded ring (9) on the slide (10) fo holding the inserted male member (1) in a sealing contact wit the female member (2), whereby the sleeve (13) is arranged a axial displacement to release the locking pawl (6) and to kee the male member (1) in a locking position by means of at leas one locking ball (4) after an initial movement outwards of th male member (1). 2. Hose coupling according to claim 1, c h a r a c t e r i z e d i n, that the locking pawl (6) is provided with a stud (15) whic momentary bears against the inside wall of the sleeve and tha the sleeve (13) is provided with a turned out spline (5), whic normally holds the locking ball (4) free, whereas by a axia displacement of the sleeve (13) the ball (4) is interengagingl locked into the male member (1) and the locking of the mal member (1) by means of the lever is disconnected.

Inventors: ENGDAHL BJOERN, ENGDAHL, BJOERN
Applicants: ENGDAHL BJOERN, ENGDAHL, BJOERN
Application year: 1993
Main classification: F16L37
IPC codes: F16L37