US 3506989 A
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Description (OCR text may contain errors)
7 April 21, 1970 0. K Ross ET GUARD RAIL FOR HOSPITAL BED Filed April 29, 1968 INVENTORS 56 OAKLAND K. ROSS ROBERT F. KNIGHT STANLEY RACHLINSKI BY7 53ml ',/%4/
United States Patent US. Cl. 8 Claims ABSTRACT OF THE DISCLOSURE This invention relates to an improved counterbalanced guard rail for a bed which is pivotally connected at one end thereof to the bed by parallel linkage to maintain the rail in a substantially vertical plane in its raised and lowered positions and which it is being raised and lowered.
Conventional hospital bed guard rails are of three basic types. A first type which was used for many years consists of a rail that is removably connected to the bed. No means was generally provided for moving the guard rail up or down. To avoid the inconvenience of having to remove and store this removable type when not needed, the trend has been to provide a bed with guard rails that are permanently attached to the bed but which can be moved to and from an upper guard position and a storage position. The most common of the second type consists of a rail which is adapted to be vertically moved to and from the two positions, in a manner similar to the operation of a drop side of a childs crib. The disadvantage of the latter type is that when the guard rail is in its storage position, it creates an obstruction which tends to interfere with sweeping and other cleaning operations. The third basic type of permanently fixed guard rail is one in which the guard rail is swung underneath the bed for storage. This type is characterized by relatively complicated construction and, like the second type it also interferes with the free space beneath the bed.
The guard rail of the present invention is carried on arm members pivotally attached to mounting brackets removably secured to each end of the bed so that movement to and from the raised and lowered positions is carried out by a swinging action of the arm members. When the guard rail is in storage position, it does not in any way interfere with the free space beneath the bed. Another feature of the invention is the provision of a torque tube which is concealed inside the guard rail. The torque tube is adapted to urge the rear or foot end of the guard rail upwardly sufficiently to counteract the tendency of the foot end of the guard rail to sag under its own weight. This arrangement obviates the need for bulky linkages for supporting the foot end of the guard rail and enables the use of a compact linkage (located below mattress level) which does not interfere with the patients feet.
The invention will be more thoroughly understood from the following description of a preferred embodiment thereof as read in conjunction with the accompanying drawings, wherein:
FIG. 1 is a perspective view of a hospital bed having an improved guard rail,
FIG. 2 is an enlarged vertical end view of the guard rail shown in FIG. 1 and showing the rail in storage position,
FIG. 3 is a view similar to FIG. 2 but showing the guard rail in its raised position,
FIG. 4 is a side elevation view taken on the line 4-4 of FIG. 3,
3,506,989 Patented Apr. 21, 1970 FIG. 5 is an enlarged detailed view of a portion of the guard rail taken along the line 55 of FIG. 3, and
FIG. 6 is a view similar to FIG. 2 but showing a mounting bracket at the foot of the bed.
Referring to FIG. 1, a hospital bed illustrated by way of example is of a type in which a movable frame 10 of the bed is raised and lowered relative to the floor by means of a parallel linkage connection with a base frame 12. However, it will be understood that the guard rail of this invention is adapted to any type of hospital bed having suitably positioned frame elements to which the guard rail and associated structure can be attached.
The improved guard rail is generally indicated by reference numeral 13 and it is provided with a pair of mounting brackets 14 and 16 attached to frame members at the head and foot of the bed and carrying first and second linkage means 18 and 20 which support the guard rail 13. It will be understood that in most cases a bed will be provided with guard rails on each side of the bed although only one is illustrated in FIG. 1. The guard rail 13 includes three tubular elements 21, 22 and 23 which are welded together to form a rigid unitary structure.
Referring now to FIG. 2, the mounting bracket 14 (which is positioned at the head of the bed) consists of a steel plate to which are pivotally attached a pair of swinging arm members 26 and 28. The pivotal attachment is achieved by conventional pre-tensioned friction devices such as nylon washers, bolt and lock nut assemblies which are provided at pivot points 30 and 32. The outer ends of the arm members 26, 2-8 are attached to an end of the guard rail 13 at points that are spaced by a distance equal to the spcaing between the pivot points 30, 32 so that the arm members 26, 28 form part of a parallel linkage assembly.
When the guard rail 13 is in the lowered position shown in FIG. 2, the lowermost arm member 28 rests upon a lower limit stop 36 preferably consisting of a small block welded to the outer face of the mounting bracket. The locking mechanism for holding the guard rail 13 in the raised position is mounted behind the head board at the head of the bed where it is out of reach of the patient, to prevent the patient from accidentally lowering the rail. The locking mechanism consists of a short bar 38 which is pivotally attached to the mounting bracket 14 by a loose rivet 40. The outer end of the bar 38 is provided with a notch 42 which is shaped to receive a stud 44 (see FIG. 3) carried by the lower arm member 28. The stud 44 has an enlarged head to prevent the bar 38 from slipping sideways off the stud. The manner in which the stud is engaged by the bar 38 is shown in FIG. 3 and it will be noted that due to the geometry of the system the parallel linkage assembly cannot drop downwardly when the bar 38 is engaged with the stud 44. To lower the guard rail 13, the bar 38 is raised slightly by hand, and to enable this to be done, a block 46 upon which the bar 38 rests is relieved or downwardly curved at its rear edge 48. The function of the block 46 is to hold the bar 38 in the position shown in FIG. 2 so that it will be engaged automatically when the guard rail is raised. The stud 44 is so placed on the arm member 28 that when the guard rail is swung upwardly, the stud 44 engages the bar 38 just slightly outwardly of the notch 42 so that the bar 38 is pushed upwardly a sufiicient degree to permit the bar 38 to drop onto the stud 44 when the guard rail 13 is raised to its uppermost position. The guard rail 13 is then ettectively locked in place until the bar 3 8 is again lifted. The lifting action to permit lowering of the guard rail 13 is done by hand and a small knob 50 is provided on the bar 38 for this purpose.
Referring now to FIGS. 2 and 3, the mounting brackets 14, 16 are preferably removably attached to the bed frame by means of holding brackets 52 (one for each mounting bracket) which are permanently attached to the bed frame and which are provided with a pair of notches 54 adapted to receive a pair of studs 58 and 60 carried by the mounting brackets 14, 16. A swing catch 56 is used for locking together the mounting brackets 14, 16 and the holding brackets 52. It is advantageous to make the guard rail removable in this manner so that if a particular bed does not require a guard rail for an extended period of time, the guard rail may be transferred to another bed having similar holding brackets 52.
The mounting bracket 16 at the foot of the bed carries a single arm member 62 which is pivotally attached at its outer end to the central tubular element 22 of the guard rail. The inner end of the arm member 62 is pivotally attached to the mounting bracket 16, and in the lower position of the guard rail the arm member 62 rests upon a block 64 secured to the mounting bracket 16. The block 64 is preferably of rubber. To support the foot end of the guard rail (which otherwise would sag), an elongated torque tube 66 is installed inside the tubular element 22. The torque tube 66 is given a permanent twist which serves to keep the guard rail horizontal in all positions.
The torque tube 66 is preferably made of 14 gauge cold rolled welded steel pipe of 'Va" outside diameter, with a length of 83 /2". The twist in the torque tube 66 is about 4 and it should be noted that the twist should be in a proper direction to cause the foot end of the guard rail to be urged upwardly. Thus, when guard rails are used on both sides of the bed, the torque tubes 66 of the respective guard rails will have opposite twists.
It is stated above that the first and second linkages 18 and 20 are attached to the guard rail 13. More specifially, the outer ends of the arms 28 and 62 of the respective linkages 18, 20' are connected to the torque tube 66. To effect this, each end of the torque tube 66 is fitted with a square-headed plug 68 which are received in square holes in the outer ends of the arm members 28 and 62 and are secured in place by machine screws 70 threaded into the plugs 68. As mentioned above, the torque tube 66 is given an appropriate twist to impart a slight lifting action on the outer end of the arm 62 at the foot of the bed. This counteracts any tendency of this arm to droop when the guard rail is in the raised position. Of course, there is no tendency of arm 62 to droop when the guard rail is in the lower position as the arm 62 then rests against the block 64 fixed to the mounting bracket 16. It is also to be noted that the uppermost tubular element 21 contains a plug 72 having an outer end 74 about which the outer end of the arm member 26 is free to pivot.
What we claim as our invention is:
1. In combination:
(a) a guard rail for a hospital bed and the like, said guard rail being positioned alongside the bed and being movable between a first position where it projects upwardly sufficiently to protect a bed occupant from accidentally falling out of bed and a second lower position where it does not interfere with the ingress and egress of the bed occupant into and out of bed,
(b) first linkage means positioned at the head of the bed and pivotally connected to one end of said guard rail, said first linkage means including a pair of vertically spaced parallel swinging arm members which are pivotal about their inner ends,
(0) second linkage means positioned at the foot of the bed and pivotally connected to the other end of said guard rail, said first and second linkage means cooperating with said guard rail to permit said guard rail to swing between said first and second positions in an approximately vertical path,
(d) means for releasably holding said guard rail in said first position, and
(e) stop means for holding said guard rail in said second position.
2. The invention claimed in claim 1 wherein said guard rail includes a pair of elongated parallel spaced apart tubular members which are connected together to form a rail, and an elongated torque tube, the ends of said torque tube respectively being connected to said first and second linkage means, said torque tube being torsionally twisted in a direction and to a degree such that the twist in said torque tube urges said second linkage means to swing upwardly sufficiently to counterbalance the weight of said guard rail at said second linkage means.
3. The invention claimed in claim 2 wheerin said parallel swinging arm members of said first linkage means are positioned adjacent to the head end of the bed at right angles to said guard rail, said swinging arm members having their outer ends respectively pivotally connected to the uppermost of said tubular members and to said torque tube.
4. The invention claimed in claim 3 wherein said second linkage means includes a single swinging arm which is pivotally connected at its outer end to said torque tube and which is pivotal about its inner end, said arm being parallel to said arm members of said first linkage means.
5. The invention claimed in claim 4 wherein the first and second linkage means are respectively connected to the bed by means of mounting brackets that are releasably secured to the respective ends of the bed, the inner ends of said swinging arm members being pivotally secured to one mounting bracket and the inner end of said swinging arm of said second linkage means being secured to the other of said mounting brackets.
6. The invention claimed in claim 4 wherein said means for releasably holding said guard rail in said first position includes a bar that is pivotal about its inner end, said bar having a slot positioned to engage a stud carried by one of said arm members, and a stop member positioned to limit the movement of said bar so that in said first position of the guard rail said bar is approximately horizontal.
7. The invention claimed in claim '6 wherein the inner end of said stop member is relieved to permit the outer end of said bar to be raised sufliciently to permit the bar to be disengaged from said stud.
8. The invention claimed in claim 5 wherein said stop means consists of a block secured to at least one of said mounting brackets and positioned to limit the downward travel of the lowermost one of said swinging arms.
BOBBY R. GAY, Primary Examiner A. M. CALVERT, Assistant Examiner US. Cl. X.R. 5100