WO1982003246A1 - Improvement in high pressure double action pumps - Google Patents

Abstract

Improvement to high-pressure double-acting pumps, having a waterproof, cylindrical jacket (3) made with a suitable flexible material, fixed between the upper part (5) of the cylinder (1) and the extreme part (8) of the element force or piston (9) which gives rise to the reciprocating movement of the pump.

Description

IMPROVEMENT IN HIGH PRESSURE DOUBLE ACTION PUMPS

This invention relates to high pressure double action pumps particularly used for pumping aggressive liquids such as atomizing ones used in agriculture. The corrosive effect of such liquids on metalic portions which they touch is very well known.

The most affected part is the one that holds the press button pump set. This set carries a metalic cylinder in its core where the end portion of a forcer works conduction piston giving raise to the alternative motion of the pump.

This press button, conventionally, comprises a gasket made of a synthetic flexible material fixed to the forcer or piston and working by pressing the walls of said cylinder. This gasket, besides pressing the liquid, works also as a packing for preventing the liquid from pouring between the walls of the cylinder into the functional inner parts of the pumps.

One of the principal problems linked to this kind of pump lies exactly on this fact, because the liquid, due to its aggressivity, injures said walls, giving raise, in a very short time, to erosion that precludes the packing action exerted by said gasket. This fact thus gives urge to frequent changes of cylinders and consequently to additional costs and deferment in production, due to the forced stoppage of the equipment.

Cylinders made out of porcelain have been regarded as a solution to this erosive process, as they do not suffer under the liquid aggressivity. Considering, however, that procelain is a very expensive imported material, subject to accidental breakage, the inadequacy of its commercial utilization becomes quite obvious. This invention, evading the various propositions offered up to now, solves this problem in a practic, cheap, efficient, also feasible under an industrial view point. The annexed drawings illustrate this invention which is characterized by the fact of applying to the inner walls of said cylinder 1, covering this wall 2 completely, an impeimeable and cylindrical jacket 3, made of a convenient flexible material substantially in the form of a drinking glass, being said jacket fixed by means of its circular flange 4 to the top portion 5 of said cylinder, and fixed by means of its bottom portion 6, preferably having central hole 7, to the end portion 8 of the forcer or piston 9 which operates inside the cylinder 1.

In the drawings, figure 1 is a view in perspective of the flexible jacket 3 before adjustment to the cylinder. Figures 2 And 3 are sectional side views of said jacket now positioned in the cylinder, duly fixed by means of said flange 4 to the top portion of said cylinder and by its bottom portion 6 to the end portion of piston 9. Hole 7 at bottom 6 is meant to easily fitting the jacket to the forcer or piston whereto said jacket is fixed by proper means such as fasting screw lock washers (10.11). Figure 4 is a partial sectioned side view of a common pump, as above mentioned, duly equiped with the improvement object of this invention. It illustrates, in special, a simple manner of fixing flange 4 of said gasket between the top portion of said cylinder and the headstock base 12, meant to the input and output of the liquid under pumping action. Figures 2 and 3 illustrate, in special, the performance of said jacket inside said cylinder when said forcer or piston is at work. These figures show that in whatever position said forcer or piston may be, said cylinder walls 2 remain permanently apart from the liquid action, free from its aggressive results. The outstanding advantage brought by this invention permits the manufacturing of such cylinders with cheap materials, on the contrary of the general use nowadays, such as common metals, even iron, because they do not have to offer any special qualification in order to resist to the corrosive effect of the liquid under pumping.

Said figures 2 and 3 clearly illustrate that said flexible jacket follows the alternative motion of the forcer or piston, inclusively protecting said piston or forcer against contact with said corrosive liquid. It most also be stressed that the pressure effect of said liquid against the neck portion 13 of said jacket becomes substancially weakened in point P (point of maximum pressure incidence) because point P changes of place according to each position of said forcer or piston performance. This fact gives origin to a regular and uniform distribution in the whole extension of said jacket of a resistance strenght that ensures to said jacket, in which concerns fatigue of materials, practically endless life.

Claims

CLAIM 1. Improvement in high pressure double action pumps having a metalic cylinder in its core where the end portion of a forcer or conducting piston works giving raise to the alternative motion of the pump, characterized by the fact of applying inside the cylinder (1), covering its inner wall (2) completely, an impermeable and cylindrical jacket (3), made of a convenient flexible material, substantially in the form of a drinking glass, being this jacket fixed by means of its circular flange (4) to the top portion (6) of said cylinder (1) and fixed by means of its bottom portion (6) preferably having a central hole (7), to the end portion (8) of the forcer or piston (9).