SE442891B

SE442891B - Impact protection for the piston rod in a hydraulic cylinder

Info

Publication number: SE442891B
Application number: SE8403416A
Authority: SE
Inventors: N E A Hall
Original assignee: Osa Ab
Priority date: 1984-06-27
Filing date: 1984-06-27
Publication date: 1986-02-03
Also published as: FI73050B; FI852511A0; SE8403416D0; NO156022B; NO156022C; SE8403416L; NO852554L; FI852511L; FI73050C; AU4420385A

Abstract

The invention concerns impact protection for the piston rod (8) of a hydraulic cylinder (5), which operates a loaded jib arm (3) on a crane column (1), where the end of the cylinder (6) is fitted in a lug on the arm (3) and the end of the piston (8) is fitted in a lug on the crane column (1). According to the invention, an impact reducing cover (10) in the form of a rectangular, thick rubber sheet is shaped in a curve so that its upper part lies against the cylinder's (6) lower part and is attached to it by a hose clip (11) or similar device. The free-hanging part of the rubber sheet has a length corresponding to the piston rod (8). At the maximum height of the crane arm (position I) and thus the maximum extension of the piston rod (8), the latter is wholly protected by the sheet against damage from impacts, such as from a swinging load. The protection ceases when the crane is lowered (positions II and III), where the curved rubber sheet is folded so as to be pressed against the crane column (1). Because of the curved shape of the sheet, its lower end (10a) is guided into position along the crane column without the need for any further guidance device.<IMAGE>

Description

8403416-4 . z 10 15 20 25 maximalt upplyfta läge I, för vilket stången är helt ut- dragen, är enligt uppfinningen cylindern 6 förlängd en mot kolvstângens längd svarande sträcka med en stången skylande, välvd mantel 10 av flexibelt material. l det visade exemplet kan manteln 10 bestå av en rektangu- lär, tjock gummiduk, som kupas för att med sin övre del an- ligga mot cylinderns 6 undre del och där fixeras medelst ett bandomslag 11, såsom en slangklämma. 8403416-4. z 10 15 20 25 maximally raised position I, for which the rod is fully extended, according to the invention the cylinder 6 is extended a distance corresponding to the length of the piston rod with a rod-curved, curved jacket 10 of flexible material. In the example shown, the jacket 10 may consist of a rectangular, thick rubber cloth, which is cupped to abut with its upper part against the lower part of the cylinder 6 and there fixed by means of a band cover 11, such as a hose clamp.

Den fritt hängande delen av den välvda gummiduken kommer uppenbarligen att helt intäcka den frilagda kolvstången, när kranarmen står upphöjd i läget I. När armen sänks till läge II och från detta till läge Ill, pressas gummiduken i allt- mer böjd form an mot kranpelaren 1. På så sätt får den välvda gummidukens nedre ände 10a en tvångsstyrd anliggning mot kranpelaren i varje kranarmsläge utan avancerad gejder- styrning, såsom klart framgår av figuren.The free-hanging part of the curved rubber cloth will obviously completely cover the exposed piston rod, when the crane arm is raised in position I. When the arm is lowered to position II and from there to position III, the rubber cloth is pressed in increasingly bent form against the crane column 1 In this way, the lower end 10a of the curved rubber sheet is forced to abut against the crane column in each crane arm position without advanced guide control, as is clear from the figure.

Uppfínníngen är ej begränsad till det beskrivna utföran- det med manteln utformad av en rektangulär gummiduk. I stäl- let skulle den välvda manteln kunna vara förformad, t ex antingen genom formgjutning av gummi eller genom längstu- delning av ett gummirör. Vidare kan man självfallet i stäl- let för gummi använda ett annat flexibelt material med till- räcklig elasticitet för att tillfyllest dämpa inverkan av stötar. Det är även uppenbart att stötskyddet enligt uppfin- ningen skulle kunna göra tjänst även vid andra hydraul- drífter än kranarmsmanövrering.The invention is not limited to the described embodiment with the jacket formed by a rectangular rubber cloth. Instead, the curved jacket could be preformed, for example either by molding rubber or by longitudinally tilting a rubber tube. Furthermore, instead of rubber, one can of course use another flexible material with sufficient elasticity to fully dampen the effect of shocks. It is also obvious that the shock protection according to the invention could also serve other hydraulic operations than crane arm operation.

Claims

8403416-4 Patent claims

Impact protection for the piston rod (8) of a hydraulic cylinder (5), inserted between a support, such as a crane column (1), and an arm pivotably mounted on the support, such as a crane arm (3), characterized by a flexible material existing, curved jacket (10), which with its one end part is fastened around the end of the piston side of the cylinder (6) with a view towards the arm (3) and extends in the extension of the cylinder a distance corresponding to the length of the piston rod (8) to protruding the piston rod protects it from damage by shocks transversely, such as from oscillating loads, and when retracting the piston rod flexibly adapts to the connected support.

Impact protection according to Claim 1, characterized in that the jacket (10) is formed by a rectangular cloth of elastic material, such as rubber, which is bonded to the cylinder (6).