Title of Invention

SLIDING DEVICE FOR A THICK SUBSTANCE PUMP AND WEAR BAR FOR THE SAME

Abstract

The invention relates to a sliding device for a pump with two conveying cylinders working in push-pull operation, for conveying thick substances, with a largely C-shaped bent swing pipe gripping into a material feeding container, that can be supported in the lower region with a pressure plate (84) against a wear bar (82) arranged in the material feeding container, and which comes into contact against it in a sliding manner while swinging a swing pipe. In order to ensure a uniform erosion of the wear bar (82) over the entire sliding and pressing surface, the invention suggests that it should have sliding and pressing surface (86) and a longitudinally stretched outline for the pressure plate (84) which is wider at the ends (88) than in the central region (90).

Full Text

Sliding Device for a Pump and Wear Bar for the same Description The invention relates to a sliding device for a pump with two conveying cylinders working in push-pull operation, for conveying thick substances that are fed to a pump through a material feeding container, with a largely C-shaped bent swing pipe gripping into the material feeding container and which is connected at its upper end to a conveying pipe through a pipe rotary joint and is limited in a pivoted manner against it around the axis of the pipe rotary joint and whose other end can be alternately connected to the openings of the conveying cylinders, and which can be supported on the side of the material feeding container lying opposite to the conveying cylinder with a pressure plate against a wear bar arranged in the interior side of the material feeding container and is in contact in a sliding manner during the swinging sequence. The invention further relates to a wear bar for such a sliding device. Sliding devices of this type (DE-C-21 62 406) are particularly suited for automobile concrete pumps on account of their compact design, in which the end of the swing pipe protruding above the rear wall of the material feeding container forms a connection to the conveying pipe, if required, through an extension pipe; this conveying pipe is guided through a distributor mast resting on the front portion of the chassis. The parts of the sliding device subjected to high wear are easily accessible from the upper side of the material feeding container and can therefore be replaced easily. The wear bars of the known sliding devices of this type have a longitudinally stretched and largely rectangular outline. On their width side towards the inner side of the material feeding container, the wear bar is provided with an abrasion-proof coating. Besides, precautionary measures are taken, that allow an adjustment on the side of the wear bar according to the wear occurring in the sliding device. During operation of known sliding devices it has been seen that, on account of the non-uniform wear over the sliding length and breadth of the wear bar, gradually a wave-shaped or ramp-type surface run gets formed on the sliding surface or the pressing surface of the wear bar, that can lead to jerky movements or jamming during reverse sequence of the swing pipe. Based on this, it is the task of this invention to develop a sliding device of the type mentioned above and a wear bar for the same that allows a uniform erosion of the material coating subjected to wear and thus ensures a jerk-free operation. The solution according to the invention is mainly based on the idea that the wear bar has a sliding surface and a pressing surface with an effective sliding length for the pressure plate corresponding to the swing of the swing pipe, and has a sliding width at its ends corresponding to the diameter of the pressure plate and a sliding width that gets reduced in its central region towards the centre. Through these measures it is achieved that uniform material erosion takes place during the life-span over the entire sliding and pressing surface. Importance is to be given thereby to the knowledge that the sliding and pressing surface has to be adapted in its size and shape to the swinging range of the pressure plate arranged on the swing pipe and that in the central region, in which only sliding friction occurs in case of slight pressing force, altogether lesser material gets eroded. Accordingly, the wear bar has an effective sliding and pressing surface for the pressure plate with a longitudinally stretched outline that is wider at its ends than in its central region. Ideally, the sliding and pressing surface has in its central region a concave outline binding on both its sides, whereby starting from its effective end over its sliding length of at least 1.5 times the diameter of the pressure plate it initially still has a constant sliding width. A preferred extension of the invention foresees that the sliding width of the sliding and pressing surface is lesser in the central region than the pressure plate diameter, whereby at the centre of the wear bar the sliding width should preferably be lesser than 0.7 times the pressure plate diameter. An advantageous extension of the invention foresees that at the ends of the wear bar fastening straps or mounting. attachments are moulded, that are staggered with respect to the sliding and pressing surface at least by the thickness of the abrasion-proof material coating provided there. The invention is explained in details below through diagrams and drawings of a design example. The following are shown: Fig. 1 A cut-out of a two-cylinder thick substance pump in partially broken up depiction; Fig.2 An explosion depiction of the swing pipe of the two-cylinder thick substance pump shown in fig. 1; Fig.3a and b A top view and a partially sectioned side view of the wear bar. The two-cylinder thick substance pump shown in the drawing is mainly meant for use in automobile concrete pumps. It mainly comprises of two conveying cylinders 10 with hydraulic plungers driven in push-pull operation, a material feeding container 14 and a sliding device 20 with a C-shaped swing pipe 16 gripping into the material feeding container 14 from above and which can be activated by a reversible mechanism 18. The conveying cylinders 10 are connected through openings 22 to the rear wall 24 of the material feeding container 14, whereby the openings 22 on the inner side of the material feeding container 14 are limited by a spectacles-shaped wear plate 26. The swing pipe 16 with its lower end supporting a wear ring 28 lies against the wear plate 26 and by means of the reversible mechanism 18 in relation to the movement direction of the plungers 12 in the conveying cylinders 10, is swung alternately before the one or the other opening 22. In this way, with the back movement of the plunger 12 indicated by the arrow 13, material from the material feeding container 14 is suctioned in the direction of the arrow 32 through the free opening 22 into the corresponding conveying cylinder 10, while through the other plunger 12 material is transported in the direction indicated by the arrows 34, 36, 38 through the swing pipe 16 into a conveying pipe situated behind the rear wall 24 of the material feeding container 14. For this purpose, the swing pipe 16 is connected through a flange 40 to an extension pipe 42, which again is connected through a pipe rotary joint 43 to the conveying pipe leading to a concrete distributor mast. The flange 40 is connected in a detachable manner by means of two clamping screws 44 to the reversing lever 46 of the reversing mechanism 18 that has at its lower ends bearing points 48 pointing to opposite sides and designed as spherical pans for connecting one of the piston-side ball head 50 of both driving cylinders 52. On the cylinder side the drive cylinders 52 are supported with another ball head 54 in a conveying cylinder-fixed, as bearing position 56 designed as ball pan. In order to ensure a tight contact of the lower end of the swing pipe 16 against the wear plate 26, a force acting perpendicular to the rear wall 24 of the material feeding container is exercised on the lower arm 80 of the swing pipe 16 by an adjusting screw 62 that can be activated form outside. During the pumping sequence, the wear ring is additionally pressed against the respective opening edge of the wear plate 26 by means of hydrostatic forces within the swing pipe 16. The lower arm 80 of the swing pipe 16 supports at its side towards the wear bar 82, a pressure plate 84 which lies against the sliding and pressing surface 86 of the wear bar 82 pointing towards the inner side of the material feeding container 14. As one can especially seen from fig. 3a, the effective sliding and pressing surface 86 of the wear bar 82 has a longitudinally stretched outline that is wider at its ends 88 than in its central region 90. The sliding and pressing surface 86 formed by an abrasion-proof material coating 100 that protrudes above the corresponding plate levels 92. In the region of both ends 88, the edge 94 of the effective sliding and pressing surface 86 pointing outwards is bent in a circular shape, with a bending radius that approx. corresponds to the radius of the circular pressure plate 84. Starting from the outer edge 94, the sliding and pressing surface 86 initially has for some distance a constant sliding width be in the region of the end 88 corresponding to the diameter of the pressure plate 84. Subsequently the sliding width bm reduces in the central region 90 towards the centre along two concave edge lines 96 by half. With these measures it is achieved that the wear over the entire sliding and pressing surface 86 takes place uniformly while swinging the swing pipe 16, so that no waves or ramps get formed along the sliding and pressing surface 86. At the ends 88, opposite to the sliding and pressing surface 86, mounting attachments 98 are moulded in a shifted back position, that rectangularly border the wear bar 82. One can sum up as follows: the invention relates to a sliding device for a pump with two conveying cylinders working in push-pull operation, for conveying thick substances, with a largely C-shaped bent swing pipe gripping a material feeding container; the swing pipe can be supported in the lower region with a pressure plate 84 against a wear bar 82 arranged in the material feeding container, and which comes into sliding contact with it on swinging the swing pipes. In order to ensure a uniform abrasion of the wear bar 82 over the entire sliding and pressing surface, the invention suggests that its effective sliding and pressing surface 86 has a longitudinally stretched outline for the pressure plate 84; this outline is wider at the ends 88 than in the central region 90. WE CLAIM: 1. Sliding device for a pump with two conveying cylinders (10) working in push-pull operation, for conveying thick substances that are fed to the pump through a material feeding container (14), with a largely C- shaped bent swing pipe (16) gripping into the material feed container (14), which at its upper end is connected to a conveyor pipe through a pipe rotary joint and is limitedly swivelable against it around the axis of the pipe rotary joint and is thereby connectable with its other end alternately to the openings (22) of the conveying cylinder (10), and the side of the material feeding container (14) lying opposite to the conveying cylinder (10) can be supported with a pressure plate (84) against a wear bar (82) arranged in the inner side of the material feeding container and comes into sliding contact against it during the swinging sequence, having the distinctive feature that the wear bar (82) has a sliding and pressure surface (86) with an effective sliding length for the pressure plate (84) corresponding to the swing of the swing bar (16), having a sliding width (be) at its ends corresponding to the diameter of the pressure plate (84) and a sliding width (be) that reduces in its central region (90) towards the centre. 2. Sliding device as per claim 1, having the distinctive feature that the wear bar (82) has at the ends of its sliding and pressing surface, a convex edge bend, corresponding to the outline of the pressure plate (84). 3. Sliding device as per claim 1 or 2, having the distinctive feature that the sliding and pressing surface (86), starting from its effective ends and going over a sliding length of at least 1.5 times the diameter of the pressure plate (84), has constant sliding width (be). 4. Sliding device as per one of claims 1 to 3, having the distinctive feature that the sliding and pressing surface (86) of the wear bar (82) has in its central region (90) a both-sided concave bordering edge. 5. Sliding device as per one of claims 1 to 4, having the distinctive feature that the effective sliding width (bm) of the wear bar (82) is lesser in its central region (90) than the pressure plate diameter. 6. Sliding device as per one of claims 1 to 5, having the distinctive feature that the wear bar (82) carries an abrasion-proof material coating (100) in the region of effective sliding and pressing surface (86). 7. Sliding device as per one of claims 1 to 6, having the distinctive feature that at the ends (88) of the wear bar (82) opposite to the abrasion-proof material coating (100), shifted back fastening straps (98) are moulded. 8. Wear bar for supporting a pressure plate (84) of a C-shaped swing pipe (16) within a material feeding container of a thick substance pump, having the distinctive feature that it has an effective sliding and pressing surface (86) for a pressure plate (84) with a longitudinally stretched outline that is wider at its ends (88) than in its central region (90). 9. Wear bar as per claim 8, having the distinctive feature that the effective sliding and pressing surface (86) has a both-sided concave outline binding (96) in the central region (90). 10. Wear bar as per claim 8 or 9, having the distinctive feature that the effective sliding and pressing surface (86) is formed by an abrasion-proof material coating (100). 11. Wear bar as per claim 10, having the distinctive feature that on the effective sliding and pressing surface (86), connected fastening attachments (98) in a single piece are provided outwards, that are shifted back with respect to the sliding and pressing surface by at least the thickness of the material coating (100). The invention relates to a sliding device for a pump with two conveying cylinders working in push-pull operation, for conveying thick substances, with a largely C-shaped bent swing pipe gripping into a material feeding container, that can be supported in the lower region with a pressure plate (84) against a wear bar (82) arranged in the material feeding container, and which comes into contact against it in a sliding manner while swinging a swing pipe. In order to ensure a uniform erosion of the wear bar (82) over the entire sliding and pressing surface, the invention suggests that it should have sliding and pressing surface (86) and a longitudinally stretched outline for the pressure plate (84) which is wider at the ends (88) than in the central region (90).

Documents:

770-kolnp-2006-granted-abstract.pdf

770-kolnp-2006-granted-claims.pdf

770-kolnp-2006-granted-correspondence.pdf

770-kolnp-2006-granted-description (complete).pdf

770-kolnp-2006-granted-drawings.pdf

770-kolnp-2006-granted-examination report.pdf

770-kolnp-2006-granted-form 1.pdf

770-kolnp-2006-granted-form 13.pdf

770-kolnp-2006-granted-form 18.pdf

770-kolnp-2006-granted-form 2.pdf

770-kolnp-2006-granted-form 26.pdf

770-kolnp-2006-granted-form 3.pdf

770-kolnp-2006-granted-form 5.pdf

770-kolnp-2006-granted-gpa.pdf

770-kolnp-2006-granted-reply to examination report.pdf

770-kolnp-2006-granted-specification.pdf

770-kolnp-2006-granted-translated copy of priority document.pdf