Patent Publication Number: US-2022233368-A1

Title: Patient Transport Apparatus With Steer Lock Assembly

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The subject patent application is a Continuation of U.S. patent application Ser. No. 16/690,232, filed on Nov. 21, 2019, which claims priority to and all the benefits of U.S. Provisional Patent Application No. 62/770,316, filed on Nov. 21, 2018, the disclosures of each of which are hereby incorporated by reference in their entirety. 
    
    
     BACKGROUND 
     Patient transport apparatuses facilitate care of patients in a health care setting. Patient transport apparatuses comprise, for example, hospital beds, stretchers, cots, wheelchairs, and chairs. A conventional patient transport apparatus comprises a support structure having a base, a frame, and a patient support surface upon which the patient is supported. The patient transport apparatus may also comprise caster assemblies with caster wheels to facilitate movement of the patient transport apparatus. Often, one or more of the caster assemblies include a steer lock assembly to facilitate steering of the patient transport apparatus during movement. Sometimes, engagement of the steer lock assembly may be difficult. 
     A patient transport apparatus with steer lock assembly designed to overcome one or more of the aforementioned challenges is desired. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a patient transport apparatus with a plurality of caster assemblies. 
         FIG. 2A  is a cross-sectional view illustrating one of the caster assemblies in a neutral mode in which the steer lock assembly is in a non-steer locked state and the brake assembly is in an unbraked state. 
         FIG. 2B  is a cross-sectional view illustrating the caster assembly of  FIG. 2A  in a steer locked mode in which the steer lock assembly is in a steer locked state and the brake assembly is in the unbraked state. 
         FIG. 2C  is a cross-sectional view illustrating the caster assembly of  FIG. 2A  in a braked mode in which the steer lock assembly is in the non-steer locked state and the brake assembly is in the braked state. 
         FIG. 3  is a perspective view of a lock receiver and a pin of the steer lock assembly. 
         FIG. 4A  is an illustration of the steer lock assembly with a steer lock pin partially engaged with the lock receiver. 
         FIG. 4B  is an illustration of the steer lock assembly with the steer lock pin fully engaged with the lock receiver. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     Referring to  FIG. 1 , a patient transport apparatus  30  is shown for supporting a patient in a health care setting. The patient transport apparatus  30  may comprise a hospital bed, stretcher, cot, wheelchair, chair, or similar apparatus utilized in the care of a patient. In the embodiment shown in  FIG. 1 , the patient transport apparatus  30  comprises a cot that is utilized to transport patients, such as from an emergency site to an emergency vehicle (e.g., an ambulance). 
     The patient transport apparatus  30  shown in  FIG. 1  comprises a support structure  32  that provides support for the patient. The support structure  32  comprises a base  34  and a support frame  36 . The base  34  comprises a base frame  35 . The support frame  36  is spaced above the base frame  35 . The support structure  32  also comprises a patient support deck  38  disposed on the support frame  36 . The patient support deck  38  comprises several sections, some of which are capable of articulating relative to the support frame  36 , such as a back section  41 , a seat section  43 , a leg section  45 , and a foot section  47 . The patient support deck  38  provides a patient support surface  42  upon which the patient is supported. 
     The base  34 , support frame  36 , patient support deck  38 , and patient support surface  42  each have a head end and a foot end corresponding to designated placement of the patient&#39;s head and feet on the patient transport apparatus  30 . The support frame  36  comprises a longitudinal axis L along its length from the head end to the foot end. The support frame  36  also comprises a vertical axis V arranged crosswise (e.g., perpendicularly) to the longitudinal axis L along which the support frame  36  is lifted and lowered relative to the base  34 . The construction of the support structure  32  may take on any known or conventional design, and is not limited to that specifically set forth above. In addition, a mattress (not shown) may be provided in certain embodiments, such that the patient rests directly on a patient support surface of the mattress while also being supported by the patient support surface  42 . 
     Side rails  44 ,  46  are coupled to the support frame  36  and thereby supported by the base  34 . A right side rail  44  is positioned at a right side of the support frame  36 . A left side rail  46  is positioned at a left side of the support frame  36  (with the left side defined relative to a person positioned at the head end of the support frame  36  and facing the support frame  36 ). If the patient transport apparatus  30  is a hospital bed there may be more side rails. The side rails  44 ,  46  may be fixed to the support frame  36  or may be movable between a raised position in which they block ingress and egress into and out of the patient transport apparatus  30 , one or more intermediate positions, and a lowered position in which they are not an obstacle to such ingress and egress. In still other configurations, the patient transport apparatus  30  may not include any side rails. 
     A pair of handle assemblies  57  may also be coupled to the support frame  36  at a position near the head end of the bed that may be raised for use in transporting the patient transport apparatus  30 , particularly when the apparatus  30  is in the lowered position. The handle assemblies  57  may also be lowered to a stowed position when not in use. 
     Wheels  58  are coupled to the base  34  to facilitate transport over floor surfaces. The wheels  58  are arranged in each of four quadrants of the base  34  adjacent to corners of the base frame  35 . In the embodiment shown, the wheels  58  are caster wheels able to rotate and swivel relative to the support structure  32  during transport. Each of the wheels  58  forms part of a caster assembly  60 . Each caster assembly  60  is mounted to the base  34 . It should be understood that various configurations of the caster assemblies  60  are contemplated. In addition, in some embodiments, the wheels  58  are not caster wheels and may be non-steerable, steerable, non-powered, powered, or combinations thereof. Additional wheels are also contemplated. For example, the patient transport apparatus  30  may comprise four non-powered, non-steerable wheels, along with one or more powered wheels. 
     In other embodiments, one or more auxiliary wheels (powered or non-powered), which are movable between stowed positions and deployed positions, may be coupled to the support structure  32 . In some cases, when these auxiliary wheels are located between caster assemblies  60  and contact the floor surface in the deployed position, they cause two of the caster assemblies  60  to be lifted off the floor surface thereby shortening a wheel base of the patient transport apparatus  30 . A fifth wheel may also be arranged substantially in a center of the base  34 . 
     A pair of loading wheels  64  may be coupled to the support frame  36  to assist with loading of the patient transport apparatus  30  into the emergency vehicle and unloading of the patient transport apparatus  30  out of the emergency vehicle. In the embodiment shown, the loading wheels  64  are arranged nearer the head end than the foot end, but the loading wheels  64  may be placed in other locations to facilitate loading and/or unloading of the patient transport apparatus  30  into and out of the emergency vehicle, or for other purposes. 
     In one embodiment, each of the wheels  58  comprises a wheel hub  59  and an outer wheel portion  61  surrounding the wheel hub  59 . The outer wheel portion  61  has an outer end surface  63  (see  FIG. 2A ), at least part of which is arranged to contact the floor surface F when rolling along the floor surface F. 
     Referring to  FIGS. 1, 2A-2C and 4A-4B , the caster assembly  60  further comprises a wheel support  72  and a caster stem  74  (see  FIGS. 2A-2C ). The wheel support  72  is arranged to support the wheel  58  for rotation about a rotational axis R (see  FIG. 1 ) and for swiveling about a swivel axis S, with the swivel axis S generally normal to the floor surface F and to the rotational axis R. The wheel support  72  may comprise various types of support structures. In the embodiment shown, the wheel support  72  comprises a fork  78  and a neck  76  fixed to the fork  78 . The wheel  58  is secured to the fork  78  via an axle  80  (see  FIG. 1 ) passing through the wheel hub  59 . The axle  80  is attached to the fork  78 . The wheel  58  is arranged to rotate about the rotational axis R defined by the axle  80 . The wheel  58  may rotate relative to the axle  80  via a wheel bearing (not shown) or, in alternative embodiments, the wheel  58  may be fixed to the axle  80  to rotate with the axle  80  relative to the fork  78 . Other configurations that allow the wheel  58  to rotate about the rotational axis R and roll along the floor surface F are contemplated. 
     As best shown in  FIGS. 2A-2C , the stem  74  is fixed to the base  34  of the patient transport apparatus  30  such that the stem  74  is unable to swivel about the swivel axis S or otherwise move relative to the base frame  35  and the base  34 . The stem  74  is hollow, and includes an interior surface  74 A defining an interior space  75 . The stem  74  can also define the swivel axis S (see  FIGS. 1 and 2A-2C ). 
     The neck  76  is coupled to the stem  74  via a bearing  82  so that the neck  76  is able to swivel relative to the stem  74  about the swivel axis S when the wheel  58  is changing orientation. An outer surface  77  of the neck  76  may generally define an outer tangential plane  81  that extends between the floor F and the base  34 . Owing to the fixed connection between the neck  76  and the fork  78 , the fork  78 , neck  76  and wheel  58  are also able to swivel relative to the stem  74  about the swivel axis S. Fasteners, press-fit connections, welding, and/or other structures may be present to secure the stem  74  to the base  34 , as is conventional in the art. The stem  74  may also be referred to as a kingpin, spindle, post, or the like. Additionally, a collar, sleeve, flange, or other suitable structure (referred to hereinafter as flange  71 ) may be fixed to the stem  74  (or may be integrally formed with the stem  74 ) and located between the stem  74  and the base  34  to further support the stem  74 . 
     In certain embodiments, the stem  74 , flange  71  and base  34  may be separate components that are fixed together or may be a single integrally formed component. In still further embodiments, the stem  74  and flange  71  may be integrally formed and separate from, but affixed to, the base  34 , while in even further embodiments the flange  71  and base  34  are integrally formed and separate from, and affixed to, the stem  74 . As illustrated in  FIGS. 2A-2C , the flange  71  and the stem  74  are formed as a single piece, and the flange  71  is positioned adjacent to, and fixed to, a portion of the base  34 . 
     In the embodiment shown, the neck  76  and fork  78  form one type of swivel assembly that provides a swivel joint for the caster assembly  60 . Other swivel assemblies that allow the wheel  58  to swivel relative to the base  34  are also possible. 
     In certain embodiments, the one or more caster assemblies  60  include a steer lock assembly  150 , which is respectively configured to facilitate preventing the caster assembly  60 , and more specifically the wheel  58  of the caster assembly  60 , from swiveling about the swivel axis S, with the steer lock assembly  150  being operable between a steer locked state and a non-steer locked state. In certain of these embodiments, one or more of the caster assemblies  60  also includes a brake assembly  100 , which is respectively configured to facilitate braking of the wheel  58  about the rotational axis R, with the brake assembly  100  being operable between a braked state and an unbraked state. 
       FIGS. 2A-2C  show these states of one of the steer lock assemblies  150  and brake assemblies  100 , and these combinations of various states create modes of the patient transport apparatus  30 . More specifically,  FIG. 2A  shows a neutral mode in which the steer lock assembly  150  is in the non-steer locked state and in which the brake assembly  100  is in an unbraked state.  FIG. 2B  shows a steer locked mode in which the steer lock assembly  150  is in the steer locked state and in which the brake assembly  100  is in an unbraked state.  FIG. 2C  shows a braked mode in which the steer lock assembly  150  is in the non-steer locked state and in which the brake assembly  100  is in a braked state. 
     The non-steer locked state, as shown in  FIGS. 2A and 2C , refers to a positioning of the steer lock assembly  150  relative to the wheel  58  wherein the steer lock assembly  150  does not impede the rotation of the wheel  58  about its swivel axis S. Conversely, the steer locked state, as shown in  FIG. 2B , places the steer lock assembly  150  in a position relative to the wheel  58  that impedes the rotation of the wheel  58  about swivel axis S to assist a user in steering the patient transport apparatus  30  along the floor surface F. The braked state, as shown in  FIG. 2C , refers to a positioning of the brake assembly  100  relative to its wheel  58  wherein a brake pad  102  of the brake assembly  100  is engaged with the outer end surface  63  of the wheel  58  so as to prevent the rotation of the wheel  58  about its rotational axis R. Conversely, the unbraked state, as shown in  FIGS. 2A and 2B , refers to a positioning of the brake assembly  100  relative to its wheel  58  wherein the brake pad  102  of the brake assembly  100  is not engaged with the outer end surface  63  of the wheel  58 , thereby allowing free rotation of the wheel  58  about its rotational axis R. 
     In the embodiments shown, the one or more caster assemblies  60  also includes an actuator  200  to change the mode of operation of the patient transport apparatus  30 . More specifically, the actuator  200  is operable to place the steer lock assembly  150  in a non-steer locked state or a steer locked state and is also operable to place the brake assembly  100  in a braked stated or an unbraked state. 
     In certain embodiments, including the embodiments shown in the Figures provided herein, the actuator  200  is in the form of a foot pedal  210 . The foot pedal  210  includes a body having a profile that defines adjacent first, second and third notched regions  220 ,  222 ,  224  that are shaped to be separately respectively engageable with the brake assembly  100  in either the braked state or the unbraked state, as will be described in further detail below. The body also includes an additional steer lock engaging region  226  distinct from the adjacent first, second and third notched regions  220 ,  222 ,  224  that is shaped to be engageable with the steer lock assembly  150  in the steer locked state. Still further, the foot pedal  210  includes an upper foot engagement region  228  and a lower foot engagement region  229 , distinct from the adjacent first, second and third notched regions  220 ,  222 ,  224  and the steer lock engaging region  226 , that are configured to be engaged by the foot of a caregiver to apply a force to the foot pedal  210 . 
     The foot pedal  210  is mounted to the base frame  35 , shown here as mounted to the base  34 , via an axle pin  230  passing through an opening. The axle pin  230  is attached to the base frame  35  or base  34 . The foot pedal  210  is arranged to rotate about a rotational axis R 1  (in either a counterclockwise direction R 1 ′ or clockwise direction R 1 ″ as shown in  FIGS. 2B and 2C ) defined by the axle pin  230  upon force F 3  being applied to the upper foot engagement region  228 , or force F 1  being applied to the lower foot engagement region  229 , so as to move the respective one of the caster assemblies  60  between the neutral mode, the steer locked mode and the braked mode, as will be further explained below. The foot pedal  210  may optionally rotate relative to the axle pin  230  about rotational axis R 1  via a foot pedal bearing (not shown). 
     The brake pad  102  has an engaging surface  104  shaped to engage the outer end surface  63  of the wheel  58  in the braked position (see  FIG. 2C ). The brake pad  102  is coupled to a bottom end  112  of a plunger  110 , and more typically is secured to the bottom end  112  of the plunger  110  via a pin  129 . 
     The plunger  110  includes a middle portion  114  extending between a bottom end  112  and a top end  116 . The middle portion  114  of the plunger  110  is at least partially contained within the interior space  75  of the stem  74 , while the top end  116  is positioned within a first cavity  37  defined within the base  34 , the flange  71 , or a combination of the flange  71  and the base  34  (see  FIGS. 2A-2C ). 
     The top end  116  include a shoulder region  118  and also includes an engaging outer surface  120  that is engageable with the foot pedal  210  to move the brake assembly  100  of the associated caster assembly  60  between the braked state and the unbraked state, as will be described further below. 
     The brake assembly  100  also includes a brake biasing device, here a ring shaped spring  130 , positioned within the first cavity  37  that is engaged between the lower outer surface  119  of the shoulder region  118  and a top shelf surface  113  of the stem  74  extending transverse to the interior surface  74 A. The spring  130  normally biases the plunger  110  such that the brake pad  102  is disengaged from the outer surface  63  of the wheel  58 , corresponding to the unbraked state (see  FIGS. 2A and 2B ). 
     The engagement of the brake pad  102  to the outer end surface  63  of the wheel  58 , and conversely the disengagement of the brake pad  102  from the outer end surface  63  of the wheel  58  is accomplished when the user applies force to one of the upper or lower foot engagement regions  228 ,  229  to rotate around the rotational axis R 1  in a clockwise or counterclockwise direction so that a desired one of the first, second or third notched regions  220 ,  222 ,  224  is engaged with the engaging outer surface  120  of the plunger  110 . 
     Specifically, as shown in  FIG. 2C , when the user applies force F 3  to move the foot pedal  210  (i.e., rotate the foot pedal  210  about the rotational axis R 1  in the clockwise direction R 1 ″) such that the first notched region  220  is positioned adjacent to the engaging outer surface  120  of the plunger  110 , a downward force F 4  is applied from foot pedal  210  on the engaging outer surface  120  of the shoulder region  118  of the plunger  110 . This force F 4  moves the plunger  110  such that the lower outer surface  119  of the shoulder region  118  of the plunger  110  exerts compressive force on the annular spring  130  between the top shelf surface  113  of the stem  74  and the lower outer surface  119 . The movement of the plunger  110  within the cavity  37  downward towards the wheel  58  also causes the movement of the coupled brake pad  102  downward to a position wherein it is engaged with the outer surface  63  of the wheel  58  and exerts a force F 5  on the outer surface  63  (corresponding to the force F 4 ), thereby preventing the wheel  58  from rotating freely about rotational axis R in a clockwise or counterclockwise direction upon force being applied to the patient transport device  30  to move the patient transport apparatus  30  along the floor surface F. 
     Conversely, referring to  FIG. 2B , when the user applies force F 1  to move the foot pedal  210  (i.e., rotate the foot pedal  210  about the rotational axis R 1  in the counterclockwise direction R 1 ′) from the first notched region  220  to rotate the foot pedal such that the second notched region  222 , or third notched region  224  is positioned adjacent to the engaging outer surface  120  of the plunger  110 , the force F 4  is relieved, and the biasing force of the annular spring  130  moves the plunger  110  upward within the cavity  37  such that the braked pad  102  is disengaged from the outer end surface  63  of the wheel  58 , wherein the wheel  58  is free to rotate about rotational axis R in a clockwise or counterclockwise direction. 
     As best illustrated in  FIGS. 2A-2C and 3 , the steer lock assembly  150  comprises a lock receiver  83  that extends outwardly in a direction away from the swivel axis S and generally parallel to the floor surface F. In certain embodiments, such as shown in  FIGS. 2A-2C , the lock receiver  83  may be a part of, or integrally formed with, the neck  76 . Alternatively, the lock receiver  83  may be coupled to and extend outwardly away from an outer surface  77  of the neck  76 . Regardless of whether the lock receivers  83  are integrally formed with the neck  76  or a separate structure coupled to the neck  76 , the lock receivers  83  swivel about the swivel axis S in conjunction with the neck  76 , fork  78  and wheel  58 . 
     Each of the lock receivers  83  includes an inner surface  84  defining one or more openings  85 , such as one or more notches. The openings  85  are respectively sized and shaped to receive a locking element, such as a steer lock pin  160  of the steer lock assembly  150  so as to prevent the rotation of the neck  76 , fork  78  and wheel  58  about the swivel axis S, when the steer lock assembly  150  is in the steer locked mode (as shown and described below in conjunction with  FIG. 2B ). 
     The trailing position of the wheels  58 , as is well understood by one of ordinary skill, refers to the positioning of the wheels  58  of the caster assemblies  60  such that the wheel planar surfaces WS of the side surfaces  65  are parallel to the longitudinal axis L and typically occurs when the patient transport apparatus  30  is being, or has been, pushed or pulled in a direction along the longitudinal axis L by a user for a sufficient distance wherein the caster assemblies  60  have rotated about the swivel axis S, with the wheels  58  offset from the swivel axis S in a position opposite the direction of force along the longitudinal axis L. Thus, for example, as shown in  FIG. 1 , the wheels  58  are positioned in a leading position relative to the head end of the patient transport apparatus  30 , and in a trailing position relative to the foot end of the patient transport apparatus  30 , which is generally indicative wherein the user has last applied force in a direction towards the foot end of the patient transport apparatus  30 . 
     As best shown in  FIGS. 4A and 4B , the steer lock assembly  150  includes a plunger, such as hollow sleeve member  151 . The hollow sleeve member  151  includes a lower portion  152 , an upper portion  154 , and a ledge portion  153  extending transverse to, and between, the lower portion  152  and the upper portion  154 . The ledge portion  153  includes an outer ledge portion  155  and an inner ledge portion  156 . The outer ledge portion  155  includes an upper exterior ledge surface  157 . The inner ledge portion  156  includes an upper interior ledge surface  158  and an opposing lower interior ledge surface  159 . 
     The upper portion  154  of the hollow sleeve member  151  includes a terminal upper surface  154   a  that is shaped to be engageable with the foot pedal  210  to position the steer lock assembly  150  in the steer locked state, as will be described further below. 
     The steer lock pin  160  has a middle pin portion  164  extending between an upper pin portion  162  and lower pin portion  166 . The middle pin portion  164  includes a stepped region  167  having an upper step surface  168 . A washer  170  is seated on an upper surface  163  of the upper pin portion  162 . 
     The steer lock assembly  150  further comprises a fastening device, shown in  FIGS. 2A-2C, 4A and 4B  as a screw  175 , that is secured to the upper pin portion  162  of the steer lock pin  160  such that the washer  170  is positioned between the head  177  of the screw  175  and the upper pin portion  162  of the steer lock pin  160 . The washer  170  acts to limit movement of the steer lock pin  160  relative to the hollow sleeve member  151  by virtue of being sized larger than an opening in the inner ledge portion  156  through which the upper pin portion  162  moves. It also allows the hollow sleeve member  151  to withdraw the steer lock pin  160  from the opening  85  by virtue of being engaged by the inner ledge portion  156  when the hollow sleeve member  151  returns to the non-steer locked state as described below. 
     The steer lock assembly also includes two biasing devices, shown best in  FIGS. 4A and 4B  as a first steer lock spring  180  and a second steer lock spring  185 , respectively, which may be compression springs or other suitable springs. The first steer lock spring  180  is positioned between the upper step surface  168  and the lower interior ledge surface  159 , while the second steer lock spring  185  is positioned between an upper shelf surface  73  of the flange  71  and a lower portion surface  152   a  of the lower portion  152  of the hollow sleeve member  151 . 
     When the caster assembly  60  is in the steer locked state, corresponding to the steer locked mode of the patient transport apparatus  30  as illustrated in  FIGS. 2B and 4B , the steer lock pin  160  is axially aligned with one of the openings  85 , or notches, of the lock receiver  83 . This occurs when the wheel  58  of the associated caster assembly  60  is positioned in the leading or trailing position relative to the head end of the patient transport apparatus  30 . 
     To place the caster assembly  60  in the steer locked state, the steer lock engaging region  226  of the foot pedal  210  is brought into contact with the terminal upper surface  154   a  and a downward force F 2  is applied on the hollow sleeve member  151  to move it towards the lock receiver  83 . In so doing, referring to  FIG. 4A , the lower portion surface  152   a  moves towards the upper shelf surface  73  of the flange  71 , compressing the second steer lock spring  185 . In addition, the movement of the hollow sleeve member  151  also moves the lower interior ledge surface  159  towards the upper step surface  168  of the middle pin portion  164 , thereby compressing the first steer lock spring  180 . The compression of the first steer lock spring  180  applies a downward force on the steer lock pin  160  sufficient to move the lower pin portion  166  toward the lock receiver  83 .  FIGS. 3 and 4A  illustrate the situation is which the wheel  58  is not yet in a trailing orientation. In this case, the first steer lock spring  180  applies a biasing force against the steer lock pin  160  so that the steer lock pin  160  is biased against an upper surface of the lock receiver  83 . However, the steer lock pin  160  is not yet axially aligned with the opening  85 . Once the wheel  58  is oriented in the trailing orientation, then the steer lock pin  160  becomes axially aligned with the opening  85  and is biased into the opening  85 , owing to the biasing force from the first steer lock spring  180 , as shown in  FIG. 4B . Once the steer lock pin  160  is in the opening, the lock receiver  83 , the neck  76  and the wheel  58  are limited or prevented from swiveling about the swivel axis S. 
     Conversely, when the patient transport apparatus  30  is in the non-steer locked state, corresponding to either the neutral mode illustrated in  FIG. 2A  or the braked mode illustrated in  FIG. 2C , the steer lock engaging region  226  of the foot pedal  210  is not in contact with the terminal upper surface  54  and is therefore not applying a downward force F 2  on the hollow sleeve member  151  to move it towards the lock receiver  83 . As such, the compression on the steer lock springs  180 ,  185  associated with the downward force F 2  has been relieved and is absent, and the biasing force of the second steer lock spring  185  moves the hollow sleeve member  151  in a direction away from the lock receiver  83  (compare  FIG. 2A  to the positioning in  FIGS. 2B and 4B ). The biasing force of the second steer lock spring  185  and associated movement of the hollow sleeve member  151  also moves the steer lock pin  160  away from the locking receiver  83  owing to engagement of the washer  170  by the inner ledge portion  156 . This movement is sufficient to move the lower pin portion  166  such that it is no longer contained or otherwise received within the opening  85  of the lock receiver  83 , thereby allowing the lock receiver  83 , the neck  76  and the wheel  58  to swivel about the swivel axis S when a user moves the patient transport apparatus  30 . 
     When a user wishes to move the steer lock assembly  150  from the non-steer locked state to the steer locked state, or from the steer locked state to the non-steer locked state, the user either applies upward force F 1  on the lower foot engagement region  229  (see  FIG. 2B ) to rotate the foot pedal  210  about the rotational axis R 1  in a first rotational direction (shown for illustrative purposes as counterclockwise rotational direction R 1 ′ in  FIG. 2B ) or applies a downward force F 3  on the upper foot engagement region  228  (see  FIG. 2C ) to rotate the foot pedal  210  about the rotational axis R 1  in a second rotational direction (shown for illustrative purposes as clockwise rotational direction R 1 ″ in  FIG. 2C ), depending upon the initial positioning of the foot pedal  210 . Additionally or alternatively, the user may apply a force on an opposing end of the foot pedal  210  to place the steer lock assembly  150  in the steer locked state. Any suitable actuation by the user may be employed. Notably, in the embodiment shown in the drawings, actuation is hands-free, which allows the user to maintain control of the patient transport apparatus  30  with their hands, such as by grasping the handle assemblies  57 , while changing the mode the patient transport apparatus  30 . 
     While the embodiments described above illustrate a caster assembly  60  that includes both a brake assembly  100  and a steer lock assembly  150 , further embodiments may be included where a respective one of the caster assemblies  60  includes only a brake assembly  100 , or a steer lock assembly  150 . Still further, other embodiments may include a caster assembly  60  that includes neither a brake assembly  100  nor a steer lock assembly  150 , with the caveat that at least one of the other caster assemblies  60  includes a steer lock assembly  150 . 
     In certain embodiments, the patient transport apparatus  30  includes at least two of the caster assemblies  60  with a respective steer lock assembly  150 . In certain of these embodiments, where two caster assemblies  60  include a respective steer lock assembly  150 , the two caster assemblies are both located at the head end, or the foot end. 
     Several embodiments have been discussed in the foregoing description. However, the embodiments discussed herein are not intended to be exhaustive or limit the invention to any particular form. The terminology which has been used is intended to be in the nature of words of description rather than of limitation. Many modifications and variations are possible in light of the above teachings and the invention may be practiced otherwise than as specifically described.