Walker with constantly applied brake

Information

  • Patent Grant
  • 6494815
  • Patent Number
    6,494,815
  • Date Filed
    Friday, February 18, 2000
    25 years ago
  • Date Issued
    Tuesday, December 17, 2002
    22 years ago
Abstract
A walker for a toddler or infant is disclosed. The walker has a base and a seat operatively coupled to the base. It also includes a plurality of rollers for supporting the base on a walking surface such as a floor. The walker also includes a brake which is positioned to constantly apply friction to at least one of the rollers to thereby inhibit the travel speed of the walker.
Description




FIELD OF THE INVENTION




The invention relates generally to infant walkers, and, more particularly, to a toddler or infant walker with a constantly applied brake.




BACKGROUND OF THE INVENTION




Infant or toddler walkers have long been known in the art. A conventional walker includes a base, a seat, a support coupling the seat to the base and a plurality of free moving rollers. When placed in the seat, an infant or toddler is supported with their feet touching a ground surface such as a floor. The infant or toddler can then roll the walker by moving their feet against the ground surface.




Various walkers have been developed that attempt to control the manner in which the walker can be propelled. For example, some prior art walkers employ complicated clutch mechanisms that suddenly engage to stop the walker when a certain speed is reached. Other prior art walkers include rollers which freely rotate in one direction, but are unable to roll in the reverse direction to prevent the walker from moving backward.




SUMMARY OF THE INVENTION




In accordance with an aspect of the invention, a walker is disclosed. The walker includes a base and a seat operatively coupled to the base. The walker also includes a plurality of rollers for supporting the base. In addition, the walker is provided with a brake positioned to constantly apply friction to at least one of the plurality of rollers.




In accordance with another aspect of the invention, a walker is disclosed which includes a base and a seat operatively coupled to the base. The walker also includes a roller coupled to the base for rotation in a first direction and a second direction opposite the first direction. The walker also includes a spring positioned to constantly force contact between the roller and a braking surface to thereby inhibit rotation of the roller.




In accordance with still another aspect of the invention, a method is disclosed for inhibiting a travel speed of the walker. The method comprises the step of providing a walker with a base, a seat supported by the base, and a roller coupled to the base. The method also includes the step of employing a spring to constantly create friction between the roller and a braking surface to thereby inhibit rotation of the roller.




In the preferred embodiments, the brake further comprises a braking surface and a spring positioned to cause frictional engagement between the at least one of the rollers and the braking surface.




Other features and advantages are inherent in the disclosed apparatus or will become apparent to those skilled in the art from the following detailed description and its accompanying drawings.











BRIEF DESCRIPTION OF THE DRAWINGS





FIG. 1

is a perspective view of a walker constructed in accordance with the teachings of the instant invention.





FIG. 2

is a bottom view of the walker of FIG.


1


.





FIG. 3

is an enlarged view of the portion of

FIG. 2

which is circled and labeled “


3


”.





FIG. 4

is an exploded view of the roller and support walls shown in

FIG. 3







FIG. 5

is an exploded view of another roller constructed in accordance with the teachings of the invention.





FIG. 6

is an exploded view of another roller constructed in accordance with the teachings of the invention.





FIG. 7

is a partial exploded view of another roller constructed in accordance with the teachings of the invention.





FIG. 8

is a partial exploded view of another roller constructed in accordance with the teachings of the invention.











DESCRIPTION OF THE PREFERRED EMBODIMENTS




A walker


10


constructed in accordance with the teachings of the invention is shown generally in FIG.


1


. Although for purposes of illustration, a specific walker


10


is shown and described, persons of ordinary skill in the art will readily appreciate that the teachings of the invention are not limited to use with any particular walker or in any other specific environment of use. On the contrary, the teachings of the invention can be employed with any walker that would benefit from the enhanced speed control it provides.




For the purpose of supporting an infant or toddler in an upright position, the walker


10


is provided with a seat


12


. In the illustrated walker


10


, the seat


12


comprises a fabric covering secured to, and suspended within, a plastic frame


13


. The fabric seat


12


includes a pair of leg openings


14


through which a child's legs extend when the child is positioned in the seat.




In the illustrated walker


10


, the seat frame


13


includes an integral tray positioned in front of the seat


12


for supporting toys, food, etc.




The walker


10


is further provided with a base


20


. The base


20


is preferably made of molded plastic. In the illustrated walker


10


, the base


20


defines a generally rectangular ring with a continuous perimeter. The center of the base


20


is open and the seat


12


is positioned so that the feet of a child located in the seat


12


can extend through the base


20


and contact the ground surface on which the walker


10


is supported.




In order to render the walker


10


usable with children of different heights and leg lengths, the seat


12


is coupled to the base


20


by a conventional adjustable frame


24


. As shown in

FIG. 1

, the adjustable frame


24


includes two U-shaped supports


23


,


25


(see FIG.


2


). The U-shaped supports


23


,


25


are oppositely oriented such that one of the supports


25


defines a pair of rear legs


26


and the other support


25


defines a pair of forward legs


28


. Each of the rear legs


26


is pivotably coupled to an inner surface of the base


20


at the rear of the base


20


by a pivot pin in a conventional manner. The front legs


28


, on the other hand, are coupled to pegs (not shown) which are sized and positioned to slide in grooves


30


defined in a forward, inner surface of the base


20


. Each side of the U-shaped supports


23


,


25


cross and are connected for pivoting relative movement by a fastener (not shown) and two plastic housings


27


(i.e., four housings


27


total). The housings


27


in each pair are pivotable relative to one another.




The upper ends of the U-shaped supports


23


,


25


are pivotably secured to the frame


13


. In particular, a central bar


32


of U-shaped support


23


is pivotably fastened to a bottom surface of the seat support


13


by a holder


34


. A central bar


36


of the other U-shaped bar


25


is also fastened to the undersurface of the seat support


13


by a holder


38


. However, whereas the holder


34


only permits the central bar


32


to rotate, the holder


38


permits both rotation and translation of the central bar


36


to permit adjustment of the height of the seat


12


relative to the base


20


. Preferably, the U-shaped supports


23


,


25


can be manipulated such that the seat


12


can be positioned adjacent the base


20


when storage of the walker


10


is desired.




To releasably lock the seat


12


in the upright position, the holder


38


is provided with a conventional lock mechanism


39


. As any locking mechanism can be employed in this role, and the structure of the lock mechanism is immaterial to the invention, in the interest of brevity the lock mechanism is not further described herein.




To support the base


20


on the ground surface, the walker


10


is further provided with a plurality of rollers


40


,


41


. As shown in

FIG. 2

, in the illustrated walker, each of the rollers


40


,


41


is located on a corner of the base


20


. The rollers


41


located at the forward corners of the base


20


are conventional casters mounted for 360° rotation about a shaft. Thus, the forward casters


41


can roll easily in any direction.




As most easily seen in

FIG. 3

, the rearmost casters


40


are each mounted to the base


20


for rotation about a horizontally mounted axis. As a result, the rearmost rollers


40


are restricted to forward and rearward rolling movement. As explained below, the rollers


40


are each provided with rubber tires


56


that substantially prevent the rollers from sliding sideways.




If the walker


10


is inappropriately employed in a location near a drop-off(e.g., a set of stairs, a sunken floor, etc.), it is possible for the walker


10


to be propelled such that a portion of the base


20


and one or two of the rollers


40


passes over the drop-off. To reduce the likelihood that the walker


10


will fall completely off of the drop-off, the walker


10


is further provided with a plurality of friction pads


44


. As shown in

FIG. 2

, in the illustrated walker


10


, the friction pads


44


are rectangular pieces of rubber secured at various positions along the undersurface of the base


40


. The friction pads


44


are located such that, if one or two rollers


40


passes over a drop-off, the base


20


will move downward with the roller(s) under the force of gravity until one or more of the friction pads


44


engages the ground surface. The frictional engagement between the friction pads


44


and the ground surface reduces the likelihood that the walker


10


will completely pass over the drop-off and fall. However, despite the enhanced safety provided by the friction strips


44


, the walker


10


should still be used only under adult supervision and in a location free of drop-offs (i.e., not near stairs).




For the purpose of limiting the travel speed at which a child positioned in the seat


12


can propel the walker


10


, the walker


10


is further provided with means for constantly applying friction to the rear roller(s)


40


. While as demonstrated by the alternative embodiments illustrated in

FIGS. 5-7

, the friction applying means can be implemented in many equivalent ways without departing from the scope or spirit of the invention, in the example shown in

FIGS. 1-4

, the friction applying means is implemented by a brake comprising a spring


50


, a hub cover


52


and a braking surface


54


coupled to the base


20


as explained in detail below. Again, although as demonstrated in the various alternative embodiments the brake can be implemented in many ways without departing from the scope or spirit of the invention, it preferably includes a braking surface and a spring positioned to cause frictional engagement between a portion of one of the rearmost rollers


40


and the braking surface. Preferably, each rear roller


40


is provided with a friction applying means.




Turning with specificity to the brake shown in

FIGS. 3-4

, each of the two rearmost rollers


40


is preferably implemented in substantially the same way. Therefore, the following description of one of the proximal rollers


40


is intended to serve for both rear rollers


40


.




The roller


40


includes a cylindrical body


56


. As shown in

FIG. 4

, a rubber tire


57


with treads is mounted on the outer circumference of the body


56


. The body


56


includes an inner tube


58


. The inner tube


58


is supported in concentric relation to the body


56


by radial ribs


60


. The inner tube


58


defines a central bore


62


which is dimensioned to slidably receive a conventional fastener


64


such as a bolt or the like. The fastener


64


forms the axis of rotation for the roller


40


.




The body


56


of the roller


40


also defines three receiving holes


68


located adjacent its perimeter. The hub cover


52


is provided with a circular plate member


70


and three projections


72


. The projections


72


are sized to slidably mate with the receiving holes


64


such that the hub cover


52


is moveable along the axis of rotation of the body


56


. Preferably, the plate member


70


of the hub cover


52


includes a raised central portion and an annular curved portion. The raised central portion preferably has a flat upper surface.




The base


20


of the walker


10


is provided with two depending walls


80


. The walls


80


each define a bore


81


which is sized to receive the fastener


64


. The walls


80


are spaced a sufficient distance from one another to define a receiving chamber therebetween in which the roller


40


can be mounted for rotation. In the example shown in

FIGS. 1-4

, the walls


80


are substantially rigid.




In the example of

FIGS. 3-4

, the spring


50


is implemented by a compression coil spring which is seated on the inner tube


58


. When the roller


40


is assembled and mounted on the walker


10


, the spring


50


is compressed between the raised central portion of the hub cover


52


and the radial ribs


60


of the roller


40


. As a result, the spring


50


applies an outwardly directed force to the hub cover


52


which biases the hub cover in a direction away from the center of the body


56


along the axis of rotation. The walls


80


and the components of the roller


40


are sized such that the spring


50


biases the raised central portion of hub cover


52


into contact with one of the walls


80


. The contacted portion of the wall, therefore, comprises the braking surface


54


mentioned above. The engagement of the hub cover


52


and the braking surface inhibits rotation of the roller


40


to thereby limit the travel speed of the walker


10


. As will be appreciated by a person of ordinary skill in the art, the spring force and/or the braking surface can be adjusted to obtain a braking force having a desired magnitude.




While in the example shown in

FIGS. 1-4

, the braking surface


54


is integrally formed with the base


20


, persons of ordinary skill in the art will readily appreciate that the braking surface


54


can be implemented by a structure separate from the base


20


without departing from the scope or spirit of the invention.




To assemble the rearmost rollers


40


of

FIGS. 1-4

, the spring


50


is first seated on the inner tube


58


. The hub cover


52


is then positioned on the body


56


with the extensions


72


located in the receiving bores


68


. With the hub cover


52


compressing the spring


50


, the assembled cover


52


, spring


50


and body


56


are positioned between the walls


80


of the base


20


. The fastener


64


is then slid through the bore


81


in a first one of the walls


80


, a bore in the hub cover


52


, the bore


62


in the inner tube


58


, and the bore


81


in the second wall


80


. A washer


84


and a nut


86


are then threaded onto the fastener


64


to secure the roller


40


to the base


20


. If the roller


40


is then rotated about the fastener


64


, the raised portion of the hub cover


52


forms a rotating surface that abuts the braking surface


54


to create friction that limits the speed of rotation of the roller


40


.




The apparatus described below are similar in many respects to the roller assembly described above in connection with

FIGS. 3-4

. Like parts have been labeled with like reference numerals but increased by “100” in

FIG. 5

, increased by “200” in FIG.


6


and by “300” in FIG.


7


. All four of the disclosed roller assemblies shown in

FIGS. 3-7

can be used with the walker


10


shown in

FIGS. 1-2

.




A roller


140


employing an alternative friction applying means is shown in FIG.


5


. Like the roller


40


described above, the roller


140


includes a body with a rubber tread


155


and a hub cover


152


with a raised central portion. Also like the roller


40


described above, the roller


140


is mounted for rotation about a horizontal axis defined by a fastener


164


journalled between two walls


180


depending from the base


20


. However, unlike the roller


40


, in the roller


140


, the spring


150


is mounted externally to the roller


140


.




More specifically, as shown in

FIG. 5

, the spring


150


is seated on the fastener


164


between a washer


151


and one of the walls


180


. The wall


180


abutting the spring


150


is flexible, whereas the wall


180


on the opposite side of the roller


140


is rigid. As a result, when the roller


140


and spring


150


are mounted on the fastener


164


and the fastener


164


is secured in its journaled position by a washer


184


and nut


186


, the spring


151


pushes or flexes the adjacent wall


180


into frictional engagement with the raised central portion of the hub cover


152


. Therefore, in the example of

FIG. 5

, the wall


180


between the spring


150


and the roller


140


comprises the braking surface of the friction applying means and the friction generated by the braking surface and the hub cover


152


inhibits the travel speed of the walker.




Another roller


240


employing yet another friction applying means is shown in FIG.


6


. As with the other rollers


40


,


140


, the roller


240


includes a body with a rubber tread


255


and is rotatably mounted on a fastener


264


journalled between two walls


280


depending from the base


20


. The fastener


264


is secured in the journalled position by a washer


284


and nut


286


.




The hub cover


252


of the roller


240


differs from the hub covers


52


,


152


described above. While all of the hub covers


52


,


152


,


252


include a central raised portion with a bore for receiving a fastener, the central raised portion of the hub cover


252


has a larger diameter such that the perimeter of the central raised portion of the hub cover


252


is located near the tread


255


.




The brake employed with the roller


240


of

FIG. 6

includes a contact


290


which is mounted for pivoting movement relative to the perimeter of the raised central section of the hub cover


252


. It also includes a spring


250


which biases the contact


290


into frictional engagement with the perimeter of the raised central section of the hub cover


252


to inhibit rotation (and, thus, the travel speed) of the roller


240


.




More specifically, the contact


290


includes a pivotable arm


291


. One end of the pivotable arm


291


is mounted on a pivot pin


292


extending from an inner surface of one of the walls


280


. The other end of the pivotable arm


291


includes a friction pad


293


which may optionally be made of rubber. The friction pad


293


is located for engaging the perimeter of the raised central portion of the hub cover


252


to thereby inhibit rotation of the roller


240


.




A further roller


340


is shown in FIG.


7


. The roller


340


is similar to the roller


240


. However, the perimeter of the hub cover


352


is stepped such that the hub cover


352


forms a ratchet and the contact


390


is implemented by a peg mounted on a wall


380


in a position for engaging the ratchet. The contact


390


is preferably flexible and can be deflected by the rotating ratchet. The interaction of the ratchet and contact


390


provides friction to inhibit rotation of the roller


352


and creates a clicking noise when the walker moves.




Still another roller


440


is shown in FIG.


8


. The roller


440


combines features of the rollers


240


and


340


. In particular, the roller


440


includes a hub cover


452


which is similar to the hub cover


252


. However, a ratchet wheel


453


similar to hub cover


352


is secured to or integrally formed with the hub cover


452


. A contact


490


identical to the contact


290


is biased by a spring


450


into frictional engagement with the smooth perimeter of the hub cover


452


. A second contact


491


identical to the contact


390


is positioned to engage the ratchet wheel


453


in a manner similar to the engagement of the hub cover


352


and the peg


390


of the roller


340


. The interaction of the contact


490


and the hub cover


452


provides enhanced inhibition of rotation of the roller


440


relative to the roller


340


, while the second contact


491


and ratchet wheel


453


provide a clicking noise as well as additional inhibition of rotation.




As still another alternative, the peg


491


can be eliminated and a shorter version of the peg


491


can be located on the contact


490


for interaction with the ratchet wheel


453


. The shortened peg


491


(not shown) can be used in place of or in combination with a friction pad such as pad


293


.




While the walkers described herein all employ a compression spring to create friction, persons of ordinary skill in the art will readily appreciate that other conventional springs including, by way of examples, not limitations, leaf springs, tension springs, torsion springs and Belleville springs could also be employed to generate the braking force without departing from the scope or spirit of the invention.




Although certain apparatus constructed in accordance with the teachings of the invention have been described herein, the scope of coverage of this patent is not limited thereto. On the contrary, this patent covers all embodiments of the teachings of the invention fairly falling within the scope of the appended claims either literally or under the doctrine of equivalents.



Claims
  • 1. A walker comprising:a base; a seat operatively coupled to the base; first and second rollers respectively mounted at first and second corners of the base; third and fourth rollers respectively mounted at third and fourth corners of the base, each of the third and fourth rollers being restricted to forward and rearward rolling movement; a first brake positioned to constantly apply friction to the third roller; a second brake positioned to constantly apply friction to the fourth roller such that the walker is constantly braked against pivoting movement, forward movement, and rearward movement; a braking surface; and a spring positioned to cause frictional engagement between the third roller and the braking surface, wherein the base includes a pair of walls, the third roller is mounted between the pair of walls, and at least one of the pair of walls comprises the braking surface.
  • 2. A walker as defined in claim 1 wherein the braking surface contacts a rotating surface of the third roller.
  • 3. A walker comprising:a base; a seat operatively coupled to the base; a first roller coupled to the base for rotation in a first direction and a second direction opposite the first direction; a first spring positioned to constantly force contact between the first roller and a first braking surface to thereby constantly inhibit rotation of the first roller; a second roller coupled to the base for rotation in the first direction and the second direction opposite the first direction; and a second spring positioned to constantly force contact between the second roller and a second braking surface to thereby constantly inhibit rotation of the second roller such that pivoting movement, forward movement and rearward movement of the walker are inhibited; wherein the first braking surface contacts a hub cover of the first roller.
  • 4. A walker comprising:a base; a seat operatively coupled to the base; first and second contact surfaces; a first roller coupled to the base and including: (a) a wheel body having a center; (b) a third contact surface coupled for movement relative to the wheel body; and (c) a spring located to bias the third contact surface in a direction away from the center of the wheel body and into frictional engagement with the first contact surface; and a second roller coupled to the base and including: (a) a wheel body having a center; (b) a fourth contact surface coupled for movement relative to the wheel body; and (c) a spring located to bias the fourth contact surface in a direction away from the center of the wheel body and into frictional engagement with the second contact surface such that the walker is constantly inhibited against pivoting movement, forward movement and rearward movement.
  • 5. A walker as defined in claim 4 wherein the first contact surface comprises a portion of the base.
  • 6. A walker as defined in claim 4 wherein the first contact surface is coupled to the base.
  • 7. A walker as defined in claim 4 wherein the base includes a first wall and a second wall, the first roller is rotatably mounted between the first and second walls, and one of the first and second walls comprises the first contact surface.
  • 8. A walker as defined in claim 7 wherein the first roller is rotatably mounted on a fastener journalled between the first and second walls.
  • 9. A walker as defined in claim 4 wherein the third contact surface comprises a hub cover.
  • 10. A walker as defined in claim 9, wherein the hub cover is coupled to the wheel body to rotate therewith and for movement relative to the wheel body in a direction perpendicular to the direction of rotation of the
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Entry
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