This invention relates generally to guided therapeutic movement (GTM). More specifically, the invention further relates to cane articulation to enhance or enable stable usage on sloping or uneven ground or floor surfaces. The invention also concerns articulation capability which varies as a function of downward force exertion on the cane shaft, to enhance stability of usage, and promote a normal stride.
In the past, canes have been provided with four legs on a base. Such “quad” canes can provide a stable reference point, which helps with the operator's balance, however when used on sloping ground the top of a quad cane can be in an awkward position and the angle of the cane can be poor for proper support. Standard quad canes generally prove unstable when all four legs are not in contact with the ground surface, which often occurs on uneven ground. Quad canes do not comfortably allow a normal stride.
Accordingly, there is a need for a cane providing better stability and providing support assurance to the user walking on uneven ground surfaces.
The invention relates to a new class of equipment to meet the needs of patients and therapists by both providing secure support and encouraging proper therapeutic movement. The user's movement is guided by the structural and mechanical design of the equipment, which encourages healthy natural movement while providing stability and security.
Walking is an important area where therapeutic motion can be very beneficial. The therapeutic equipment needed can be quite simple. By providing a cane or walking stick with the proper articulation, the user can be guided into a therapeutic pattern or gait. Security and support are crucial needs. By a controlled locking of the articulation, both free motion and firm support can be provided as needed.
Currently available equipment such as quad canes and walkers generally provide only support. Unfortunately, these types of equipment will often result in an awkward gait and prove a hindrance to relearning proper natural movement. In contrast, controlled cane articulation is a good way to provide a person with security and support and also encourage therapeutic motion.
In a first aspect of the invention, a cane with articulation allows for a normal stride, promoting good posture as well as assured balance on level ground and uneven surfaces. In a second aspect, the present cane acts as an assistive device for guiding the user into therapeutic and recuperative motion in addition to providing stability and support. Guided Therapeutic Motion (GTM) is promoted through the use of pivot parameters and articulation combinations. As a result, the present cane becomes an effective therapeutic tool in addition to a support device. As used here, the words articulation or articulated refer to a connection or joint between two (or more) elements. The words controlled or variable resistance refer to selecting, adjusting or varying the characteristics of relative movement between two (or more) elements, to, for example, provide more or less resistance to bending, pivoting or torsional movement between the elements.
In a third aspect, equipment is provided for guiding the body in proscribed motion as, for example, by providing guided motion in a compact piece of equipment that can also serve as a mobile support (i.e. cane, crutch, walker or support stand). The guided motion apparatus is well suited to use in articulated canes, with user controlled resistance to articulation. Such cane embodiments provide stability on sloping ground.
In a preferred design, the shaft of a cane is connected to a base through an articulated connection. The connection preferably has a pivot providing variable resistance. The pivot is operatively connected to one of the shaft and base, and a gripper is connected to the other of the shaft and base. Resistance to pivoting movement increases in response to increasing downward loading on the shaft. The pivot may comprise a ball which may have a spherical or oval shaped surface.
The gripper, or plurality of grippers, typically engage the ball as downward pressure is exerted on the handle. The grippers can be forced together by a sliding collar with taper and low sliding friction. Low friction can be achieved by use of rollers held in a carrier. A four-jaw gripper arrangement may be provided with collar and rollers. As the taper angle is reduced, the gripping leverage of the assembly is increased, but the stroke of the gripping is reduced. Because of the high leverage needed and resulting short stroke, the gripper assembly may require rigid construction, so that the gripping stroke is not all consumed “taking up the slack” in the system.
In an alternative embodiment, the gripping action can be achieved by deformation of the ball rather than motion of gripping jaws. To reduce ease of articulation the ball may be expanded by means of internal fluid pressure. The fluid pressure can be produced by a piston and cylinder arrangement actuated by relative force between the shaft and the ball supporting tube assembly. In this expanding ball system, the ball can articulate with the shaft and handle assembly rather than with the lower assembly as in the moving gripper jaw arrangement. To achieve a firm reduction in articulation, the expanding ball can have internal dividers or septums. These dividers can act as a shear web that restricts any significant rotation of the ball relative to the ball supporting assembly and the shaft. The number of forms of the septums, as well as other ball parameters, can be used to guide articulation.
In one preferred embodiment, a gripper assembly includes first and second parts, the first parts engaging the ball at laterally opposite sides thereof, and the second parts located to exert lateral force on the first parts tending to displace them laterally toward one another in response to increasing downward loading on the second parts. The gripper may define a socket in which the ball is received, and typically, the socket may be formed by the above referenced first parts. The gripper assembly may advantageously include friction surface inserts that engage the surface of the ball.
Tension members interconnecting the first and second parts transmit increasing lateral force components to the first parts as the second parts are displaced downwardly relative to the first parts. This reduces shaft articulation. Such tension members may extend in generally lateral directions to become “cocked” or skewed when downward force is exerted on the cane shaft. The tension members may advantageously be located or extend generally below the level of a center point defined by the pivot or ball.
Ball and socket interfaces, at least one of which is textured to provide enhanced frictional gripping, may be used.
The base may be in the form of a platform having at least two downward protrusions such as legs to engage said surface. Three such protrusions are preferably employed. Such protrusions are preferably outside a zone within which downward projections from the parts extend.
These and other objects and advantages of the invention, as well as the details of an illustrative embodiment, will be more fully understood from the following specification and drawings.
a is a plan view of a base plate and legs;
b is a schematic elevation view of assembly elements;
In
A base 15 is provided to engage the ground or floor surfaces 16, which may be uneven, sloped or slanted, as seen at 16a in
Four such legs are shown at 17a–17d, projecting from the four corners, respectively, of the plate 15, as seen in
It is a feature of the invention that an articulated connection is provided between the shaft 10 and base 15 allowing the base to pivot relative to the upright shaft, depending upon the slope of the ground or floor surface 16, below the base. See in this regard the sidewardly sloping surface 16a in
A further feature as provided by the articulating connection is characterized in that articulation capability decreases as downward loading on the shaft is increased, and articulation capability increases as downward loading on the shaft is decreased.
In this regard, the connection, generally designated at 21 in the
In the preferred form of the invention seen in
The preferred embodiment has a pivot with two approximately conic friction surfaces engaging a ball. The size and shape of the friction surfaces will determine the tracking in the pivot. “Tracking” in a pivot can be expressed by the variation of resistance to motion about various axes. The tracking ratio can be defined as the ratio of maximum to minimum resistance. A stiff hinge pivot has a very large ratio (theoretically infinite), a symmetrical ball socket joint has a tracking ratio of one. By increasing the vertex angle of the conic friction surfaces and reducing their effective diameter, the tracking ratio of the ball joint is increased. Tracking ratios of between one and ten are suitable in many therapeutic situations. In practice, the friction surfaces may be annular and conform to the ball surface, over a ring-like area.
In a versatile embodiment, the pivot can incorporate both: a pair of large diameter grippers that provide a low tracking ratio, and a pair of small diameter grippers with a large ratio. By varying the proportion of force in the two pairs of grippers a wide range of programmable tracking ratios can be attained in a single pivot mechanism. In a more complex embodiment multiple grippers with different tracking directions can be employed.
The gripper typically includes first and second parts, the first parts engaging the ball at laterally opposite sides thereof, and the second parts located to exert lateral force on the first parts tending to displace them laterally toward one another in response to increasing downward loading on the second parts.
In
In
Also provided are tension members interconnecting the first and second parts to transmit increasing lateral force components to the first parts as the second parts are displaced downwardly relative to the first parts, for reducing shaft articulation capability. See for example the links (rods) 60–63 extending in generally lateral directions, and organized as follows:
Note that the tension members or links are located below the level of the ball center; and they are configured relative to the plate so as to deflect by pivoting at their ends, or “cock” (see in
The gripper mechanism's leverage can be set so that the locking action is firm, allowing the cane to be rocked up on one leg of the base while under load, or set looser, as needed. In addition to this main gripping action, the ball pivot can be provided with an adjustable low friction damper and/or spring centering mechanism as at 23 in
The pivot joint can be provided with a key and keyway so that the base may rotate about the lateral axis and the longitudinal axis, but not about the vertical cane axis. In other words, the relative yaw motion of the two elements is constrained while relative pitch and roll have freedom of motion.
In an alternative embodiment, as shown in
In another alternative embodiment, shown in
In another embodiment, as shown in
The pivot arrangement can provide a path of least resistance to guide correct motion. A textured surface 436 on parts or all of the ball 432 and/or receiver 434 can provide another form of user tactile feedback guiding proscribed operator movement.
a. an upright shaft 100, a base 115, and an articulated connection in the form of assembly 120, allowing the base to pivot relative to the shaft, depending upon the slope of the surface 116 below the base,
b. the connection or assembly 120 characterized in that articulation capability decreases as downward loading; on the shaft is increased, and articulation capability increases as downward loading on the shaft is decreased.
As shown, the connection 120 includes a pivot, including ball 121, operatively connected at 122 to the base 115, and gripper in the form of jaws 123 and 124 operatively connected to the shaft 100, and having concave surfaces 125 for increasingly gripping opposite sides of the ball in response to increasing downward (manual) loading on the shaft. In this example, lower sleeve extent or extents 100a of the handle is or are divergently downwardly tapered at surfaces 165; and anti-friction means or bearing 126 is provided between the surfaces 125 and the jaws, so that gripping forces are transmitted by means 126 to the jaws, tending to displace them toward the ball, as handle lower extensions 100a are displaced downwardly. Means 126 may take the form of rollers 127, caged at 128, and engaging surfaces 165 as well as linear races 228 on the jaws. The taper indicated angle a defined by each surface 125 is preferably less that 15°.
Upper extents of jaws 123 and 124 are carried by a vertically floating slider or carrier 129 extending within a bore 130 in the lower sleeve extent 100b of the handle; and a compression spring 131 fits between the top 129a of 129 and a shoulder 132 in the handle, to urge the slider and jaws downwardly relative to 100, 100a and 100b, for unlocking (positively disengaging) the assembly from ball clamping, when the handle is elevated. A stop shoulder 133 limits downward relative movement of 129. Friction damping or guiding of such movement may be provided as by a sleeve 136 on 129 and slidably engaging bore 139. Stiff pivot springs 137 carried by 129 yieldably and pivotably urge the jaws toward and adjacent the ball. A friction damper 140 presses downwardly on the top of the ball, to frictionally resist flopping of the ball and base, when the handle is not pushed down to effect ball gripping. A compression spring 141 yieldably urges damper 140 downwardly to forcibly engage the top of the ball.
A piston 210 within a cylinder is pushed downwardly as the cane shaft 201 is lowered, resulting in pressure transmission to liquid 205 within the ball. Shaft lower cylindrical extension 212a guides on the cylinder 211 carried at 211a by the ball, to pivot therewith. Piston 210 and cylinder 211 define an actuator. Ball 203 receives the lower end of the cylinder 211, which carries the ball.
A bearing 308 for member 304 is defined by a post 310 extending upwardly from base 301. Member 306 supports a cylindrical guide 312 for shaft 300, so that the shaft pivots bi-directionally with 306, but is movable downwardly within 312, to frictionally slide at 313 adjacent an arcuate section or sector 314 acting as a friction damper to resist pivoting of the shaft about axis 307. Another section or sector 315 carried by member 304 resists pivoting of the shaft about axis 305, there being a friction surface 316 on 310 that engages 315.
In alternative embodiments, the base platform can be replaced with a second handle or other means of attaching to the user's body. Also proscribed pathways of motion can be defined by other means such as light, sound, vibration, electrical stimulation, pressure etc.
Thus, novel designs have been shown and described. Various modifications and substitutions can of course be made, without departing from the spirit and scope of the invention. The invention, therefore, should not be limited, except by the following claims, and their equivalents.
Number | Name | Date | Kind |
---|---|---|---|
332684 | Tuttle | Dec 1885 | A |
710074 | Pratt | Sep 1902 | A |
2230406 | Johnson | Feb 1941 | A |
2642074 | Pedley et al. | Jun 1953 | A |
3289685 | McCall Parker et al. | Dec 1966 | A |
3731698 | Buchalter | May 1973 | A |
4440186 | Lottner | Apr 1984 | A |
4493334 | Semanchik et al. | Jan 1985 | A |
4510957 | Frank | Apr 1985 | A |
4708154 | Edwards | Nov 1987 | A |
4940203 | Hayakawa | Jul 1990 | A |
4947882 | Levasseur | Aug 1990 | A |
5088513 | Ostermeyer | Feb 1992 | A |
5782256 | Bradley | Jul 1998 | A |
6138699 | Su | Oct 2000 | A |
6164305 | Herman | Dec 2000 | A |
20040250845 | Rudin et al. | Dec 2004 | A1 |
Number | Date | Country |
---|---|---|
41 08 834 | Sep 1992 | DE |
0 071 982 | Feb 1983 | EP |
2 637 178 | Apr 1990 | FR |
Number | Date | Country | |
---|---|---|---|
20040206384 A1 | Oct 2004 | US |