The present invention relates to a track with a removable stop assembly that is configured to distribute the forces to the track in a manner so that the track can better withstand high impact loading.
A suitable application includes an ambulance cot and loading and unloading system that has a movable track to load an ambulance cot into an emergency vehicle. One of the challenges in an ambulance cot and loading and unloading system is to minimize the footprint of the loading and unloading system in the emergency vehicle so as not to interfere with access by an emergency medical service (EMS) attendant to a patient supported on a loaded ambulance cot while at the same time providing a loading and unloading system that can extend at a sufficient distance outwardly from the vehicle to load the cot into the vehicle. Another challenge is to provide a loading and unloading system that can withstand impact loads, for example, impact loads that occur during a crash.
Accordingly, there is a need to provide a track and stop assembly that can withstand impact loads associated with a crash, which may be employed in an ambulance cot and loading and unloading system.
Accordingly, in one embodiment of a track assembly for mounting a movable object, the track assembly includes a track having a web and at least one flange joined with the web. A stop assembly is mounted to the track at the web by a releasable connection and configured to engage the flange to form a moment restraint for the connection of the stop assembly to the web.
In one aspect, the stop assembly is mechanically coupled to the flange.
In a further aspect, the flange comprises an upper flange, and the track has a lower flange joined with the web, wherein the stop assembly is engaged with the lower flange. For example, the stop assembly may be mechanically coupled to the lower flange.
In another embodiment, the stop assembly frictionally engages the flange.
In another embodiment, the stop assembly includes a bumper and a dead stop member, with the dead stop member mounted to the web through the bumper.
In one aspect, the bumper includes a slot to receive the web. When the stop assembly is mounted to the web, the bumper straddles the web.
In yet other aspects, the bumper includes a base and a bearing member cantilevered from the base. For example, the bearing member may be cantilevered from the base by a bumper arm. In this configuration, the dead stop member straddles the bumper arm when mounted to the track.
In a further aspect, the flange comprises an upper flange, and the track has a lower flange joined with the web, with the dead stop member engaging the upper and lower flanges.
In another aspect, the upper and lower flanges have a fixed spacing, and the dead stop member has a height greater than the fixed spacing of the flanges. The upper and lower flanges are notched to allow the dead stop member to be mounted to the web at the notches.
In another embodiment, a track assembly includes a track and a stop assembly mounted to the track. The stop assembly includes a bumper and a dead stop member. The bumper has a base and a bearing member cantilevered from the base by a bumper arm. The dead stop member straddles the bumper arm when mounted to the track.
In one aspect, the track includes a web and a flange extending from the web, and the stop assembly is mounted to the web.
In a further aspect, the dead stop member is mounted to the web and engages the flange to transfer forces to the flange.
In another embodiment, a track assembly for mounting a movable object includes a track, with the track having a web and at least one flange joined with the web, and a stop assembly. The stop assembly is mounted to the track at the web by a fastener. The stop assembly has a bumper and a dead stop member that engages the web through the bumper and has a bearing surface. The fastener extends through the dead stop member and through the bearing surface to engage the web at an edge distance less than the minimum distance outlined per RISC-ANSI-360-10 can be achieved.
In one aspect, the property is selected from the group consisting of diameter, cross-sectional area, and shear capacity.
In another embodiment, a track assembly for mounting a movable object includes a track and a stop assembly. The track has a web and at least one flange joined with the web, with the web having a terminal edge. The stop assembly is mounted to the track at the web by a fastener, which has a fastener spacing to the terminal edge of the web. The stop assembly is configured to transfer forces from the web to the flange wherein the fastener spacing is less than a minimum edge distance without compromising the web.
A method of installing a stop assembly on a track includes the steps of providing a track with a web and upper and lower flanges joined with the web at a fixed spacing and providing a stop assembly, which includes a bumper and a dead stop member having a height greater than the fixed spacing. The bumper is inserted onto the web of the track, and then the dead stop member is inserted into the bumper to engage the web and the flange.
In one aspect, the method further includes notching at least the lower flange to allow the dead stop member to be inserted into the bumper and into engagement with the web.
In another embodiment, a method of installing a stop assembly on a track includes providing a track with a web and upper and lower flanges joined with the web at a fixed spacing, the web having a terminal edge, and providing a stop assembly with a bumper and a dead stop member having a height greater than the fixed spacing. The method further includes the steps of inserting the dead stop member into the bumper, and sliding the bumper and the dead stop member onto the web of the track from the terminal edge.
In one aspect, the method further includes notching at least the upper and lower flanges to the terminal edge of the web to allow the bumper and the dead stop member to be slid onto the web without interference from the flanges.
In any of the above, the track may be movable and/or a track of an ambulance cot and loading and unloading apparatus.
In one form of the invention, an ambulance cot loading and unloading apparatus includes a base for mounting to an emergency vehicle deck, the track mounted for linear movement along the base, and a trolley, which is configured to engage a cot, mounted for linear movement along the track from a retracted position to an extended position.
In a further embodiment, the trolley includes at least one arm to engage a cot.
Accordingly, the present invention provides a track assembly with a track and a stop assembly that can redistribute loading from the web to the one or more flanges of the track to reduce the stresses in the web. These and other advantages will become more apparent to one of ordinary skill in the art upon reading the following specification and inspecting the accompanying drawings, which follow.
Referring to
As best seen in
Further as will be more fully described below, track 10 is configured to be releasably latched to the base 16 wherein the trolley 14 can translate along track 10, but then can be unlatched so that the trolley 14 and track 10 may move in unison relative to the base 16. Further, with this configuration, track 10 and trolley 14 form a nested, telescoping arrangement to provide greater extension or reach of the trolley from the emergency vehicle.
In the illustrated embodiment, and referring to
Referring to
As noted above, rods 30 are mounted in channels formed on the respective flanges 22c, 24c of each I-beam 22, 24 (
In the illustrated embodiment, track 10 is a unitary track with beams 22, 24 joined and held in spaced registry by an upper plate 32, which may be integrally formed together as an extrusion. For example, in the illustrated embodiment, upper plate 32 forms the upper flanges 22c, 24c of each respective beam 22, 24. Similarly, referring to
To stop the motion of the track 10 along the base 16 and the motion of the trolley 14 along the track 10, each end of track 10 includes one or more stop assemblies 50. In the illustrated embodiment, each beam 22, 24 of track 10 includes a stop assembly at each end thereof, which provide inner and out stops for the base and for the trolley, respectively. As noted above, although described and illustrated in reference to an ambulance cot loading and unloading apparatus and system, it should be understood that the stop assemblies described herein may be used with other types of tracks and/or in other applications. For example, although illustrated and described below in the context of the track being formed by two beams, the stop assemblies described herein may be used and configured for mounting to a track formed from a single beam. Additionally, although track 10 is illustrated and described herein as having a stop assembly for each beam, a single stop assembly is also contemplated that can straddle both beams to provide a single stop assembly at one or both ends of the track. Further, while track 10 is illustrated as moveable track, and namely a transfer track, the track may be a stationary track and, further, have a different cross-section from the I-beam described herein.
In the illustrated embodiment, trolley 14 includes an inverted channel at its underside, which straddles track 10 and is mounted to track 10 by rollers 20, such as wheels, that ride along outer bearing surfaces 22b, 24b, 26b, and 28b in either direction until rollers 20 reach stop assemblies 50 mounted at the ends of track 10. As described in the referenced patents and application, track 10 is movably mounted on base 16 but may be selectively latched to the base 16. When track 10 is unlatched from base 16, track 10 is configured to fully extend in either direction along base 16 until stop assemblies 50 reach rollers 40 (either foot end rollers or head end rollers) on base 16. Thus, when track 10 is fully extended along base 16 (where the head end stop assemblies on track 10 reach the foot end rollers on base 16) and trolley 14 is fully extended along track 10 (where the head end rollers 20 reach the foot end stop assemblies on track 10), trolley 14 extends from track 10 beyond base 16 (see above referenced patents). In this manner, trolley 14 can be extended from the cargo area of the emergency vehicle and, further, such that trolley 14 is outside of the emergency vehicle to allow an emergency cot to be unloaded from or loaded onto the trolley 14 for unlading or loading the cot from or into the emergency vehicle.
On the other hand, when a cot is supported on trolley 14 and loaded into the emergency vehicle, trolley 14 can then be retracted along track 10, and then track 10 and trolley 14 together retracted along base 16 until track 10 and trolley 14 are fully loaded into the emergency vehicle compartment (where head end rollers 20 reach the head end stop assemblies on track 10), and track 10 is fully retracted along base 16 (where the foot end stop assemblies reach the foot end rollers on base 16).
Referring to
Dead stop members 52 are formed from metal, such as a powdered metal, such as powdered stainless steel. Bumper 54 may be formed from a resilient, compressible material, such a rubber, to reduce the noise when the stop is subject to a load. To better distribute the loading that can be applied to stop assemblies 50, whether it is dynamic loading from quickly loading or unloading a cot into or out of the vehicle or dynamic loading that can occur when an emergency vehicle is in a crash, stop assemblies 50 are configured to transfer some of the load off the web 22d, 24d of the beams 22, 24 to one or more of the flanges 22c, 24c of the beams 22, 24 and/or rods 30, as noted above.
As best seen in
As best seen in
Collars 56a (bosses) are sufficiently rigid and robust to transfer the shear load from the dead stop members 52 to webs 22d, 24d of beams 22, 24 to thereby allow the shear forces to by-pass the fasteners 60, which would otherwise be transferred to the webs 22d, 24d via the fasteners 60. Thus, the bosses reduce, if not eliminate, the shear load on the fasteners 60. As would be understood from
Bearing blocks 56 are configured to contact and bear on the respective webs 22d, 24d of the respective beams 22, 24 about the respective fasteners 60 and further contact and bear on the respective webs above and below the respective fasteners (e.g. above and below the footprint of a standard washer would contact) and also with a non-circular interface. As best understood from
Optionally, the bearing surface 57 of each bearing block 56 may have a high friction surface, such as a knurled surface, over at least a portion of its surface area to increase the friction between bearing blocks 56 and webs 22d, 24d to better distribute the shear forces from dead stop members 52 to the respective webs 22d, 24d. Alternately or in addition, the outer surface of collars 56a may have a high friction surface, such as a knurled surface, to increase the friction between bearing blocks 56 and webs 22d, 24d, again to better distribute the shear forces from dead stop members 52 to the respective webs 22d, 24d.
In the illustrated embodiment, bearing blocks 56 have a generally cylindrical shape body 64 with enlarged tapered lobes 66, which are flat or planar on their outer surfaces 66a, but curved on their inner surfaces 66b to form generally P-shaped bearing blocks that face each other. In other words, bearing blocks 56 are mirror images of each other about a plane 56c that bifurcates the two bearing blocks 56. As best seen in
Lobes 66 extend along an axis 66c that is spaced from and parallel to central axes 56b of collars 56a and are sufficient in height to extend and bear along the downwardly and upwardly facing surfaces of the respective flanges 22c, 24c at their juncture with the web 22d, 24d of the respective beam 22 or 24. In this manner, outer surfaces 66a of lobes 66 each form a bearing surface to increase the torsional resistance of dead stop members 52 (and hence stop assemblies 50) and redistribute some of the torsional load from the respective web 22d, 24d to the respective flange or flanges 22c, 24c of beams 22, 24. For example, lobes 66 may extend in a range of 1.0 cm-2.0 cm, or about 1.5 cm, beyond the central axes 56b of cylindrical shaped bodies 64 where the diameter of the cylindrical shaped bodies 64 is about 1.0 cm-2.0 cm or about 1.5 cm.
Alternately or stated another way, lobes 66 may form a bearing surface of at least a length (in the direction of force) equal to the diameter of the cylindrical shaped bodies 64, optionally about 110% of the diameter of the cylindrical shaped bodies 64, optionally about 120% of the diameter of the cylindrical shaped bodies 64, or optionally about 130% of the diameter of the cylindrical shaped bodies 64. Further, in the illustrated embodiment, the bearing surface (outer surfaces 66a) of each lobe 66 of each dead stop member 52 may be offset from the central axes 56b of collars 56a so that the centroid of the bearing surface is offset from the central axes 56b of collars 56a to increase the torsional resistance provided by the respective bearing surface.
In one embodiment, the area of the bearing surface 57 (
Dead stop members 52 also include a body 70 on which bearing blocks 56 are commonly formed on or mounted. As best viewed in
Thus, when dead stop members 52 are mounted to the respective beams 22, 24 by fasteners 60 (
By reducing the stress on the webs of the beams 22, 24, the stop assemblies 50 may be located closer to the end of the beam without compromising the web of the beam, thus increasing the range of motion of track 10 along base while minimizing the footprint of the loading and unloading apparatus. For example, the edge distance for fasteners 60 with a diameter of about 3/16 inches, the edge distance (distance from the center of openings 62 to edge of webs 22d, 24d) may be reduced to ½ inches, optionally to about ⅓ inches, and optionally, about ¼ inches while still maintaining the integrity of the web (22d, 24d).
Although all four dead stop members 52 are described and shown as engaging the respective upper and lower flanges of each beam 22, 24, it should be understood that each stop assembly 50 may have a single projection 72 to engage a single flange of a beam. Alternately, each stop assembly 50 may have two projections 72 to engage two of the flanges (upper or lower or inner or outer) of a beam. Similarly, each stop assembly 50 may have three projections 72 to engage three flanges of the beam flanges. In addition, as noted above, the dead stop members 52 may be engaged with, and optionally coupled, to one or more rods 30. Thus, the dead stop members 52 may engage one or more flanges (and/or the webs) and/or one or more rods to redistribute the stresses in the web of the respective beam.
Further, although illustrated as having the stop assemblies 50 mounted using fasteners 60 that extend through the collars 56a of one dead stop member 52, through the web (22d or 24d), and then through the respective collars 56a of the opposed dead stop member 52, additional fasteners 74 may be used to mount the respective stop assemblies to the beams. For example, referring to
As noted, to reduce the noise upon impact with stop assemblies 50, stop assemblies 50 may include bumpers 54. Referring to
To provide some limited lateral restraint of the respective rollers (20 or 40) when engaged with stop assemblies 50, each bearing member 82 may have a profiled bumper contact bearing surface 82a that has a raised central ridge 82b facing the direction of the respective rollers 20, 40, which extends into the respective roller (which have annular recesses at their outer perimeter for engaging rods 30) and thereby can provide some lateral support to the rollers 20, 40 when the rollers 20, 40 engage the stop assemblies.
Arms 84, bearing members 82, and base 80 are shaped to receive in close registry (between base 80 and members 82) a pair of dead stop members 52. Further, each arm 84 and bearing member 82 is shaped so that the bearing blocks 56 of dead stop members 52 straddle the arms 84 and fill the space between members 82 and base 80. Additionally, base 80 is dimensioned so that it has the same footprint as the bearing blocks 56 and may also have upwardly projecting flanges 80a at its opposed sides that engage angled sides (
In addition, as best seen in
In the illustrated embodiment, the track 10 is modified so that the bumpers 54 may be mounted on the beams without the dead stop members 52, but thereafter have the dead stop members 52 mounted to the respective webs of the beams over bumpers 54. Thus, when bumpers 54 are mounted on the respective webs 22d, 24d of beams 22, 24 they form inner and outer dead stop mounting locations. To facilitate mounting the dead stop members 52 after bumpers 54 have been mounted, and as will be more fully described below, beams 22, 24 may have portions of their flanges notched to further facilitate installation of the dead stop members 52.
As best seen in
Optionally, each bumper 54 includes a base plate 54a, for example, formed from a plastic material, which forms the outer surface of the stop assembly 50 when mounted to the respective beam.
As best seen in
As noted above, in the illustrated embodiment, track 10 is slidably mounted on a base 16. Because the sliding arrangement, one end of the track 10 may have the stop assemblies mounted to one of its ends, while the other stop assemblies must be mounted after the track is already fed on the base 16. For example, the foot end of track 10 can be mounted to the base with the foot end of the track extended beyond the base, which can allow fairly easy access for mounting the stop assemblies 50 to the foot ends of beams 22, 24. However, when mounted to base 16, the head end of track 10 is always positioned adjacent base 16, regardless of the position of track 10 along base 16. To facilitate installation of stop assemblies 50 onto the head end of beams 22, 24, the inner lower portions of flanges 22c, 24c may have extended notches or slots 22s, 24s that extend from adjacent notches 22n, 24n to the end (e.g. terminal edges) of the respective beam 22, 24. In this manner, the dead stop members 52 can be mounted on the inside dead stop member position in bumper 54 before installation and then slid onto the respective web 22d, 24d from the terminal edge of the web. The remaining stop assemblies may be mounted by first sliding the bumpers 54 on to the webs 22d, 24d followed by the insertion of the dead stop members 52 into the spaces between members 82 and the base 80 of the respective bumper.
As would be understood, the integration of the stop assemblies into the beam and, further, with the flanges of the beams helps better redistribute the forces applied to dead stop members. It should be understood that the integration can be at any location along the beam and/or with the rods as noted, and further, as noted, may include a single point of integration (e.g., one lobe of the dead stop member or one rod) or more than one, and may be a combination of any of the load transferring mechanisms described above.
Although several forms of the invention have been disclosed for illustrative purposes, it will be recognized that variations or modifications of the disclosed apparatus, including the rearrangement of parts, lie within the scope of the present invention. Further, as noted, the track and stop assembly described herein may be used in a variety of different applications and may be used with stationary tracks or moving tracks, such as the nested arrangement described herein.
This application claims the benefit of U.S. Prov. Pat. Appl. Ser. No. 62/781,195 (P-618) filed Dec. 18, 2018, by inventors Caitlin Marie Braun et al. and entitled TRACK ASSEMBLY and relates to U.S. patent Ser. No. 15/253,140 (P-269E), entitled AMBULANCE COT AND LOADING AND UNLOADING SYSTEM and filed Aug. 31, 2016, which is a continuation of U.S. patent Ser. No. 14/630,681 (P-269D), entitled AMBULANCE COT AND LOADING AND UNLOADING SYSTEM and filed Feb. 25, 2014, by Applicants Clifford Lambarth et al., which is a divisional application of U.S. co-pending application Ser. No. 13/888,654 (P-269C), entitled AMBULANCE COT AND LOADING AND UNLOADING SYSTEM and filed May 7, 2013, now U.S. Pat. No. 8,973,963, issued on Mar. 10, 2015, by Applicants Clifford Lambarth, et al., which is a divisional application and claims priority to application Ser. No. 12/886,987 (P-269B), entitled AMBULANCE COT AND LOADING AND UNLOADING SYSTEM and filed Sep. 21, 2010, now U.S. Pat. No. 8,439,416, issued on May 14, 2013, by Applicants Clifford Lambarth, et al., which claims the benefit of provisional application Ser. No. 61/248,374 (P-269), entitled AMBULANCE COT AND LOADING AND UNLOADING SYSTEM and filed Oct. 2, 2009, and provisional application Ser. No. 61/248,654 (P-269A), entitled AMBULANCE COT AND LOADING AND UNLOADING SYSTEM and filed Oct. 5, 2009, which are incorporated herein in their entireties and commonly assigned to Stryker Corporation of Kalamazoo, Mich.
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Number | Date | Country | |
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62781195 | Dec 2018 | US |