ES2531423B1 - Load lifting device with intermediate rotating rolling element elastically connected to the main body of the jack - Google Patents

Abstract

Load lifting apparatus, comprising a main body (2), comprising at least one rear rolling element (7), located in a rear area (8) of the user-operated apparatus for maneuvering with the apparatus; at least one front rolling element (10), located in a front zone (11) of the apparatus closer to the force applicator (5) than the rear zone (8); an intermediate rotating rolling element (12), located between the rear zone (8) and the front zone (11) of the apparatus and elastically connected to the main body (2), and the center of gravity of the apparatus being arranged behind the rotating rolling element intermediate (12) so that in a load situation all the rolling elements (7, 10, 12) rest on the ground while in the unloading situation the front rolling elements (10) do not support, increasing the maneuverability of the apparatus.

Description

5

10

fifteen

twenty

25

30

35

LOAD LIFTING DEVICE WITH ROLLING INTERMEDIATE ROLLING ELEMENT ELASTICALLY CONNECTED TO THE MAIN BODY OF THE CAT

DESCRIPTION

Technology Sector

The invention relates to load lifting apparatus, for example a truck jack of the type that assist in the lifting of vehicles or other objects of high weight.

State of the art

In the state of the Industrial technique, very diverse lifting devices are known, to allow the lifting of objects of high weight, for example of vehicles. Some devices of this type are the jacks (truck, bottle, etc.) that lift the load by pushing it from below, and the cranes, which raise the load by pulling it from above. Occasionally, lifting devices include wheels to move with respect to the ground.

For example, trolley jacks are devices commonly used in workshops and other mechanical work environments, which allow lifting heavy objects such as vehicles. A truck jack generally comprises a main body, with respect to which some type of lifting element is movably disposed that, duly operated by a hydraulic system or the like, is capable of being lifted by exerting sufficient force under the vehicle or heavy object to cause its elevation. Examples of lifting elements are an articulated lifting arm, a telescopic mechanism capable of extending vertically or inclined, and in any case with a vertical component facing up, etc. Additionally, the truck jack comprises drive means so that the user can cause the actuation of the hydraulic system or the like and the consequent rise of the lifting element. Similarly, the jack comprises drive means for

allow the controlled descent of the lifting element, said descent having to be carried out in a controlled manner since generally the lifting element is lowered in load, that is, while supporting the weight of the vehicle, and therefore to ensure safety it is vital to avoid imbalances, overturns or falls.

Known wheelbarrow jacks are capable of moving by wheels, rollers or other rolling elements comprised in the main body. Since the main body is generally very close to the ground and has a relatively reduced height, the jacks usually comprise a lever that projects from the main body upwards to provide the user with a grip area to pull or on the to push to move the cat from side to side, or to turn the car.

fifteen

As for the distribution of the wheels in the jack, a known solution is that the jack has two swivel wheels in its rear zone (zone closest to the lever and therefore to the user) and two fixed wheels in its front zone . Another known solution is that the jack also has an additional fixed wheel placed on a lifting element in the form of a folding arm, where said additional fixed wheel only rests on the ground when the arm is not raised. In this case, when the elevation of the lifting element occurs, the additional fixed wheel is raised together with said lifting element and the jack is then supported on the two remaining fixed wheels and on the two rotating wheels. On the other hand, if the lifting element is not raised, the fixed wheel rests on the ground. In this second scenario the additional fixed wheel, resting on the ground, allows a vehicle force applicator, that is, a point or surface of the lifting element that exerts the lifting force on the vehicle, to perform the same angle of rotation than the lever, therefore improving the maneuverability with respect to the previous solution without additional fixed wheel.

35 Wheelbarrow jacks are devices that can be presented

A fairly high weight. For example, a cat capable of lifting 2 tons

it can weigh approximately 45 kg; A cat capable of lifting 6 tons can weigh 81 kg.

Due to the high weight of some wheelbarrow jacks, in practice it is not always easy to move or turn a cat, even though the cat has wheels and even though it has an additional fixed wheel on the lifting element. The complication of the rotation can be seen in the fact that in the trolley jacks actuates it is necessary to perform a high turn of the lever to achieve a rotation of a certain magnitude of the front end of the cat, which is where the element point is normally located of elevation destined to push the vehicle vertically. If the jack is very heavy, causing the lever to rotate requires a very large effort and therefore entails risks for the user who has to repeat this task regularly.

fifteen

The invention has as a particular objective the design of a truck jack that simplifies and facilitates the realization of turns of the same, reducing the effort that the user must make. This is intended to improve the maneuverability of the jack to facilitate its positioning, for example to facilitate the user the action of positioning the jack properly with respect to the vehicle before proceeding to lift it.

And, in general, the invention aims to achieve a load lifting apparatus that, being provided with wheels or rolling elements for moving on the ground, has improved maneuverability with respect to conventional rolling load lifting devices.

30 Brief description of the invention

The object of the invention is a load lifting apparatus, comprising a main body with respect to which a lifting element is capable of ascending or descending to lift a heavy object, wherein said lifting element comprises a force applicator capable of exert an ascending force on the object. The body

The main one can rest and move on a floor by means of rolling elements. The apparatus according to the invention has the particularity that it comprises at least one rear rolling element, located in a rear area of the user-operated apparatus for maneuvering with the apparatus; at least one front rolling element, located in a front zone of the apparatus closer to the force applicator than the rear zone; and an intermediate rotating rolling element. The intermediate rotating rolling element is connected to the main body by an elastic element. Said elastic element tends to cause a separation of the intermediate rotating rolling element with respect to the main body until all the rolling elements (front, rear and intermediate rotating) are not in the same piano. In addition, said elastic element is able to deform until the rolling elements are found in the same piano. The intermediate rotating rolling element is located between the rear zone and the front zone. Also according to the invention, the mass ratio of the apparatus distributed between the intermediate rotating rolling element and the rear rolling element is greater than the proportion of distributed mass between the intermediate rotating rolling element 20 and the front rolling element. That is, the center of gravity is behind the intermediate rotating rolling element.

The apparatus according to the invention works as follows. In the absence of a load, that is to say, by not exerting a force the force applicator of the apparatus on the object, the elastic element separates the intermediate rotating rolling element enough so that the rolling elements of the apparatus are not on the same piano. Consequently, as a consequence of the position of the center of gravity and the action of the force of gravity, the 30 rear rolling elements and the intermediate rotating rolling element are supported on the ground, the front rolling elements remaining in the air. On the other hand, in a load situation, in which the lifting element is exerting an ascending force on a heavy object and consequently receiving the corresponding reaction force of the heavy object, the elastic element flexes sufficiently so that all the rolling elements happen to be in the same piano and therefore

the front rolling elements rest on the ground.

Thus, the apparatus according to the invention has the following advantages. On the one hand, the fact of having an intermediate rotating rolling element 5 closer to the rear area of the device (user actionable area for maneuvering with the device) than the front rolling elements, added to the fact that in the absence situation loading the front rolling elements do not rest on the ground, it allows the device to be highly maneuverable. By 10 maneuverability it is understood that the rotation of the front area of the apparatus is maximized, where generally the force applicator or zone of the lifting element that pushes the heavy object is located, for the same angle of rotation of the rear area of the apparatus where the operating lever or other actionable actuating means 15 is located by the user. Elio reduces the effort that the user must make, since to perform the same rotation of the force applicator it is necessary for the user to make a smaller rotation of the lever or other actuation means, compared to conventional devices. On the other hand, the fact that in front of loading the front rolling elements 20 go on to rest on the ground allows to provide the apparatus with a great resistance, since said front rolling elements, especially if they are fixed, can be designed with a high ability to support the weight of the device load. On the other hand, the intermediate rotating rolling element should only provide maneuverability and it will not be necessary to support high weights, since in a load situation the weight is supported to a greater extent by the front rolling elements.

Brief description of the figures

30

The details of the invention can be seen in the accompanying figures, not intended to be limiting the scope of the invention:

35 - Figure 1 shows a perspective view of a mode of

realization of an apparatus according to the invention, in this

5

10

fifteen

twenty

25

30

35

case in the form of a wheelbarrow jack.

- Figure 2 shows a side view of the cat of Figure 1 in an unloading or resting situation.

- Figure 3 shows a front view in enlarged section, according to the section piano A-A illustrated in Figure 2.

- Figure 4 shows a side view of the cat of Figure 1 in loading situation.

- Figure 5 shows a front view in enlarged section, according to section piano B-B illustrated in Figure 4.

- Figures 6, 7 and 8 show schematic top views of two cats known in the state of the art and of the cat according to the invention represented in the previous figures.

Detailed description of the invention

Figure 1 shows a perspective view of an embodiment of a load lifting apparatus according to the invention. In the embodiment shown, the load lifting apparatus is a jack (1) of the type known as a truck jack. As can be seen in the figure, the jack (1) comprises a main body (2) with respect to which it is capable of ascending or descending a lifting element (3) intended to exert a force on a heavy object to produce the elevation of the same and also intended to support the heavy object during the descent operation. In the embodiment of the figure, the lifting element (3) is a lifting arm capable of folding with respect to the main body (2), as indicated by an arrow (4). The lifting element (3) has a force applicator (5) at its end, said force applicator (5) being precisely the area in charge of exerting the ascending force on the object to produce its elevation. In the embodiment shown, the force applicator (5) is a flat circular surface intended to come into contact with the bottom of a vehicle or with a lower surface of the object to be raised. The cat (1) has been represented resting on a floor (6). The main body (2) can move with respect to said floor (6) by means of various rolling elements. More concretely,

The jack (1) comprises at least one rear rolling element (7) located in a rear area (8) of the jack (1). The rear area (8) of the jack (1) is the area that is user-operated for maneuvering with the jack (1), specifically acting on a handle (9a) of a 5-drive lever (9). In this particular case, the jack (1) comprises two rear rolling elements (7) in the form of fixed wheels, that is, two rear wheels whose axis of rotation does not change direction. In addition, the jack (1) comprises at least one front rolling element (10) located in a front zone (11) of the apparatus closer to the force applicator (5) than the rear zone (8). In this case, the front rolling element (10) is a single cylinder or roller that is fixed, that is, whose axis of rotation does not change direction. The jack (1) also comprises an intermediate rotating rolling element (12). In the embodiment shown, the intermediate rotating rolling element (12) is a wheel 15 which is capable of rotating on itself according to a central axis of rotation (13) to be able to roll with respect to the ground (6). The intermediate rotating rolling element (12) is also capable of rotating also with respect to a vertical axis of rotation (14), causing the axis of rotation (13) to have a variable direction. In addition, the intermediate rotating rolling element (12) 20 is elastically fixed to the main body (2) allowing said elastic connection that the vertical position of the intermediate rotating rolling element (12) can vary. By elastic connection it is understood that the intermediate rotating rolling element (12) is fixed to the main body (2) by means of an elastic element (16).

25

According to the invention, moreover, the mass ratio of the jack (1) distributed between the intermediate rotating rolling element (12) and the rear rolling elements (7) is greater than the proportion of mass distributed between the intermediate rotating rolling element ( 12) and the 30 front rolling element (10). That is, the center of gravity of the jack (1), in the absence of a load, is located behind the intermediate rotating rolling element (12), between the intermediate rotating rolling element (12) and the rear area (8) of the jack (1). ).

35 Figure 2 shows a schematic side view of the cat (1)

of Figure 1 in a situation in which the elevation element (3) is

It is knocked down against the main body (2) and in which the jack (1) is devoid of charge, that is, it is not exerting a force on an object. In this situation, as can be seen, the lowest points of the rolling elements (7, 11, 12) are not in the same piano, but the lowest point of the intermediate rotating rolling element (12) is below of an imaginary piano (15) that joins the lowest points of the rear rolling elements (7) and the front rolling element (10). In this situation, because the center of gravity of the jack (1) is behind the intermediate rotating rolling element 10 (12), between the intermediate rotating rolling element (12) and the rear area (8), it is produced that the intermediate rotating rolling element (12) and the rear rolling elements (7) rest on the ground (6) while the front rolling element (10) remains in the air. Thus, in the absence of load, only the rear rolling elements (7) and the intermediate rotating rolling element (12) act, achieving maximum maneuverability, as explained below.

Figure 3 shows a front sectional view of the jack (1) of the previous figure, in which it is clearly seen that the intermediate rotating rolling element (12) is fixed to the main body (2) by means of an element elastic (16), which in this case has the form of a strap that extends between two inner walls (2a, 2b) of the main body (2). The intermediate rotating rolling element (12) is fixed to the central area of said strap and is capable of varying its height depending on the deformation of the strap.

Figure 4 shows the jack (1) of Figure 2 in load situation, that is, in a situation in which the lifting element (3) 30 is exerting a force on a heavy object (17), schematically represented as an irregular polygon, and consequently the object (17) exerts a reaction force (F) on the lifting element (3). The lifting element (3) is shown in its lowest position, even without starting to turn upwards as indicated by the arrow (4). In this load situation, the reaction force (F) on the lifting element (3) is transferred to the main body (2), by

be the lifting element (3) fixed to it. Because the intermediate rotating rolling element (12) is supported on the ground (6) and between the intermediate rotating rolling element (12) and the main body (2) there is an elastic connection that allows relative vertical movement 5 between them, the reaction force (F) applied on the main body (2) causes the main body (2) to descend with respect to the intermediate rotating rolling element (12) while the elastic element (16) is flexed. There comes a time when the elastic element (16) flexes sufficiently so that the front rolling element 10 (10) rests on the ground, as can be seen in the figure. Thus, in a loading situation, the front rolling element (10) starts supporting the weight of the object (17), the intermediate rotating rolling element (12) not having to support it, which has a lower capacity to support weight by the Made of being rotating.

fifteen

Figure 5 shows a front sectional view of the jack (1) of the previous figure, which clearly shows that the elastic element (16) has been deformed allowing the descent of the main body (2) with respect to the rolling element intermediate swivel (12) 20 that is resting on the floor (6).

The elastic element (16) is configured so that it exerts an elastic force that tends to cause the intermediate rotating rolling element (12) to descend with respect to the main body (2) to 25 than the lowest points of the rolling elements ( 7, 10, 12) are not found are not found on the same piano. That is, it tends to return the jack (1) to the rest situation of Figure 2, in which the lowest point of the intermediate rotating rolling element (12) rests on the ground while the lowest point of the rolling element 30 forward (10) is in the air. Therefore, in the absence of load, the jack (1) automatically returns to said resting situation.

Figures 6, 7 and 8 show schematic top views of two cats known in the state of the art and of the cat (1) according to the invention represented in the previous figures, in order to illustrate the improvement in maneuverability achieved in the cat of the present

invention. Figure 6 shows a conventional jack (100) equipped with two rear wheels (107) rotating in its rear area (108), two front wheels (110) fixed in its front area (111), and a drive lever (109). ) located in its rear area (108). When a user 5 turns the operating lever (109) by pushing a handle (109a) thereof to the left or to the right, the rear wheels (107), being rotatable, rotate freely while the front wheels (110) , being fixed, they do not spin freely. Consequently, the turning point (150) of this first conventional jack is between the fixed and equidistant front wheels 10 (110) in front of the force applicator (105) (jack zone (1) intended to exercise the force on the object to be raised). Then, when the user rotates the handle (109a) of the operating lever (109) an arc (A1) as illustrated in the figure, the rotation of the practically zero front area (111) is caused, and a rotation of the very small force applicator (105), indicated with the arc (B1). That is, the user must rotate the rear area (108) of the jack (100) enormously to achieve a very small rotation of the front area (111) and the force applicator (105), therefore demanding a great effort. Figure 7 shows another conventional jack (200), in this case equipped with two rear wheels (207) rotating in its rear area (208), two front wheels (210) fixed in its front area (211) and a fixed wheel intermediate (212). In this second conventional jack (200) the intermediate fixed wheel (212), because it is fixed, serves as the turning point (250) of the jack. Therefore, an arc of rotation (A2) 25 similar to the arc of rotation (A1) of the previous figure causes the force applicator (205) to rotate an arc (B2) larger than the arc (B1) of the previous figure. This is equivalent to saying that the conventional jack (200) of this figure requires the user to make a smaller effort to rotate the front area (211) thereof in comparison with the conventional jack (100) of the previous figure 30, and consequently it is more maneuverable. Figure 8, on the other hand, shows the cat according to the invention, provided with two wheels or rear rolling elements (7) in its rear area (8), a radillo or front rolling element (10) in its front area (11) and a wheel or intermediate rotating rolling element (12). In the unloading situation, the front rolling element 35 (10) is not resting on the ground whereby the pivot point (50) of the jack is in the area of the rolling elements

rear (7) for being these fixed and for being rotating the intermediate rotating rolling element (12). Specifically, the pivot point (50) is located between the rear rolling elements (7) and equidistant from them, very close to the operating lever (9). The actuator lever (9) is represented in a more advanced position compared to the actuation levers (109, 209) of the two previous figures, but if its handle (9a) had been similarly represented it would be positioned at the point represented in the present figure. Then, if a user turned the handle (9a) an arc (A3) even smaller than the arches (A1, A2) of the previous figures, he would rotate the front area (11) and, in particular, the force applicator ( 5) an arch (B3) noticeably larger than in the previous two figures. That is, the maneuverability achieved by the jack (1) of the invention is very high since it will be enough for the user to turn the cat's rear area (8) slightly to produce large turns in the front area (11) where it is located the force applicator (5).

In the embodiment shown, as can be seen in Figure 4, in load situation the lowest points of all 20 the rolling elements (7, 10, 12) are on the same piano, so that all the rolling elements (7, 10, 12) rest on the ground (6). In this situation in which all the rolling elements (7, 10, 12) rest on the ground (6), the weight of the jack (1) and the object (17) or load is preferably supported by the rear rolling elements 25 (7) and the front rolling element (10), and not by the intermediate rotating rolling element (12) although the latter is in contact with the ground (6).

As mentioned, in the embodiment shown 30 the elastic element (16) is a strap connected to the main body (2) and to which the intermediate rotating rolling element (12) is fixed. Alternatively, the elastic element (16) can be a spring or a shock absorber connected to the main body (2) and to which the intermediate rotating rolling element (12) is fixed. No other 35 modes of performance in this regard are discarded.

5

10

fifteen

twenty

25

In the embodiment shown, the intermediate rotating rolling element (12) is located approximately in the center of the main body, seen said body in plan. In alternative embodiments, the intermediate rotating rolling element (12) according to the invention can be found at other points of the main body (2) away a certain distance from the center and located between the rear rolling elements (7) and the rolling elements front (10).

According to the invention, both the front rolling elements and the rear rolling elements can be fixed - as in the embodiment represented in the figures - or rotating. Fixed means that its axis of rotation does not change direction. Rotary means that its axis of rotation can change direction.

The fact that the rear rolling elements are fixed, as in the embodiment of the figures, has certain advantages that can be seen in the jack (1) of the figures. On the one hand, the resulting cat (1) may be narrower. On the other hand, the rear rolling elements (7) can be large and consequently cause the jack (1) to be much more pleasant and easy to handle.

In the embodiment shown, the force applicator (5) is a flat circular surface intended to come into contact with the bottom of a vehicle or with a lower surface of the object to be raised. The invention contemplates different force applicators, capable of pushing the object or load upwards (for example, an axis of a piston) or capable of pulling the object from above (for example, a hook or a claw).

Claims (11)

5 10 fifteen twenty 25 30 35 1. Load lifting apparatus, comprising a main body (2) with respect to which an elevation element (3) is capable of ascending or descending to lift a heavy object (17), where said elevation element (3) It comprises a force applicator (5) capable of exerting an ascending force on the object (17), where the main body (2) can rest and move on a floor (6) by means of rolling elements, characterized by comprising : - at least one rear rolling element (7), located in a rear area (8) of the user-actionable apparatus for maneuvering with the apparatus; - at least one front rolling element (10), located in a front zone (11) of the m3s apparatus close to the force applicator (5) than the rear zone (8); - an intermediate rotating rolling element (12), located between the rear zone (8) and the front zone (11) of the apparatus and connected to the main body (2) by means of an elastic element (16), where said element the £ static (16) tends to cause a separation of the intermediate rotating rolling element (12) with respect to the main body (2) until the rolling elements (7, 8, 9) are not found on the same piano, and where the element the The static (16) is able to deform until the rolling elements (7, 8, 9) are found on the same piano; and where - the proportion of mass of the apparatus distributed between the intermediate rotating rolling element (12) and the rear rolling element (7) is greater than the proportion of mass distributed between the intermediate rotating rolling element (12) and the front rolling element (10) . 2. Apparatus, according to revindication 1, characterized in that the rear rolling elements (7) are fixed. 3. Apparatus, according to revindication 1, which is characterized by 5 10 fifteen twenty 25 the rear rolling elements (7) are rotatable. 4. Apparatus, according to claim 1, characterized in that the front rolling elements (10) are fixed. 5. Apparatus, according to claim 1, characterized in that the front rolling elements (10) are rotatable. 6. Apparatus, according to claim 1, characterized in that the elastic element (16) is a strap connected to the main body (2) and to which the intermediate rotating rolling element (12) is fixed. 7. Apparatus, according to claim 1, characterized in that the electric element (16) is a spring connected to the main body (2) and to which the intermediate rotating rolling element (12) is fixed. 8. Apparatus, according to claim 1, characterized in that the elastic element (16) is a shock absorber connected to the main body (2) and to which the intermediate rotating rolling element (12) is fixed. 9. Apparatus, according to claim 1, characterized in that one or more of the rolling elements is a wheel. 10. Apparatus, according to claim 1, characterized in that one or more of the rolling elements is a ball. 11. Apparatus, according to claim 1, characterized in that one or more of the rolling elements is a roller.