The present invention is related to the field of ambulatory assist devices, that is, walkers. Specifically, aspects of the invention provide a self leveling walker having assemblies on each side of the walker for continuous and reciprocal extension and retraction of the front set of legs and the back set of legs in order to assist the user in negotiating slopes and steps while maintaining a relatively erect standing position, without the need to lean forwards or backwards. The proposed invention therefore relates to a novel approach to improving walkers in such a way that walking functions for users are greatly improved when traversing uneven or sloped surfaces and stairs, and transitioning easily between level and inclined surfaces and stairs.
Known approaches for walkers often incorporate rigid legs and the like, something which is not desirable because they cannot offer a square, level frame for constant upright standing posture throughout the entire range of user motion, a key feature that is important for the stable ambulation of a user who is prone to fall when leaning backwards or forward when traversing inclined, or conversely, declined slopes or stairs.
The subject matter which is regarded as one embodiment of the invention is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other objects, features, and advantages of the invention will be readily understood from the following detailed description of aspects of the invention taken in conjunction with the accompanying drawings in which:
The walker in accordance with this invention relates to a novel approach to improving the use of walkers, by offering a walker that can continuously and automatically level its four legs, in some cases independently from each other, with a simple hydraulic or pneumatic circuit or other means. The initial height of the walker can first be customized for the individual user by manipulating telescopic extensions as in conventional devices, then the relative lengths of each leg can be adjusted for uneven surfaces and stairs through the use of tubes within the legs of the walker which are filled with hydraulic fluid (or gas, in cases of pneumatic instantiations) that along with the lower, adjustable members define a closed cylinder. Alternatively, the lower portion of each leg can contain an individual leveling piston or cylinder. With the above, a valve is located in the hydraulic circuit between the front and back legs on each side, and is normally closed (whereby all four legs are of fixed and unchanging height), until activated. When activated (either by manual control by pushing and holding a control button, or alternatively, by automatic control through the use of sensors), both valves are opened and fluid can flow back and forth between the respective sets of front and back legs. As the user leans forward, body weight creates pressure on the front legs causing fluid to flow to the rear legs, shortening the front and extending the back of the walker. When the control is released, the valves close to stop fluid flow and lock the new height of the front and back legs in place. The inventive walker then maintains its new configuration as the user negotiates the slanted or uneven surface, so that the user can more easily negotiate up or down ramps or ascending or descending steps in a stable upright vertical posture, thereby eliminating the problems inherent in a conventional walker which severely obstructs usage on sloped surfaces, especially during the climbing of stairs because of the fixed leg height which makes the walker unstable on steps and the like. In one embodiment, the hydraulic circuit between the front and back legs may be connected with additional valves between the left side and right side of the self leveling walker, in order to adjust for surfaces that are laterally (e.g. side-to-side) uneven in view of the path of travel by a user. In other embodiments, hydraulics and pneumatics may be supplanted by alternative variants employing chain- or cable-driven linkages between front and back legs, with a clutches that would engage or disengage with the press of a control button, or by controlling the same with electric motors. When implemented as described herein, the inventive self leveling walker essentially employs a self leveling mechanism that is able to consistently ensure that the walker and the user thereof, maintain a vertical posture that is consistently perpendicular to a gravitational vector (e.g., perpendicular along a vertical axis to a horizontal level or axis). Also, in at least one embodiment, the inventive self leveling walker provides for automatic self-leveling features described herein, the provision of which affords smooth, continuous adjustability when compared with say, discrete, inflexible gradients of user-initiated adjustment based mechanics.
In affording the above, the present invention provides for the following beneficial advances relating to: (1) Provision of a unique design that allows the walker, and therefore the user thereof, to remain in a substantially erect or upright standing position, essentially eliminating any leaning forwards or backwards from the vertical position during the course of traversal of uneven or sloping surface areas (e.g., the user need not lean backwards or forward with respect to the slope of the surface of traversal); (2) Provision of features which, unlike conventional static (e.g., non-adjustable) walkers, are hydraulic, pneumatic, spring loaded and/or air piston (cylinder) based, all of which is self sensing in terms of relative leg adjustment heights between the front and rear legs; (3) Provision of dual control actuation for accidental engagement of the leveling mechanism; (4) Provision of optional single-sided (keyed or squared) leveling cylinders with spring assisted returns which minimize friction, reduce the weight of the configuration, and which also facilitate returning the legs of the walker to an initial default (equally extended) configuration. The above therefore prevents falls that can occur from leaning to accommodate slopes or stairs, and increases independence and quality of life overall. To this end, the present invention overcomes the aforementioned and other disadvantages inherent in the prior art.
The present invention therefore provides an ambulatory “self leveling walker,” having a leveling assembly that can raise (extend) and/or lower (retract) the front legs cooperatively with the back legs, and vice-versa when on flat surfaces, or in opposition to each other in order to assist the user in negotiating slopes, uneven surfaces and stairs. Referring now to the embodiment shown in
As referenced, the activation mechanism comprises control valves that are chosen from the group comprising at least one directional control valve (not depicted) as a means for controlling the pair of adjustable rear legs 18a, 18b and the pair of adjustable front legs 16a, 16b on the respective left and right sides (e.g., on left frame support 6 and a right frame support 8 respectively), or as depicted, one left side valve 20a and one right side valve 20b and at least one complementary left side activation line 12a and at least one complementary right side activation line 12b which all can be externally or internally attached to the frame assembly as a means for controlling said pair of adjustable rear legs 18a, 18b and said pair of adjustable front legs 16a, 16b. As contemplated, adjustable rear leg 18a extends from the rear, lower portion of left frame support 6, and the adjustable front leg 16a extends from the front, lower portion of left frame support 6, wherein both are connected to each other via at least one complementary left side activation line 12a, and similarly, the adjustable front leg 16b extends from the front, lower portion of right frame support 8 and the adjustable rear leg 18b extends from the rear, lower portion of right frame support 8 wherein both are connected to each other via at least one complementary right side activation line 12b. In certain embodiments, complementary left side activation line 12a and complementary right side activation line 12b can be either pneumatic lines or hydraulic lines, while leveling assembly 10 can electrically (electronically) control the same respectively through the activation mechanism as described, but can also utilize sensors, such as tilt sensors, such as inertial or pressure sensors (not depicted), in providing an automatic control option. In such an automated embodiment, pressure sensors can sense pressure values within the complementary left and right side activation lines 12a, 12b or alternatively, can sense the inclination, acceleration, stress and the like of frame assembly 4, so as to open and close at least one respective left side valve 20a, right side valve 20b attached thereto, whereby the sensors redistribute fluid or air within the complementary left and right side activation lines 12a, 12b, to a plurality of leveling pistons (not depicted) that are situated so as to be contained within each respective leg of the pair of adjustable rear legs 18a, 18b and of the pair of adjustable front legs 16a, 16b. It is noted that, in one embodiment, the activation mechanism may be provided as part of, or electrically connected to leveling assembly 10, and can operate in either an automatic mode setting that employs the sensors to provide deployment of the activation mechanism, or in a manual mode setting that uses single or dual control buttons 24 that can prevent mistaken deployment of the activation mechanism. Another alternative embodiment also provides for the activation mechanism to include an automatic lock/unlock feature (not depicted) of control and at least one accelerometer or other inertial sensor for use when operating in the automatic mode. In a further alternative embodiment, adjustable rear legs 18a, 18b and adjustable front legs 16a, 16b may each include friction and weight reduction mechanisms (not depicted) which may comprise leveling cylinders/pistons complete with the addition of spring-assisted returns that reduce weight and friction in certain cases. When provided in accordance with the above, self-leveling walker 2 can adjust, as depicted in
In accordance with illustrative structural materials and exemplary components described above, the following text describes in greater detail the composition, operation, and uses of each of the aforementioned components of the inventive lift walker. As mentioned, self leveling walker 2 can use either pneumatic or hydraulic cylinders (pistons), and associated control valves therewith to direct fluid flow to adjust the height of the legs. When traversing a substantially flat or even surface, self leveling walker 2 is normally locked, with no dynamic output from leveling assembly 10. However, with input (either by manually pressing activation button 24, or by automatic means, such as electronic sensors as described herein) elevator assembly 10 can activate the activation mechanism which in turn manipulates the hydraulic or pneumatic pressure within complementary left side activation line 12a and complementary right side activation line 12b through opening and closing of the control valves, namely exemplary left side valve 20a and right side valve 20b (as illustratively depicted by way of the detailed illustration of one side, seen in
It is noted that in one alternative embodiment, self leveling walker 2 may provide opening and closing of left side valve 20a and right side valve 20b through the use of solenoid valves, as generally depicted in
Alternatively, the present invention provides for a power-free embodiment that need not be electrically actuated at all, and which consequently would not need to employ solenoid valves as described above. To this end, self leveling walker 2 may provide opening and closing of left side valve 20a and right side valve 20b through the use of check valves which open at a fixed pressure (i.e. cracking pressure”), wherein fluid would flow from say, front legs 16a, 16b to rear legs 18a, 18b (and vice-versa) thereby leveling self leveling walker 2 if enough weight were put on one set of legs so as to increase the pressure in the aforementioned pneumatic or hydraulic cylinders (pistons) enough in such a way as to blow past the check valves. In a further embodiment, the check valves could be field customizable and tunable according to user indicia. Such field customization and tuning according to user indicia might, in one embodiment, be accomplished by selecting a check valve rated for some percentage of the user body weight from an inventory of components spanning a range of characteristics and installing it in the circuit. For example, after measuring user body weight and determining that a specific user normally places say, 50% of body weight on his/her legs while using the walkers, check valves rated at perhaps 25% of body weight could be selected and installed between the front and rear legs on each of the left and right sides of the self leveling walker. This would allow fluid to flow from the front to rear legs to adjust their relative lengths to accommodate changes in surface height when the user places more than a total of say, 50% body weight on the front legs, such as when ascending a ramp. Once on a level surface again, the user would lean backwards or change the positions of their hands on the walker handles to place more than 50% body weight on the rear legs until the walker is leveled and returns to the nominal position. Operation can then be evaluated and customized for user comfort and safety by replacing the check valves initially selected by ones with higher or lower ratings. In an alternative embodiment, check valves with adjustable cracking pressures that are field tunable by a technician or the user in the field can be incorporated into the self leveling walker, rather than replacing valves with fixed flow through pressures. The appropriate cracking pressure might, in one illustrative embodiment, be set by say, manipulating an adjusting screw to alter a poppet spring tension or other internal configuration of the valve and locking the new spring length and cracking pressure at the desired value.
One alternative embodiment of the present invention provides for automation of activation of leveling assembly 10 through the addition of sensors such as strain gages, accelerometers, gyroscopes and/or magnetometers and the like, and a microcontroller (not depicted) that could allow for an optional automatic lock/unlock control of self leveling walker 2 based upon sensed values, wherein the sensors would augment or replace the sensing of any pressure sensors used as pressure monitors of fluid/air, for signaling redistribution of the fluid or air within complementary left side activation line 12a and within complementary right side activation line 12b, to a plurality of leveling pistons (cylinders) situated contained within adjustable legs 16a, 16b, 18a, 18b. Such a feature would be beneficial for individuals with limited finger dexterity and strength. In this embodiment, the sensors would act to sense inclination, orientation with respect to gravity, or forces and stresses on the frame assembly. An example of this type of sensor would be the LIS344ALH, 3-axis linear accelerometer available from ST Microelectronics of Geneva, Switzerland. Note the small size of this type of sensor (4×4×1.5 mm) and it could very easily be integrated into the design of self leveling walker 2. The distribution of the gravitational vector on the accelerometer axes would indicate the angle of self leveling walker 2. The microcontroller could continuously sense or sample the accelerometer outputs and automatically lock/unlock self leveling walker 2 based on theses accelerometer values. As illustratively depicted in
Although described herein primarily within the context of a specific embodiment that contemplates self leveling walker that is specifically constructed as an entire integrated unit, it is noted that the present invention also contemplates provision of the inventive features by modification of non-self leveling walkers through provision as a retrofit kit that can be added on to existing walkers, as shown in detached form in
To this end, the present invention overcomes the aforementioned and other disadvantages inherent in the prior art. While several aspects of the present invention have been described and depicted herein, alternative aspects may be implemented by those skilled in the art to accomplish the same objectives. Accordingly, it is intended by the appended claims to cover all such alternative aspects as fall within the true spirit and scope of the invention.
This application claims priority from U.S. provisional application No. 61/795,744, filed on Oct. 23, 2012, the contents of which are hereby incorporated by reference in the entirety.
This invention was made with government support under grant number EB001889 awarded by the National Institutes for Health. The government has certain rights in the present invention.
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Number | Date | Country | |
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20140109944 A1 | Apr 2014 | US |
Number | Date | Country | |
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61795744 | Oct 2012 | US |