WO2015112000A1

WO2015112000A1 - Improved wheelbarrow with plastic tray and method for the production thereof

Info

Publication number: WO2015112000A1
Application number: PCT/MX2014/000026
Authority: WO
Inventors: Rodrigo MEDINA ESPINOSA
Original assignee: Medina Espinosa Rodrigo
Priority date: 2014-01-27
Filing date: 2014-01-27
Publication date: 2015-07-30
Also published as: MX2015009079A

Abstract

The invention relates to a wheelbarrow comprising a tray consisting of various parts made of high-density polyethylene, which are interconnected by means of the projections and cavities thereof. The method for producing the wheelbarrow comprises the following steps: 1) producing high-density polyethylene plastic sheets by way of extrusion, heating up to 220°C for 120 seconds, with melting and roller lamination; 2) cutting to measure; 3) holding in a frame and heating between 120 and 130°C for 120 seconds, thermoforming, transfer to moulding step; 4) moulding of the parts of the multiple tray and vacuum sealing; 5) cutting and cooling; and 6) assembly by welding points.

Description

TRAILER WITH IMPROVED PLASTIC TRAY AND ITS PROCESS

ELABORATION.

TECHNICAL FIELD OF THE INVENTION

The present invention is related to the technical field of construction or gardening, more specifically in the area of ^• manufacture and construction of furniture.

BACKGROUND OF THE INVENTION

The present invention is created with the interest of re-impelling the construction and / or gardening industry in one of its articles necessary for the transportation of cargo such as the caretilla.

The first illustrations of wheelbarrows from a wheel come from the Han Dynasty of China in the 2nd century AD. and they were found in murals of tombs and reliefs in brick tombs. The mural painted on a tomb showing a man pushing a wheelbarrow was found in Chengdu, Sichuan province and dated exactly 18 a. C. Another relief carved in stone showing the same scene was found in the tomb of Shen Fujun in the province of Sichuan, dated around 150 A.D. The mural of the Wu Liang shrine in Shandong (dated 147 AD) shows the story of the pious Dong Yuan, unlocking his father in a wheelbarrow, Lu Che. However, there are still older records dating back to the 1st century BC. C. and I A.D.

The truck is a small, normally single-wheeled vehicle designed to be propelled by a single person and used for hand-carrying cargo.

There are several types: The ^" single wheel" front wheel is designed to distribute the weight of the load between the wheel and the worker, which allows carrying heavier loads than if they had to be transported totally by the person. It is commonly used in the construction industry and in gardening. Its approximate capacity ^is' 1 70 kilos of material.

The two-wheeled trolley, more stable at ground level, is widely used to load boxes or other things that can be stacked, while the almost universal one wheel has greater maneuverability in small spaces, on wooden planks or when a floor leaning would throw the load. The one wheel also allows greater control of emptying of load. The industrial truck, more sophisticated, has hydraulic suspension system, two stringers, each with a small wheel -.- and another pair of front wheels rotating. The latter is used for heavier loads and in commerce it is used to transport household appliances. All these types of existing trucks, are manufactured in rigid and strong materials, such as metals, wood and even in polymers or plastics, that today any polymer or resistant plastic materials, there are already several trucks that are manufactured today with a resistant plastic tray, and with stronger and stronger structural designs that give hardness to the tray when transporting heavy or liquid materials, but have the deficiency that the plastic tray to be manufactured, is of a relatively thin thickness runs the risk of breaking or tearing, or deterioration due to constant use and more when used in construction or gardening, and for daily use when transporting heavy items; the existing forklifts today, which we find in the market or in stock are made of thin plastic materials that suffer rapid deterioration and can easily break, or if they use thicker material, weigh much more and in the long run it is tired for the user, load both the truck and the transported material; Therefore, to counteract the aforementioned problems, several patents have been developed, for example, the US201001317 ¹ ), describes an improved truck tray that is formed as an integral unitary piece! through injection molding of plastic or polyethylene. The improved tray does not include any holes in the lower part of the tray for bolted joints in the truck frame, thus eliminating a possible source of leaks when the transport is of powders or liquids. In addition, the underside of the truck tray, on the outside of the cup portion, is a reinforced protruding bar that adds strength and provides a location to screw the truck tray to the truck frame. The inclusion of protruding bars in the lower part of the front part of the perimeter tray and a dumping effect, while the plastic tray maintains its strength and shape, while the liquids can easily be poured over the part. front of the trolley tray.

Patent US2005087958, This invention relates to an improved tire including a pair of legs that are shown in the four-bar links and are collapsible. Each leg includes an advantageously simple lock to releasably lock the leg in extended and retracted positions. The truck includes a frame assembly, a wheel, a tray, and a pair of handles. The frame assembly can be assembled by the manufacturer, and ^■ the truck can be provided as a kit according to the present invention which can be assembled by the retailer or the consumer simply by joining the wheel, the tray, and the handles to the Frame set. A block of support is given to know what facilitates the assembly and strengthens the legs. In order to eliminate all these drawbacks mentioned, a new wheelbarrow with improved plastic tray was developed and its manufacturing process, which would facilitate construction technicians, plumbers or gardeners, have a wheelbarrow with tray Improved plastic and much lighter, and at the time you want, the user can manipulate the truck according to their needs, plus if in the future you want to change the tray for any eventuality that may arise, you can remove and put another plastic tray, without any problem; thus saving time and material, likewise this truck has the characteristic of being thermal since it has two or even more injected plastic trays fused together, which also makes it acoustic and avoids excessive vibration as the cameras internal between each tray make a thermal-acoustic camera, avoiding that the temperature of the environment increases in the interior causing that the plastics do not undergo an expansion or extreme dilatation and with time the trays suffer deformation, in the same way it is acoustic because the design of its inner camera causes that when the user goes on paved or uneven roads the vibrations that go through the body of the truck diminish to the hands and arms of the user. The material with which this product is suggested is manufactured with polymer or any transformable plastic product that exists in the market or could exist, although it does not simply limit these materials to its industrialization, with the following particularities and advantages:

DESCRIPTION OF THE INVENTION The characteristic details of the present acoustic thermal conductor wall, which are described below, based on the figures mentioned, are cited by way of example, so they should not be considered as limiting.

Brief description of the figures:

Figure 1 is a conventional perspective side view of the truck with improved plastic tray and its manufacturing process. Figure 2 is a right side view of the truck with improved plastic tray and its manufacturing process.

Figure 3 is a front view of the truck with improved plastic tray and its manufacturing process.

Figure 4 is a top view of the truck with improved plastic tray and its manufacturing process. Figure 5 is a bottom view of the truck with improved plastic tray and its manufacturing process.

Figure 6 is an explosive view of the parts with which the truck with improved plastic tray and its manufacturing process is formed.

Figure 7 is an explosive view of the two plastic trays.

Figure 8 is a side view of the inner plastic tray.

Figure 9 is a top view of the lower face of the outer plastic tray.

This truck with improved plastic tray and its manufacturing process, consists of: A truck having a support frame or body (1) preferably metallic or any other rigid material which is in turn made up of an upper portion ( 2) with a pair of bars (3) a pair of ergonomic handles (4), in the middle portion (5) of the frame or support body (1) is drilled a series of holes (6) passed through where they couple on the lower face (7) of the frame or support body (1) a pair of preferably metallic legs (8) which are coupled by means of fastening (9) already known as screws or bolts, the aforementioned pair legs (8) are subject or secured by a rectangular frame (10) made of any rigid material, which is secured by means of screws (1 1) to a last holes (12) ^'are located in different areas the legs (8) said rectangular frame (10), has the function of giving greater rigidity to the legs (8); in the upper part of the frame or support body (1) in the middle portion (5) is attached by means of screw or bolt fastening (9) an open container called improved plastic tray (13) which is shaped to a outer tray (14) which on its lower face (18) has at least two channels (1 7) fitting snugly on the rail of the middle portion (5) of the frame or support body (1), said outer tray (14) in all its upper periphery (15) has a grooved projection (16) and especially the surrounding body (1 9) of the outer tray (13) are convex, concave lateral and posterior reliefs and concave frontal lines

(20) simulating ribs which when coupling the plastic tray inside

(21) which is completely smooth in all its periphery of the body (22) and in its lower face (23) is flat and with several holes of attachment and fastening (24) arranged between them, which are coupled to the same holes with which the outer tray (14) has, in the upper periphery is a ribbed projection (25) in the same way as (15) and (16) of the outer tray, that when the two outer trays (1) are coupled together lower (21) are sealed or fused throughout its upper periphery (1 5) and (25). by means of a machine which commands ultra sound shocks and merges the two outer (14) and inner (21) trays, leaving between each tray an internal air chamber (not illustrated), which has the function of making the tray (13) is acoustic and thermal at the same time, and with the convex and concave reliefs (20) simulating ribs, making the tray rigid and firm, since it is fastened on the front with two metallic lines ( 26) detained by fastening means (9) to the front face (27) of the tray (13) and also joined to the front body (28) of the frame or support body (1) .. it also has a wheel or front rim (29) Impossible subject to the support body (1) by means of attachment (10) known by. an expert in the field, with this the truck is shaped with improved plastic tray; Now we will explain e! process of making the plastic tray.

The first step is to manufacture plastic sheets of the color and measure that is required, where raw material, HDPE in ground or palletized grain, is mixed and poured into the hopper of the plastic extruder to later pass through the screw where the material reaches temperatures of 220 degrees Celsius, with a time of 1 20 where it melts and subsequently is introduced to the rollers, which will give the flat shape to the sheet and are responsible for giving the desired thickness, in the case of the sheets the Density gauge preferably used for the plastic tray of the truck is between 5.5 mm to 6 mm. Or 6 mm. to 7 mm. thick.

Second step: Afterwards they pass to the guillotine or machine that cuts the sheet to a certain extent, said sheets already sectioned, cut to the required measure, they pass to the fermoformaclo machine;

Third step: the sheet is held in a frame and heated in an oven at a temperature between 1 20 to 1 30 degrees centigrade, for a time of 1 20 seconds the combination of time and exposure to the temperature of the resistances make it malleable the plastic, the resistances to the thermoforming are calibrated in some areas to 90% and in others between 70 to 65% depending on the area of the mold, when it is at its ideal point, the sheet passes to the station of the molds, "the ideal point is "when the plastic is heated, it is hanging from the frame due to gravity as the temperature rises, this phenomenon is called bell, in some plastics the bell falls, then it contracts again and that's when it goes to the next step or station. The time of the first season (heating) and 2nd station (thermoformed) try to balance, if the fermoforming is longer than the heating, heat the sheet in the first station, if the heating time is shorter than the formed the pieces do not cool well. In relation to the time of forming and calibration of the machines we bring a heating cycle of 1 20 seconds.

Fourth step: a thermoformed and calibrated plastic sheet, accommodates in a mold called male that is convex with protuberances or protrusions being a positive mold, the plastic will be in contact with the "internal" face of the piece, the finish of the thermoforming in this mold order ^'is that impurities mold and sections of assemblies with vacuum holes are copied, the face that the plastic does not touch AEL mold is used as "view of the part" because it has better finish denominándole external tray to the piece; The other female mold is concave, it is a negative cavity or mold, it is used for the internal shell because the face of the plastic that touches the mold will be on the outside, the one with the best finish will be inside, and it is the one that gives sight to the inner shell, Later a seal is made between the molds and the air between the plastic and the mold is sucked by means of vacuum to form the trays;

Step Five: they go to the clipping area where the surplus plastic is cut by means of a spinning saw, and goes to cooling;

Step Six: subsequently the inner and outer trays are assembled and passed to the fusion machine, which is an ultrasonic shock machine calibrated to leak by means of vibrations, welding with at least 10 shock points on the entire periphery of the two trays, making the two trays join with the heat of the ultrasound or three or more forming a single piece that can be attached; Seventh step: holes are drilled in the base of the tray through which the fastening means pass.

Eighth step: the improved plastic tray is attached to the support body of the truck, holding it with the fastening means (screw), the truck being joined and formed.

Claims

Having sufficiently described my invention, and this being a novelty, claim as my exclusive property, contained in the following clauses. l. A wheelbarrow with improved plastic tray and its manufacturing process, characterized in that it comprises: i. A wheelbarrow having a supporting frame or body (1) preferably made of metal or any other rigid material which in turn is constituted;

II. from a top portion (2) a pair of baths (3) a pair of ergonomic handles (4),

III. in the middle portion 5) of the frame or support body (1) is drilled a series of holes (6) past which are coupled to the lower face (7) of the frame or support body (1) a pair preferably metallic legs (8) which are coupled by means of clamping (9) as screws or bolts;

IV. The aforementioned pair of legs (8) will be held or secured by a rectangular frame (10) made of any rigid material, which will be fastened by means of screws (11) to past holes (12) that are located in different areas of the legs (8); 2. the truck with improved plastic tray of claim 1, characterized in that it comprises: in the upper part of the frame or support body (1) in the middle portion (5) is attached by means of fastening screws or bolts (9) an open container called double plastic tray (13);

3. a wheelbarrow with improved plastic tray of the preceding claim, characterized in that it comprises:

I. of an outer tray (14) which on its lower face (18); II. has at least two channels (17) that fit snugly in e! rail of the middle portion (5) of the frame or support body (1);

III. said outer tray (14) along its entire upper periphery (15) has a grooved projection (16);

IV. and especially the surrounding body (19) of the outer tray (14) are convex, concave and concave frontal lines or any other design (20) simulating ribs; 4. the truck with improved plastic tray of claim 2 and 3, characterized in that it comprises:

I. an inside plastic tray 21),

II. it is completely smooth in all its periphery of the body (22);

II !. its lower face (23) is flat and has several holes for coupling and fastening (24) arranged between each other, which are coupled to the same holes that the outer tray (14) has:

IV. in the upper periphery there is a grooved projection (25) in the same way as (15) and (16) of the outer tray; 5. the truck with improved plastic tray of the preceding claim, characterized in that it comprises: when coupling the two outer (14) and lower tray 21) are sealed and fused throughout its upper periphery (15) and (25) by means of a heat generating machine;

6. the truck with improved plastic tray of the preceding claim, characterized in that it comprises: between the two outer (14) and inner (21) trays, there is an internal air chamber, which has the function of making the tray (13) be acoustic and thermal at the same time, and with the convex and concave reliefs (20) simulating ribs make the tray rigid and firm, and not suffer deformation; the truck with improved plastic tray of the preceding claim, characterized in that it comprises: that the tray 1 3) is fastened in the front part with two metal lines (26) stopped by fastening means (9) to the front face (27) ) of the tray (1 3) and also connected to the front body (28) of the frame or support body (1), as well as with a front wheel (29) imposed on the support body (1) by means of restraint (1 0);

8. the truck with improved plastic tray of the preceding claims, characterized in that it comprises: more than 2 trays and between each of them, some thermal and antiacust material is added to fill the dead spaces; the truck with improved plastic tray of the preceding claims, characterized in that it comprises: an improved plastic tray manufacturing process (1 3),

AND! First step: it consists in manufacturing plastic sheets of! color and measure that is required, where raw material, HDPE in ground or palletized grain, is mixed and poured into the hopper of the plastic extruder to later pass through the screw where the material reaches temperatures of 220 degrees Celsius, with a time of 1 20 where it melts and then is introduced to the rollers, which will give a flat shape to the sheet and are responsible for giving the desired thickness, in the case of the sheets the density gauge preferably used for the plastic tray of the truck is between 5.5 mm to 6 mm. Or 6 mm. to 7 mm. thick. Second happened: Later they go to the guillotine or machine that cuts the sheet to a certain extent, said sheets already sectioned, cut to the required measure go to the thermoforming machine;

Third step: the sheet is held in a frame and heated in an oven at a temperature between 1 20 to 1 30 degrees centigrade, for a time of 1 20 seconds the combination of time and exposure to the temperature of the resistances makes malleable the plastic, the resistances of the thermoformed are calibrated in some areas to 90% and in others between 70 a! 65% depending on the area of the mold, when it is at its ideal point, the sheet passes to the station of the molds,

"the ideal point is" when the plastic is heated, it is hanging from the frame due to gravity as the temperature rises, this phenomenon is called bell, in some plastics the bell falls, then it contracts again and that's when it passes to the next step or station. The time of the first season (heating) and 2nd season (thermoforming) try to equilibrate, if the thermoforming is longer than the heating, heat is transferred to the sheet in the first station, if the heating time is shorter than the of formed the pieces do not cool well. In relation to the time of forming and calibration of the machines we bring a heating cycle of 1 20 seconds.

Fourth step: a thermoformed and calibrated plastic sheet, accommodates in a mold called male that is convex with protuberances or protrusions being a positive mold, the plastic will be in touch with the "internal" face of the piece, the finish of the thermoformed in This mold is intended to copy the impurities of the mold and the sections of the assemblies together with the vacuum holes, the face that the plastic does not touch of the mold is used as "piece view" ¹ because it has a better finish, calling the tray external to the piece, the other female mold is concave, it is a negative cavity or mold, it is used for the internal shell because the face of the plastic that touches the mold will be on the outside, the best finish is inside, and is what gives sight to the inner shell, then a seal is made between the molds and vacuum is vacuum vacuum between the plastic and the mold to form the trays ;

V. Fifth Step; they pass to the trimming area where the plastic excess is cut by means of a spinning saw, and it goes to cooling; SAW . Step Six: Afterwards, the inner and outer trays are assembled and passed to the fusion machine, which is an ultrasonic shock machine calibrated to melt by means of vibrations, welding with at least 1 0 shock points throughout the periphery of the two trays causing the two trays to join with the heat of the ultrasound or up to three or more forming a single piece that can be attached;

VII. Seventh step: holes are drilled in the base of the tray through which the fastening means pass.

HIV Eighth step: the plastic tray is improved to the support body of the truck, holding with the fastening means (screw), the truck being joined and formed together with the taxable rim.