OBJECT OF THE INVENTION
[0001] The present invention generally belongs to the field of the emergency healthcare.
[0002] The object of the present invention is a new anchoring system for a stretcher which
prevents, in a simple and effective manner, the person operating it from having to
support a considerable part of its weight during an operation of introducing it into
an ambulance.
BACKGROUND OF THE INVENTION
[0003] As is known, stretchers commonly used in emergency healthcare feature retractable
legs having two usage positions: an extended position in which the legs are extended
so as to allow moving a patient over the surface of the floor or ground; and a compressed
position in which the legs are compressed such that the stretcher can be placed on
the lower surface of an ambulance patient compartment. The operation of introducing
a stretcher into the ambulance involves the stretcher transitioning from the extended
position to the compressed position.
[0004] This operation of introducing the stretcher into the ambulance today has a considerable
drawback because there is a moment when the person performing said operation, i.e.,
the paramedic, must almost completely support all the weight of the stretcher and
the patient lying on it. In fact, the paramedic first pushes towards the ambulance
the stretcher (100) supported on wheels arranged at the lower end of the retractable
legs (101) in their extended position. The stretcher (100) furthermore features a
pair of auxiliary wheels (102) fixed to a front portion of the structure or frame
of the stretcher (100), this pair of auxiliary wheels (102) constituting the first
element of the stretcher (100) that enters the ambulance patient compartment. In that
moment, the retractable legs (101) start to fold up. The folding up can be done in
various ways, for example due to the retractable legs (101) hitting against the lower
edge of the ambulance patient compartment. When only the front pair of retractable
legs (101) has folded up, the stretcher (100) is supported on the rear pair of retractable
legs (101) and on the auxiliary wheels (102), as shown in Figure 1a. Therefore, in
this situation the paramedic is still not supporting any weight. However, once the
rear pair of retractable legs (101) folds up, the stretcher (100) is supported only
on the auxiliary wheels (102), and the paramedic must therefore hold the stretcher
(100) at its rear end, supporting virtually all the weight of the stretcher and the
patient. This situation is depicted in Figure 1b.
[0005] Therefore, there is a need in the art today for an anchoring system that anchors
a stretcher to an ambulance that prevents the need for the paramedic to support all
its weight during the operation of introducing it into the ambulance.
DESCRIPTION OF THE INVENTION
[0006] This patent document solves the aforementioned problem as a result of a novel anchoring
system which supports all the weight of the stretcher and the patient at all times
during the process of introducing the stretcher into the ambulance. This prevents
the paramedic from having to support all the weight of the stretcher and the patient,
which thereby prevents the occurrence of the usual injuries caused by handling conventional
stretchers used today.
[0007] The anchoring system according to the invention is designed for anchoring a stretcher
to an ambulance floor, wherein the stretcher comprises a rectangular frame supporting
a surface for bearing the patient and to which there are fixed two pairs of retractable
legs equipped with wheels at their free ends. The frame is typically formed by four
bars that are parallel to one another in twos, where the two longest bars are referred
to as "
side bars" and the two shortest bars are referred to as "
end bars". As regards the legs, there are two pairs of conventional retractable legs that
can alternate between an extended position, in which they allow moving the stretcher
by rolling it over the floor or ground, and a retracted position, designed for when
the stretcher is inside the ambulance. The retractable legs have wheels at their lower
end that allow moving the stretcher over the floor or ground.
[0008] The term "
front end" of the stretcher will be interpreted herein according to the direction of movement
of said stretcher upon introducing it into the ambulance. In other words, the "
front end" of the stretcher is that end which is first introduced into the ambulance. Similarly,
the term "
rear end" of the stretcher will be interpreted according to the direction of movement of said
stretcher upon introducing it into the ambulance. Therefore, the "
rear end" of the stretcher is that end which enters the ambulance last. The term "
longitudinal direction" refers to the natural direction of movement of the stretcher for introducing same
into the ambulance, and therefore also to the direction of the rails arranged therein.
[0009] Taking this into account, the anchoring system of the invention comprises:
- a) A pair of horizontal rails coupleable to an ambulance floor. These rails are usually
integrated at the sides of a structure or assembly formed by a rectangular plate designed
to be fixed on the floor of an ambulance patient compartment. This structure may further
comprise other auxiliary elements of the anchoring system that are not the object
of the present invention.
- b) A pair of first auxiliary wheels, wherein each first auxiliary wheel is rigidly
fixed to a front end portion of a respective side bar of the frame of the stretcher,
and wherein the pair of first auxiliary wheels is slidingly coupleable in the longitudinal
direction to said pair of horizontal rails. Therefore, this pair of first auxiliary
wheels essentially constitutes the first element of the stretcher that enters the
ambulance patient compartment during an operation of introducing the stretcher, being
coupled to the aforementioned rails and thereby providing front support.
[0010] The usual elements in anchoring systems conventionally used today have been described
up to this point. However, the anchoring system of the invention differs from them
fundamentally in that it further comprises the following features.
c) The anchoring system of the invention further comprises a pair of second auxiliary
wheels. Each second auxiliary wheel is rigidly fixed to the respective side bar of
the frame of the stretcher in a position longitudinally adjacent to, and aligned with,
the first auxiliary wheel fixed to the same side bar. Therefore, the pair of second
auxiliary wheels is also slidingly coupleable in the longitudinal direction to said
pair of horizontal rails. In other words, a forward longitudinal movement of the stretcher
causes the successive introduction of the first auxiliary wheels and the second auxiliary
wheels into the rails.
The second auxiliary wheels will preferably be located in a longitudinal position
located between the attachment of front retractable legs to the frame of the stretcher
and the position of the first auxiliary wheels. It is thereby assured that the second
auxiliary wheels enter the rails before the retractable legs start to fold up. This
is important because once the second auxiliary wheels are inside the rails, the stretcher
is completely supported by the anchoring system. After this moment, the retractable
legs can be folded up without the paramedic having to support the weight of the stretcher
and the patient.
On the other hand, the distance between each second auxiliary wheel and the first
auxiliary wheel fixed to the same side bar is preferably between 10 cm and 100 cm.
d) The horizontal rails of the invention have a profile comprising a lower horizontal
segment and an upper horizontal segment separated from one another by a distance essentially
equal to the diameter of the auxiliary wheels. So when the auxiliary wheels are introduced
into the rails, they are confined between the lower horizontal segment and the upper
horizontal segment of said rails, preventing any vertical movement thereof. As a result
of the auxiliary wheels not being able to move vertically with respect to the rails,
once both pairs of auxiliary wheels are introduced into the rails, the stretcher is
completely supported, being borne on said auxiliary wheels.
Preferably, the profile of the rails adopts an essentially C-shape formed by the lower
horizontal segment, an intermediate vertical segment, and the upper horizontal segment.
The open side of the C leaves room for the connecting element between the auxiliary
wheels and the corresponding side bars of the stretcher. The lower and upper horizontal
segments prevent any movement of the auxiliary wheels in a direction other than the
longitudinal direction of the rails.
[0011] The operation of this novel anchoring system is therefore as follows. The paramedic
first pushes the stretcher with its front end towards the ambulance such that the
first pair of auxiliary wheels enters the rails. The paramedic then continues pushing
until the second pair of auxiliary wheels also enters the rails. Since the profile
of the rails has an upper horizontal segment, none of the auxiliary wheels can move
vertically upwards, i.e., none of the auxiliary wheels can lift off the ambulance
floor. Therefore, the stretcher cannot tip over when the retractable legs fold up,
since it is forced to maintain its horizontal position. The paramedic can thereby
retract the retractable legs, either by hand or automatically, and then finish completely
introducing the stretcher into the ambulance, making the pairs of auxiliary wheels
roll forward in the rails. The paramedic does not need to hold the weight of the stretcher
and the patient at any time throughout the entire operation.
[0012] In a preferred embodiment of the invention, the system further comprises centering
rollers arranged in a position adjacent to each of the auxiliary wheels. For example,
they can be rollers having a vertical axis of rotation which are fixed to the connecting
element between the auxiliary wheels and the corresponding side bar of the frame of
the stretcher. These rollers tend to center the auxiliary wheels with respect to the
ends where said rollers enter the rails, thereby making the initial operation of introducing
the auxiliary wheels into the rails easier when the stretcher is introduced into the
ambulance.
[0013] In another preferred embodiment of the invention, the anchoring system further comprises
locking means which are automatically activated after the second pair of auxiliary
wheels enters the rails to prevent any longitudinal movement of the auxiliary wheels
along the rails. In other words, these locking means are automatically activated once
the stretcher is completely supported by the anchoring system. During the process
in which the retractable legs fold up, the locking means prevent an outward longitudinal
movement of the stretcher, which causes the second auxiliary wheels to pop out of
the rails, with the subsequent risk of the stretcher tipping over, from taking place.
For example, this is particularly useful when the ambulance is located on a sloped
surface. Therefore, once the locking means are activated, the paramedic can then fold
up the retractable legs, by hand or automatically depending on the particular design
of the stretcher, without the risk of said stretcher rolling out of the ambulance.
[0014] In another preferred embodiment, the anchoring system further comprises means for
unlocking the locking means that can be operated from a rear end of the stretcher.
This will allow the paramedic to deactivate the locking means once the retractable
legs have been completely folded up, such that said paramedic can then continue pushing
the stretcher into the ambulance.
[0015] In principle, the locking means can be configured in different ways, depending on
each particular application, although in one particularly preferred embodiment of
the invention, the locking means comprise a spring-driven projection rigidly fixed
to the frame of the stretcher, and a corresponding housing rigidly fixed to the pair
of horizontal rails. In this context, it must be understood that the expression "
rigidly fixed" to the frame of the stretcher or to the horizontal rails includes both a direct
fixing to said elements and an indirect fixing through other parts. In any case, the
underlying concept is that the projection moves integrally with the stretcher and
the housing is in a fixed position like the horizontal rails are. The respective positions
of the projection and the housing are conceived so that the projection gradually moves
closer to the housing as the first auxiliary wheels longitudinally move along the
rails into the ambulance. The projection reaches the position in which the housing
is located and is automatically introduced therein once the second auxiliary wheels
have entered the rails.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016]
Figures 1a and 1b show two moments of introducing a stretcher into an ambulance with
an anchoring system according to the prior art.
Figure 2 shows a perspective view of a stretcher equipped with an anchoring system
according to the present invention.
Figure 3 shows a detail view of the front end portion of a stretcher equipped with
an anchoring system according to the present invention.
Figure 4 shows a perspective view of a pair of rails of an anchoring system according
to the present invention.
Figure 5 shows a cross-section of the rails of an anchoring system according to the
present invention.
Figure 6 shows an enlarged cross-section of a rail of an anchoring system according
to the present invention.
Figure 7 shows a perspective view of a stretcher at a moment of its coupling to rails
in an anchoring system according to the present invention.
Figure 8 shows a detail of the operation of the locking means which prevent any longitudinal
movement of the auxiliary wheels along the rails.
Figures 9a and 9b show two moments of introducing a stretcher into an ambulance with
an anchoring system according to the present invention.
PREFERRED EMBODIMENT OF THE INVENTION
[0017] The invention is described below in reference to the attached drawings, which show
various views of a particular example of an anchoring system according to the present
invention. However, the scope of protection of this application is not limited by
the details described in these examples, but rather by what is defined by the attached
claims.
[0018] Figure 2 shows a perspective view of a stretcher (1) equipped with an anchoring system
according to the present invention. The stretcher (1) is fundamentally formed by a
frame (11) having a rectangular shape with two lateral sides in the longitudinal direction,
and rear and front sides perpendicular to the longitudinal direction. A horizontal
surface (12), which is usually cushioned, is fixed to the frame (11) so as to allow
the patient to lie or sit down on same. Furthermore, rear retractable legs (13t) and
front retractable legs (13d), respectively, are fixed to the frame (11) on the lower
part thereof. Retractable legs (13t, 13d) are known in the art and can be implemented
in different ways, although as can be seen in Figure 2 they adopt a scissor structure
which allows alternating between an extended position and a folded up position. The
free ends of the retractable legs (13t, 13d) comprise wheels which allow moving the
stretcher (1) over the floor or ground before introducing it into the ambulance.
[0019] This stretcher (1) also includes a pair of first auxiliary wheels (3) fixed to the
side bars of the frame (11) in a front portion of said side bars, as can be seen in
further detail in Figure 3. Specifically, in this example the first auxiliary wheels
(3) are fixed through a rigid connecting element to the front end of the side bars
of the frame (11). A pair of second auxiliary wheels (4) is located a greater distance
away from the front end of the side bars of the frame (11) in a fixed manner. As can
be seen, the first and second auxiliary wheels (3, 4) are aligned in twos for the
purpose of allowing them to be introduced into the rails (2) which will be described
below.
[0020] Centering rollers (5), which are fixed to the connecting elements between the auxiliary
wheels (3, 4) and the side bars of the frame (11) in this example, are also seen in
Figure 3. The centering rollers (5) have a cylindrical shape and are oriented in the
vertical direction. Their position, next to the auxiliary wheels (3, 4) and somewhat
ahead of them, allow for their guiding function to make it easier to introduce the
auxiliary wheels (3, 4) into the rails (2), as will be described in further detail
below.
[0021] The locking projection (6a) cooperating with a housing (6b) to lock the position
of the stretcher (1) with respect to the rails (2) can also be seen in Figure 3. It
must be observed that this configuration of the locking means (6a, 6b) constitutes
only one example, and that other types of mechanisms and other locations would be
possible. The operation of the locking means (6a, 6b) will also be described herein
in further detail below.
[0022] Figures 4 to 6 show a structure which is designed for being fixed to the ambulance
floor and includes the rails (2). The rails (2) are separated from one another by
a distance equal to the gap between the auxiliary wheels (3, 4), and have an essentially
C-shape formed by three segments: a lower horizontal segment (21), an intermediate
vertical segment (22), and an upper horizontal segment (23). The distance between
the upper surface of the lower horizontal segment (21) and the lower surface of the
upper horizontal segment (23) is essentially equal to the diameter of the auxiliary
wheels (3, 4). The auxiliary wheels (3, 4) can thereby roll in the longitudinal direction
supported on the inner horizontal segment (21), its highest point almost rubbing against
the upper horizontal segment (23). Therefore, once an auxiliary wheel (3, 4) is introduced
into a corresponding rail, only its forward longitudinal movement (into the ambulance)
or backward longitudinal movement (out of the ambulance), is allowed, but any movement
in the vertical direction either downward (where it would hit against the lower horizontal
segment (21)) or upward (where it would hit against the upper horizontal segment (23))
is prevented.
[0023] Figures 7 and 8 show a stretcher (1) with an anchoring system according to the invention
at an initial moment of introducing it into an ambulance. First, the first auxiliary
wheels (3) are introduced through the end of the rails (2). During this operation,
the centering rollers (5) help the paramedic to suitably center the first auxiliary
wheels (3) with the open end of the rails, thereby making it easier to introduce it
into the rails. The paramedic then pushes the stretcher (1) until also introducing
the second auxiliary wheels (4) into the rails (2). Once the second auxiliary wheels
(4) are inside the rails (2), the projection (6a) is introduced into the housing (6b)
and thereby prevents any longitudinal movement of the stretcher (1). To that end,
it can be seen how there is a vertical surface that is sloped with respect to the
longitudinal direction arranged right before the housing (6b). As the spring-driven
projection (6a) slides along that sloped surface, it is retracted against the force
of the spring. As a result, when movement of the stretcher (1) continues and the projection
(6a) is arranged opposite the housing (6b), the spring drives the projection (6a)
into the housing (6b), the stretcher (1) being locked in place.
[0024] In the locking position, it is possible to completely fold up the retractable legs
(13d, 13t) of the stretcher (1) without the paramedic having to support its weight.
In fact, although the weight of the stretcher (1) and the patient exerts a downward
vertical force on a central portion of the overhanging stretcher (1), and as a result,
the stretcher tends to tip over supported on the second auxiliary wheels (4), the
upper horizontal segment (23) of said rails (2) prevents the first auxiliary wheels
(3) from raising up. The stretcher remains held firmly in the horizontal position,
preventing it from tipping over. The locking means (6a, 6b) furthermore prevent the
stretcher (1) from sliding backward and causing the second auxiliary wheels (4) to
come out of the rails (2).
[0025] Figures 9a and 9b schematically show an actual case in which the stretcher (1) is
first introduced into the ambulance according to the process described above until
the means (6a, 6b) are activated. First, as shown in Figure 9a, the position of the
stretcher (1) is locked with the two pairs of auxiliary wheels (3, 4) introduced into
the rails (2). Then, as shown in Figure 9b, the retractable legs (13t, 13d) are folded
up. The operation of folding up the retractable legs (13t, 13d) can be carried out
by hand or automatically, for example by means of using mechanisms based on springs,
hydraulic cylinders, electric motors, or the like. Once the legs (13t, 13d) are completely
folded up, the paramedic must simply push the stretcher (1) until completely introducing
it into the ambulance.
[0026] As can be seen, this mode of use completely eliminates the need for the paramedic
to support the weight of the stretcher (1) and the patient during the operation of
introducing the stretcher (1) into the ambulance, thereby resolving the problems that
have been described.
1. An anchoring system for a stretcher (1), wherein the stretcher (1) comprises a rectangular
frame (11) supporting a surface (12) for bearing the patient and to which there are
fixed two pairs of retractable legs (13d, 13t) equipped with wheels at their free
ends, the anchoring system comprising:
- a pair of horizontal rails (2) coupleable to an ambulance floor; and
- a pair of first auxiliary wheels (3), wherein each first auxiliary wheel (3) is
rigidly fixed to a front end portion of a respective side bar of the frame (11) of
the stretcher (1), and wherein the first auxiliary wheels (3) are slidingly coupleable
in the longitudinal direction to said pair of horizontal rails (2),
the anchoring system being
characterized
in that it further comprises a pair of second auxiliary wheels (4), wherein each second auxiliary
wheel (4) is rigidly fixed to the respective side bar of the frame (11) of the stretcher
(1) in a position longitudinally adjacent to, and aligned with, the first auxiliary
wheel (3) fixed to the same side bar, such that the pair of second auxiliary wheels
(4) is also slidingly coupleable in the longitudinal direction to said pair of horizontal
rails (2), and
in that the profile of the pair of horizontal rails (2) comprises a lower horizontal segment
(21) and an upper horizontal segment (23) separated from one another by a distance
essentially equal to the diameter of the auxiliary wheels (3, 4), such that when the
auxiliary wheels (3, 4) are introduced into the rails (2), they are confined between
the lower horizontal segment (21) and the upper horizontal segment (23) of said rails
(2), preventing any vertical movement thereof.
2. The anchoring system according to claim 1, wherein the profile of the rails (2) adopts
an essentially C-shape formed by the lower horizontal segment (21), an intermediate
vertical segment (22), and the upper horizontal segment (23).
3. The anchoring system according to any of the preceding claims, wherein the distance
between each second auxiliary wheel (4) and the first auxiliary wheel (3) fixed to
the same side bar of the frame (11) is between 10 cm and 100 cm.
4. The anchoring system according to any of the preceding claims, further comprising
centering rollers (5) arranged in a position adjacent to each of the auxiliary wheels
(3, 4).
5. The anchoring system according to claim 4, wherein the centering rollers (5) are rollers
having a vertical axis of rotation which are fixed to a connecting element between
the auxiliary wheels (3, 4) and the corresponding side bar of the frame (11) of the
stretcher (1).
6. The anchoring system according to any of the preceding claims, further comprising
locking means (6a, 6b) which are automatically activated after the second pair of
auxiliary wheels (4) enter the rails (2) to prevent any longitudinal movement of the
auxiliary wheels (3, 4) along the rails (2).
7. The anchoring system according to claim 6, further comprising means for unlocking
the locking means (6a, 6b) that can be operated from a rear end of the stretcher (1).
8. The anchoring system according to any of claims 6 to 7, wherein the locking means
(6a, 6b) comprise a spring-driven projection (6a) rigidly fixed to the frame (11)
of the stretcher (1), and a corresponding housing (6b) rigidly fixed to the pair of
horizontal rails (2).