AU2017344056A1

AU2017344056A1 - Mechanical actuation device with automatic compensation for secondary scrapers in conveyor belts

Info

Publication number: AU2017344056A1
Application number: AU2017344056A
Authority: AU
Inventors: Franklin AGUIAR
Original assignee: Pur Equipamentos Ind Ltda
Current assignee: Pur Equipamentos Industriais Ltda
Priority date: 2016-10-11
Filing date: 2017-10-10
Publication date: 2019-06-20
Anticipated expiration: 2037-10-10
Also published as: AU2017344056B2; BR102016023744A2; CL2019001763A1; WO2018068116A1

Abstract

Mechanical actuation device with automatic compensation for actuating secondary scrapers, which is totally mechanical and not dependent on external energy action, providing constant pressure to the scraper after actuation since, in step with the blades wearing down and becoming smaller, there is balancing of actuation as a function of the force exerted by the spring. Owing to the pressure of the blades against the conveyor belt being constant, scraping efficiency is guaranteed up to the end of the service life of the blades. The actuation device (2) comprises tensioning device (2.1), lock-nut (2.2), nut (2.3), guide bush (2.4), tensioning device support (2.5), spring (2.6), fixing pin (2.7), fixing bush (2.8), articulation pin (2.9). rods (2.10), actuation limiter (2.11), eyelet (2.12), articulation pin (2.13), bush (2.14) and shaft locking pin (2.15).

Description

MECHANICAL DEVICE OF ENERGY SELF-COMPENSATING DRIVE FOR

SECONDARY SCRAPERS IN CONVEYOR BELTS [001] The present patent invention refers to a mechanical device of energy self-compensating drive for driving secondary scrapers, being applied to mining, iron and steel, fertilizer sectors, among others, that utilize conveyor belts for displacing bulk materials for cleaning through scraping of the conveyor belts.

[002] The device herein described is completely mechanical, independent of outer energy action, providing for constant pressure to the scraper after driving, once, as the blades are worn out and reduced in size, there is a balance due to the force exerted by the driving spring.

[003] Due to the pressure of the blades against the conveyor belt is constant, the scraping efficiency is guaranteed up to the end of the service life of the blades. Therefore, the working stroke is preset and driving is activated only when installing or changing the scraping blades. Consequently, the use of the present device results in the reduction of people in the work area, because it does not require constant regulations, preventing possible accidents .

[004] The scrapers are equipments of simple mechanics, for cleaning conveyor belts through scraping and are deemed as secondary when operating in the free area of the belt, that is, in the region where the belt does not directly contact the drum. They are comprised of wearing blades fitted and/or fixed in a metallic structure, functioning as a holder and driving the scraping system.

[005] In the present state of the art, in the secondary scrapers with a spring-driven mechanical device, the drive causes the scraper blades to be pressed against the conveyor belt. In addition to the replacement of these, there is a constant need for drive regulation, therefore, high labor cost and exposure to accident risks, due to circulation in the work area are unavoidable.

[006] There are secondary scrapers in which the driving springs are replaced by pneumatic, hydraulic and electrical actuators that do not require regulation, theoretically requiring human intervention only in the replacement of secondary scraper blades. In practice, one of the problems presented in solutions using auxiliary energy systems is that they are presented as an additional item for inspection and maintenance. Another problem is that by adding auxiliary energy systems, in addition to the additional cost of the aggregate system itself to the secondary scraper, there is the cost of auxiliary energy supply. But so far, they were the only resources that partially reduced human presence in areas deemed as at risk.

[007] The present patent discloses an energy selfcompensating driving device for secondary scrapers, completely mechanical, based on the same pantographic elevator mechanism, without independent of external energy action, providing for constant force to the scraper after driving the device. As the blades are worn out and reduced in size, the force exerted by the spring generates a resultant force that will ensure constant pressure of the blade against the belt.

[008] The present invention was developed from physical concepts expressed by classical mechanics, being, Hook's Law, mechanical stress and concepts of decomposition of forces. Before applying these concepts to the pantographic lift, usually used for lifting vehicles, the backgrounds were based on the natural behavior of the diamond shape, which, from the beginning to the middle of its course, performs small displacements of horizontal closure, promoting large displacements of vertical opening. By applying the spring to the horizontal hinges, very little pressure is lost when the blade wears out in the direction of the vertical hinges. Thus, in order to compensate for this small displacement of the spring, the adjustments were given from the concept of decomposition of forces, due to the angle formed in the driving body with a horizontal line .

[009] The mechanical device described in the present patent presents the following advantages:

[0010] - it efficiently maintains all conveyor belt cleaning control, without requiring external energy action; [0011] - the cost of implementing is the same as the conventional scrapers of manual regulation, besides having no cost with external power;

[0012] - effective reduction of inspection and maintenance, as there are no other accessories necessary for the drive;

[0013] - effective reduction of people in the area, preventing possible accidents, as it eliminates the regulation of manual systems and the inspection of auxiliary systems, which do not exist in this device.

[0014] - single adjustment of the secondary blades, made at the time of installation or replacement of the blades; [0015] - the service life of the blades is increased, favoring the scraping efficiency, considering that the pressure of the blades against the conveyor belt is constant;

[0016] - purely mechanical drive, designed from the principles of classical physics, to eliminate the need for regulations during the service life of the scraper blades, maintaining constant pressure there, without reguiring additional energy resources;

[0017] The mechanical device of energy self-compensating drive for driving secondary scrapers in conveyor belts may be better understood according to the appended drawings, wherein :

[0018] Figure 1 illustrates a perspective view of the secondary scraper with the device installed on its ends. [0019] Figure 2 illustrates the device with its components .

[0020] Figure 3 illustrates the view of one of the ends of the scraper with the holder and the device.

[0021] Figures 4, 5, 6, and 7 illustrate section views of the device.

[0022] According to Figure 1, the scraper assembly (1) where the driving device (2) will be installed is comprised of holders (1.1 and 1.2), blades (1.3) and shaft (1.4); each holder (1.1, 1.2) is fixed on the outer region of the transfer chutes of the conveyor belt (1.5) by welding, bolts or spacer shoes.

[0023] According to Figure 2, the driving device (2) is comprised of tensioner (2.1), counter nut (2.2), nut (2.3), guide bush (2.4), tensioner holder (2.5), spring (2.6), fastening pin (2.7), fastening bush (2.8), hinge bolt (2.9), rods (2.10), driving limiter (2.11), eyebolt (2.12), hinge bolt (2.13), bush (2.14) and shaft locking pin (2.15) .

[0024] Still, according to Figure 2, the driving device (2) is comprised of four rods (2.10) equal in size forming a diamond figure. The tensioner (2.1), horizontally installed, is positioned in the middle of the driving device (2), passing through the tensioner holder (2.5) and fixed by hinge bolt (2.9) passing through the eyebolt (2.12) welded in the tensioner (2.1) . The tensioner holder (2.5) has one of its ends fixed by the hinge bolt (2.13) and the other end is free having a bush (2.14) welded in the tensioner holder (2.5) . This bush (2.14) will contact one of the spring ends (2.6). The other spring end (2.6) is secured by a guide bush (2.4) which has the nut (2.3) tightened and, after the spring driving (2.6), it has a counter nut (2.2) tightened. This spring driving (2.6) is preset for the pressure exerted by the blades (1.3) against the belt to be not different from the ideal pressure previously calculated. To this end, the driving limiter (2.11) is welded to the tensioner (2.5) and the spring drive (2.6) is finished when the guide bushing (2.4) abuts the driving limiter (2.11), which in turn does not allow for greater compression of the spring (2.6).

[0025] According to Figure 3, the driving device (2) located on the holder (1.1) of the scraper (1) is completely free, without tensioning the spring (2.6), the drive being predefined between the two spring-guide bushes

(2.4),	responsible	for	generating	the	pressure	of the
blades	(1.3) against	the	belt (1.5) .
[0026]	According	to	Figure 4,	the	scraper	1 is
positioned with the	blade (1.3), exerting	pressure	against

the belt (1.5) at the beginning of its service life, having the least vertical distance (D) between the shafts and post-driving angle (β).

[0027] According to Figures 5 and 6, the scraper (1) is positioned with the blade (1.3) exerting pressure against the belt (1.5), highlighting the wear path of the blade (1.3) through the vertical distance (D) between shafts, which gradually increases due to the force exerted by the spring (2.6) and variation of the angle (β).

[0028] According to Figures 4, 5, 6, the positioning of the scraper 1, in relation to the belt, represents the behavior of the device 2 across the distances (A and D) and the angle (β) and the wear of the blades (1.3) through the measurement (C). The short stroke (C) corresponds to the service life of the slides (1.3), showing its beginning in Figure 4 and its end in Figure 6. The variation of the measurement (A), which is the measure of the variation of the length of the spring (2.6), can comprise the effect of the energy compensation, when due to the wear of the blades (1.3), the spring (2.6) will distend losing force until the end of the service life of the blades (1.3) . However, this loss of force of the spring (2.6) is compensated by the increasing variation in the value of the angle (β), that is, the force of the spring (2.6) is lost, but vertical force is gained.

[0029] According to Figure 6, the drive of the spring (2.6) is defined by the moment of compression of the spring (2.6) when the guide bush (2.4) abuts the driving limiter (2.11), which in turn does not allow more compression of the spring (2.6), due to the limiter (2.11) is welded to the tensioner (2.1).

[0030] According to Figure 7, the force exerted by the spring (2.6) on the guide bushes (2.4 and 2.14) displaces the tensioner holder (2.5) which, being fixed to one of the horizontal ends indicated by the hinge bolts (2.9 and 2.13 ), causes the opposite end to approach, and once the fastening pin (2.7) is fixed to the holder (1.1 and 1.2), the locking pin of the shaft (2.15) is displaced upwardly together with the blades (1.3), keeping the pressure constant against the belt (1.5) due to the increasing variation in the angle value (β) and the reduction in compression of the spring (2.6).

Claims

1. Mechanical device of energy self-compensating drive for secondary scrapers in conveyor belts, completely mechanical, to be installed in a scraper assembly (1) provided with holders (1.1 e 1.2) fixed on the outer region of the transfer chutes of the conveyor belt (1.5), blades (1.3) and shaft (1.4), characterized in that the driving device (2) is comprised of tensioner (2.1), counter nut (2.2), nut (2.3), guide bush (2.4), tensioner holder (2.5), spring (2.6), fastening pin (2.7), fastening bush (2.8), hinge bolt (2.9), four rods (2.10), driving limiter (2.11), eyebolt (2.12), hinge bolt (2.13), bush (2.14) and shaft locking pin (2.15) .

2. Mechanical device of energy self-compensating drive for secondary scrapers in conveyor belts, according to claim 1, characterized in that the device (2) of the conveyor belt scraper (1) is what will be positioned together with the blades (1.3) exerting pressure against the belt (1.5) having the four isometric rods (2.10) arranged in a hinge manner by pantographic system, with the least vertical distance (D) between the shafts, which gradually augments due to the force exerted by the spring (2.6) and variation of the post-driving angle (β) ; the force exerted by the spring (2.6) over the guide bushes (2.4 e 2.14) displaces the tensioner holder (2.5), that for being fixed on one of the horizontal ends, indicated by the hinge bolts (2.9 e 2.13), causes the opposite end to be approached, and once the fastening pin (2.7) is fixed on the holder (1.1 e 1.2), the shaft locking pin (2.15) is displaced upwards together with the blades (1.3), keeping the pressure constant against the belt (1.5) from the beginning to the end of service life of the blades (1.3) due to increasingly variation on the angle value (β) and reduction in spring compression (2.6); the spring driving (2.6) is defined by the moment of its compression, when the guide bush (2.4) abuts the driving limiter (2.11), which in turn stops compressing the spring (2.6), because the limiter (2.11) is welded in the tensioner (2.1) .

3. Mechanical device of energy self-compensating drive for secondary scrapers in conveyor belts, according to claims 1 and 2, characterized in that the tensioner (2.1) is horizontally installed positioned in the center of the driving device (2) passing through the tensioner holder (2.5) and fixed by the hinge bolt (2.9) passing through the eyebolt (2.12) welded in the tensioner itself (2.1); the tensioner holder (2.5) presents a fixed end through the hinge bolt (2.13) and the other end is free having a bush (2.14) welded in the tensioner holder (2.5); the bush (2.14) contacts one of the spring ends (2.6); the other spring end (2.6) is secured through a guide bush (2.4) having the nut (2.3) tightened and after the spring driving (2.6) , having a counter nut (2.2) tightened; the driving limiter (2.11) is welded in the tensioner (2.5), and the spring driving (2.6) is finished when the guide bush (2.4) abuts the driving limiter (2.11), which in turn, stops compressing the spring (2.6); the driving device (2) is installed on the holder (1.1 and 1.2) of the scraper (1) free from tensioning on the spring (2.6), the driving being preset between two guide bushes of spring (2.4), responsible for generating constant pressure of the blades (1.3) against the belt (1.5) from the beginning to the of its service life.