PORTABLE WORKING PLATFORM

Abstract: The invention concerns a portable working platform (20) for engaging the rungs of a ladder. The working platform comprises a plane surface with grooves to improve the friction, and is secured to the rung of the ladder by means of a spring-loaded locking device (9). The working platform (20) is kept in horizontal position bymeans of a stay (5) to be fastened on the rung above. The platform according to the invention provides a safe working position.

Description: Portable working platform The invention relates to a portable working platform by engaging two rungs of a ladder. The ladder is preferably a usual ladder of aluminium, but the invention can be utilised in any ladder with holes in the rungs. The invention can be used during work in a ladder, which is tilted against a wall or anything other, and will provide a very safe and secure position during the work in the ladder. The working platform will also decrease the strain on the user's feet and legs, as the platform provides a more stable and steady base than the usual rungs of a ladder. EP 0106583 describes a device for engaging the rungs of a ladder. The device is hooked on two rungs, but it is not equipped with any safety- or locking systems. The lack of safety systems is a major drawback and renders it an unsafe working platform. It is not possible for the user to ascend or descend the rungs without removing the platform in advance. GB 1,179,970 describes a device for fastening in two rungs in a way that the platform is hanging beneath the ladder. The device has two vertical arms to be adjusted in a way so that the platform is in a horizontal position. US 2,871,067 is a simple platform for engaging a ladder. The platform fits on a rung by means of two hooks, and can be tipped between two rungs when it is not in use. The platform has no means for safety or adjustments, and can therefore only be used in ladders with a fixed distance between the rungs. In addition there will be hazard that the platform can impinge the wall or break a window, when the platform is tipped between the rungs. US 4,211, 307 describes a portable shelf which uses three rungs for fastening. The shelf can be pushed between two rungs, but the attachments are unsecured. In contrast to these patents the present invention provides a safe and flexible platform to be used during work in a ladder. The platform according to the invention is lockable by means of a spring-loaded device that can only be trigged as a result of an active action. The platform is in addition provided with edges on two sides, and grooves to prevent that the user and other equipment fall off the platform. The devices of prior art described in the above referenced patents have no broadwise safety devices for the feet, and the user cannot move up or down and pass by the platforms before they are removed from the rungs of the ladder. The object and purpose with the present invention is to provide a device that in an easy way can be fastened to and locked to the rung. The user can by means of hand- or foot movements elevate or secure the platform in the rung above, and the user can stand in different positions during the work in the ladder. Before the user descends and passes by the platform, he lifts the platform with his hand or foot in a handle, and in that way the platform is inserted between two rungs without any risk of hitting and breaking a glass pane in the wall. More specific the invention concerns a device comprising a portable working platform for engaging the rungs of a ladder to provide a safe and secure working position, characterised by that the working platform has an approximate plane surface and two side plates that continue into side edges and further with overhang to be hooked on the rung, said platform is secured to the rung by means of a locking device, a stay is mounted on the platform which is pivotally fastened with bolts in the side plates, and the stay in the upper end is bended in a terminal bend which secures the platform in the above rung, whereas the stay on one side has a handle in a way that the platform can be elevated or sinked by means of a hand or foot by lifting the stay. The invention is further characterised by the spring-loaded locking pin which fastens the platform to the lower rung, said locking pin can be manual pulled backward by means of a knob by which with a spring pressure will return back into a locked position when the pin is released. The platform is preferably made of a light and robust material, e. q. aluminium or other suitable metal. The pressure load and the weight of the user and possible other equipment which are on the platform, are distributed between four points on two rungs. The invention will be further explained with reference to the accompanying drawings, wherein fig. 1 - 3 depict schematic embodiments of the portable working platform according to the present invention. Fig. 1 depicts the working platform according to the invention engaging two rungs of a ladder, Fig. 2 depicts the working platform in the ladder as seen from one side, while the dotted line shows the platform in a depressed position, Fig. 3 shows the platform engaged in a ladder as seen from the front. Figure 1 and 2 show a working platform 20 engaged in a ladder 2. The working platform 20 comprises a plane surface 1 to stand on. This plane surface is equipped with grooves, rubber coating, knobs or similar which prevent the user to fall off the platform when it is slippery. Two of the sides of the platform have side plates 4 of varying height above the plane surface 1. The side plates 4, which continue evenly to side plate 12, shall prevent that equipment which is on the platform fall to the ground. The side plates 4 have in the sides facing away from the ladder, elevations with holes and a through bolt 6 for fastening of a stay 5. The stay has a length such that when the other end is hooked on the above rung, the plane surface 1 will be in an approximate horizontal position. Despite different types of ladders the distance between the rungs are relative equal. The stay 5 is preferably tubular and has a terminal bend 7 to be hooked on the rung. A handle 11 is fastened to the upper part of stay 5, and can be used when the platform is to be lifted or removed. The handle can be operated with the hand or foot. The stays 5 on both sides of the platform will provide further securing and abutment during the work on the platform. The side plates 4 have on the ends that are in contact with the ladder two overhangs 8 to be hooked on the rung 3 in the ladder. The overhangs 8 which preferably are half-moon circular formed are secured not to fall off the ladder due to two locking devices 9, and can be manually operated by means of a spring-loaded, underlying pin 10. The overhangs 8 are dimensioned and are half-moon formed in a way that they fit in most of the rungs. The working platform 20 can only be removed from the rung 3 when the locking device 9 is withdrawn. As the locking devices are spring-loaded, the locking pins 10 will always be secured to the rung 3 of the ladder, and secure the device during work and when the ladder is being removed. Figure 2 depicts the working platform 20 engaged in the ladder as seen from one side. Of simplicity reasons the ladder is shortened above and below, and the ladder is tilted to the wall 21. When the working platform is to be lowered or removed, one takes the handle 11 with a hand or foot, and lifts the stay 5. The lifting movement is illustrated with the arrow 23. The broken lines depict the position of the platform in the depressed position, and the platform is turned around the lower rung 3. The platform does not reach the wall and there is no risk that the platform collides with the wall and any glass panes. The working platform will not fall down as it is secured with locking devices 9 that have to be manually opened before moving the platform. It is important to notice that it is possible to remain standing on the rung 3 without obstructions during lifting and lowering of the platform. A person can move up and down the ladder and use all rungs, when the working platform is in a depressed position. The figure 3 depicts the working platform 20 engaged in a ladder 2 as seen from the front. As seen from the figure the plane surface 1 of the platform will be in an approximate horizontal position, which secures stable and secure working conditions.

Claims: P a t e n t C l a i m s 1. Working platform (20) for engaging in the rungs of a ladder to provide a safe, secure and stable working position, c h a r a c t e r i s e d b y that the working platform (20) has an approximate plane surface (1) and two side plates (4) that continue into side edges (12) and further with overhang (8) to be hooked on rung (3), said platform (20) is secured to the rung (3) by means of a locking device (9), a stay (5) is mounted on the platform which is pivotable fastened with bolts (6) in the side plates (4) and the stay (5) in the upper end is bended in a terminal bend (7) which secures the platform in the above rung, whereas the stay (5) on one side has a handle (11) in a way that the platform can be elevated or sinked by means of a hand or foot by lifting the stay (5). 2. Working platform according to claim 1, c h a r a c t e r i s e d b y that the locking device (9) is spring- loaded and can be manually withdrawn by means of a locking pin (10) and the locking device will due to the spring pressure return to the locked position when the locking pin (10) is released. 3. Working platform according to claims 1 - 2, c h a r a c t e r i s e d b y that the user can stand between the two overhangs (8) on the rung (3) during elevating or lowering the platform. 4. Working platform according to claims 1-3, c h a r a c t e r i s e d b y that the working platform (20) on each side has an elevated edge (12) above the plane (1) of the platform, which prevents slipping. 5. Working platform according to claims 1 - 4, c h a r a c t e r i s e d b y that it is equipped with frictional means, i. e. grooves (16) to improve the friction and safety. 6. Working platform according to claims 1-5, c h a r a c t e r i s e d b y that the user can move up or down all rungs (3) in the ladder (2) when the working platform (20) is in a depressed position. 7. Working platform according to claims 1-6, c h a r a c t e r i s e d b y that the overhangs (8) are formed like a half-moon.

Inventors: FAANES PER AAGE, FAANES, PER, AAGE
Applicants: FAANES PER AAGE, QUICK FIX AS, FAANES, PER, AAGE
Application year: 2000
Main classification: E06C7
IPC codes: E06C7