Multi-Pivot Seat Base Assembly

Described herein are illustrative embodiments of a multi-pivot seat base assembly including a first pivot assembly having a fixed part mountable to a floor and a pivotable part, a proximate arm having a proximate end mounted to the pivotable part of the first pivot assembly and a distal end including a fixed part of a second pivot assembly, a distal arm having a proximate end provided with a pivotable part of the second pivot assembly; the proximate end of the distal arm being pivotally mounted to the fixed part of the second pivot assembly; the distal arm including a distal end provided with a seat receiving post; and a controllable damping mechanism provided between the fixed part and the pivotable part of the first pivot assembly.

FIELD

The present disclosure relates to seat bases. More specifically, the present disclosure is concerned with a multi-pivot seat base assembly.

BACKGROUND

Many vehicles, such as emergency vehicles and transport vehicles, are provided with seats that are fixedly mounted to the floor of the vehicle via seat bases for safety reasons.

In some cases, the seat bases are mounted into tracks, embedded in the floor of the vehicle, to allow some restricted movements of the seat occupants. These tracks have many drawbacks including the fact that foreign matter may be stuck therein and prevent desired movements.

DETAILED DESCRIPTION

An object is to provide a multi-pivot seat base assembly.

More specifically, according to an illustrative embodiment, there is provided a multi-pivot seat base assembly including a first pivot assembly having a first shaft mountable to a floor, a proximate arm having a proximate end pivotally mounted to the first shaft of the first pivot assembly and a distal end, a distal arm having a proximate end and a distal end provided with a seat receiving element, a second pivot assembly pivotally interconnecting the distal end of the proximate arm and the proximate end of the distal arm, a pivot linking mechanism so configured that a pivotal movement of the distal arm about the second pivot assembly causes a pivotal movement of the proximate arm about the first pivot assembly, a damping mechanism associated with at least one of the first and second pivot assemblies, and a controllable locking mechanism associated with at least one of the first and second pivot assemblies to selectively prevent pivotal movement thereof.

According to another aspect, there is provided an ambulance compartment including a floor, wheel wells defining a generally square portion of the floor, an elongated floor mounted rail allowing a conventional stretcher mounted thereto to be positioned in a forward position in the ambulance compartment, and at least two seat bases mounted in the generally square portion of the floor.

In the present specification and in the appended claims, various terminology which is directional, geometrical and/or spatial in nature such as “longitudinal”, “horizontal”, “front”, rear”, “upwardly”, “downwardly”, etc. is used. It is to be understood that such terminology is used for ease of description and in a relative sense only and is not to be taken in any way as a limitation upon the scope of the present disclosure.

The expression “connected” should be construed herein and in the appended claims broadly so as to include any cooperative or passive association between mechanical parts or components. For example, such parts may be assembled together by direct coupling, or indirectly coupled using further parts.

It is to be noted that while the present detailed description refers to an emergency vehicle such as an ambulance, other vehicles using seats that are fixedly mounted to a floor using a base can be provided with a multi-pivot base as described herein.

Other objects, advantages and features of the multi-pivot seat base assembly will become more apparent upon reading of the following non-restrictive description of illustrative embodiments thereof, given by way of example only with reference to the accompanying drawings.

Generally stated, an illustrative embodiment is concerned with a multi-pivot seat base assembly designed to be fixed to the floor of an emergency vehicle. The multi-pivot base includes proximate and distal arms so hinged together by a pivot and gearing that their movements are coordinated. Furthermore, a movement damping and locking mechanism is provided to provide a controllable level of damping and to allow an automatic lock of the multi-pivots in emergency situations.

FIG.1of the appended drawings illustrates a seat10mounted to a multi-pivot seat base assembly12according to a first illustrative embodiment. The seat assembly10conventionally includes a seat14and a back rest16.

The multi-pivot seat base assembly12includes a generally circular anchoring plate18, configured to be fixedly mounted to the floor, a proximate arm20so mounted to a first pivot assembly22as to be pivotable about a first pivot axis24, a distal arm26so mounted to a second pivot assembly28, provided between the proximate and distal arms, as to be pivotable about a second pivot axis30. The free end of the distal arm26includes a seat receiving element in the form of a post32, that may be viewed as a third pivot.

As will be clear from the following description, the second pivot assembly28includes elements that cause the proximate arm to pivot about the first pivot axis24when the distal arm26pivots about the second pivot axis30.

In this first illustrative embodiment, the multi-pivot seat base assembly12also includes a controllable damping and locking mechanism34mounted to the proximate arm20and associated with the first pivot assembly22to control the force required to pivot the proximate arm20about the first pivot axis24as will be described herein.

FIG.1also illustrates, in dashed lines, two possible positions of the seat10with respect to the circular anchoring plate18.

Turning now toFIGS.2to5of the appended drawings, the multi-pivot seat base assembly12will be described in greater details.

As can be seen from these figures, the first pivot assembly22has a generally cylindrical body36to which the proximate arm20is fixedly mounted, for example via welding. The controllable damping mechanism34is provided between the two plates that form the proximate arm20.

As can be better seen fromFIGS.3and5, the controllable damping and locking mechanism34is connected to the first pivot assembly22via a double chain38anchored to sprockets (not shown) mounted to a centrally located fixed shaft40of the first pivot22. This shaft40and the sprockets (not shown) are fixedly and non-rotatably mounted to the anchor plate18.

The cylindrical body36, defining the pivotable portion of the first pivot assembly22, is mounted to the shaft40via bearings (not shown) provided between the shaft40and a support42, which is fixedly mounted to the body36.

One skilled in the art will understand that since the controllable damping and locking mechanism34is fixedly mounted to the proximate arm20, should the mechanism34be so controlled as to prevent rotation of the double chain38, the cylindrical body36cannot pivot about the fixed shaft40, effectively locking the multi-pivot seat base assembly12.

Of course, the double chain38and associated sprockets (not shown) could be replaced by other suitable means of transmitting movement, such as belts and pulleys, for example.

One skilled in the art will understand that the controllable damping and locking mechanism34could be hydraulic, electrical or pneumatic but that it should be designed with fail safes against power failures.

The second pivot assembly28includes a bottom fixed part44mounted to the distal end of the proximate arm20and a top pivotable part46mounted to the proximate end of the distal arm26.

More specifically,FIG.5shows that the fixed part44includes a first bevel gear48that is fixedly mounted to the casing of the bottom fixed part and therefore to the proximate arm20. A second bevel gear (see50inFIG.4) is similarly fixedly mounted to the pivotable part46and therefore to the distal arm26. First and second bevel gears48and50are so configured as to receive a shaft52that is fixedly mounted to the bottom fixed part44and to which the pivotable part46is so mounted that it can pivot.

One skilled in the art will understand that the pivotable part46includes bearings (not shown) allowing the shaft52to freely pivot therein.

The shaft52includes a transversal short shaft54, to which are mounted secondary bevel gears56and58.

Fasteners60and62are used to assemble the second pivot assembly28.

FIG.4illustrate the interconnection of the bevel gears48,50,56and58.

Since bevel gears48and50are respectively fixedly mounted to the fixed and pivotable parts44and46of the second pivot assembly28, one skilled in the art will understand that a pivoting action of the pivotable part46about the shaft52causes the rotation of the secondary bevel gears56and58that, in turn causes the pivot action of the proximate arm20about the first pivot axis24. Accordingly, the bevel gears48,50,56and58can be viewed as a pivot linking mechanism since they are so configured that a pivotal movement of the distal arm about the second pivot assembly causes a pivotal movement of the proximate arm about the first pivot assembly.

Indeed, since the bevel gear48is fixedly mounted at the distal end of the proximate arm20and the pivot action of the distal arm26causes rotation of the secondary gears56and58that cannot rotate about the second axis30since the shaft52is not rotatable with respect to the fixed part44, the rotation of the gears56and58onto the gear48causes a rotation of the proximate arm20about the first axis24.

This is interesting since in the event that the controllable damping mechanism34is so controlled as to prevent any pivoting movement of the proximate arm20about the first pivot axis24, it also simultaneously prevents movement of the distal arm26about the second pivot axis30.

Accordingly, in an emergency situation, a controller (not shown) may so control the multi-pivot seat base assembly as to prevent any movement thereby.

Furthermore, the controllable damping and locking mechanism34may be so controlled by the user, using inputs to the controller (not shown) to vary the resistance to movement according to the user's preference.

One skilled in the art will understand that the multi-pivot seat base assembly12may also include sensors (not shown) that supply position data of the various pivot assemblies to the controller.

For safety purpose, the controller (not shown) may monitor the multi-pivot seat base assembly12to ensure that its power supply is operating adequately and take safety measures, such as, for example, automatically locking the seat base assembly12, should power fail.

Turning now toFIGS.6and7of the appended drawings, possible movements of seats mounted to multi-pivot char base assemblies will be illustrated in the context of an ambulance.

The interior space of the ambulance100is shown in a top plan view. A conventional stretcher102is mounted to a conventional but elongated rail104to allow the conventional stretcher102to be positioned farther in the ambulance100. The ambulance100includes three seats mounted to multi-pivot seat base assemblies. These seats are generally referred to as the curb side seat106, the street side seat108and the head seat110.

The elongated rail104allows the curb side seat106and the street side seat108to be positioned between the wheel wells (not shown) of the vehicle to thereby be on a flat portion of the ambulance floor and enable a greater freedom of positioning of the seat bases. This seat positioning also allows the user to attend to the core and head of the patient present in the stretcher102, thanks to the forward positioning of the stretcher102made possible by the elongated rail104.

FIGS.6and7each shows 3 possible positions for each of the seats106,108and110. As seen from these figures, the multi-pivot bases can be used to move towards and away from the stretcher, to move laterally and to turn around to reach equipment mounted onto horizontal surfaces or walls of the ambulance, as shown by the various arrows.

One skilled in the art will understand that even though three seats provided with a multi-pivot seat base mechanism as described herein are shown inFIGS.6and7, only one or two of the seats shown could be provided with such a multi-pivot seat base assembly.

Similarly, whileFIGS.6and7show an ambulance configuration where an elongated rail104allows the stretcher102to be positioned in a generally central location of the ambulance compartment100, the multi-pivot seat base described herein could be used in a conventional ambulance layout and in other vehicles.

Turning now toFIGS.8to14of the appended drawings, multi-pivot seat base mechanism200according to a second illustrative embodiment will be described. Since the mechanism200is very similar to the mechanism12illustrated inFIGS.1to7and discussed hereinabove, only the differences therebetween will be described in detail, for concision purpose.

Generally stated, two main differences exist between the mechanism200and the mechanism12ofFIGS.1to7. The first difference is related to the interconnection between the first and second pivot assemblies and the elements that cause the proximate arm to pivot about the first pivot axis when the distal arm pivots about the second pivot axis, as will be discussed hereinbelow. The second difference involves the controllable damping and locking mechanism.

The multi-pivot seat base mechanism200includes a generally circular anchoring plate202, configured to be fixedly mounted to the floor, a proximate arm204so mounted to a first pivot assembly206as to be pivotable about a first pivot axis208, a distal arm210so mounted to a second pivot assembly212, provided between the proximate and distal arms, as to be pivotable about a second pivot axis214. The free end of the distal arm210includes a seat receiving element216.

As can be better seen fromFIG.10, the first pivot assembly206includes a fixed shaft218mounted to the plate202via fasteners220, a controllable damping and locking mechanism222, and a first sprocket224, fixedly mounted to the fixed shaft218by a key and keyway assembly. The fixed shaft218defining the first pivot axis208.

The proximate end of the proximate arm204is pivotably mounted to the fixed shaft218via bearings226,228.

The second pivot assembly212includes a shaft230is fixedly mounted to the proximate end of the distal arm210via fasteners232provided in the top portion of the shaft230. A second sprocket234is mounted to the shaft230, for example by welding, so as to be rotatable therewith.

The bottom portion of the shaft230is pivotally mounted to the distal end of the proximate arm204via bearings236,238. The distal arm210may therefore pivot about the second pivot axis214defined by the shaft230.

A chain240interconnects the first and second sprockets224and234. Accordingly, a pivotal movement of the distal arm210about the second pivot axis214causes a corresponding pivotal movement of the proximate arm204about the first pivot axis208. Accordingly, the first and second sprockets224and234and the chain240can be viewed as a pivot linking mechanism since they are so configured that a pivotal movement of the distal arm about the second pivot assembly causes a pivotal movement of the proximate arm about the first pivot assembly

Indeed, since the second sprocket234is fixedly mounted to the shaft230, it pivots with it when the distal arm210pivots about axis214. This pivotal movement of the second sprocket234creates a force in the chain240that tries to pivot the first sprocket224. However, since the first sprocket224is fixedly mounted to the fixed shaft218, it cannot pivot, and this force is transferred to the proximate arm204that pivots about the first pivot axis208since the second sprocket234is mounted in the distal end of the proximate arm204.

As can be better seen fromFIG.10, the controllable damping and locking mechanism222. While the controllable damping and locking mechanism34of the assembly12ofFIGS.1to7combines the functions of damping and locking, the mechanism222of the assembly200separates these two functions.

Indeed, the mechanism222includes a locking sub-mechanism in the form of a claw coupling having a fixed part242provided with upwardly facing claws243and a movable part244provided with downwardly facing claws245. As can be better seen fromFIG.11, the fasteners220securing the shaft218to the base202extend past the base202and secure the fixed part242to the base202. The movable part244is so mounted to the proximate end of the proximate arm204via fasteners246so as to be movable along the axis208.

The controllable damping and locking mechanism222also includes a fork actuator248which is so mounted to the proximate end of the proximate arm204via pins250that engage apertures252of the arm204as to be pivotable about the axis defined by the pins250. The fork248is linked to the movable part244via pivot pins254.

As will be described hereinbelow, a pivotal upward movement of the fork248brings the movable part244in engagement of the fixed part242of the claw coupling.

The fork248also includes a generally C-shaped pad256made of a plastic material allowing it to embody the damping function of the mechanism222. Indeed, the pad256is so mounted to the underside of the fork248that a pivotal downward movement of the fork248bring the pad256in contact with the flat portion of the fixed portion242of the claw coupling. The pad256may thus be viewed as a friction inducing means between the proximate end of the proximate arm204and the first shaft218since the fixed portion242of the claw coupling, the base202and the shaft218are fixedly interconnected via the fasteners220.

As a non-limiting example, the pad256could be made of polyurethane.

The pivotal movements of the fork248is done by an actuator (not shown) that it controlled by a controller (also not shown). The technology used in this actuator can be electrical, hydraulic of pneumatic, depending on the technologies available in the vehicle. It is believed within the reach of one skilled in the art to select an appropriate actuator.

One skilled in the art will notice that a seal, in the form of an O-ring258is provided between the proximate arm204and the base202to prevent foreign matter to enter.

Turning now toFIGS.12to14of the appended drawings, the operation of the controllable damping and locking mechanism222will be described.

FIG.12illustrates the fork248in a neutral position. Indeed, when the fork248is in that position, the claws243and245are not in an engaged configuration and the pad256does not contact the fixed part242.

FIG.13shows the fork248when it has been pivoted downwardly about pins250so that the pad256is in contact with the fixed part242. The mechanism222is then in a damping position.

One skilled in the art will understand that since the force applied by the actuator to move the fork248be controllable, the damping effect of the pad contacting the fixed part242is also variable. For example, a user could have a control over the pressure applied and therefore the force required to manually pivot the seat base.

FIG.14shows the fork248when it has been pivoted upwardly about pins250so that the pad claws243and245are meshed, thereby locking any pivotal movement of the multi-pivot seat base assembly.

One skilled in the art will understand that since the first and second pivot assemblies206and212are linked by a chain looping about two sprockets, the path described by the distal end of the distal arm depends on the characteristics of the chain and of the sprockets. It is believed to be within the skills of those skilled in the art to determine these characteristics depending on the desired path.

It is also to be noted that the multi-pivot seat base mechanism200also includes many elements to ensure that the various mechanical parts are properly spaced and maintained in their desired positions. These elements are believed well known to those of ordinary skills in the art and will not be discussed further herein.

Turning now toFIG.15of the appended drawings, a multi-pivot seat base mechanism300according to a third illustrative embodiment will be described. Since the mechanism300is very similar to the mechanism200illustrated inFIGS.8to14and discussed hereinabove, only the differences therebetween will be described in detail, for concision purpose.

The difference between the mechanism300and the mechanism200is the damping assembly which is completely separated from the locking mechanism.

Indeed, while the locking mechanism of the assembly300is identical to that of mechanism200, the damping mechanism is not associated with the fork controlling the breaking mechanism.

More specifically, the damping mechanism302is provided between the fixed shaft304and the pivoting proximate end of the proximate arm306and includes damping pads308(two shown inFIG.15) that are urged against the arm306by springs310pushing backer plates312secured to the pads308. Fasteners such as set screws314allow installation, maintenance and force adjustments to the damping mechanism302. The pads308may thus be viewed as friction inducing means between the proximate end of the proximate arm306and the first shaft304.

One skilled will understand that the damping mechanism302is always in operation and, could include variable compression features (not shown) that allow the damping level to be controllable by the user.

Should one desire a controllable damping mechanism similar to the mechanism302, the springs310could be replaced by a linear pushing actuator (not shown) provided inside the shaft304. Should that be the case, a controller (not shown) could control the damping level in some instances, such as a severe braking action or a high speed cornering, for example.

Turning now toFIGS.16and17of the appended drawings, a multi-pivot seat base mechanism400according to a fourth illustrative embodiment will be described. Since the mechanism400is very similar to the mechanisms200and illustrated inFIGS.8to15and discussed hereinabove, only the differences therebetween will be described in detail, for concision purpose.

The difference between the mechanism400and the mechanism200is the locking mechanism402which is completely separated from the damping mechanism.

Indeed, the locking mechanism402of the assembly400is a one-time use locking mechanism that is triggered by a controller (not shown) when sensors (also not shown) detect a collision.

The one-time use locking assembly402includes first and second sprockets404and406respectively fixedly mounted to first and second shafts408and410, and actuator assembly412provided with four (4) pistons414-420each provided with a locking sprocket422-428facing one of the sprockets404and406. As can be seen fromFIG.16, the actuator assembly412is fixedly mounted to the proximate arm430.

When the actuator assembly402receives a signal from a controller (not shown) that a collision or other catastrophic event takes place, the pistons414-420are forcefully extended generally tangentially towards the sprockets404and406and the locking sprockets422-428forcefully contact the sprockets404and406and are jammed between the sprockets404,406and the portions of the proximate arm430adjacent these sprockets. Accordingly, the arms of the multi-pivot seat base mechanism400are definitively prevented from pivoting.

Alternatively, the controller (not shown) of the actuator assembly402can be configured to extend only the pistons facing one of the sprockets404and406. Since these are chain linked, this would be sufficient, in most cases, to prevent further pivoting of the arms.

One skilled in the art will understand that two pistons and locking sprockets are provided for each shaft to ensure that, once the pistons have been deployed, the arms cannot be pivoted in either direction.

One skilled in the art will also understand that the positioning of the sprockets404and406could be different than illustrated as long as they are attached to both shafts408and410. Similarly, the shape of the locking sprockets could be different as long as they are adequately shaped as to become jammed when brought into contact with the sprockets404and406.

Finally, one skilled in the art will understand that the pistons414-420could be replaced by other mechanisms that could perform the same function. As a non-limiting example, a spring loaded cam could replace the pistons.

Turning finally toFIGS.18and19of the appended drawings, a multi-pivot seat base mechanism500according to a fifth illustrative embodiment will be described. Since the mechanism500is very similar to the mechanisms400and illustrated inFIGS.16and17and discussed hereinabove, only the differences therebetween will be described in detail, for concision purpose.

The main difference between the mechanism500and the mechanism400is the fact that the mechanism500includes a permanent locking mechanism502, operating in a similar manner as the locking mechanism402ofFIGS.16and17, and a temporary locking mechanism504.

As mentioned hereinabove, the permanent locking mechanism502is similar to the mechanism402since it relies on sprocket parts506-512that can be brought in forceful contact with sprockets514and516as discussed hereinabove with respect toFIG.16.

FIG.18illustrates the permanent locking mechanism in a non-locking position. However, instead of pistons, a centrally located spring loaded cam518is maintained in such a loaded position by an actuator520(see piston521). When the cam518is in this position, the sprocket parts506-512are maintained away from the sprockets514-516. When a signal is sent to the actuator520, for example when an accident is detected, it retracts its piston521(seeFIG.19), the spring loaded cam518is released and the sprocket parts506-512are forcefully moved tangentially towards and brought into contact with the sprockets514and516to prevent further rotation thereof as can be seen inFIG.19.

This is a permanent locking mechanism since it is believed that there is a risk that parts deformation may occur that would render the mechanism502operable only once, when an accident is detected.

One skilled in the art will understand that the electrically controlled actuator520could be replaced by other actuators, mechanical or otherwise, that would react when an accident is detected.

The temporary locking mechanism504is shown in its locking position inFIG.18and in its non-locking position inFIG.19. The mechanism504is intended to be actionable when a controller (not shown) detects a severe braking action or a high speed cornering, for example. The mechanism504includes a sprocket portion522and an actuator524provided with a piston525. The sprocket portion522faces the sprocket514and the activation of the actuator524brings the sprocket portion522and the sprocket514in contact (seeFIG.18). Since the movement of the sprocket portion522is radial with respect to the sprocket514, it is believed that the risks of parts deformation is minimized and that the temporary locking mechanism504can be used repeatably.

Optionally, the user could be provided with means to activate the temporary locking mechanism504when desired.

One skilled in the art will understand that the locking sprockets422-426and the sprocket elements506-512and522could be replaced by suitable locking elements that can interconnect with the sprockets to prevent pivotal movements of the arms about the shafts.

While the multi-pivot seat base mechanisms shown herein are provided with two pivots, one skilled in the art could design a similar seat base mechanism with more or less than two pivots while following the teachings of the present application.

It will be readily understood by those skilled in the art that the various features of the embodiments discussed hereinabove and shown in the appended drawings could be combined differently depending on the desired requirements of the intended use thereof.

As will be obvious to those skilled in the art, other types of seats could be mounted to the multi-pivot seat base assemblies described herein.

It is to be understood that the multi-pivot seat base assembly is not limited in its application to the details of construction and parts illustrated in the accompanying drawings and described hereinabove. The multi-pivot seat base assembly is capable of other embodiments and of being practiced in various ways. It is also to be understood that the phraseology or terminology used herein is for the purpose of description and not limitation. Hence, although the multi-pivot seat base assembly has been described hereinabove by way of illustrative embodiments thereof, it can be modified, without departing from the spirit, scope and nature thereof.