with continued reference to the drawings , the emergency vehicle 10 of the present invention is shown as being in the form of an ambulance having an elongated body 11 which is unitized construction with a tubular roll cage 13 as will be discussed in greater detail hereinafter . the chassis includes a front frame section 14 and a continuous rear frame 15 . the suspended frame portion 15 is shown as providing the support for the floor 16 of a patient compartment 17 . the front frame 14 of the chassis is supported by two pairs of wheel assemblies 18 and 19 . each of the wheel assemblies 18 and 19 includes an axle 20 and 21 , respectively , which are mounted to the frame by shock absorbing tag air bag assemblies 22 and 23 . unlike conventional emergency type vehicles , the vehicle of the present invention is designed to have tandem front end steering and therefore does include steerable axles 20 and 21 . the specifics of the steering mechanism are not shown . the purpose for incorporating tandem front end steering is to allow shocks to be absorbed by each of the separate axles so that as the front axle 20 reacts to a road obstruction or bump wheel assembly 19 will carry the weight of the vehicle stabilizing the front end and thereby further absorbing shocks which would otherwise be imparted to the frame and to a patient being transported by the vehicle . in a like manner , when the axle 21 reacts to a bump or road shock , wheel assembly 18 will stabilize the vehicle . the rear frame 15 is supported by a wheel assembly 25 which incorporates a rear axle 26 mounted to the rear by shock absorbing tag air bag assembly 27 . each of the air bag assemblies 22 , 23 , and 27 are independently controlled and pneumatically pressurized by an on - board computer monitoring system to thereby compensate for road vibrations and to prevent diving or rocking of the vehicle frame . the design of the carriage or chassis of the emergency vehicle of the present invention is such as to reduce vibrations and shocks to the floor 16 of the patient compartment to a minimum . as previously discussed , the tandem front wheels absorbs shocks by effectively allowing one of the two front axles 20 or 21 to steady the vehicle while the other wheel assembly encounters a bump , hole or other object . further , it should be noted that the suspended patient support portion 16 of the frame is designed to be as close to the center of gravity of the vehicle as possible . in this respect , the central portion 16 of the suspended frame 15 is shown as being positioned intermediate the rear axle and a point spaced between the front tandem axles . the distances shown at ( a ) and ( b ) in fig3 of the drawings should equal each other as closely as possible . in addition , it should be noted that the level of floor 16 relative to the axles 20 , 21 and 26 is such that the floor is suspended at a low point to provide a low center of gravity for the floor structure and also for any patient support which is mounted on the floor 16 of the patient compartment . in conventional ambulances , floor or loading heights may exceed 30 inches whereas , in the present invention , the suspended frame portion 15 is positioned between one to two inches above the axles thereby creating a loading or floor height of approximately 17 - 18 inches with the vehicle axles being at a height of approximately 9 inches from the ground . by providing a low center of gravity and by positioning patient supports at the mid point between the axles as previously discussed , not only will there be less vibration due to road shocks but the floor of the vehicle 16 will also be stabilized during turning motions of the vehicle . although the types of patient supports provided within the patient compartment 17 of the vehicle may vary in type and number , in the preferred embodiment of the invention at least one primary patient support base 30 is shown which is pivotally mounted to the floor 16 of the patient compartment by bearing assembly 31 which is centrally located within the compartment and the side doors thereof . the bearing assembly may be of any conventional design and permits the base 30 to be rotated a full 360 ° with respect to the floor 16 . in fig4 the base is shown as supporting a conventional collapsible stretcher ( s ) which has been wheeled onto the base in a manner which will be described in greater detail hereinafter . in an effort to provide increased response time to accident and emergency victims and also to protect the crew of the rescue vehicle , the present invention permits patients to be loaded from either side and rear of the vehicle . the vehicle therefore includes a pair of side doors 45 and 46 on the left side of the vehicle and another pair of doors 47 and 48 on the right side of the vehicle , as is shown in fig1 and 2 . rear doors 61 , 62 , and 63 provide rear access with door 63 providing quick top loading capabilities as shown in fig6 and 7 . with specific reference to fig4 the top plan view of the patient compartment is disclosed in greater detail . it will be noted that the base 30 which is shown in dotted line for supporting the stretcher ( s ) may be rotated toward either side and rear of the vehicle so that patients may be loaded through access doors 45 and 46 , 47 and 48 or rear access doors 61 , 62 , and 63 , depending on the approach of the vehicle . as previously discussed , the base 30 having the stretcher ( s ) located thereon , is shown as being oriented along the center line of the vehicle and intermediate the side doors . any suitable locking means may be provided for securing the base 30 relative to the vehicle floor when either rotated in line with the central axis of the vehicle or when moved as indicated by the arrows in the drawing figure so as to align the base for loading or unloading of the stretcher ( s ) from the sides . in order to permit rotation of the base , a pair of opposing technician lift seats 49 and 50 , which are located on either side of the base 30 , may be raised or lowered so as not to interfere with the rotation of the stretcher and base 30 . additional technician or patient seating is provided by seats 51 and 52 provided adjacent the rear portion of the vehicle . storage areas 53 are also provided along the side and rear portions of the compartment 17 for storing medical equipment and supplies . additional patient bedding or seating may be provided along the front portion of the patient compartment , as indicated at 54 , for less critical patients . to further assist rescue personnel in loading and unloading patients with respect to the emergency vehicle , the base portion 30 may include a separate or integrally formed ramp extension 60 as shown in dotted line in fig4 . the ramp is inclined vertically so that the stretcher ( s ) may be rolled down the ramp and to the ground in order to remove the stretcher from the vehicle without requiring that the crew lift the patient and stretcher . in other embodiments it may be possible to provide hydraulic extensions for the base 30 . with reference to fig5 another embodiment of stretcher support base 70 is disclosed in greater detail . in this embodiment , the stretcher base includes a platform 71 which is secured in fixed relationship to the central portion of the vehicle in the same area as was described with respect to the first embodiment by a rotatable and vertically adjustable pedestal 72 . the stretcher may be carried by the platform in a manner similar to that discussed with respect to base 30 . further , the platform may be raised or lowered by use of a pneumatic piston 73 which is provided beneath the support platform . the pedestal permits the raising and lowering of the platform and the piston allows the platform to be pivoted about the vertical so that a patient can be inclined from head to toe as may be necessary . the platform also includes extension 74 which is pneumatically operated and which will act as a ramp to allow stretchers to be loaded from the exterior of the vehicle through either the side or rear doors . with particular reference to fig8 the tubular roll cage 13 of the present invention is shown in greater detail . the roll cage is provided for increased vehicle stability and for personal protection . the frame includes a plurality of horizontally and vertically oriented tubular members 65 and 66 , respectively , which form the primary structure of the cage and which are directly welded to the frame components 14 and 15 so as to provide a unitized body construction . due to the combined components of the vehicle , it is possible to obtain a mobile surgical environment which permits critical procedures to be performed on a patient while being transported . the drop frame 15 associated with the specific suspension system , tandem front wheel drive , together with the center of gravity positioning of the patient reduce road shocks and vehicle dive and pitch effects to an absolute minimum . thus , it is possible to provide proper cpr and iv injection administration as well as other medical procedures during patient transport . in addition , the opposing side doors and rear access with low level flooring , facilitates not only patient loading and unloading but provides for the maximum safety of the crew in moving patients to and from the transport vehicle .
an emergency rescue vehicle which includes a patient compartment which is accessible for patient loading through doors located along both sides and rear of the vehicle and wherein the primary patient support stretcher is pivotally carried centrally of the compartment and is extendable outwardly through any one of the access doors . the patient compartment is separated between tandem front wheel assemblies and a rear wheel assembly to obtain a continuously level and low loading height and the primary patient support is positioned generally at the center of mass of the vehicle .