GB2144195A

GB2144195A - Machine safety device

Info

Publication number: GB2144195A
Application number: GB08414195A
Authority: GB
Inventors: Lars-Ake Svensson
Original assignee: Hymo AB
Current assignee: Hymo AB
Priority date: 1983-06-10
Filing date: 1984-06-04
Publication date: 1985-02-27
Also published as: GB8414195D0; SE464760B; SE8303299L; FR2547808B1; DE3420225A1; GB2144195B; SE8303299D0; FR2547808A1

Abstract

A device for a so-called terminal strip (6) is intended to stop the motion of a lifting table, an elevator, an industrial door or similar movable object (3) when the terminal strip (6) is affected by a thing (19) having come in between the movable object (3) and an immobile object (20). Said thing (19) could otherwise be squeezed between said movable and immobile objects (3, 20). The device includes a profile which is displaceably mounted in the direction of motion of the movable object (3) at an edge (12) of the same which is so arranged that an edge line of the same is situated in level with the edge (12) of the movable object (3) and which is arranged to affect the switches (15) that stop the motion when the profile is displaced in the direction of the movable object (3). The profile has two sides approximately parallel both mutually and with the direction of motion and is at least partly countersunk in a U-shaped canal or a U-shaped track. The two opposite side walls of the canal or track fit to said sides of the profile. The profile has a longitudinal flange (7) which as well as the rest of the profile is made from a rigid material, preferably aluminium. The outer free end forms said edge line of the profile. <IMAGE>

Description

SPECIFICATION Device for so-called terminal strip The present invention relates to a device for a so-called terminal strip intended for stopping the motion of a lifting table, and elevator, an industrial door or similar movable object when the terminal strip is affected by a thing having come in between the movable object and an immobile object, where said thing otherwise could be squeezed between said movable and immobile objects, including a profile which is displaceably mounted in the direction of motion of the movable object at an edge of this whereby the profile is arranged so that an edge line of it is situated on level with the edge of the movable object and is arranged to affect the switches that stop the motion when the profile is displaced in the direction of the movable object.

At such terminal strips of known type the design is such that someone may block the function of the terminal strip either by thoughtlessness in order to work faster or by ill will. Naturally this can cause both personal as well as material damages.

A primary object ofthe present invention is to achieve a terminal strip of introductory said type, where the design and shape does not allow it to be blocked and this is facilitated as the profile has two sides approximately parallel both mutually and with the direction of motion and is at least partly countersunk in a U-shaped canal ora U-shaped trackthe two opposite side walls of which fit to said sides of the profile which has a longitudinal flange which as well as the rest of the profile moulding is made from a rigid material, preferably aluminium and whereby the other free end forms said edge line of the profile.

A profile included in a terminal strip according to the invention has a preferably U-shaped cavity in the cross-section facing the canal or the track so that its shape looks like a chair viewed from the side, with a back rest slanting outwards consisting of said flange and where the legs and the seat are formed by a preferably right angular U-profile (turned up-side down).

As, according to a specific characteristic of the invention, above mentioned switches and the necessary wires are placed in the cavity of the profile and that the canal consists of another somewhat larger U-profile or of an inner wall of the movable object and a Z-profile co-operating with said wall the switches and the wires become completely protected against damage and can be pushed from behind in between the terminal strip and the movable object.

lithe following the invention will be explained further with reference to the enclosed drawing on which the invention as an example is shown applied as a so-called safety frame on an electrically or hydraulically manoeuvered shear lifting table. Figure 1 shows such a lifting table in a plane view from aside. Figures 2a and 2b show the design and function of a cross section of the safety frame and Figure 3 shows a detailed perspective view of a preferred design of a safety frame.

The shear lifting table in Figure 1 is generally speaking conventionally built up and includes a frame-shaped undercarriage 1, two pairs of lifting arms 2 arranged in shear-shape, out of which only one pair is visible in the drawing, one platform 3 and a hydraulically working cylinder-piston unit 4. The ends marked 5 of the lifting arms 2 are swevellingly fixed to the undercarriage 1 and the platform 3 respectively and the two remaining ends are preferably equipped with rollers and slidingly arranged along guide paths, not visible in the drawing, in the undercarriage 1 and the platform 3. The platform 3 is raised by means of the cylinder-piston unit 4 acting between two shanks of the lifting arms. The platform is lowered by its own weight or by reversing.

To avoid squeeze accidents when lowering the platform 3 there is a so-called safety frame 6 along the edge of the platform 3, where said safety frame is upheld in such a way that it can be displaced in a direction towards the safety platform by a comparatively low force. The lowering motion is stopped via switches, the function of which will be explained further in connection with Figure 2 and which are affected when displacing the safety frame 6.

The design and function of a safety frame according to the invention will be explained in further detail referring to Figures 2a, 2b and 3. The sides of the safety frame 6 are made of a profile, which according to the invention has a longitudinal flange 7 and the sides are joined in the corners with special corner parts 8. The frame is displaceably shackled in special corner attachments 9 and, if so is required, with regards to the lengths of the sides, there are also attachments 10 at the sides of the frame.

The flange 7 forms an acute angle a with the direction of displacement of the safety frame 6, which in Figure 2a is marked with a dotted line 11 and is mounted relative to the edge 12 of the platform 3 so that the free edge line of the flange 7 is at the same plane as the edge 12 of the platform. The shape of the cross-section of the profile preferably resembles a chair turned up-side-down and viewed from the side. The outwardly slanting back-rest of the chair consists of the flange 7 and its legs and seat consist of a preferably right angular U-profile, whereby the mutually parallel flanges arranged at a distance from each other are marked 13 and 14, see Figure 2.

According to the invention the earlier mentioned switches 15, which are affected at the displacement of the safety frame, and wires 16 for connection of these are placed in between the flanges 13, 14 of the U-profile. The safety frame is at least partly surrounded by the inner wall 17 of the platform 3 and a Z-profile 18 co-operating with said wall 17, so that the switches 15 and the wires 16 are completely protected against damage.

The safety frame according to the invention works in the following way, see Figures 2a and 2b and Figure 1 where the positions of the lifting table shown in Figure 2 are marked with the dotted and dashed line. An object 19 is assumed to be in such a position that it may be squeezed between the platform 3 and the floor in Figures 2a and 2b marked 10. In Figure 2a the flange 7 of the profile has just come in contact with the object 19 by the lowering motion of the platform 3. When the platform 3 is lowered further, still having a good safety margin for damages of the object 19, the safety frame 6 is pushed upwards whereby one or more of the switches 15 is brought in contact with the Z-profile 18 and the movement is stopped.

Claims

1. Device for a so-called terminal strip (6) intended for stopping the motion of a lifting table, an elevator, an industrial door or similar movable object (3) when the terminal strip (6) is affected by a thing (19) having come in between the movable object (3) and an immobile object (20), where said thing (19) otherwise could be squeezed between said movable and immobile objects (3, 20), including a profile which is displaceably mounted in the direction of motion of the movable objet (3) at an edge (12) of the same which is so arranged that an edge line of the same is situated in level with the edge (12) of the movable object (3) and which is arranged to affect the switches (15) that stop the motion when the profile is displaced in the direction of the movable object (3), characterized in, that the profile has two sides approximately parallel both mutually and with the direction of motion and is at least partly countersunk in a U-shaped canal or a U-shaped track the two opposite side walls of which fit to said sides of the profile which has a longitudinal flange (7) which as well as the rest of the profile is made from a rigid material, preferably aluminium and whereby the outer free end forms said edge line of the profile.

2. Device according to claim 1, characterized in, that a profile has a preferably U-shaped cavity in the cross-section facing the canal or the track so that its shape looks like a chair viewed from the side, with a back rest slanting outwards consisting of said flange (7) and where the legs and the seat are formed by a preferably right angular U-profile (turned up-sidedown).

3. Device according to claims 1 and 2, characterized in, that said switches (15) and the necessary wires (16) are placed in the cavity of the profile moulding and that the canal consists of another somewhat larger U-profile or of an inner wall (17) of the movable object and a Z-profile (18) co-operating with said wall (17) so that said switches (15) and the wires (16) are completely protected against damage and so that no object can be pushed from behind in between the terminal strip (6) and the movable object (3).

4. Device for so-called terminal strip constructed, arranged and adapted for use substantially as hereinbefore described.