Safety System Of Roll Guards

Technical Field

This invention relates to a safety system of roll guards for wheel assemblies that depend from a vehicle such as an anesthesia machine and support the vehicle on a floor surface for its movements in all directions on the floor surface. Each wheel assembly has and is pro¬ tected by its own roll guard, unconnected with any part of such wheel assembly or with the vehicle. Each roll guard sweeps away any object that would otherwise be en¬ countered by its wheel assembly on the floor surface and would obstruct, snag or prevent movement of the wheel on such floor surface. And any wheel assembly that would otherwise encounter a dangling object that would ob¬ struct, snag or prevent movement of the wheel on the floor surface is swept away by its roll guard. Background Art

The background art which, as far as is known to the applicant, can be regarded as useful for the understand¬ ing, searching and examination of the invention, is Unit¬ ed States Patent 5,170,528. Disclosure of Invention

The problem in the art to which this invention apper- tains is further rolling or turning movement being pre¬ vented by an anesthesia machine, having depending wheel assemblies mounting wheels, when anyone, or more, of the numerous electrical cords, electrical cables, electric wires, hoses, tubings (hereinafter referred to as "ob- jects"), and having a variety of sizes ranging from 3/32" to 1/2" in diameter and lengths ranging from 3 feet to 19 feet, is in the path of the anesthesia machine's roll¬ ing or turning movement, whether a portion of such object is lying upon the floor surface or whether a portion of such object is in proximate dangling relationship, by a wheel snagging the portion of such object lying upon the floor surface and thereby preventing continued rolling or turning movement of such snagged wheel or by a portion of the wheel assembly snagging the portion of such object

in proximate dangling relationship thereto to thereby block and prevent continued rolling or turning movement of the wheel mounted by such wheel assembly.

The anesthesia machine has to roll or turn freely on its floor surface for the following reasons:

1. Instant access to the anesthesia machine is nec¬ essary for: a. Safety inspection to make certain that the air hoses, electrical plugs and outlets are properly con- nected, and which procedure must be performed every morning pursuant to prescribed guidelines. b. Turning on the peripheral electrical equipment that has on-off switches located on the rear of the anesthesia machine. c. Adjusting the alarm volume switches located to the rear of the peripheral electrical equipment. d. Trouble-shooting electrical problems. e. Calibrating carbon dioxide gas monitors. f. Changing anesthesia gas containment cylinders lo- cated on the back of the anesthesia machine.

2. The position of the anesthesia machine, in rela¬ tion to the operating table, changes with the practition¬ er, some of whom prefer the anesthesia machine on the right, some on the left, some perpendicular to the O.R. (operating room) table, some a little less perpendicular, some a little more, etc. Basically, the machine's loca¬ tion has to be adjusted for accessibility and comfort of the practitioner.

3. An anesthesia machine may have to be moved from its working position when a patient is brought into the

O.R. on a stretcher in order that the head end of the stretcher is even with the head end of the O.R. table. This problem arises because of the limited space availa¬ ble in the O.R. for all the equipment required to perform today's highly sophisticated operations. This procedure is repeated in reverse order when the patient is moved from the O.R. table to his stretcher.

4. When a patient is finally situated on the O.R. table, the anesthesia-machine's position may have to be

readjusted so that the anesthesia provider can reach both the patient and his anesthesia machine without moving his own body.

5. After the patient has been anesthetized, the po- sition of the patient on the O.R. table may need to be changed to accommodate the surgery, such as sitting, lat¬ eral, prone or lithotomy position, which often requires the anesthesia machine to be brought closer to the pa¬ tient in order that the anesthesia breathing circuit, usually 30 to 36 inches in length, will reach the pa¬ tient's airway.

6. In certain surgeries, the O.R. table is rotated 90° or more in order that the surgeon can have good ac¬ cess to the upper body areas of the head, neck and shoul- ders. In such instances, the anesthesia machine must fol¬ low the patient to prevent the breathing circuit from be¬ ing disconnected which could cause the patient to become hypoxic (lack of oxygen). At the end of these kinds of surgeries, the O.R. table must be returned to its origi- nal position in order that the anesthesia provider can properly support the patient*s airway when anesthesia is discontinued. The anesthesia machine must be able to fol¬ low such return movement.

7. During surgery, rapid access to the back of the anesthesia machine may be necessary to replace depleted oxygen tanks if a mainline oxygen source failure occurs. A mainline nitrous oxide gas source failure requiring de¬ pleted tank replacement would require moving the machine to a more accessible position. 8. Rapid access to the back of the anesthesia ma¬ chine would be necessary in the event of a sudden elec¬ trical power failure to allow the practitioner to evalu¬ ate the machine for power cord disconnection.

9. An anesthesia machine is moved when so required for another anesthesia provider to travel behind the ma¬ chine in order to get to the anesthesia care area to as¬ sist in anesthesia care, give consultations, assist in emergency situations and to provide relief for breaks and meals.

10. An anesthesia machine often has to be reposition- ed to allow x-ray access to the O.R. table from the head area.

11. When the anesthesia machine needs servicing and/or equipment maintenance, it is usually moved to a location or other room to afford access to all its sides.

12. If, during surgery, the anesthesia machine has a serious equipment failure, such as a patient ventilator failure, the failed machine would be rolled out for re- moval with its place being taken by rolling in a new an¬ esthesia machine.

13. An anesthesia machine is top heavy, and, if a person were to give the machine a hard shove to move it and its wheels were blocked or obstructed, such person not only can injure himself, but also such hard shove could cause the top-heavy machine to topple over.

Accordingly, the objects of the invention are to con¬ tribute to the solutions of the discussed problems of the art by providing a safety system of cylindrical roll guards for the wheel assemblies. Each wheel assembly com¬ prises a spindle that depends from the bottom of the an¬ esthesia machine's cabinet and has a wheel mounted on an axle carried by a yoke fixed to the bottom of the spin¬ dle. The wheel assemblies hence mount wheels for rolling or turning movements in all directions on the floor sur¬ face. Each wheel assembly and its inclusive wheel is sur¬ rounded and protected laterally by its open cylindrical roll guard that is in vertical free upstanding relation¬ ship from the floor surface, and is not connected to any part of the wheel assembly, its inclusive wheel, or the anesthesia machine. The cylindrical roll guard extends vertically from the floor to just below the bottom of the anesthesia machine's cabinet with its top open end closed by a top cap, with clearance provided between the top surface of the cap and the bottom surface of the cabi¬ net's bottom. Cross-sectionally, the spindle is round. The top cap receives the spindle therethrough via a con¬ centric opening of sufficiently greater diameter to pro¬ vide an annular open space between the spindle and the

top cap's opening. In the course of the wheel's rolling or turning movement, the spindle contacts and engages the top cap's concentric opening, thereby moving the roll guard in the same direction of movement as the wheel to make contact with and sweep away the portion of any ob¬ ject that lies upon the floor surface with which the wheel would otherwise make contact with and become snag¬ ged. The cylindrical roll guard, closed by its top cap, makes contact with and sweeps away or moves away that portion of any object in proximate dangling relationship to a portion of the wheel assembly with which such por¬ tion of the dangling object would otherwise make contact with and snag. Brief Description of Drawings These objects and other objects of the invention should be discerned and appreciated from the detailed de¬ scription for the hereinafter set forth "Best Mode for Carrying Out the Invention", taken in conjunction with the drawing figures, wherein like reference numerals re- fer to similar elements throughout the several drawing figures, in which: Fig. 1 is a perspective view depicting a conventional O.R. (operating room) environment; Fig.

2 is a perspective view showing portions of objects lying upon the floor surface and snagged by the front wheels mounted by their respective wheel assemblies that depend from the cabinet bottom of the anesthesia machine; Fig.

3 is a perspective view of the roll guard (without its top cover) sweeping away an object; Fig. 4 is a side ele- vational view; Fig. 5 is a top plan view; Fig. 6 is an exploded perspective view; and Fig. 7 is a view of the top cover in cross-section, taken in the direction of the arrows 7-7 in Fig. 6. Best Mode for Carrying Out the Invention

Fig. 1 of the drawings depicts a conventional O.R. (operating room) environment, to wit: a patient lying upon an O.R. mattress 1, supported by an O.R. table 3, its hydraulic pedestal 5 and base 7; an O.R. electrical power inlet box 9; a wall-mounted electrical and medical gases outlet panel 11; an O.R. table electrical power

cord 13 which is connected to the wall outlet 15 and runs to the power inlet box 9; the anesthesia machine 17; the main electrical power supply cord 19 that runs from the wall outlet 15 to the anesthesia machine 17; the "E" cyl- inder 21 for oxygen; the "E" cylinder 23 for oxygen; the connecting hose 25 for air supply running from the wall outlet 27 for medical air to the anesthesia machine 17; the connecting hose 29 for nitrous oxide supply running from the wall outlet 31 to the anesthesia machine 17; the connecting hose 33 for oxygen supply running from the wall outlet 35 to the anesthesia machine 17; the connect¬ ing hose 37 for suction supply running from the wall out¬ let 39 for suction to the suction containment canister 41; the suction tubing 43 from the canister 41 for the patient; the "E" cylinder 45 for nitrous oxide; the "E" cylinder 47 for nitrous oxide; the "E" cylinder 49 for medical air; the forane vaporizer 51; the ethrane vapor¬ izer 53; the halothane vaporizer 55; the oxygen flow me¬ ter 57; the nitrous oxide flow meter 59; the medical air flow meter 61; the pulse oximetry cable 63 running from the electric pulse oximetry machine 65 to the patient; the electrocardiograph cable 67 running from the electro- cardiographic machine 69 to the patient; the blood pres¬ sure cuff inflation hose 71 running from the electric blood pressure monitor 73 to the patient; the esophageal temperature probe wire 75 running from the electric tem¬ perature monitor 77 to the patient; the carbon dioxide absorption canister 79, having a delivery head 81, swivel-mounted via a swivel bracket 83 mounted on a sup- port post 85, carried by the anesthesia machine 17, with inflow and outflow tubing branches 87 and 89 running from the delivery head 81 to a "Y" piece connector 91 that connects to an endotracheal tube 93; and a continuous carbon dioxide sampling machine 94. The bottom of the anesthesia machine's cabinet 97 has recessed therein four conventional spindle housings 99, each of which receives therein, in pivotally mounting re¬ lationship, the top portion of a spindle 101 whose bottom is fixed to a yoke 103 having lateral sides. A wheel 105

is mounted within the yoke 103 for rotation about a hori¬ zontally disposed axle 107 carried by the lateral sides of the yoke 103. The axle 107 is offset from the spindle 101 such that the wheel 105 and yoke 103 will swivel to the position shown in Fig. 2, with the axle 107 located behind the spindle 101 when the anesthesia machine 17 is moved forwardly. As used herein, "wheel assembly" is gen¬ erally referred to by reference numeral 109 and means the spindle 101, yoke 103, wheel 105 and axle 107. The four wheels 105 support the anesthesia machine 17 upon the flat floor surface for movement of the anesthesia machine 17 in all directions upon the flat floor surface 111.

"Objects", used herein include cords, hoses, tubings, cables and wires, herein described with their reference numerals. For reason of the many required movements of an anesthesia machine 17, in all directions upon the flat floor surface 111 during the course of an operation, as explained under the heading "Disclosure of Invention", the objects not only lie on the flat floor surface 111, but also are in dangling relationships above the flat floor surface 111. A wheel 105 is snagged upon its coming into contact with an object lying upon the flat floor surface 111 that is in the path of the anesthesia ma¬ chine's movement and with further movement obstructed. A spindle 101 of the anesthesia machine 17 would be ob¬ structed and blocked from further movement when the spin¬ dle 101 comes into contact with an object in dangling re¬ lationship above the flat floor surface 111. In addition to which, a yoke 103 or a bottom corner 113 of the anes- thesia machine's cabinet 97 can be snagged by such a dan¬ gling object.

The problems described under the heading "Disclosure of Invention" are aggravated because of the additional needs in an operation for cable hookups for arterial lines, central venous pressure lines and pulmonary artery lines; an electrical cord powering an inspired gas humid¬ ifier; electrical cords from intravenous fluid warmers and intravenous medication control pumps; water hoses running to temperature controlled heating blankets; elec-

trical wires connecting and grounding the patient to an electrocautery unit; and electrical wires running to vid¬ eo cameras, microscopes, etc. Fig. 2 shows the front wheels 105 snagged upon coming in- to contact with objects lying upon the flat floor surface 111 in the course of forward movement of the anesthesia machine 17.

Fig. 3 shows a wheel assembly 109 protected by its roll guard 115 which is sweeping away, in the path of the movement of the wheel 105, an object lying upon the flat floor surface 111.

With reference to Figs. 3, 4, 5, 6 and 7 of the draw¬ ings, the roll guard 115, made of plastic or other suita¬ ble material, has two halves 117 and 119 whose respective bottoms 121 and 123 are correspondingly flared out. One half 117 has two vertical offset flanges 125 that comple- mentally receive the lateral end portions 127 of half 119. Half 119 has receiving holes 129 aligned with tapped holes 131 formed in half 117. Screws 133 disposed through the receiving holes 129 are threadingly engaged suffi¬ ciently with the tapped holes 131 such that the heads of of the screws 133 will be flush with the exterior surface 135 of half 119. Such assembly completes the vertically upstanding portion 137 of the roll guard 115. For opera- use of such cylindrical portion 137, the anesthesia ma¬ chine 17 can be appropriately raised and a wheel assembly 109 lowered within such cylindrical portion 137 to the floor surface 111; or, more easily, the wheel 105 of such such assembly 109 can remain on the flat floor surface 111 with such cylindrical portion 137 being simply assem¬ bled around its wheel assembly 109. The top portions 139 and 141 of the respective halves 117 and 119 have corres¬ ponding outturned rims. The top cap 143 has two semicir¬ cular portions 145 and 147 having respective inturned flanges 149 and 151 complemental with the outturned rims 139 and 141. Semicircular portion 145 has beveled por¬ tions 153 with depending detents 155. Semicircular por¬ tion 147 has two laterally projecting beveled portions 157 having complemental detent recesses 159. The beveled

portions 153 are in complemental correspondence with the the beveled portions 157. The detents 155 are aligned with the detent recesses 159. To complete the assembly of the top cap 143, one simply slides its semicircular portions 145 and 147 together sufficiently such that the inturned flanges 149 and 151 engage the outturned rims 139 and 141, and the detents 155 engage the aligned de¬ tent recesses 159. The semicircular portions 145 and 147 have aligned semicicular openings 161 and 163, respec- tively, which have like radii such that when the semicir¬ cular portions 145 and 147 are assembled, the openings 161 and 163 define a diametral opening concentric with the spindle 101 of the wheel assembly 109 and greater than the diameter of the spindle 101 such that the dia- metral opening provides an annular clearance space 165 between the diametral opening and the spindle 101.

As shown in Fig. 4, it should be noted that with the assembly of the top cap 143 completed, the vertical height of vertically upstanding cylindrical portion 137 of the roll guard 115 with its halves 117 and 119 resting upon the flat floor surface 111 is such that there is a vertical clearance of 1/16" or less between the top sur¬ face of the cap 143 and the bottom 95 of the anesthesia machine 17 to prevent a small dangling object, such as a small dangling wire, from entering into such 1/16" clearance to contact and obstruct or snag the spindle 101 or from looping around and snagging a bottom corner 113 of the anesthsia machine 17.

With a spindle that cross-sectionally is square, rec- tangular or of other configuration, it is within the con¬ cept of this invention that the two semicircular portions 145 and 147 would have a central opening configured to accommodate such spindle that is square, rectangular or of other configuration, cross-sectionally, and concomi- tantly to provide a clearance therebetween.