WO2009009405A1

WO2009009405A1 - Ambulance cot lock release

Info

Publication number: WO2009009405A1
Application number: PCT/US2008/069122
Authority: WO
Inventors: Steve Schrand
Original assignee: Ferno-Washington, Inc.
Priority date: 2007-07-06
Filing date: 2008-07-03
Publication date: 2009-01-15

Abstract

A lock release mechanism and method for height adjustment of an emergency cot are disclosed. The lock release mechanism has a locked configuration and an unlocked configuration. The locked configuration abuts angled sides of a pivot latch and a post to cause an interference fit therebetween to prevent pivoting of the pivot latch about the post such that pulling of an actuator causes contact a prong to contact the pivot thereby arresting movement of the actuator. The unlocked configuration provides the pivot latch translated about the post such that the angled sides do not abut thereby clearing the interference fit and permitting pulling the actuator to permit the height adjustment of the emergency cot.

Description

AMBULANCE COT LOCK RELEASE

The present invention relates to height adjustable ambulance cots, and in particular to a lock release mechanism for height adjustment of an emergency cot. Height adjustable cots are available in which the cot frame is mounted on legs which are designed to collapse as the cot is placed in the vehicle. Cots of this type may have two positions of use, or may have multiple adjustable positions. That is, such cots have a first "down" position in which the legs are fully collapsed and an elevated "up" position in which the cot is at a standard predetermined height for transferring the patient to a bed. Cots having adjustable positioning features may be positioned at a number of intermediate heights between the fully down and up positions. Cots have also been designed so that the legs collapse as the cot is loaded into the rear of an emergency vehicle such as an ambulance.

Necessary features of adjustable cots where the legs are designed to collapse relative to the cot frame are sliding/rolling mechanism which permit movement of the cot legs relative to the frame, and a latching mechanism for releasably holding the sliding/rolling mechanism in a relative position which secures the cot legs at a particular height. For example, Ferneau et al, U.S. Pat. No. 4,767,148, teach a multiple level roll-in cot having a latching mechanism comprising an elongated locking bar and latch pin combination which releases the cot frame for elevation and lowering. A hand actuator is connected to the locking bar which when actuated unseats the latch pin from a secure engagement with a frame member of the cot, thereby permitting movement of the cot legs relative to the cot frame. However, should the hand actuator be operated accidentally, such as by an operator initially grabbing onto the cot without care when provided in an elevated position, the cot could collapse completely and cause injury to a patient carried on the cot or the person operating the cot.

It is against the above background that the present invention provides a lock release mechanism for an actuator or pull mechanism used to adjust the height of an ambulance cot and to prevent the unwanted height adjustment thereof. In one embodiment, a lock release mechanism for height adjustment of an emergency cot is disclosed. The lock release mechanism comprises a spring biased actuator; a bar pivotally connected to the actuator; a fork mounted to the bar and having two spaced apart prongs extending away from a surface of the bar; a post having an angled side; and a spring biased pivot latch having an angled side and pivotally mounted to the post, and wherein the lock release mechanism has a locked configuration and an unlocked configuration. The locked configuration comprises the pivot latch and post having the angled sides abutting and causing an interference fit therebetween to prevent pivoting of the pivot latch about the post and wherein pulling the actuator causes one of the two prongs on the bar to contact and be arrested by the pivot latch, and the unlocked configuration comprises a translation of the pivot latch about the post wherein the angled side of the pivot latch does not abut with the angel side of the post to cause an interference fit wherein pulling the actuator causes the bar to translate away from its rest position to permit the height adjustment of an emergency cot.

In another embodiment, a method for preventing unwanted adjustment of height of an emergency cot is disclosed. The method comprises providing a lock release mechanism to the emergency cot having a spring biased actuator, a bar pivotally connected to the actuator, a fork mounted to the bar and having two spaced apart prongs extending away from a surface of the bar, a post having an angled side, and a spring biased pivot latch having an angled side and pivotally mounted to the post, wherein the lock release mechanism has a locked configuration and an unlocked configuration. The method further includes placing the lock release mechanism in the locked configuration which prevents translation of the bar from a rest position to effect a height adjustable of the emergency cot by the pivot latch and post having the angled sides abutting to cause an interference fit therebetween which prevents pivoting of the pivot latch about the post, and wherein pulling the actuator causes one of the two prongs on the bar to contact and be arrested by the pivot latch.

In still another embodiment, a wanted adjustment of height of an emergency cot is caused by placing the lock release mechanism in the unlocked configuration by positioning the pivot latch about the post wherein the angled side of the pivot latch does not abut with the angel side of the post to cause an interference fit, and wherein pulling the actuator causes the bar to translate away from the rest position to permit the height adjustment of an emergency cot. These, and other features and advantages of the present invention will become apparent from the following detailed description, and the accompanying drawings.

The present invention is illustrated by way of example and not limitation in the accompanying figures, in which like references indicate similar elements, and in which: FIG. 1 is a perspective view of one adjustable cot configuration useable in the present invention;

FIG. 2 is a top plan view, partially cut away, showing the lock releases of the present invention used with trolley mechanisms;

FIG. 3 is a side plan view showing an adjustable cot in an elevated position; FIG. 4 is a side plan view showing an adjustable cot is a down position;

FIG. 5 is an enlarged top plan view, partially cut away, showing in greater detail the trailing end of the cot including a lock release according to the present invention; and

FIG. 6 is a sectional side view of the trailing end lock release of FIG. 5.

Skilled artisans appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiment(s) of the present invention.

Referring first to FIG. 1, an adjustable roll-in cot 10 is illustrated in an elevated position. It should be understood that the particular construction of the cot, including the legs, is for purposes of illustrating the trolley and ambulance cot lock release of the invention. The trolley and ambulance cot lock release may be adapted for use in any of a number of other roll-in adjustable cot configurations. However, for purposes of explanation and illustration, the cot configuration shown in FIG. 1 will be used.

Cot 10 has a frame 12 having a leading end 14, a trailing end 16, and a pair of opposed side frame members 18, 20. Typically, the frame members will be of a tubular metal and will be connected together in a conventional manner. Cot 10 is supported by leading and trailing pairs of collapsible legs 22, 22' and 24, 24', respectively. A pair of loading wheels 26, 28 are mounted using conventional hardware on side frame members 18, 20 adjacent leading end 14 of the cot frame. As is conventional in the art, these loading wheels 26, 28 are used when inserting the cot onto the floor of an emergency vehicle such as an ambulance. -A-

For the particular configuration illustrated in FIG. 1, the leading pair of collapsible legs 22, 22' includes a first pair of frame members 30, 30' having first ends thereof pivotally mounted on a first trolley assembly 32. The second (opposite) ends of the frame members 30, 30' are connected, via fittings 34, 34' to transport wheels 36, 36' which may be conventional caster wheels with foot-operated locking mechanisms 38. Collapsible legs 22, 22' also include a second pair of complementary support members 40, 40' which are pivotally mounted at their first ends to respective frame members 30, 30'. The opposite ends of complementary support members are pivotally mounted to cot frame 12. The legs may include cross-supports 41, 41' for added strength and stability. Likewise, cot 10 includes collapsible trailing legs 24, 24' which have a first pair of frame members 42, 42'. The first ends of frame members 42, 42' are pivotally mounted to cot frame 12 through rotatable fittings 44, 44'. A crosspiece 45 passes through rotatable fittings 44, 44' and is mounted to opposing side cot frame members 18 and 20, respectively. The opposite ends of frame members 42, 42' are connected to transport wheels 46, 46' via fittings 49, 49'. Collapsible legs 24, 24' also include a second pair of complementary support members 48, 48' having first ends pivotally mounted to respective frame members 42, 42'. The opposite ends of support members 49, 49' are pivotally mounted to second trolley assembly 50. Again, the trailing pair of collapsible legs 24, 24' may include cross-supports 51, 51' for added strength and stability to cot 10. First and second trolley assemblies 32 and 50, and their construction and operation, are best illustrated in FIG. 2 to which reference is now also made. The means for adjusting the height of cot frame 12 relative to the transport wheels includes a pair of generally C- shaped channels 52, 54 which are mounted within cot frame 12. By "C-shaped" it is meant that the channel has three sides, with a generally vertically oriented side and top and bottom legs which are generally horizontally oriented. Channels 52, 54 are secured to the cot frame adjacent the leading 14 and trailing 16 ends thereof using brackets 55, 55' and 56, 56' which are themselves mounted through support bars 58, 58' and secured using fittings 59 at opposing sides of frame members 18, 20.

In the embodiment shown, channels 52 and 54 are also secured, through brackets 60, 60', cross piece 45, and fittings 59 to opposing sides of frame members 18, 20. While the channels 52 and 54 are described as generally C-shaped, it will be apparent that the top and bottom legs of the C need not be of identical length. In the embodiment shown, the top leg of the C is somewhat longer than the bottom leg.

Within opposite-facing C-shaped channels 52, 54 are first and second trolley assemblies 32 and 50, respectively. As both trolley assemblies 32 and 50 include the same basic elements and operate in a like manner, reference will be made to second trolley assembly 50 associated with trailing legs 24, 24'. Trolley assembly 50 includes a pair of trolley blocks 62, 62' secured to a plate 64. Each trolley block includes a pair of rollers 66, 66' and 68, 68' which are adapted to roll in opposing C-shaped channels 52, 54. The rollers 66, 66' and 68, 68' are preferably constructed of rubber or are covered with rubber for smooth, quiet operation with no metal-to-metal contacts. The rollers 66, 66' and 68, 68' are preferably constructed using sealed bearings which require no lubrication.

Included within each trolley assembly 32, 50 are latching mechanisms generally indicated at 70, 72, respectively, for the cot 10. The latching mechanisms 70, 72 are designed so that cot 10 may be adjusted into a number of predetermined operating positions. Two such positions are shown in FIGS. 3 and 4. In FIG. 3, cot 10 is shown in a fully elevated position for patient transport and loading into an emergency vehicle. FIG. 4 illustrates cot 10 in a lowered position from which a patient may be loaded onto the cot 10 or may be transported.

As the latching mechanisms 70, 72 included the same basic elements, reference will be made to latching mechanism 70 associated with second trolley assembly 50 for a description of the construction and operation of both latching mechanisms 70, 72. Latching mechanism 72 includes like elements which operate in a like manner. Latching mechanism 70 includes a pair of opposing lock pins 72, 72' slidably mounted within lock pin tube 76. A spring 80 urges the respective lock pins 72, 72' into a series of slots or holes 82, 84 in each of the opposing C-shaped channels 52, 54. Slots 82, 84 are positioned at predetermined locations as desired for adjustable positioning of cot frame 12 with respect to the cot wheels.

Lock pins 72, 72' are actuated to be withdrawn from the respective slots 82, 84 by levers or handles 86, 88 located at opposite ends of cot frame 12. As shown in FIGS. 1 and 2, removal of the lock pins from the slots in the C-shaped channels requires operators or technicians positioned at both the leading and trailing ends of cot 10. However, it will be recognized that an adjustable cot could be designed such that a single operator could actuate single adjustment and latching mechanisms.

As best shown in FIG. 2, a lock release 100, 102 for each handle 86, 88 provides additional security and insures that the adjusting of the height of the cot at either or both ends is intentional. A more detailed discussion of the lock releases 100, 102 is provided in a later section in reference to FIGS. 5 and 6.

In one embodiment, after operating the respective lock release 100, when handle 86 is pulled toward the trailing end 16 of cot frame 12, an elongated bar 90 pivotally connected thereto causes cam 94 to urge bar 90 to translate in a direction away from its at rest position adjacent C-shaped channel 52. Bar 90 bears upon a load bearing pin 98 which extends through lock pin 72 substantially normal thereto and causes lock pin 72 to be withdrawn from slot 82. Simultaneously, at first trolley assembly 32, bar 90 is causing another load bearing pin to translate and withdraw another lock pin from a corresponding slot on C-shaped channel 52. Also as shown, at the leading end 14 of cot frame 12, another operator may after operating the respective lock release 102, actuate handle 88 by pulling it toward leading end 14. This causes a corresponding elongated bar 92 pivotally connected to handle 88 and in conjunction with a corresponding cam 96 to urge bar 92 to translate in a direction away from its at rest position adjacent C-shaped channel 54. Bar 92 bears upon a load bearing pin 98' which extends through lock pin 72' substantially normal thereto and causes lock pin 78' to be withdrawn from slot 84. Simultaneously, at first trolley assembly 32, bar 92 is causing another load bearing pin to translate and withdraw another lock pin from a corresponding slot on C-shaped channel 54.

In another embodiment, pulling handle 86 after operating the respective lock release 100, causes the urge bar 90 to cause lock pins 98 and 98' to be withdrawn simultaneously from slots 82, 84, thereby permitting the second trolley assembly 50 to translate freely along C-shaped channels 52, 54 such that one operator may adjust the height of the trialing end 16 of the cot independent of the leading end 14 of the cot. Likewise, in this embodiment, pulling handle 86 after operating the respective lock release 102, causes the urge bar 92 to cause the lock pins each engaged in a corresponding slot on C-shaped channel 52, 54 to be withdrawn, thereby permitting the first trolley assembly 32 to translate freely along C-shaped channels 52, 54 such that an operator may adjust the height of the leading end 14 of the cot independent of the trailing end 16 of the cot.

Turning now to FIGS. 5 and 6, the lock release 100 is shown. As the lock releases 100, 102 included the same basic elements, reference will be made to lock release 100 associated with first handle 86 for a description of the construction and operation of both lock releases 100, 102. Lock release 102 includes like elements which operate in a like manner. Lock release 100 includes a base 104 through which urge bar 90 translates. The base 104 is provided to a frame member 106 of the cot, and supports a pivot latch 108 for pivoting movement about a post 110. Was best sown by FIG. 6, the pivot latch 108 has an angled side 112 that resides against a similar angled side 114 of the post 110. In this locked position shown, pivot latch 108 will not pivot with sides 112 and 114 mated due to abutting surfaces of the sides 112, 114 causing an interference fit. Accordingly, pulling on handle 86 will cause a first prong 116 of a fork 118 mounted on urge bar 90 to contact and be arrested by pivot latch 108 such that the pins holding the trolley mechanisms in a fixed position cannot be withdrawn from their respective slots.

As shown by FIG. 6, lifting in the direction of the arrow 120 and twisting in the direction of arrow 122 (FIG. 5), unseats side 112 from side 114, and positions the pivot latch 108 in an unlocked condition as shown in the dashed lines, which is about 180° from the locked position (i.e., sides 112 and 114 mated). In the unlocked position, an operate pulling handle 86 will cause a second prong 124 of the fork 118 to contact and translate the pivot latch 108 in the same direction of arrow 122. As the handle 86 is pulled further, the pivot latch 108 will become situated in the space 126 provided between the prongs 116 and 124, such that the pivot latch 108 does not interfere with the operation of the handle 86 such that the cot may be height adjusted. Releasing the handle 86, which being spring biased, returns the handle to it non- operated position which is shown by FIG. 5. As the handle 86 transitions back to the non- operated position, the pivot latch 108 also being spring biased in the opposite direction to arrow 120, will also automatically transition back to its lock position once cleared from space 126 provided between prongs 116 and 124. The automatic transition to the locked position is another safety feature of the cot, which again requires an operator to intentional transition the pivot latch to the unlock position before again height adjusting the cot. The operation as described above for lock release 100 is the same for lock release 102. While certain representative embodiments and details have been shown for purposes of illustrating the invention, it will be apparent to those skilled in the art that various changes in the methods and apparatus disclosed herein may be made without departing from the scope of the invention, which is defined in the appended claims.

Claims

1. A lock release mechanism for height adjustment of an emergency cot having a frame, said lock release mechanism comprising: a spring biased actuator; a bar pivotally connected to the actuator; a fork mounted to the bar and having two spaced apart prongs extending away from a surface of the bar; a post having an angled side; and a spring biased pivot latch having an angled side and pivotally mounted to the post, and wherein the lock release mechanism has a locked configuration and an unlocked configuration, the locked configuration comprises the pivot latch and post having the angled sides abutting and causing an interference fit therebetween to prevent pivoting of the pivot latch about the post and wherein pulling the actuator causes one of the two prongs on the bar to contact and be arrested by the pivot latch, and the unlocked configuration comprises a translation of the pivot latch about the post wherein the angled side of the pivot latch does not abut with the angel side of the post to cause an interference fit wherein pulling the actuator causes the bar to translate away from its rest position to permit the height adjustment of an emergency cot.

2. The lock release mechanism of claim 1 further comprising a base mounted to the frame of the emergency cot through which the bar may translate and supporting the post.

3. The lock release mechanism of claim 1 wherein the pivot latch is configured such that when in the unlocked configuration releasing the actuator causes the pivot latch to automatically transition to the locked configuration wherein the angled side of pivot latch abuts again with the angel side of the post to cause an interference fit.

4. The lock release mechanism of claim 1 wherein the pivot latch is arranged such that in the unlocked configuration pulling the actuator causes the prongs to transition forward on either side of the pivot latch.

5. The lock release mechanism of claim 1 wherein the pivot latch is arranged on the post such that pulling upwardly and turning the pivot latch places the lock release mechanism in the unlocked configuration.

6. A height adjustable emergency cot comprising the lock release mechanism of claim 1.

7. A height adjustable emergency cot comprising a pair of the lock release mechanisms of claim 1.

8. A method for preventing unwanted adjustment of height of an emergency cot comprising: providing a lock release mechanism to the emergency cot having a spring biased actuator, a bar pivotally connected to the actuator, a fork mounted to the bar and having two spaced apart prongs extending away from a surface of the bar, a post having an angled side, and a spring biased pivot latch having an angled side and pivotally mounted to the post, wherein the lock release mechanism has a locked configuration and an unlocked configuration; and placing the lock release mechanism in the locked configuration which prevents translation of the bar from a rest position to effect a height adjustable of the emergency cot by the pivot latch and post having the angled sides abutting to cause an interference fit therebetween which prevents pivoting of the pivot latch about the post, and wherein pulling the actuator causes one of the two prongs on the bar to contact and be arrested by the pivot latch.

9. The method of claim 8 wherein a wanted adjustment of height of an emergency cot is caused by placing the lock release mechanism in the unlocked configuration by positioning the pivot latch about the post wherein the angled side of the pivot latch does not abut with the angel side of the post to cause an interference fit, and wherein pulling the actuator causes the bar to translate away from the rest position to permit the height adjustment of an emergency cot.

10. The method of claim 9 wherein the lock release mechanism is placed in the unlocked configuration by pulling upwardly and turning the pivot latch about the post to clear the interference fit between the angled sides.