Wheeled carriages for supporting a patient in a substantially horizontal position are well-known in the art and a representative example of an early version of such a device is illustrated in Dr. Homer H. Stryker's U.S. Pat. No. 3,304,116, reference to which is incorporated herein. Dr. Stryker's innovative wheeled carriage included a fifth wheel which is raisable and lowerable by the attendant by directly manually manipulating the wheel support frame oriented beneath the patient supporting portion of the wheeled carriage. The orientation of the fifth wheel was sometimes awkward to reach and, therefore, made the operation of the raising and lowering feature of the fifth wheel difficult to attain.
Other structure was added to the wheeled carriage to facilitate an activation of the brakes for the wheels on the wheeled carriage from positions adjacent the head end and/or the foot end of the wheeled carriage. However, if the wheeled carriage were to be placed into a position where the head end and the foot end of the wheeled carriage were inaccessible to the attendant, operation of the brake became difficult without first moving the wheeled carriage to a position wherein at least one of the head and/or foot end of the wheeled carriage would be accessible for operation of the brake. If a fifth wheel is present and is deployed to its floor engaging position, situations where this might be considered a problem would be where an overbed table was to be placed in association with the wheeled carriage and the fifth wheel was blocking entry of the wheeled carriage of the overbed table beneath the wheeled carriage because of the presence of the lowered fifth wheel. Thus, it became a desire to provide an easily accessible fifth wheel and brake activation device oriented at least within the lateral side region of the wheeled carriage as well as within the head and foot regions of the wheeled carriage.
As wheeled carriages for supporting a patient further developed from Dr. Stryker's earlier patent, the mechanism for raising the patient support relative to the wheeled base generally included a pair of horizontally spaced hydraulic jacks which were simultaneously pumped with hydraulic fluid by operation of a single foot activated pedal. Once the hydraulic jacks had raised the patient support to the desired elevation, either the head end of the patient support, the foot end of the patient support or both ends of the patient support could be selectively lowered by activation of one or two foot activated pedals. For example, one foot activated pedal, when depressed, would activate a hydraulic fluid release valve for allowing hydraulic fluid to exit the hydraulic jack at one end of the bed so that that end of the bed would be lowered. The second foot pedal would accomplish the same task. When it was desired to lower both the head end and the foot end of the patient support at the same time, it was necessary for both foot pedals to be depressed at the same time. Attendants have found this difficult to achieve. Accordingly, it became a desire to provide for an easy to use mechanism for effecting the simultaneous lowering of the head end and foot end hydraulic jacks.
Accordingly, it is an object of this invention to provide a wheeled carriage for supporting a patient in a substantially horizontal position having a wheel braking and unbraking mechanism and/or an auxiliary wheel and support structure therefor mounted on a wheeled base, one and/or the other being actuatable by a manually manipulatable control element at at least one of the pair of lateral side regions or at least one of the head or foot ends of the wheeled carriage so that an attendant can operate the manually manipulatable control element to effect a movement of the auxiliary wheel solely from the head or foot end and solely from within the lateral side region.
It is a further object of this invention to provide brakes for the wheels of the wheeled carriage and a control mechanism for activating the brakes while the auxiliary wheel is in a position spaced from the floor surface and deactivating the brakes while the auxiliary wheel is in a floor engaging position, all utilizing the aforesaid same control mechanism.
It is a further object of this invention to provide a wheeled carriage, as aforesaid, wherein plural control elements are provided around the perimeter of the wheeled carriage to facilitate an attendant operating a selected one of the manually manipulatable control elements to effect a movement of the auxiliary wheel from its raised or lowered position and/or activation of a brake mechanism for the wheeled carriage solely from within a selected one of the head, foot and two lateral side regions of the wheeled carriage.
It is a further object of the invention to provide a control mechanism for actuating the raising and lowering feature of the fifth wheel and/or activation of a brake mechanism for the wheeled carriage by utilizing a rotational movement of the activating devices to facilitate compact construction of a rotary transmission device to interconnect the multiple locations for activating the raising and lowering of the fifth wheel feature and/or activation of a brake mechanism for the wheeled carriage.
It is a further object of the invention to provide a wheeled carriage, as aforesaid, wherein the manually manipulatable control element at each of the multiple locations around the perimeter of the wheeled carriage are identical to one another thereby standardizing the appearance of the control element to the attendant thereby minimizing confusion as to which of the many manually manipulatable elements on a wheeled carriage for supporting a patient in a substantially horizontal position is to be activated.
It is a further object of the invention to provide a wheeled carriage, as aforesaid, wherein the fifth wheel activating structure is durable and requires little or no maintenance over the lifetime of the wheeled carriage.
It is a further object of the invention to provide a wheeled carriage, as aforesaid, wherein the control element for activating the brakes and/or the auxiliary fifth wheel is a unitary pedal construction.
It is a further object of the invention to provide a wheeled carriage, as aforesaid, wherein hydraulic jacks are utilized to raise and lower the patient support relative to the wheeled base and wherein a unitary pedal construction is utilized to effect an independent lowering of the head end and the foot end of the patient support as well as a simultaneous lowering of both the head end and the foot end of the patient support.