ES1069470U - MULETA OR BASTON AMORTIGATED THROUGH THE VARIATION OR CHANGE OF THE VISCOSITY OF MAGNETORREOLOGIC FLUIDS. - Google Patents

Abstract

1. Crutch or cane damped by variation or change in the viscosity of magnetoreological fluids characterized by using magnets that approach or move away from the fluid and modify its viscosity depending on the support force exerted. 2. Crutch or cane cushioned by varying or changing the viscosity of magneto-rheological fluids according to the preceding claim, comprising at least the following elements: a. Two or more interconnected cavities filled with magneto-rheological fluid. b. Two or more pistons located in the widest area of the cavities that push or resist the passage of fluid between the cavities. c. Magnets whose position varies depending on the pressure exerted on the system modifying the viscosity characteristics of the fluid. d. Elements that allow the magnets to approach the fluid passage ducts between cavities by exerting supporting force. and. Elements that allow the magnets to return to their initial position in the absence of a supporting force. 3. Crutch or rod cushioned by varying or changing the viscosity of magnetoreheological fluids according to any of the preceding claims, further comprising a mechanism that allows the position of the magnets to be fixed in relation to the magenetorheological fluid in the absence of pressure.

Description

Crutch or cane cushioned by variation or change in fluid viscosity magnetorheological

Object of the invention

The object of the present invention is provide a continuous and uniform adaptation system for a crutch used as a means of support and support, based on the use of magnetorheological and controllable fluids through of magnetic fields produced by magnets located in a way convenient, to vary its viscous properties in the fluid.

Technical sector

The technical sector of this invention is the of the support surfaces, crutches and canes that determine a improved support of the body at a fixed point and serve as assistance and help with walking, walkers and / or crutches that people use prevented from walking temporarily or permanently.

State of the art

The proposed damping system is preferably useful for damping on canes and crutches and It has magnetorheological fluids, an elastic spring type element as a recovery system, two or more fluid filled cavities magnetoreological and magnets arranged with a system of drive such that, by exerting a vertical force on the support system, this simply, bring one or more magnets to one more passageways between the cavities and over the fluid magnetorheological causing the desired damping.

The damping systems for crutches and canes whose description approximates the present invention are described below and those considered closest to the object of this are listed. Among them are: ES1036959Y, ES1034631Y, 9601865, DE10054982-A1, EP1118363-A, JP11309007-A, ES2212475T3,
ES2222503T3, JP2000070022-A, GB2318510-A, EP701807-A; E701807-A1, DE3121095, BE1010671-A6,
WO9929272, EP0628296, WO9641599, US5571205 and subfamilies of each.

Patent DE20205015460-U1 and Subfamilies describe a walking stick or ski stick type, with an impact absorption mechanism, and with the possibility of Block if necessary. It is composed of a system of absorption and a recovery spring. In the patent JP2001211915-A is a crutch or cane with damping near the handle and a shock absorber system with the possibility of changing the length of the support system.

EP978268 and subfamilies are described damping system for crutches and canes with a system telescopic tubular and recovery spring with the addition of a hole system for compression depth control of the recovery spring and a mooring system if necessary.

FR2668690-A / A1 patents, US4881564-A FR2616304-A, have a system similar to those described above and in some cases it used as a buffer, foam rubber, or rubber in Its terminations as coating.

In GB22743889-A / B patents viscous type fluids are used in the system tubular damping and in conjunction with recovery springs  similar to patents DE4105836-A / C2, where the damping system is located in some cases in the part lower or in the upper handle.

No specific documentation found on fluid shock absorption technology magnetorheological in the area of stick devices or crutches However we have found damping systems for other applications using classic hydraulic dampers, or by absorption rubbers, together with recovery springs, There are many designs, either with the incorporation into the lower base of the system or in the handle of the same. The Fluid utilization with variable viscosity is only found in cushioning systems for cars, motorcycles, seats heavy machinery and seismic dampers. Only found a closer application of these fluids in the use of a prosthesis for an orthopedic leg, which uses a shock absorber pressurized magnetorheological type with an electronic system highly sophisticated to change and generate magnetic fields in the damping system.

In the present invention fluids are used magnetorheological, with a construction system consisting of two concentric elements, preferably cylindrical, arranged so that one can slide inside another and docks of recovery and magnets, which when approximating them, due to the force exerted on the top or grip of the crutch or cane, these approach or move away from the conduit where the fluid varying the magnetic field in the passage channel, causing the change in fluid viscosity and therefore the damping of the force exerted continuously.

Magneorerological fluids

It is known as magnetic fluids those systems formed by ferromagnetic particles or ferromagnetic in a carrier fluid. When the particle size is enough, these fluids are called magnetorheological and they have the important property of varying their properties of flow (rheological) quickly and significantly by being subjected to a moderate magnetic field.

That is, the system can be changed from a normal (Newtonian) low viscosity fluid to a fluid with high threshold effort (pseudo-plastic or plastic) with a high effective viscosity controlled by the applied magnetic field This property confers fluids magnetorheological the possibility of controlling its properties mechanical and therefore use them in many applications techniques in which you want a fluid (often an oil or water) vary its viscosity or present creep threshold effort at our will

Description Description of the figures

Figure 1. Detail of the crutch or cane together with the location of the damping system (S), of the modes of embodiment 1 and 3. (F) Force exerted by the handle respectively.

Figure 2. Damping system without presetting force, in which the cavities (p and p ') are funnel-shaped, where the narrowest section of one of them joins through a conduit (c) with the other cavity that It is arranged symmetrically. The fluid (f) passes through the conduit (c) from one cavity (p) to another (p '). The system has two pistons arranged symmetrically so that the upper one is integral with the handle of the crutch and the lower one is integral with the recovery spring M1 . In the second spring it is denoted by M2 , the magnets used in the system are represented by i , the force applied by F , the support on which the magnets are placed and which allows them to be brought closer to the conduit by exerting pressure on the system by t and the magnet recovery system by b . tb1 and tb2 denote the two concentric elements that, when sliding inside each other, allow to shorten the length of the crutch in a controlled way and produce the damping effect.

Figure 3. Representation similar to figure 2, in which the effect resulting from exerting a vertical force on the handle of magnitude greater than the recovery constant of the spring M1 and greater than the recovery constant of the spring M2 is shown . The fluid (f) passes from one cavity (p) to another (p '), compressing only the spring M1 . The magnets used in the system are represented by i , the support on which the magnets are placed and which allows them to be brought closer to the conduit by exerting pressure on the system by t and the force applied by F.

Figure 4. Representation similar to Figure 3, for the case in which a vertical force is exerted on the handle of magnitude greater than both recovery constants of springs M1 and M2 . The fluid (f) passes from one cavity (p) to another (p '), in this case compressing both springs. A compression of the spring M2 causes the outer tubular element (tb2) to rise proportionally to the force (F) applied, bringing the magnets closer to the passageway (c) between the cavities (p) by changing the viscosity of the fluid in the duct and cushioning the system. The magnets used in the system are represented by i , the support on which the magnets are placed, and which are shown in their position closest to the conduit, by t and the force applied by F.

Figure 5. Detail of the crutch or cane together with the location of the damping system (S) and the system of preset (a), of embodiment 2. (F) Force exerted by the handle respectively.

Figure 6. Preset system without activation. The system, preferably adjustable by means of a thread, (r) not gets close to the magnets (i) to the passage (c) of the fluid (f), so the magnetic field does not act and the damping is due solely to the initial viscosity of the fluid in the cavities (p and p ').

Figure 7. Preset system activated. To the activated, the system (r) brings the magnets (i) to the passageway (c) of the fluid (f) gradually and the magnetic field of the magnets (i) acts by changing the viscosity of the fluid in the passageway damping the force exerted by the user.

Figure 8. Combined system of presetting and damping in the same place. The presetting of the system, which is preferably carried out by means of a screw-in element, (r), is integral with the outer cylinder or tube, which is raised if the force (F) is of sufficient magnitude. The threaded type system brings the magnets (i) closer without an applied force (F), so the magnets (i) will be closer to the passage duct (c), before the force that will make the tube outside move the magnets further to the center of the duct. M1 and M2 represent the system springs.

Object of the invention

The object of the present invention is that of serve as a continuous and adaptable damping system in function of the pressure exerted on the upper support point preferably useful for crutches or canes. It includes the use of magnetorheological fluids, an elastic element, preferably a spring or spring, as a recovery system, two or more cavities or zones that contain said fluid and are interconnected with each other by conduits, preferably more narrow, and magnets arranged through a system of drive that by exerting a vertical force on the system support, bring one or more magnets to the passageway between the cavities filled with fluid, causing the desired damping.

Detailed description of the invention

Figure 1 details the location of the damping system when it does not have a preset of damping In Figure 5 the system incorporates in the part superior a damping preset system.

The proposed system comprises two or more cavities (represented in the figures by p and p ') whose part upper is much larger than its bottom, resembling its Form a funnel. To achieve the damping effect, in the narrower end of the cavity (p) joins a duct (c) very narrow. Next to this duct, another cavity is attached (p ') equal to the previous one but arranged symmetrically, in such a way that the duct joins them together, letting the fluid pass magnetorheological between the cavities. The system incorporates magnets permanent (i) arranged on an element (t) that allows the put pressure on the system, so that the magnets can approximate the conduit (c) of union between the cavities and that serve of adaptation system continues to the force exerted on the support surface, by approaching these, when exerts a vertical pressure or force.

The system is arranged in the cane by means of two concentric tubular elements, preferably cylindrical, and of different diameter arranged so that one of them is allowed to slide inside the other, actuate the element t so that the approach of the magnets occurs to the fluid when a support is made on the stick (force F) and, when returning to its original position, the magnets separate from the fluid thanks to the recovery element b .

In the widest part of the cavities find a plunger that in the case of the upper cavity pushes the fluid down performing a vertical correlation movement with the support force exerted. In the lower cavity, arranged symmetrically to the other cavity, the function of the plunger is stop the fluid opposing the vertical thrust.

By exerting a vertical force (F) on the top of the crutch, it translates into a directly proportional force at the base of the crutch. If the force (F) is less than a predetermined value by the constant k1 and k2 of the recovery springs M1 and M2 , the system only dampens and is recovered by the action of the spring M1 , whose recovery constant k1 must be less than the recovery constant k2 of the spring M2 respectively. In this case there is no approach of the magnets to the conduits and therefore the fluid that passes through the conduit (c) flows normally depending on its initial viscosity (Figure 3).

If the force exerted is not enough high to overcome the resistance determined by the constant of the recovery springs and the preset proximity of the magnets of performance is not adequate, these do not exert a magnetic field appreciable so the system will reduce its resistance and will recover homogeneously due to the initial viscosity of the fluid.

If the force (F) is large enough compared to the recovery constant k2 of the spring M2 , and consequently of the recovery constant k1 of the spring M1 , the damping system acts by compressing both spring M1 and M2 and the spring M2 does that the outer tube causes the magnets to approach, this approach being proportional to the vertical force exerted. In other words, the outer tubular element (tb2) moves up and modifies the separation of the permanent magnets that cause the magnetic field in the passageway (c) between the cavities, varying the viscosity of the fluid (f) in the conduit ( c) thanks to the magnetorheological effect caused by the magnets. Figure 4

If the strength and presetting of the magnets are more sensitive to the force exerted as mentioned above, the system will brake the upper piston, cushioning and preventing by changing the viscosity of the magnetorheological fluid (f) inside the duct (c) that crosses. However, by stopping apply this force, the system recovers immediately thanks to which the spring acts recovering. The magnets will separate from the passageway by letting the fluid pass again normally and its viscosity will not be affected the magnetic field of the magnets

This action, thanks to the effect of the field magnetic, will harden or soften the fluid allowing a continuous adaptation to the posture and force exerted by the Username.

The characteristics of the magnetorheological fluid (concentration and viscosity, among others) will depend on the type of required damping (depending on the individual's weight and use of the cane, among other features).

The function of the magnets and the magnetic field is to change the viscosity of the fluid in the passageway between the cavities. These magnets are subject to a device (schematically represented by the elements tyb) that keeps them away from the passageway to the magnets and that allows them to approach or move away depending on the pressure exerted, due to the vertical movement of the outer tubular element, tb2 , which in its path brings the magnets closer to the conduits by moving the element t towards the conduit (c) and which, when returning to its resting position, allows the magnets to return to their original position due to the traction exerted by the recovery element b . The magnet approaches and moves away to the conduit (c) according to the pressure and weight applied to this structure, causing the magnetic field exerted on the fluid to change and, therefore, changes the properties of the fluid by increasing or decreasing its initial viscosity . These ducts act as a passage valve between each cavity, increasing or decreasing the speed of the fluid in the ducts. Thus, the exchange of fluid between the cavities will depend on the force received at the upper support point of the system and depending on the magnitude of said force, it will be able to dampen the sliding movement of a tubular element inside another, and therefore the support of the cane, through the magnetoreological effect of the fluid and will cease to act by not exerting said force. If the force exerted is less than that determined when adapting the system, the system will not exert any action, only a damping determined by the initial viscosity of the fluid will occur.

The system can also be adjusted by a system that allows changing the position of the magnets when The damping system is not subjected to any force. In Figure 6 shows the details of a preset system, where the magnet recovery system can be observed (i) and its preset system (r) which, by changing its position vertical, preferably by threading, you can modify the position of the magnets relative to the passageway (c) between the cavities (p). In figure 6 the system is not activated, that is the magnets have not approached the passage duct so no Open an active system preset. If the preset system (r) has been used to bring the magnets closer to the passageway (Figure 7) the damping is modified by changing the viscosity of the fluid (f) at rest.

The preset system and damping system can be combined into a single device (Figure 8) so that the system (r) gradually brings the magnets permanently closer to the passageway, modifying the magnetic field that is exerted on it and achieving that the fluid has a different initial viscosity. In this way the system is conditioned for different users or forces exerted on any of the handles e1 and e2 .

Modes of realization

Mode one

Crutch with a single damping system without presetting force

In this preferred embodiment, the damping system (S) is located at the bottom of the crutch or cane (Figure 1). The system comprises (Figure 2) the cavities (p and p ') that contain magnetorheological fluids and are connected to each other through a conduit (c) through which the fluid (f) can pass from one cavity to another. In addition, magnets (i) are disposed in a substantially perpendicular manner and located near the passageway between zones or cavities, which thanks to the elements t will approach the conduit when a vertical force is exerted on the system so that the tubular element tb1 slides inside the tubular element tb2 and will move away when the force ceases thanks to the recovery elements b , preferably flexible or elastic elements positioned so that when the force ceases and when the element tb1 slides out of the element tb2 it allows to return to the magnets to their original position. The sliding of tb1 to its original position occurs thanks to the M2 spring.

In this way, zooming in or out of the field magnetic to the passage duct (c) a change in the fluid viscosity in the area of action of the applied field, the fluid in the duct becomes denser (viscosity increases) and therefore the speed of passage of the rest of the fluid between the cavities producing damping. The shape in which the damping occurs depends on the magnetic field applied, whose magnitude depends on the proximity of the magnets (i) to the conduit (c) and the type of fluid used.

The system (Figure 3) has two recovery springs M1 and M2 with damping / recovery constants k1 and k2. If the force exerted on the handle is greater than the recovery constant of the spring M1 and of magnitude lower than the spring M2 , the piston compresses the spring M1 and does not have sufficient magnitude to compress the spring M2 , so that the system is damped with only by the spring M1 and by the resistance to the passage of the fluid from one cavity to another determined by its initial viscosity. In this case the magnets do not act.

In the case where the vertical force exerted on the system is of magnitude greater than the recovery constant of the springs M1 and M2 (Figure 4), the compression of the spring M2 causes the outer tube to rise proportionally with the force applied producing the approach of the magnets to the fluid. When the force ceases to act, the magnets automatically move away and the fluid in the passage duct returns to its initial viscosity and the system recovers using the spring M1 , raising the lower and upper piston respectively, returning the system to its state of rest.

Mode 2

Crutch with a single damping system with presetting of force

In this embodiment it has been incorporated into the top of the mode 1 system (Figure 5) another system (a) similar to the previous one that includes two additional cavities, interconnected by a passageway and whose difference lies in that the magnets that cause the magnetic field are arranged in the proximities of the passageway (preferably on the conduit), and the approach of these to the conduit is made manually with an element (r) that brings the magnets closer to the duct Permanently.

This approach (Figures 6 and 7) can be done by practicing grooves in the outer tubular element, tb2 , so that an internally threaded element could modify its vertical position and consequently, modify the position of the element t so that the magnets are zoomed in or out (i) to the conduit (c).

Through the static or fixed approach, PRE-condition the damping system, due to the change in the viscosity of the fluid in the passage duct.  This preset is controlled by the user and gives the system as a whole a change in the initial hardness of damping

Embodiment favorite

Crutch with a single combined damping system of simultaneous presetting and damping

In this preferred embodiment, modes 1 and 2 have been combined. The system is shown in Figure 8 and consists in carrying out the preset mentioned in the preferred mode 2, directly on the main damping system described in mode 1. In this way, the damping preset is carried out by approaching or moving away in a controlled manner the magnets of the system with an element (r) mounted on the outer tubular element tb2 of the damping system (S in Figure 1), thus achieving the presetting. of damping required by the user.

Claims (3)

1. Muleta or cushioned cane by means of the variation or change of the viscosity of magnetorheological fluids characterized by using magnets that approach or move away from the fluid and modify its viscosity depending on the support force exerted. 2. Crutch or cane cushioned by variation or change in the viscosity of magnetorheological fluids according to previous claim, comprising at least the following elements:

to.

Two o more fluid-filled interconnected cavities magnetorheological

b.

Two o more plungers located in the widest area of the cavities that they push or resist the passage of fluid between the cavities.

C.

Magnets whose position varies depending on of the pressure exerted on the system by modifying the viscosity characteristics of the fluid.

d.

Elements that allow the approach from the magnets to the fluid passageways between cavities to exert supportive force

and.

Elements that allow returning to magnets to their initial position in the absence of force of support for.

3. Crutch or cane cushioned by variation or change in the viscosity of magnetorheological fluids according to any of the preceding claim, which comprises, in addition, a mechanism that allows to fix the position of the magnets in relation to the magenetorheological fluid in the absence of pressure.