WO2007053264A2

WO2007053264A2 - Child safety stool

Info

Publication number: WO2007053264A2
Application number: PCT/US2006/039318
Authority: WO
Inventors: Alan Greer
Original assignee: Alan Greer
Priority date: 2005-11-01
Filing date: 2006-10-06
Publication date: 2007-05-10
Also published as: WO2007053264A3; US20070095612A1

Abstract

A child safety stool that includes movable engaging elements for selectively engaging the stool with the raised base portion of a cabinet so as to prevent tipping. The stool includes a main body, one or more engaging elements, and a locking mechanism. The main body has a top surface and a front surface, the top surface being a step surface. The one or more engaging elements extend rearwardly from the main body. The locking mechanism is in mechanical connection with the one or more engaging elements and is for selectively locking the one or more engaging elements in an engagement position with the raised base portion of the structure, whereby the stool is prevented from tipping when the one or more engaging elements are in the engagement position.

Description

CHILD SAFETY STOOL CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Utility Application No. 11/265,325, filed November 1, 2005, the contents of which are hereby incorporated by reference herein.

DESCRIPTION OF THE INVENTION

Field of the Invention

The present invention relates to a stool for aiding access to raised structure such as a cabinet or vanity. Background of the Invention

Interacting with elements of the adult world is often difficult for children given their small size. For instance, access to structures such as cabinets, tabletops, vanities, etc. is difficult given the relative height of their top surface as compared to a child. As such, children may become reluctant to engage in educational or personal hygiene activities (e.g., teeth brushing) when the use of such structures is required.

Conventionally, various step stools have been used to allow children and shorter people access to the top surface of such structures. However, many conventional stools are prone to tipping, which may cause injury to the user. Some step stools include designs for attaching the stool to certain cabinets so as to help prevent tipping. However, these stools are generally unacceptable as they are designed for only one specific type of cabinet, and the attachment to such cabinets is semi-permanent and cumbersome to remove. Often, the attachment of such stools to a cabinet or vanity renders the lower cabinet shelving space unusable. SUMMARY OF THE INVENTION

In view of the foregoing, the present invention provides a child safety stool designed to selectively engage with a vanity, cabinet, or other structure of varying heights so as to provide a low-profile, tip-resistant stool. The stool will allow users, typically children, to reach a sink, e.g., and encourage them to perform personal hygiene. By engaging with the lower lip of a raised base portion that exists on a majority of cabinets and vanities, the stool is prevented from tipping outward. Because the stool is making contact with the vanity on the back portion, it is unable to tip in that direction, thus producing a stable, low-profile standing platform for use by children to access a sink of counter for hygiene or education purposes. The stool utilizes selectively movable engaging elements to "lock" the stool in place to a structure. The stool utilizes a mechanically activated locking mechanism to raise the engaging elements into a locked position. For example, one embodiment of the invention utilizes a rotary plate on the front of stool, along with a pulley and bearing assembly, to convert the rotary motion of the plate to linear motion of rigid arms that engage with the structure. A lock release mechanism lowers the engaging elements from the cabinet and allows the stool to be moved. The quick engagement and detachment allows the stool to be quickly and easily moved for allowing access to cabinets that may be located in the engagement area.

As such, the invention provides a tip-resistant stool for aiding access to an elevated surface of a structure having a raised base portion. The stool includes a main body, one or more engaging elements, and a locking mechanism. The main body has at least top surface and a front surface, the top surface being a step surface. The one or more engaging elements extend rearwardly from the main body. The locking mechanism is in mechanical connection with the one or more engaging elements and is for selectively locking the one or more engaging elements in an engagement position with the raised base portion of the structure, whereby the stool is prevented from tipping when the one or more engaging elements are in the engagement position.

The stool may also include a selectively accessible intermediate step that is made accessible when the one or more engaging elements are in the engagement position. The intermediate step comprises a recess in the front surface of the main body including an intermediate step surface disposed within the interior of the main body, wherein the intermediate step has a predetermined size to accommodate a user's foot. The stool may further include a selectively movable blocking member cooperating with the one or more engaging elements such that the blocking member restricts access to the intermediate step when the one or more engaging elements are not in the engagement position.

The locking mechanism may include an artistic design, wherein the artistic design becomes properly aligned when the one or more engaging elements is in the engagement position. In this way, children are encouraged to use the locking mechanism to lock the stool into place. It is to be understood that the descriptions of this invention herein are exemplary and explanatory only and are not restrictive of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure IA depicts a child safety stool according to one embodiment of the invention in a typical operating environment. ^" Figure IB depicts a child safety stool according to one embodiment of the invention in an engaged position.

Figure 2 depicts a front view of a child safety stool according to one embodiment of the invention.

Figure 3 depicts a side view of a child safety stool according to one embodiment of the invention. Figure 4 depicts a back view of a child safety stool according to one embodiment of the invention.

Figure 5 depicts a locking arm assembly of a child safety stool according to one embodiment of the invention. Figure 6 depicts a locking arm adjuster of a child safety stool according to one embodiment of the invention.

Figure 7 depicts a back view of a pulley and bearing assembly of a child safety stool according to one embodiment of the invention.

Figure 8 depicts a back view of a pulley assembly and lock mechanism of a child safety stool according to one embodiment of the invention.

Figure 9 depicts a lock mechanism of a child safety stool according to one embodiment of the invention.

Figure 1OA depicts the rotary front plate in the unlocked position according to one embodiment of the invention. Figure 1OB depicts the rotary front plate in the locked position according to one embodiment of the invention.

Figure 11 depicts a pull-out step locking mechanism according to one embodiment of the invention.

Figure 12 depicts a slide-down step locking mechanism according to one embodiment of the invention.

Figure 13 depicts a side actuator locking mechanism according to one embodiment of the invention.

Figure 14 depicts an L-shaped pivot locking arm according to one embodiment of the invention. Figure 15 depicts a rotating locking arm according to one embodiment of the invention.

Figure 16 depicts a sliding locking arm according to one embodiment of the invention. Figure 17 depicts a cam-actuated locking arm according to one embodiment of the invention.

Figure 18 depicts a ratcheting locking arm according to one embodiment of the invention.

Figure 19 depicts an end view of the ratcheting locking arm. Figure 20 depicts a top view of the ratcheting locking arm.

Figure 21 depicts a release mechanism for the ratcheting locking arm. Figure 22 depicts a weight-activated locking arm according to one embodiment of the invention.

DESCRIPTION OF THE EMBODIMENTS Reference will now be made in detail to the present exemplary embodiments of the invention, examples of which are illustrated in the accompanying drawings.

Figure IA shows a child safety stool according to one embodiment of the invention in a typical operating environment. Safety stool 100 including main body 102, rotary front plate 104 and locking arm(s) 112 is positioned next to structure 50. Structure 50 is a cabinet, vanity of any other structure with a raised base portion. As shown here, structure 50 has a raised base portion 55. In operation, safety stool 100 is placed next to structure 50 so that its engaging elements (i.e., locking arms 112) are positioned under raised base portion 55. A locking mechanism is then mechanically activated so that the engaging elements are moved into an "engagement position." This engagement position occurs when locking arms(s) 112 are raised so that they make contact with raised base portion 55. In this way, stool 100 is locked to structure 50 and the stool is prevented from tipping backward. Figure IB shows the safety stool in the engagement position.

In Figure IA, the locking mechanism is shown as a rotary front plate 104 that converts rotational movement of the plate to linear motion (in this case vertical motion) of the locking arms. Once the rotary front plate moves the locking arms into the engagement position, the front plate locks and the arms are held in place. The locking arms are released from the locking position by locking arm release knob 110. The features and operation of safety stool 100 will be discussed in more detail below with reference to Figures 2 to 10.

Figure 2 shows a front view safety stool 100. As seen from the front, main body 102 includes a rotary front plate 104, an intermediate step access hole 106, an intermediate step 108, and a locking arm release knob 110. Main body 102 houses all components of the stool and acts as the structural support of the stool. Preferably, main body 102 is made of wood or plastic, however any material that is able to support the weight of a user is suitable. Top surface 103 of main body 102 serves as the primary step. Top surface 103 is preferably covered in a non-skid material to prevent the primary step from becoming slippery if wet, however any surface finish is suitable. In addition, the rear surface of safety stool 100 may be covered in a non-marring material such that contact with a cabinet or structure would not damage the cabinet or structure. Furthermore, a non-skid material may be applied to the tops locking arms 112 and/or the bottom surface safety stool 100 to prevent it from sliding away from the cabinet while in the engaged position.

Preferably, main body 102 is box-shaped and has a substantially flat top surface 103, however any shape capable of bearing the weight of a user may be used. Preferably, main body is 12 to 16 inches high, 16 to 20 inches wide, and 5 to 7 inches deep. However, any size of stool may be suitable. For example, taller or shorter stools may be desirable for use with cabinets or structures of different heights. In addition, deeper or narrower stools may be advantageous depending on the amount of overhang on the upper surface of a structure. For example, a structure with a deep upper overhang may be more suitable for a deep stool so that the user may stand far enough back to gain access to the upper surface of the structure. In addition, wider or narrower stools may be advantageous in certain situations. For example, a wider stool may be desirable so that two or more users may use the stool at once.

Rotary front plate 104 serves as the primary lever for raising locking arms 112. Rotary front plate 104 contains intermediate step access hole 106 such that when rotary front plate 104 is turned into the locking position (i.e., counter-clockwise), access is granted to intermediate step 108. Rotary front plate 104 could also be made to turn clockwise to engage the locking position. Rotary front plate 104 is preferably 11 to 12 inches in diameter and approximately centered in both the vertical and horizontal planes of the front of main body 102. However, any size, shape or position of rotary front plate may be used.

Figure 1OA and 1OB show rotary front plate 104 in the unlocked and locked positions, respectively. In one embodiment, rotary front plate 104 bears an artistic design 105 so as to encourage proper use by children. Artistic design 105 is setup in such a manner that it is completed or properly aligned when rotary front plate 104 is in the locked position.

Referring back to Figure 2, intermediate step access hole 106 is an opening in rotary front plate 104 that provides a gripping surface for turning rotary front plate 104. Intermediate step access hole 106 is positioned such that intermediate step 108 is only accessible when rotary front plate 104 is in the locked position. When rotary front plate 104 is not in the locked position, intermediate step 108 is blocked by rotary front plate 104 and intermediate step access hole 106 is backed by a solid piece to prevent use. Intermediate step 108 serves as a stepping aid to allow easier access to the primary step on top surface 103.

Locking arm release knob 110 activates a mechanism to unlock the stool when pulled mechanically. This allows the stool to be detached from the engaging point of a structure. The actual size of release knob 110 is not limited, but may be any size that is reasonable for a small child to operate. For example, the release knob may be approximately .75 to 1 inch in diameter. Preferably, the release knob is located approximately one inch from the rear surface of main body 102 and approximately six to seven inches from the bottom. However, the exact final position may be located in any place, so long as the release mechanism is operable vis a vis the internal mechanical components. The locking and release mechanism will be discussed in more detail below with respect to Figure 8 and 9.

Figure 3 shows a side view of safety stool 100. As can be seen from the side, main body 102 includes a locking arm 112 that extends rearwardly from the main body Locking arm 112 is a moveable arm that will rise to make contact with the lower lip of a cabinet (structure 50), vanity or other right overhang to allow the stool to be locked in place to prevent inadvertent tippling. These arms are mechanically linked to rotary front plate 104 such that when rotary front plate 104 is rotated, locking arm 112 moves vertically. In position A, locking arm 112 is in an unlocked position. In position B, locking arm 112 is in a locked position. Locking arm 112 is preferably rigid and made of wood or plastic, however, any material suitable for engaging with a structure may be used. Preferably, locking arm 112 is seven to eight inches long, with three inches protruding from the rear of main body 102, and is rectangular-shaped when looked at on end (approx. 1.25 to 1.5 inches high and .75 inches wide). However, longer or shorter locking arms may be used to effect engagement with different structures.

Figure 4 shows a back view of safety stool 100. As can be seen from the back, there are two locking arms 112 that are positioned within locking arm slots 114. More or fewer locking arms could be used. Locking arm slots 114 are holes in the rear cover panel of the stool that allow movement of locking arms 112 such that they can move vertically to engage with the engaging point. Preferably, locking arms 112 experience .75 to 3 inches of when moved from the unlocked to the locked position. As such, locking arms slots 114 are preferably 4.5 to 5 inches high. However, the stool may be designed for greater or lesser locking arm travel for use with cabinets and structures of varying sizes.

Pulley and bearing assembly 116 is represented with dashed lines as it is contained within the interior of main body 102. Pulley and bearing assembly 116 supports and contains the pulleys and bearings used to convert rotary motion of rotary front plate 104 into linear motion of locking arms 112. Pulley and bearing assembly 116 also serves as the support member for lock mechanism 318 which will be discussed in more detail with reference to Figures 8 and 9. Pulley and bearing assembly 116 will be discussed in more detail with reference to Figures 7 and 8.

Figure 5 shows a detailed view of the locking arm assembly. Locking arm retraction cable 202 mechanically connects locking arms 112 to pulley and bearing assembly 116 such that, when rotary front plate 104 is rotated into the locking (engagement) position, locking arms 112 are lifted to make contact with the engaging point. Locking arm retraction cable pin 204 mechanically connects locking arm retraction cable 202 to locking arms 112.

Locking arm return spring 206 forces locking arms 112 to full down position (i.e., unlocked position) when rotary front plate 104 is other than in the locked position. This allows the stool to be more easily displaced from the cabinet or other engagement point. Spring control rod 208 forces locking arm return spring 206 to be aligned in a predetermined position to ensure maximum designed spring response such that the spring is allowed to work properly on locking arms 112. As locking arms 112 are raised, spring control rod 208 slides up through the center of locking arms return spring 206 and through a hole in support member 214.

Spring retention plate 210 contacts support member 214 and locking arm return spring 206 to prevent the locking arm return spring from transiting through the hole designed for

10 spring control rod 208. This allows for spring control rod 208 to travel through the center of spring retention plate 210 without interfering with its free travel. Control rod pin 212 mechanically links spring control rod 208 to locking arms 112.

Support member 214 connects to main body 102 of the stool to provide extra support from the frame as well as to be a contact point for locking arm return spring 206. Pivot pin support block 216 is located on the inner side of each locking arm 112. Pivot pin support block 216 contains a hole into which pivot pin 218 is allowed to rotate. Pivot pin 218 then transits through locking arm 112 and into a hole in main body 102. This provides for the locking arm to be allowed to pivot freely and be attached in a secure manner to the frame. Pivot pin 218 passes from the frame of main body 102, through locking arms 112, and into pivot pin support block 216. This allows for a secure pivot point for the locking arms, allowing them to move freely in the vertical.

Adjuster access hole 220 is a small hole through locking arms 112 that allows for the adjuster block retention screw 222 (see Figure 6) to penetrate the locking arms in order that it may link with and lock into place with adjuster block 224 (Figure 6). In this way, the locking arms may engage with varying heights of the lower rigid portion of the engagement surface of a structure.

Figure 6 shows the locking arm adjuster in more detail. Adjuster block retention screw 222 is a screw with which to attach adjuster blocks 224 to locking anus 112. Preferably, the end of the screw has male threads to engage with matching female threads internal to the adjuster blocks. However, any type of connector is suitable. The other end of retention screw 222 is a knob designed for easy grip to allow the retention screw to be hand tightened into the adjuster blocks. Adjuster blocks 224 are blocks of varying size, preferably with internal female threads and protruding bumps such that the bumps are designed to engage with divots (not shown) in locking arms 112 to increase the security of the

11 engagement. By attaching adjuster blocks 224, the locking arms are allowed to engage with the lower rigid portion of the engagement surface of varying heights. Spacer washer 226 is a small washer that is optionally used to reduce the amount of penetration adjuster block retention screws 222 when thin adjuster blocks are used. Figure 7 shows pulley and bearing assembly 116 in more detail. Bearing and pulley support member 302 is the primary support and load bearing member that keeps pulley assembly 310 securely in place while allowing it to freely rotate so as to allow for the conversion of rotary force imparted by rotary front plate 104 to linear motion for locking arms 112. Bearing and pulley support member 302 also acts as the housing for the bearing on which the pulley assembly is allowed to rotate.

Rotary shaft 304 connects pulley assembly bearings 308 and pulley assembly 310 which is attached to rotary front plate 104 together. Rotary shaft 304 is secured to the frame via pulley assembly bearings 308 and retaining nut 306. Spacer inserts may be used to prevent the pinching of the pulley assembly bearing casing when retaining nut 306 is tightened. Retaining nut 306 screws onto rotary shaft keeping all components securely fastened to pulley support member 302.

Pulley assembly bearings 308 are used for smooth and low friction rotary motion of rotary front plate 104 and attached pulley assembly 310. Pulley assembly bearings reduce the amount of force required to overcome rotational friction allowing for easier operation of the device. Preferably they are ball bearings, however any type of bearing may be used. Pulley assembly 310 includes drive pulley 311 acid the attached bearings and hardware that are mechanically and positively attached to rotary front plate 104. Drive pulley 311 is mechanically attached to locking arm cable 312. Drive pulley 311 is designed to collect locking arm cable 312 as rotary front plate 104 is rotated into the locked position. By being mechanically attached to the locking arm retraction cable 202, drive pulley 311

12 converts the rotary motion of rotary front plate 104 and attached pulley assembly 310 to linear motion of locking arms 112. Pulley assembly 310 also contains ratchet mechanism

324 (see Figure 8) that interacts with friction plate 326 (see Figure 8) such that rotary motion is not restricted when rotary front plate 104 is rotated in the direction to engage locking arms 112. However, additional friction is applied when rotary front plate 104 is rotated in the direction to disengage the locking arms such that the rotary front plate is not allowed to

"snap" back to the unlocked or disengaged position.

Locking arm cable return spring 313 applies spring pressure to help fully retract locking arm retraction cable 202 when the stool is unlocked. Cable routing pulleys 314 are pulleys used to route and properly align, with minimal junctional losses, locking arm retraction cables 202 from locking arms 112 to attachment point on drive pulley 311.

Intermediate step housing 316 is an enclosed step and associated supports to provide an internal step that allows for an intermediate step, while preventing an inserted foot from becoming entangled with the inner workings of the stool. Access to intermediate step housing is provided by intermediate step access hole 108 when rotary front plate 104 is in the locked position (see Figure 2).

Lock mechanism 318 is an assembly that locks drive pulley 311 and attached rotary front plate 104 and locking arms 112 in place to provide positive engagement with the lower edge of an engagement point of a structure. Lock release cable 320 is a cable attaching release knob 110 to release pivot 336 to transfer force applied to release knob 110 to be transferred to release pivot 336 to unlock and lower locking arms 112.

Pulley position locking notch 322 is a notch in drive pulley 311 into which locking pin 328 is inserted when rotary front plate 104 is rotated into a locked or engaged position.

When locking pin 328 is inserted in pulley position locking notch 322, drive pulley 311 and attached components are mechanically locked in place. This forces locking arms 112 to

13 make positive and rigid contact with lower edge of the overhang of a structure (i.e., the engagement point) such that the stool is prevented from tipping.

Figures 8 and 9 show the pulley assembly and lock mechanism in more detail. Ratchet mechanism 324 includes tabs on the edge of drive pulley 311 that interact with friction plate 326 such that rotary motion is not restricted when rotary front plate 104 is rotated in the direction to engage locking arms 112, however, additional friction is applied when rotary front plate 104 is rotated in the direction to disengaged the locking anus such that the rotary front plate is not allowed to "snap" back to the unlocked or disengaged position. It is desired to reduce the rate at which the stool unlocks to prevent injury in the case of inadvertent failure to fully lock the stool or if care is not taken during the unlock process.

Friction block 325 is a block designed to make contact with and rub on the outer edge of friction plate 326 creating a small amount of resistance to the friction plate rotating so as to reduce the rate of unlocking or disengaging. Friction block 325 is held against friction plate 326 by friction block springs 327. Friction plate 326 is a disc with detents that interact with the ratchet mechanism tabs on drive pulley 311 such that the drive pulley rotation has resistance only applied when rotary front plate 104 is rotated in the unlocking position. Friction block springs 327 are springs which hold pressure on the friction blocks to increase the rotational friction applied to drive pulley 311 when rotated in the unlocking direction. Friction block springs 327 are attached to the bearing and pulley support member to apply force on, and keep in place the friction blocks.

Locking pin 328 is a spring actuated pin designed to interconnect with pulley position locking notch 322 to mechanically lock locking arms 112 in an engaged position. Locking pin 328 is held firmly in alignment and allowed to move in only one axis by retainer housing for lock assembly 338 and spring actuated by lock mechanism spring 330. Lock mechanism spring 330 is a spring designed to apply positive pressure on the locking pin such that when

14 rotary front plate 104 is rotated into the locked (engaged) position, the locking pin and the pulley position locking notch are aligned and the locking pin is forced into the pulley position locking notch. Locking pin 328 is disengaged from pulley position locking notch 322 by activation of locking arm release knob 110 via lock release cable 320 and release pivot 336. The disengagement of locking pin 328 allows pulley assembly 310 and all attached components to be rotated to the unlocked position by locking arm cable return spring 313. When locking pin 328 and pulley position locking notch 322 are not engaged, the locking pin will slide on the outer edge of drive pulley 311.

Lock mechanism spring retainer 332 is a ring that is physically and mechanically attached to locking pin 328 such that the force from lock mechanism spring 330 is applied to the locking pin. Lock release lift plate 334 is a circular plate physically attached to the top of locking pin 328 such that the motion of release pivot 336 can be applied to the locking pin, thus disengaging the locking pin from pulley position locking notch 322. Release pivot 336 is an L-shaped pivoting bracket designed to redirect linear force applied to lock release cable 320 from locking arm release knob 110 to disengage locking pin 328 on command. Release pivot stop block 342 prevents release pivot 336 from over-rotating, thus preventing the pivot from disengaging with lock release lift plate 334.

Retainer housing for lock assembly 338 securely holds locking pin 328, forcing it to remain aligned at a specified axis from pulley position locking notch 322. Along that axis, locking pin 328 is allowed to move in such a manner as to be able to move predictably to engage with and disengage from pulley position locking notch 322. The retainer housing also serves as the rigid point from which lock mechanism spring 330 applies pressure to locking pin 328. Release knob return spring 340 is a spring designed to provide pressure on locking arm release knob 110 such that the locking arm release knob is returned to the stowed position when not physically being operated by the stool operator.

15 The child safety stool of the invention is not limited to the embodiment described above with reference to Figures 1 to 10. In fact, any engagement element (e.g., locking arms 112) and locking mechanism (e.g., rotary front plate 104 in conjunction with pulley and bearing assembly 116) that facilitates selective engagement with a structure may be employed. Figures 11 to 22 present some additional examples of engagement elements and locking mechanisms.

Figure 11 depicts a pull-out step locking mechanism. Pull-out locking mechanism 1100 includes a pull-down step 1106 that is mounted to main body 1102 of a stool by pivot pin 1108. Pull-down step 1106 rotates about pivot pin 1108 and acts as an actuating lever for any engagement elements, such as a locking arm. The mechanical function of raising the locking arm may be accomplished by direct linkage or through cables. The mechanical linkage or cable could be attached to either triangular support step 1110 or to an additional lever that could be extended from the pull-down step. Triangular step support 1110 also functions as an intermediate step in conjunction with intermediate step cutout 1104. Figure 12 depicts a slide-down step locking mechanism. The front panel of main body 1212 includes intermediate step cutout 1214 which is covered by sliding step cover 1216. Access to the intermediate step cutout is gained by sliding down sliding step cover 1216. In addition, the act of sliding down the step cover also actuates the engaging elements, such as locking arms 112, to engage with a structure. The mechanical motion of the engaging elements is activated by restraint/actuation point 1218. Restraint/actuation point 1218 is a tab that is attached to a cable to cause the linear motion to move the locking arms. In addition, restraint/actuation point 1218 holds sliding step cover 1216 in position such that the sliding step cover moves in a vertical direction. This slide-down step locking mechanism would be used in place of the rotary front plate and pulley mechanism described above.

16 Figure 13 depicts a side actuator locking mechanism. In this embodiment, main body 1320 includes a permanently accessible intermediate step 1322. Engaging elements are locked into place by pulling down actuating lever 1324. Actuating lever 1324 is a lever arm that is attached to a cable or other linkage method that, when moved, would mechanically move the locking arms. This method would be hand operated and internal locking linkage would work essentially the same as previous other methods.

Figure 14 depicts an L-shaped pivot locking arm. Rather than a rigid, straight locking arm that is as shown in Figures 1 to 10, Figure 14 shows an L-shaped pivoting locking arm 1404 that pivots on pivot pin 1406. One end of pivoting locking arm is mechanically pulled down to so that the L-shaped end moves up into an engagement position. Pivoting locking arm 1404 is housed within a sliding adjuster section 1408 in main body 1402. This allows the locking arm to be slid up and down so as to accommodate structures of varying heights. Sliding adjuster section 1408 may be constructed a sliding housing for the locking arm and the locking arm could be L shaped as shown. This would provide another way to adjust to structures of varying heights.

Figure 15 depicts a rotating locking arm. Main body 1510 includes a rotary locking engaging arm 1512 on its back surface. Rotary locking engaging arm 1512 is rotated about shaft 1512 into an engagement position. Rotary locking engaging arm 1512 may be raised into the engagement position using any mechanical means, including the rotary front plate and pulley and bearing assembly described with reference to Figures 1 to 10.

Figure 16 depicts a sliding locking arm. Main body 1616 includes a sliding locking arm 1618. Sliding locking arm 1618 is connected to a backing plate 1622 on the inside of the main body via connecting rod 1620. Mechanical force is applied to backing plate 1622 to move sliding locking arm 1618 into an engagement position. The internal operation of this embodiment would be the same as that described above with reference to Figures 8 and 9.

17 However, rather than raising, the locking arm of this embodiment slides. An engagement cable would pull on the upper portion of backing plate 1622 forcing sliding locking arm 1618 to engage with the lower lip of the kick plate of a cabinet. Connecting rod 1620 attaches backing plate 1622 and sliding locking arm 1618 together such that they cooperate to counteract torque put on the sliding locking arm from engagement and to force the sliding locking arm and the backing plate to slide along a specified track together.

Figure 17 depicts a cam-actuated locking arm. Main body 1724 includes a locking arm 1726 extending rearwardly from the back surface. Locking arm 1726 is positioned in locking arm slot 1730. Locking arm slot 1726 rotates about locking arm pin 1728. Locking arm 1726 is raised by the rotation of cam 1732. As the larger diameter lob of the cam is rotated to point up, locking arm 1726 raises into the engagement position. In this embodiment, locking arms 1726 are mechanically raised in a similar fashion as locking arms 112 (as described above with reference to Figures 1 to 10). Rotary force of a rotary front plate (via cables, chains or rotating gears) is transferred to cams 1732. As the cams are rotated, locking arms 1726 are lifted into place.

Figure 18 depicts a ratcheting locking arm. The locking arm structure includes ratcheting locking arm 1812, engaging wire and spring 1814, support frame 1816, retraction spring and guide bar 1818, locking ratchet mechanism 1820, and ratchet unlock cable 1822. Locking ratchet mechanism 1820 is preferably contained, at least partially, in the interior of ratcheting locking arm 1812. However, it is also acceptable to mount the locking ratchet mechanism to the outside of the locking arm, such as on the top of the locking arm. Likewise, ratchet unlock cable 1822 is preferably contained within the interior of the locking arm, but may also be mounted on the outside.

In this embodiment, by raising engaging wire and spring 1814, the locking ratchet mechanism 1820 engages with ratchet engagement teeth 1824 (see Figure 19) to raise locking

18 arm 1812 into an engagement position with cabinets of varying heights. The spring tension lifts locking arm 1812 to touch the bottom of the engagement surface. The engaging wire and spring may be raised by any mechanism, and is preferably raised utilizing the rotary front plate and pulley and bearing assembly described above with reference to Figures 1 to 11. In this embodiment, the ratchet mechanism provides the force to the locking arms in place, rather than the locking pin as described in the first embodiment. As such, less stress is exerted on the mechanical assembly used to raise the locking arm when the locking arm is in the engagement position.

As in the first embodiment, the locking arm is lowered from the engagement position by retraction spring and guide bar 1818 when ratchet unlock cable 1822 is pulled. The operation of ratchet unlock cable 1822 will be described in more detail with reference to Figures 20 and 21.

Figure 19 shows an end view of ratcheting locking arm 1812 and locking ratchet mechanism 1820. As the locking arm is raised, locking ratchet mechanism 1820 slides over and locks into ratchet engagement teeth 1824 which are contained within a channel in the main body of the stool. As previously indicated, most components of locking ratchet mechanism are internal to the locking arm, and as shown, only the locking elements of the locking ratchet mechanism protrude from the locking arm. However, the locking ratchet mechanism may be mounted outside the locking arm, such as on top of the locking arm. Figure 20 shows the top view of the ratcheting locking arm and locking ratchet mechanism. Locking ratchet mechanism 1820 includes locking elements 1834, engagement members 1832, spring chamber 1830, and ratchet spring 1828. Point A of locking ratchet mechanism 1820 is fixed, while Point B is movable. In operation, when there is tension on release cable 1822, Point B of the locking ratchet mechanism is pulled in and engagement members 1832 compress ratchet spring 1828. This causes locking elements 1834 to be pulled

19 away from ratchet engagement teeth 1824 (Figure 9) and the locking arm lowers to an unengaged position.

When engaging wire and spring 1814 is raised, such as through the rotation of a rotary front plate and a connected pulley and bearing assembly as described above, the locking arm is raised and locking elements 1834 are pulled over ratchet engagement teeth 1824. When the locking arm hits an overhang of a structure (i.e. the engagement point), movement of the locking arm is stopped and the locking elements into the ratchet engagement teeth. In cases where the stool has more than one locking arm (two is preferable), each locking arm may raise independently of the other, and as such, the locking arms may raise to different heights to engage an uneven surface or surface with varying overhang heights.

As described in the paragraph above, as the locking anus are raised, locking elements 1834 "ratchet" and lock over each subsequent ratchet engagement tooth. However, such continual ratcheting is not required. It may be preferable to have the locking elements only "lock" when the mechanism for raising the arms (e.g., the rotary front plate and bearing and pulley assembly) is locked. This would avoid situations where the locking arms become "stuck" in a halfway position when the rotary front plate is not fully rotated to the locked position.

Figure 21 shows a mechanism in combination with ratchet unlock cable 1822 that prevents the locking elements from "locking" with the engagement teeth unless the mechanical raising mechanism is also in a locked position. As shown, ratchet unlock cable 1822 is connected to release rocker arm 1860. Tension on release cables 1840 and 1842 are transferred through release rocker arm 1860 to ratchet unlock cable 1822. Release cables 1840 and 1842 are in tension so long as locking pin 1850 is not in a locked position. For example, with reference to the description in Figure 7 above, locking pin 328 is inserted into pulley position locking notch 322 when rotary front plate 104 is rotated into a locked or

20 engaged position. As such, when using the raising mechanism described with reference to Figure 7, release cables 1840 and 1842 would be tension until the locking pin is inserted into the locking notch (i.e., the rotary front plate is in a locked position).

When locking pin 1840 is in the locked position, tension is released from release cables 1840 and 1842, and as such, tension is released from ratchet unlock cable 1822. In turn, a release of tension from ratchet unlock cable 1822 causes ratchet spring 1828 to decompress the ratchet mechanism allowing locking elements 1834 to lock with engagement teeth 1824 (see Figures 18 and 19).

Figure 22 depicts a safety stool that includes a weight-activated locking arm. The safety stool according to this embodiment includes main body 2200, locking arm 2202, step 2204 (optional), and adjustment/engagement device 2206. Locking arm 2202 is raised into a locking position by applying weight to the stool. The weight applied to the stool causes the adjustment/engagement device to raise the locking arms. Typically, weight is applied to the stool by stepping on it. Preferably, the weight required to activate the locking arm is large enough that only adults may activate the stool, however, any weight threshold for activation may be employed.

Adjustment/engagement device 2206 is a dual function device that includes adjustment screw 2208, adjustment thumb wheel 2210, engagement piston 2212, engagement spring 2214, and contact point 2216. Adjustment/engagement device 2206 is mounted in main body 2200 such that the lower portion of engagement piston 2212 protrudes below the lower surface of the stool so that when the weight of a user is applied to the stool, engagement spring 2214 compresses forcing contact point 2216 to press on adjustment screw 2208 transferring force to locking arm 2202 and forcing contact with the lower portion of an overhang or kick plate of a cabinet or structure.

21 Adjustment screw 2208, when twisted, forces locking arm 2202 to a higher resting (unlocked) position such that when activation force is applied, the locking arm reaches a higher engagement height allowing for cabinets of various sizes to be used. Adjustment screw 2208 is adjusted with adjustment thumb wheel 2210 which protrudes through the side of the stool.

Engagement piston 2212 receives force from compressed engagement spring 2214 via contact point 2216 such that force is transferred to the adjustment screw and onto the locking arm. Engagement spring 2214 allows for compression such that damage is lessened to the lower lip of a cabinet to which the stool is engaging. An adjuster could be used in conjunction with the engagement spring so as to provide different levels of engagement force for different weights of users. Contact point 2216 provides for a transfer of force from the engagement spring to the adjustment screw and then onto the locking arms.

Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and embodiments disclosed herein. Thus, the specification and examples are exemplary only, with the true scope and spirit of the invention set forth in the following claims and legal equivalents thereof.

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Claims

WHAT IS CLAIMED IS:

1. A tip-resistant stool for aiding access to an elevated surface of a structure having a raised base portion comprising: a main body having at least a top surface and a front surface, the top surface being a step surface; one or more engaging elements extending rearwardly from the main body; and a locking mechanism in mechanical connection with the one or more engaging elements, the locking mechanism for selectively locking the one or more engaging elements in an engagement position with the raised base portion of the structure, whereby the stool is prevented from tipping when the one or more engaging elements are in the engagement position.

2. The tip-resistant stool of claim 1 further including a selectively accessible intermediate step, the intermediate step being made accessible when the one or more engaging elements are in the engagement position.

3. The tip-resistant stool of claim 2 wherein the intermediate step comprises a recess in the front surface of the main body including an intermediate step surface disposed within the interior of the main body, the intermediate step having a predetermined size to accommodate a user's foot.

4. The tip-resistant stool of claim 3 further including a selectively movable blocking member cooperating with the one or more engaging elements such that the blocking

23 member restricts access to the intermediate step when the one or more engaging elements are not in the engagement position.

5. The tip-resistant stool of claim 1 wherein the main body is box-shaped.

6. The tip-resistant stool of claim 1 wherein the step surface has a non-skid coating.

7. The tip-resistant stool of claim 1 including two engaging elements.

8. The tip-resistant stool of claim 1 wherein the one or more engaging elements are rigid arms.

9. The tip-resistant stool of claim 8 wherein the locking mechanism locks the one or more engaging mechanism in the engagement position with the use of cables and pulleys.

10. The tip-resistant stool of claim 1 wherein the one or more engaging elements are L-shaped arms.

11. The tip-resistant stool of claim 1 wherein the locking mechanism includes a rotary plate on the front surface of the main body, wherein rotation of the rotary plate causes the one or more engaging members to be locked in the engagement position.

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12. The tip-resistant stool of claim 12 wherein the rotary plate includes an artistic design, wherein the artistic design is properly aligned when the one or more engaging elements is in the engagement position.

13. The tip-resistant stool of claim 1 wherein the locking mechanism is a pull-down lever.

14. The tip-resistant stool of claim 1 wherein the engaging elements include a locking ratchet mechanism.

15. A tip-resistant stool for aiding access to an elevated surface of a structure having a raised base portion comprising: a main body having at least a top surface and a front surface, the top surface being a step surface; one or more engaging elements extending rearwardly from the main body; and a raising mechanism in mechanical connection with the one or more engaging elements, the raising mechanism for selectively raising the one or more engaging elements in an engagement position with the raised base portion of the structure, whereby the stool is prevented from tipping when the one or more engaging elements are in the engagement position.

16. The tip-resistant stool according to claim 15 wherein the raising mechanism is activated by the weight of a user.

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