EP2100578B1

EP2100578B1 - Adjustable siderail and lock therefor

Info

Publication number: EP2100578B1
Application number: EP09250678.1A
Authority: EP
Inventors: Michael Z. Sleva; Richard H. Heimbrock; Keith A. Huster; David W. Hornbach; Craig Mcneely; David C. Newkirk
Original assignee: Hill Rom Services Inc
Current assignee: Hill Rom Services Inc
Priority date: 2008-03-12
Filing date: 2009-03-11
Publication date: 2016-11-30
Anticipated expiration: 2029-03-11
Also published as: US20090229049A1; EP2100578A2; EP2100578A3

Description

The subject matter of the present application relates to siderails for a patient support apparatus, such as a bed, and more particularly to lockable, adjustable height and length siderails for a hospital bed.
Many patient support apparatuses, such as hospital beds, include a frame, a deck, and a support surface, such as a mattress, supported by the deck. Such beds may also include siderails. The siderails can be lowered to facilitate patient movement into and out of the bed. The siderails can also be raised to safeguard the patient. When the siderails are raised, they typically extend higher than the support surface of the bed by an amount Δh.
From time to time an overlay may be placed on top of the support surface, or a thicker than normal mattress may be substituted for a mattress of customary thickness. Either way, it is desirable for the siderail to be adjustable to maintain the same Δh as with a standard mattress. Moreover, it is desirable to be able to easily adjust the siderail to any desired height and to be able to easily lock the siderail in a desired position and unlock it for further adjustment.
US2006/0090260A1 discloses a patient support apparatus which operates as described above.
US 6076209 discloses an articulated medical bed for supporting a person in articulated movement. A side rail is supported on a base and includes telescoping inner and outer horizontal rail members extending between vertical rail members. A detent supported on one of the inner horizontal rail members is engagable with a plurality of recesses formed in one of the outer horizontal rail members. Engagement of the detent with one of the recesses locks the inner horizontal rail member relative to the outer horizontal rail member thereby defining a plurality of positive stop positions.
The invention is defined by the claims.
The invention will now be further described by way of example with reference to the accompanying drawings, in which:

FIG. 1 is a perspective view of a patient support apparatus with a frame, a deck, a patient support surface, siderails and a vertically extendable siderail extension shown in a retracted position.
FIG. 2 is a perspective view of the siderail of FIG. 1 showing a siderail base and the extension in a deployed position.
FIG. 3 is a view similar to that of FIG. 2 showing the siderail extension separated from the siderail base.
FIG. 4 is a view similar to that of FIG. 2 with a portion of the base cut away to reveal the relationship between the siderail extension and a rotary lock for the siderail extension.
FIG. 5 is a perspective view of a corner of the siderail showing the rotary lock residing in a bore of the siderail base.
FIG. 6 is a view similar to FIG. 5 showing the rotary lock partially exploded.
FIG. 7 is a view similar to FIG. 5 showing the rotary lock nearly fully exploded.
FIG. 8 is a view similar to that of FIG. 4 with a grip handle removed from the lock to reveal additional components of the lock.
FIGS. 8A and 8B are side elevation views showing the rotary lock in an engaged state and a disengaged state respectively.
FIG. 9 is a perspective view of the assembled rotary lock.
FIG. 10 is a perspective view of a D-rod and an end cap of the rotary lock.
FIG. 11 is a perspective view of the teeth of the lock engaging a toothed siderail extension.
FIG. 11A is a side elevation view showing a ratchet arrangement.
FIG. 12 is a side view of a siderail having a linear lock engaging a leg of a siderail extension.
FIG. 13 is a view similar to that of FIG. 12 showing a notched siderail extension.
FIG. 14 is a view similar to that of FIG. 13 showing a ratchet arrangement.
FIG. 15 is a side view of a siderail assembly having a base and a horizontally extendable extension shown in its retracted position.
FIG. 16 is a view similar to that of FIG. 15 showing the extension in a deployed position.
FIG. 17 is a side elevation view of the horizontal extension of FIGS. 15 and 16 .
FIG. 18 is a view similar to that of FIG. 15 showing the base with the extension removed.
FIG. 19 is a view showing portions of the siderail base, a siderail extension, and a vertical linear lock.
FIG. 20 is a view similar to that of FIG. 19 showing a siderail extension with a notched leg.
FIG. 21 is a view similar to that of FIG. 20 showing a variant of the notched leg.
FIG. 22 is a view similar to that of FIG. 20 but showing a ratchet arrangement.

Referring to FIG. 1 , a patient support apparatus, such as a hospital bed 10 includes a frame 11, a deck 12, a headboard 14 and a footboard 15. The deck supports a patient support surface 13 such as a mattress. The support surface includes multiple sections such as a head section, a seat section, a thigh section, and a foot section, all of which are configured to articulate and move relative to one another in a manner known to those skilled in the art. The patient support apparatus 10 also includes foot end siderails 16 and 17 and head end siderails 18 and 19, all of which may be carried or supported by frame 11 or deck 12. Each of the siderails 16, 17, 18, and 19 is mounted to either the frame 11 or the deck 12 by a mounting device 20, which is a mounting device for foot end siderail 16. Mounting device 20 includes a mechanism for raising or lowering the foot end siderail 16 with respect to the frame 11 and deck. Similar mounting devices are also present for siderails 17, 18, and 19. Other types of mounting devices such as clocking mounting devices may also be used.
FIGS. 2-5 depict one variant of a siderail such as siderail 17. Siderail 17 includes a base 22 and an extension 23. The extension approximately defines a plane and includes a top rail 21 and extension legs 24, 25, 26. Apertures 27, 28, and 29 in the base 22 translatably receive the extension legs so that the extension 23 is extendable, i.e. adjustable between a retracted position (e.g. FIGS. 1 , 5 ) and one or more deployed positions, one of which is shown in FIG. 2 . At the retracted position, the rail 21 is adjacent the base. As used herein, "adjacent" means that rail 21 is in the lowest position, (i.e. as close to the base) intended by design. The adjacent condition includes conditions in which the top rail 21 is flush with the base, is in contact with the base (e.g. FIGS. 1 , 5 ) and is separated from the base by a minimum prescribed distance. At a representative deployed position (e.g. FIG. 2 ), the rail 21 is spaced further from the base 22 than it is when retracted. Movement of the extension between the retracted and deployed positions occurs substantially along the plane defined by the extension.
Referring additionally to FIGS. 6-10 , siderail base 22 has a bore 33 with an axis 34. A rotary lock 30 occupies in the bore. The lock includes a number of components serially distributed along the bore axis. These components include an end cap 80 with a blind hole 100 having a part-circular or D-shaped cross-section (FIG. 10 ) an interior spacer 70 with a central circular hole 71, an oblong locking cam 68 with a D-shaped hole 75 and a socket 69. Teeth 82 extend along at least a portion of the periphery of the cam. The lock also includes an indexed spacer 66 having a socket 67. A lug 73 extends radially from the spacer and into groove 61 in the siderail bore 34 to render the spacer non-rotatable. The lock also includes a grip handle 40. The grip handle, like the end cap 80, includes a blind hole, not visible in any of the illustrations, with a D-shaped cross-section. The lock also includes a coil spring 62 having a spacer end 63 and a cam end 65. When the lock is fully assembled, socket 69 of cam 68 receives cam end 65 of the spring while socket 67 of spacer 66 receives spacer end 63 of the spring (FIG. 8 ). Spring end 65 is referred to as a displaceable end because it moves along with socket 69 when cam 68 rotates about axis 34. Spring end 63 is referred to as a fixed end, because it is trapped or mechanically grounded in socket 67 of spacer 66.
The lock also includes a D-rod 64 having a laterally outer end 83 and a laterally inner end 84. When the lock is fully assembled, the inner end 84 is captured in blind hole 100 of the end cap (FIG. 10 ) while outer end 83 is captured in the similar blind hole of the grip handle. The D-rod extends through the center of the coil spring 62, and through holes 75 and 71 in the cam and interior spacer. Because cam hole 75 mimics the cross-sectional shape and size of the D-rod, rotation of the grip handle 40 causes the cam to rotate. The D-Rod and grip handle serve as a means for rotating the cam from the locked state to an unlocked state.
The lock is selectively engageable with and disengageable from the extension for resisting or enabling movement of the extension relative to the base. The lock has an engaged state in which the lock is engaged with the siderail extension 23 (FIGS. 8 , 8A ) and a disengaged state in which the lock is disengaged from the extension (FIG. 8B ). When the lock is engaged it secures the extension in any of multiple deployed positions. In the engaged state, the force exerted by spring 62 rotates the cam 68 so that the toothed portion of the cam contacts extension leg 24. Friction between the cam and the extension leg resists movement of the extension leg, and therefore of the entire extension 23 relative to the base 22. Moreover, any influence tending to urge the siderail to a lower elevation will also tend to rotate the cam clockwise (as seen in FIGS. 8 , 8A ), which, because of the oblong shape, causes the cam to bear even more tightly against the leg 24. The engaged state is the default state. The disengaged state is achieved through operator intervention. Specifically, an operator grasps the handle 40 and rotates it in a direction counter to the spring force (counterclockwise as seen in FIGS. 7 and 8 -8B or clockwise as seen in FIG. 11 ). Because the cam is oblong, such rotation moves the cam periphery out of contact with the extension leg so that the extension 21 can be easily raised or lowered. Because the spring force biases the lock to its engaged state, the operator continually grasps the handle 40 to exert a counterforce on the spring to keep the cam periphery out of contact with the extension leg. After the operator has satisfactorily positioned the extension 23, the operator releases the handle 40 so that the spring can urge the cam back into contact with the extension leg 24 to prevent further movement of extension 23. Depending on how tightly the cam bears against the extension, it may be possible for the operator to merely pull up on the extension without first having to independently disengage the lock.
When the extension 24 is in its retracted position, it is at a retracted elevation relative to the top surface of the mattress 13. When the extension is at any of its deployed positions, it is at a deployed elevation relative to the top surface of the mattress 13. The deployed elevation is greater than the retracted elevation.
The illustrated lock also shows the use of teeth 82 to facilitate engagement of the cam with the extension leg. Alternatively, a friction enhancing treatment such as a friction tape or a coating could be applied to the periphery of the cam. In addition, the periphery of the cam could be left in a smooth state provided the coefficient of friction between a smooth cam and the extension leg is sufficient to secure the extension in the desired position.
The variant of the lock and siderail extension illustrated in FIG. 11 includes teeth 91 on extension leg 24. Teeth 82 on the cam periphery engage the teeth 91 on the extension leg to help secure the extension leg in a desired position. Alternatively, teeth could be provided on the extension leg but not on the cam periphery.
FIG. 11A shows an arrangement similar to that of FIG. 11 but in which extension leg 24 has a number of curved teeth 86 defining notches that form a ratchet arrangement. The ratchet arrangement dispenses with the need to independently disengage the lock prior to raising the extension from its retracted position to a deployed position or from one deployed position to a higher deployed position. Instead, the caregiver simply pulls up on the siderail extension 23 to raise it to a desired location. During such upward movement the teeth push back against the cam so that the extension leg can be raised. Once the operator is satisfied that the extension has been raised to the desired position, it is necessary only for the operator to cease pulling up on the extension. The spring load on the cam will then urge the cam into tight engagement with the extension leg. To lower the siderail extension, it is necessary to first turn the rotary lock to disengage the cam teeth from the extension leg. Once the siderail extension has been lowered to the desired height, the caregiver releases the handle 40 allowing the spring to urge the cam teeth 82 back into engagement with the ratchet thereby preventing further vertical movement of the extension.
The above described configuration employs a spring to continuously urge the cam into contact with the extension leg. However a latch that holds the lock in the disengaged state may be used in conjunction with the spring or substituted for the spring. If a latch is used in conjunction with the spring, partial rotation of the handle would suffice to disengage the lock from the extension leg, and additional rotation of the handle in the same direction would engage the latch. Once latched, the operator may release his or her grip on the handle without the spring force urging the cam back into contact with the extension leg.
FIGS. 12-21 illustrate linear locks. The linear locks, like the rotary lock described above, are selectively engageable with and disengageable from the extension for resisting or enabling movement of the extension relative to the base. Referring to FIG. 12 , lock 130 resides in siderail base 22 and comprises a pull pin having a handle 132, a piston 131, a plunger 136 and a spring 138. A force exerted by spring 138 urges the plunger 136 into contact with extension leg 24 to resist movement of the leg. Plunger 136 may include a friction pad 133 or other feature to increase the coefficient of friction between the plunger and the extension leg 24. Vertical movement of extension leg 24 is resisted until an operator pulls on the handle 132 to disengage the plunger from the extension leg. The extension can then be raised or lowered to a desired position and the handle can then be released allowing the plunger 136 to move back into contact with the extension leg, thereby resisting further movement of the extension.
FIG. 13 shows an arrangement similar to that of FIG. 12 using an alternative style handle 142 and an alternative extension leg 24 featuring multiple notches 144 along its length. Lock 140 resides on siderail base 22 and comprises a pull pin having handle 142, a piston 141, a plunger 146 and a spring 148. A force exerted by spring 148 urges the plunger 146 into contact with extension leg 24 to resist movement of the leg. Vertical movement of extension leg 24 is resisted until an operator pulls on the handle 142 to disengage the plunger from the teeth. The extension can then be raised or lowered to a desired position and the handle can be released allowing the plunger 146 to move back into one of the notches, thereby resisting further movement of the extension.
FIG. 14 shows an arrangement similar to that of FIG. 13 but in which extension leg 24 has a number of curved notches 154 that form a ratchet arrangement. This ratchet arrangement, in contrast to the notches of FIG. 13 , dispenses with the need to pull on handle 152 to disengage plunger 156 from the extension leg prior to raising the extension from its retracted position to a deployed position or from one deployed position to a higher deployed position. Instead, the caregiver simply pulls up on the siderail extension 23 to raise it to a desired location. To lower the siderail extension, it is necessary to first pull the handle 152 to withdraw plunger 156 from teeth 154. Once the siderail extension has been lowered to the desired height, the caregiver releases the pull pin handle 152 allowing the spring to urge the piston 156 back into a teeth 154 of the ratchet arrangement and prevent further vertical movement of the extension.
The principles disclosed above in the context of a siderail with a vertically deployable extension are also applicable to a siderail with a horizontally deployable extension. Referring first to FIGS. 15-19 , siderail 160 includes siderail base 162, a siderail extension 163, and extension legs 164, 166. Apertures 168, 170 in the base 162 translatably receive siderail extension legs 164, 166. Lock 200 resides on siderail base 162 and comprises a pull pin having a handle 202, a piston 201, a plunger 206 and a spring 208. A force exerted by spring 208 urges the plunger 206 into contact with extension leg 24 to resist movement of the extension leg. Plunger 206 may include a friction pad to 10 or other feature to increase the coefficient of friction between the plunger and the extension leg 24. Horizontal movement of extension leg 24 is resisted until an operator pulls on the handle 202 to disengage the plunger from the extension leg. The extension can then be translated horizontally to a desired position and the handle can then be released allowing the plunger 206 to move back into contact with the extension leg, thereby resisting further movement of the extension.
FIG. 20 illustrates a horizontally adjustable arrangement similar to the vertically adjustable arrangement of FIG. 13 . Extension leg 164 has a plurality of notches 212 along its length. Lock 200 includes a pull pin whose plunger 206 extends into notches 212 to resist movement of the extension leg 164 in a horizontal direction. In operation, a caregiver pulls up on pull pin 200 to withdraw the plunger from its host teeth and enable horizontal movement of siderail extension 164 relative to the siderail base.
FIG. 21 shows an embodiment similar to that of FIG. 20 . However, notches 212 are on the side of the extension leg rather than on its top and the pull pin 200 is oriented horizontally rather than vertically.
FIG. 22 shows a horizontally adjustable arrangement similar to that of FIG. 20 but with a ratchet arrangement not unlike the one show in FIG. 14 .
A latch that holds the linear lock in the disengaged state may be substituted for or used in conjunction with the spring or other device. If a latch is used in conjunction with the spring loaded pull pin, partial translation of the plunger would suffice to disengage the lock from the extension leg, and additional movement of the handle would engage the latch. Once latched, the operator may release his or her grip on the handle without the spring force urging the cam back into contact with the extension leg.
In view of the preceding descriptions, additional aspects of the extendable siderail can now be appreciated.
Although the illustrated variants have two or three extension legs, more or fewer extension legs could be used. Further, as shown in FIGS. 3 , 17 and 18 , because siderail extension 23 or 163 is removable from siderail base 22 or 162, other types or styles of extension could be used with the same siderail base 22.
Although the illustrated locks disclose the use of a spring to urge the cam or plunger into engagement with the extension leg 24, forces resulting from the use of alternative devices, for example electromagnetic devices, could also be employed.
In the illustrated arrangements, the lock is situated so that it engages exactly one of the extension legs, specifically extension leg 24 or 164. However it could also be situated to engage one of the other extension legs. Alternatively, locks could be associated with two or more of the extension legs. Such multiple locks could be interconnected so the operation of any of the locks concurrently operates the other locks.
It will further be appreciated by those of ordinary skill in the art that patient support apparatus 10 may include a bed or patient support apparatus suitable for use in any care facility, including homes, hospitals, medical clinics or centers, rehabilitation centers, healthcare or medical facilities, nursing homes, surgical centers, or other patient care provider facilities.

Claims

A bed, comprising a frame (11), a deck (12) connected to the frame, a siderail (16, 17, 18, 19, 160) supported by either of the frame and the deck, the siderail including a base (22, 162) and a lock (30, 130), wherein the siderail also includes an extension (23, 163) having a retracted position adjacent the base and at least one deployed position spaced further from the base, and wherein the bed further comprises a lock (30, 130), characterized in that the lock (30, 130) resides in the base (22, 162) and is selectively engagable with and disengagable from the extension (23, 163) for resisting or enabling movement of the extension (23, 163) relative to the base (20, 162).
The bed of claim 1 wherein the extension (23, 167) is securable by the lock in multiple deployed positions.
The bed of either claim 1 or claim 2 wherein the lock (30, 130) has an engaged state in which the lock (30, 130) is engaged with the extension (23, 163) and a disengaged state in which the lock is disengaged from the extension and wherein the engaged state is a default state and the disengaged state is achieved through operator intervention.
The bed of any preceding claim wherein the extension (23, 163) includes at least one extension leg (24, 25, 26, 164, 166) translatably received in an aperture (27, 28, 29, 168, 170) of the base (22) and the lock (30, 200) is engagable with and disengagable from at least one extension leg (24, 25, 26, 164, 166) for selectively resisting and enabling movement of the extension (23, 163) between the retracted and deployed positions.
The bed of any preceding claim, wherein movement between the retracted position and the deployed position is substantially vertical or movement between the retracted position and the deployed position is substantially horizontal.
The bed of any preceding claim, further comprising a mattress (13) having a top surface, the extension (26, 163) being at a retracted elevation relative to the top surface when the extension (26, 163) is retracted and at a deployed elevation relative to the top surface when the extension (26, 163) is deployed, the deployed elevation being greater than the retracted elevation.
The patient support apparatus of any preceding claim, wherein the extension includes at least one notch (144, 154, 212) for receiving a mating element of the lock.
The bed of claim 7 wherein the notch (154, 212) is configured as a ratchet.
The bed of any preceding claim wherein the extension includes teeth (91).
The bed of any preceding claim wherein the lock is a rotary lock (30).
The bed of any preceding claim, wherein the lock includes a cam (68) movable between a locking position that resists movement of the extension (23) relative to the base and an unlocking position that enables movement of the extension (23) relative to the base.
The bed of any preceding claim, wherein the lock includes an oblong member (68) having a periphery with teeth (82) occupying at least a portion of the periphery.
The bed of any one of claims 1 to 10 wherein the siderail base (22, 162) includes a bore (33) having an axis (34), the lock (30) resides in the bore and includes a cam (68) rotatable with respect to the bore, a spring (62) having a displaceable end (65) connected to the cam and a mechanically grounded end (63), and wherein the spring biases the cam into a locked state.
The bed of claim 13 including an indexed spacer (66) residing in the bore (33) axially adjacent the cam (68), the spacer having a lug (73) received in a groove (61) of the bore to resist rotation of the spacer, the grounded end (63) of the spring being received in a socket (67) of the spacer (66).
The bed of any one of claims 1 to 9 wherein the lock is a linear lock.