US3341875A

US3341875A - Conveyance gangway

Info

Publication number: US3341875A
Application number: US619483A
Authority: US
Inventors: Joseph C Wollard; John S Slaney; Lester L Preiss
Original assignee: WOLLARD AIRCRAFT SERVICE EQUIPMENT Inc
Current assignee: WOLLARD AIRCRAFT SERVICE EQUIPMENT Inc
Priority date: 1967-02-28
Filing date: 1967-02-28
Publication date: 1967-09-19
Anticipated expiration: 1984-09-19

Description

Sept 19, 1967 J. c. WOLLARD Em 3,341,875

CONVEYANCE GANGWAY Original Filed April 6, 1964 3 Sheets-Sheet l INVENTORS JOSEPH C. WOLLARD ATTORNEY Sep- 19, 1967 J. c. woLLARD ETAL 3,341,875

CONVEYANCE GANGWAY 5 Sheets-Sheet 3 Original Filed April G. 1964 I N VENTORS, JOSEPH C. WOLLARD JOHN S. SLANEY LESTER L. PREISS A TTORNE Yl United States Patent 3,341,875 CONVEYANCE GANGWAY Joseph C. Wollard, Miami Springs, John S. Slaney, Opa- Locka, and Lester L. Preiss, Miami, Fla., assignors to Wollard Aircraft Service Equipment Inc., a corporation of Florida Continuation of abandoned application Ser. No. 357,358, Apr. 6, 1964. This application Feb. 28, 1967, Ser. No. 619,483

3 Claims. (Cl. 14-71) ABSTRACT F THE DISCLOSURE A conveyance loader having a vertically and horizontally movable conveyance end, a iixed terminal end and a connecting passageway pivotally connected at one end to the conveyance end and pivotally connected at the other end to the terminal end, the pivotal connections providing for longitudinal movement of the connecting passageway and resisting rotational movement of the connecting passageway around an axis passing through both pivotal connections.

This application is a continuation of application Ser. No. 357,358 iiled on Apr. 6, 1964, and now abandoned.

The present invention relates to conveyance gangways, more particularly of the aircraft loading and unloading type in which an elongated gangway provides covered and weather-proof protection -for passengers walking through the gangway, between an elevated door of an airport or other terminal building and an elevated door of an aircraft or `other vehicle that is loading or unloading passengers.

In addition to protecting passengers from the weather, gangways such as those of the present invention are also intended to shield passengers from noise and jet blasts and to enable them to avoid oil slicks. Gangways acc-ording to the present invention also remove any uncertainty as to which of several vehicles undergoing loading the passenger is to enter.

It is an object of the present invention to provide conveyance loading apparat-us adapted to register with conveyance doors in any of a plurality of positions of the conveyance.

Another object yof the present invention is the provision of a conveyance loading apparatus designed for use with conveyances of greatly varying exit door heights while maintaining substantially uncanted thresholds and iioors in the apparatus.

Still another object of the present invention is the provision of conveyance loading apparatus that permits ready movement of personnel between an elevated doorway of a conveyance and the ground immediately adjacent the conveyance, and at the same time provides an enclosed passenger gangway between the conveyance and a terminal building.

Finally, it is an object of the present invention to provide conveyance gangways and particularly aircraft loading apparatus, which will be relatively simple and inexpensive to manufacture, easy to install, operate, maintain and repair, and rugged and durable in use.

Other objects and advantages of the present invention will become apparent from a consideration of the following description, taken in connection with the accompanying drawings, in which:

FIGURE 1 is a side elevational view of a conveyance gangway according to the present invention;

FIGURE 2 is a top plan view of the gangway of FIG- URE 1, with parts removed for clarity of illustration;

FIGURE 3 is an end elevational view of the structure of FIGURE l, showing the gangway of the present inven- ICC tion endwise in elevation and in use in connection with an airplane; and

FIGURE 4 is an enlarged view in section on the line 4-4 of FIGURE l.

In each of FIGURES l, 2 and 3, extreme raised and lowered positions of the apparatus are shown in full and phantom line, respectively.

In broad outline, there is shown in the drawings a .passenger gangway 1 which is generally elongated and which extends between a xed passenger terminal 3 such as an airport and a movable conveyance 5 such as an aircraft and shields passengers from the weather as they pass between the terminal and the vehicle. Gangway 1 has a fixed inner end or terminal portion 7 which is secured to the terminal and an elongated midportion 9 which occupies the principal portion of the length of the gangway. Midportion 9 is mounted for vertical swinging movement on and relative to terminal portion 7 and is connected at its other end to an outer end portion 11 that extends generally transversely to the length oi midportion 9. Outer end portion 11 is mounted for bodily vertical movement without swinging or rocking, and midportion 9 and outer end portion 11 are pivotally interconnected for relative Vertical swinging movement. Outer end portion 11 extends generally to one side of midportion 9 and carries at its outer end a horizontally swingable vestibule 13 for the accommodation of passengers entering or leaving the aircraft or other vehicle. A stairway 15 extends from the rear end of outer end portion 11 downwardly toward vestibule 13 and is disposed parallel to outer end portion 11 as seen in plan in FIGURE 2.

The parts of the invention described above in broad outline will now be described in greater detail in that same order. Fixed inner end portion 7 comprises a short floor 17 that extends outwardly from terminal 3 and is supported on a pedestal 18 that extends between the underside of floor 17 and the ground. Sidewalls 19 of terminal portion 7 extend upwardly from the side edges of floor 17 and have 'their forward edges upwardly outwardly inclined as seen in FIGURE 1. A roof 21 bridges across the tops of sidewalls 19. It will therefore 4be seen that terminal portion 7 of the gangway is in effect a short passageway or corridor that projects outwardly from the terminal building.

Vertically swingable elongated midportion 9 is comprised of a Hoor 23 and sidewalls 25 that rise from the outer side edges of floor 23. A plurality of windows 27 are spaced along the length of sidewalls 25. A roof 29 bridges across the upper edges of sidewalls 25 to thereby form a tunned. At the -rear or terminal end of midportion 9, a pair of coaxial rollers 31 are carried by midportion 9 and ride on member 32 of terminal portion 7 below .the iioor surface of floor 17. At the opposite or outer end of midportion 9, midportion 9 carries a plurality of downwardly depending ears 33 that carry coaxial pivots 34 by which midportion 9 is interconnected with outer end portion 11 for relative vertical `swinging movement. As will be explained in greater detail later, pivots 34 move only vertically `and do not swing in an arc. Therefore, the inner end 'of midportion 9 not only turns about rollers 31 but also moves horizontally on rollers 31 as midportion 9 swings vertically.

Outer end portion 11 comprises a base frame 35 which provides the framework for portion 11. A support frame 37 is in unitary assembly with base frame 35, and it is to the inner or terminal side of support frame 37 that midportion 9 is pivotally connected through pivots 34. Support frame 37 also comprises sidewalls 391and 41 best seen in FIGURE 2 which provide in effect continuations of sidewalls 25 of midportion 9 and extend lengthwise outwardly of midportion 9. The sidewall 39 is disposed on the same side of the gangway as the rear of outer end portion 11, while sidewall 41 is disposed on the side of the gangway that is toward the vehicle, that is7 toward the front end of outer end portion 11. Sidewall 41 also has a leg 42 extending transversely at right angles to sidewall 41. The upper edges of

sidewalls

39 and 41 are bridged over by a roof 43.

Outer end portion 11 also carries a sliding frame 45 that slides lengthwise of itself perpendicular to the length of mdportion 9 and that provides the principal passengersupporting portions of end portion 11. Sliding frame 45 includes in unitary assembly therewith a floor 47 and a pair of

upstanding sidewalls

49 and 51. Sidewall 49 is on the outer side of end portion 11 relative to the terminal, while sidewall 51 is on the inner or terminal side of end porion 11. A roof S3 is provided for sliding frame 45 and extends between the upper edges of

sidewalls

49 and 51 of sliding frame 45 thereby forming a relatively short tunnel. Sliding frame 45 also has a rear end wall 55 that is interconnected along its inner or terminal edge with the outer edge of sidewall 39 of support frame 3S by means of a flexible sidewall 57 that is spring urged to roll up in -a housing 58 so as to maintain flexible sidewall 57 taut at ,all times and to lclose what would otherwise be the gap between sidewall 39 and end wall 55 when sliding frame 45 is in a rearward or retracted position as shown in phantom line in FIGURE 2. As is best seen in FIGURE 3, sliding frame 45 is supported on rollers 59 carried by base frame 35 for sliding movement on base frame 35 and is actuable to slide horizontally relative to base frame 35 between the full and phantom line positions of FIGURES 2 and 3 by suitable power means (not shown).

Ves-tibule 13 is mounted `for horizontal swinging movement on and relative to sliding frame 45 of outer end portion 11 by means of coaxial pivots 61 that define beween them a vertical axis. Pivots 61 are carried by sliding fra-me 45 adjacent the floor 47 and roof 53 thereof. Vestibule 13 has a floor 63 the rear end portion of which is Hush with floor 47 and is cut on an arc about the axis of pivots 61 so that in any horizontally swung position of vestibule 13 the

oors

47 and 63 will have only the smallest possible crack between them. Sidewalls 65 are provided that are up-standing from oor 63 on both sides thereof, and a vestibule roof 67 interconnects the upper edges of sidewalls 65.

A hood 69 is mounted for vertical swinging movement about a horizontal axis on sidewalls 65 of vestibule 13. Flexible curtains 71 carried by hood 69 and by the forward edges of sidewalls 65 are positionable against vehicle 5 to lclose the gap between outer end portion 11 and vehicle against .the elements. A bumper 73 disposed along the forward edge of floor 63 of vestibule 13 prevents damage to the vehicle upon forward movement of sliding frame 45. Curtains 71 and bumper 73 also assure that no metal on the gangway touches the vehicle thereby preventing the transmission of static electric charges.

Vestibule 13 is also provided with a plurality of doors 75 that extend across a substantial width. For this purpose, vestibule 13 is widened relative to the rear portions of outer end portion 11 of the gangway. This unusually wide expanse of doors 75 thus makes it possible to position doors 75 usefully with respect to a vehicle without having to position the vehicle exactly with respect to the gangway.

As was noted above, base frame 35 of outer end portion 11 is supported for vertical rectilinear movement without tipping. To this end, a permanently emplaced support 77 is provided for outer end portion 11. Support 77 includes a base 79 from which a pair of fluid motors 81 extend vertically upwardly to suport base frame 35. Fluid motors 81 are of the usual cylinder and piston variety, and fluid under pressure is supplied to one or the other side of uid motors 81 as required, by a pump S3 set in a pit within base 79. Fluid motors 81 carry suspended from their upper ends each a rack 85 which meshes with a pinion (not shown) mounted for rotation about a fixed axis on a cross shaft 87 which in turn is mounted for rotation but not for bodily movement on and relative to base 79. Cross shaft 87 with its .pinions assures that racks 85 will move exactly in unison, so that neither fluid motor 81 can move in a way differently from the other fluid motor 81. In this way, racking and tilting of the gangway are avoided. Reference is made to our copending application Ser. No. 326,794, filed Nov. 29, 1963, now Patent No. 3,263,253, for a more complete description and discussion of the uid motors and their coordinating mechanism. Suftce it to say :that outer end portion 11 thus moves as nearly exactly vertically as posible, without tilting in any direction, and obviously the telescoping cylinder and pistons of motors 81 further act in conjunction with each other as guide mem-bers in the sense of preventing rotational movement of outer end portion 11 in a horizontal plane. As was pointed out above, pivots 34 thus move rectilinearly vertically and this movement is accommodated at the inner end of mid-portion 9 by pivotal and horizontal movement on rollers 31.

On the side of outer end portion 11 opposite the terminal and adjacent the rear of outer end portion 11 there is provided a door 89 that swings outwardly above an elevated landing 91 that is disposed at a level adjacent the level of oor 47. Stairway 15 descends from landing 91 and is comprised on each side of a pair of spaced parallel side frame members 93 and 95 each separately, pivotally connected at its upper to landing 91 at spaced points and pivotally interconnected by a plurality of parallel step treads 97 that are pivotally secured to each of side frame members 93 and 95 at the front and rear, respectively, of the step treads. Stairway 15 is supported at its lower end by a pair of spaced coaxial wheels 99 on members 95 that roll on the pavement or other surface at ground level. Landing 91 and side frame members 93 and 95 and step treads 97 thus form a plurality of articulated parallelogram linkages, such that upon vertical movement of outer end portion 11 so that landing 91 is positioned at variable eievations above ground level, stairway 15 will automatically adjust to the required level by swinging movement of step treads 97 and side frame members 93 and 95 relative to each other with side frame members 93 and 95 remaining parallel to each other at all times and step treads remaining parallel to each other at all times. The fact that landing 91 remains horizontal at all times and is parallel to step treads 97 thus assures that step treads 97 in turn Will be horizontal at all times, thereby to provide a safe and convenient means of access between ground level and the interior of the vehicle without the need to pass through the terminal. Aircraft or other transportation personnel can thus leave the vehicle and pass through outer end portion 11 and down stairway 15 to get to ground level, or can go up stairway 15 and through outer end portion 11 to get to the vehicle, without having to transverse midportion 9 or go in or out of the terminal proper.

In operation, it is necessary only to position the doorway of the airplane or other vehicle facing and adjacent vestibule 13, after which the gangway can be adjusted as desired to bring a portion of the doorway of the vestibule into registry with the door of the vehicle. In order to do this, fluid motors 81 can be actuated to raise or lower outer end portion 11 to position the level of oor 63 of vestibule 13 at a desired elevation relative to the vehicle door. Also, vestibule 13 can be swung to various negative or positive acute angles relative to that vertical plane which passes through the axis of horizontal swinging movement of vestibule 13 and which is also parallel to the length of outer end portion 11 and perpendicular to the length of midportion 9. In respect to this feature, the forward edges 98 of

sidewalls

49 and 51 of sliding frame 45, in coaction with walls 65 of vestibule 13, limit the swinging movement of the vestibule to the acute angles just described. Furthermore, the disposition of stairway parallel to end portion 11 and descending in the direction of vestibule 13 is also important, in that stairway 11 can thus roll freely with reciprocatory movement of frame 45 and is never caused to slew sideways and is quite compact relative to the length of end portion 11 because it extends toward but is free from connection with vestibule 13. Moreover, outer end portion 11 can be reciprocated lengthwise, that is, perpendicular to midportion 9, so as to position bumper 73 against the side of the vehicle. Finally, the wide span of doors 75 enables that door 75 to be opened which is nearest the door of the vehicle, thereby to avoid the need for making the gangway extensible in a direction parallel to midportion 9.

It will also be noted from FIGURE 2 that in connection with sliding frame 45, the rear edge of side wall 51 is spaced sufficiently far from the end wall 55 that a wide range of reciprocatory movement of sliding frame 45 is made possible without interfering with the movement of passengers between outer end portion 11l and midportion 9. As will be evident from FIGURE 2, the use of the passageway in rearwardly disposed positions of sliding frame 45 is facilitated by means of flexible sidewall 57 and also by the fact that therear edge of sidewall 51 does not close ofi the passageway between outer end portion 11 and midportion 9 even in the rearwardly disposed position of sliding frame 45 which is shown in phantom line in FIGURE 2. To achieve this spacing of the rear edge of sidewall 51 from rear wall S5, it is desirable to make the rear edge of sidewall 51 terminate on the forward side of sidewall 41 in the forwardly disposed position of outer end portion 11 which is shown in full line in FIGURE 2. It will therefore be apparent that leg 42 of sidewall 41 closes what would otherwise be the gap between

sidewalls

41 and 51 in this forward position of the structure.

From a consideration of the foregoing disclosure, therefore, it will be evident that all of the initially recited objects of the present invention have been achieved.

Although the present invention has been described and illustrated in connection with preferred embodiment, it is to be understood that modifications and variations may be resorted to without departing from the spirit of the invention, as those skilled in this art will readily understand. Such modifications and variations are considered to be within the purview and scope of the present invention as defined by the appended claims.

What is claimed is:

1. A conveyance gangway comprising:

(a) a fixed terminal end portion,

(b) an elongated midportion,

(c) an outer end portion including a conveyance engaging portion,

(d) first pivot means including a first pivot element associa-ted with the midportion and a second pivot element associated with the terminal end portion, the first and second pivot elements cooperating to mount the midportion and the terminal end portion for vertical Swingin g movement,

(e) second pivot means including a third pivot element associated with the midportion and a fourth pivot element associated with the outer end portion, the third and fourth pivot elements cooperating to mount the midportion and the outer end portion for vertical swinging movement relative to each other,

(f) means associated with one of the pivot means for allowing movement of the pivot elements of said one of the pivot means relative to one another in a substantially horizontal plane,

(g) means associated with the other end portion support means mounting the conveyance engaging portion of the outer end portion for movement along a horizontal line toward and away from a conveyance,

(h) support means for the outer end portion including a ground supported extensible motor means having a vertically disposed element in rigid supported relation to the outer end portion and a vertically disposed element in rigid supported relation to the ground, the outer end portion supported element and the ground supported element having telescoping relationship with one another, and means acting between the elements for raising and lowering the outer end portion along a straight vertical line, and

(i) guide means acting between the ground and the outer end portion having a vertically disposed element in rigid supported relation relative to the outer end portion and a vertically disposed element in rigid supported relation to the ground, the outer end portion supported element and the ground supported element having telescoping relationship with one another, to thereby prevent rotational movement of the outer end portion around the support means.

2. A conveyance gangeway comprising:

' (a) a fixed terminal end portion,

(b) an elongated midportion,

(c) an outer end portion including a conveyance engaging portion, the outer end portion further including base means and fioor means,

(d) first pivot means including a first pivot element associated with the midportion and a second pivot element associated with the terminal end portion,` the first and second pivot elements cooperating to mount the midportion and the terminal end portion for vertical swinging movement,

(e) second pivot means including a third pivot element associated with the midportion and a fourth pivot element associated with the outer end portion, the third and fourth -pivot elements cooperating to mount the midportion and the outer end portion for vertical swinging movement relative to each other,

(g) ground-engaging support means for the outer end portion rigidly connected to the base means of the outer end portion,

(h) the support means for the outer end portion including means for raising and lowering the outer end portion,

(i) means constraining the outer end portion support means to movement in a straight vertical line,

(j) means associated with at least one of pivot means (d) and pivot means (e) for resisting rotation of the midportion around a longitudinal axis passing through the midportion caused by lateral forces directed against the midportion,

(k) means associated with the outer end portion support means maintaining the floor means of the outer end portion horizontal at all times,

(l) means associated with the outer end portion constraining the conveyance engaging portion of the louter end portion to horizontal movement toward and away from a conveyance in a straight line path which is fixed relative to the outer end portion base means, and

(m) means mounting the vestibule for horizontal swinging movement relative to the remainder of the outer end portion about a vertical axis, the vestible being horizontally swingable between extreme positions in which the vestibule is disposed at negative and positive acute angles to a vertical plane passing through said upright axis and perpendicular to the length of the midportion.

3. A conveyance gangeway comprising:

(a) a fixed terminal passageway means,

(b) an elongated tunnel means having an open terminal end and an open outer end forming a passageway,

(c) means interconnecting the fixed terminal passageb way means and the open -terminal end of the elongated tunnel means for vertical swinging movement of the elongated tunnel means relative to the Xed terminal passageway means,

(d) a ground supported elevating mechanism,

(e) a horizontal support means rigidly mounted on the ground supported elevating mechanism,

(f) a horizontally disposed relatively short tunnel means carried by the horizontal support means, having an open end facing in the direction of a conveyance,

(g) means forming an opening in the end portion ofthe short -tunnel means removed from said open end, the opening being in registry with the open outer end of the elongated tunnel me ans,

(h) means connecting the open outer end of the elongated tunnel means and the horizontal support means for vertical swinging movement of the' elongated tunnel means relative to the horizontal support means,

(i) means forming part of at least one of means (c) and means (h) for resisting rotation of the elongated tunnel means around a longitudinal axis passing through the midportion caused by lateral forces directed against the midportion,

(j) conveyance vestibule means carried by the open end of the short Itunnel means,

(k) means mounting the conveyance vestibule means for swinging movement in a horizontal plane relative to the short tunnel means,

(l) means associated with the last claimed means limiting the horizontal swinging movement to positive and negative acute angles relative to the open end of the short tunnel means,

(In) means associated with the horizontal support means and the short tunnel means supporting the conveyance vestibule means for movement relative to the horizontal support means toward and away from a conveyance, and

(n) means associated with means (m) constraining the last claimed movement of the conveyance vestibule means toward and away from a conveyance to a straight line, horizontal path which is xed relative to the horizontal support means.

No references cited.`

CHARLES E. OCONNELL, Primary Examiner.

NILE C. BYERS, Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,341,875 September 19, 1967 Joseph C. Wollard et a1. It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below Column 2, line 50, for "tunned" read tunnel column 3, line 70, for "suport" read support column 4, line 13, for "posible" read possible line 29, after "upper" insert end column S, line 40, for "embodiment" read embodiments line 69, for "other" read outer column 6, line 61, after "means," insert the conveyance engaging portion of the outer end portion comprising a vestibule,

Signed and sealed this 5th day of November 1968. (SEAL) Attest:

EDWARD J. BRENNER Edward M. Fletcher, Jr.

Commissioner of Patents Attesting Officer

Claims

2. A CONVEYANCE GANGEWAY COMPRISING: (A) A FIXED TERMINAL END PORTION, (B) AN ELONGATED MIDPORTION, (C) AN OUTER END PORTION INCLUDING A CONVEYANCE ENGAGING PORTION, THE OUTER END PORTION FURTHER INCLUDING BASE MEANS AND FLOOR MEANS, (D) FIRST PIVOT MEANS INCLUDING A FIRST PIVOT ELEMENT ASSOCIATED WITH THE MIDPORTION AND A SECOND PIVOT ELEMENT ASSOCIATED WITH THE TERMINAL END PORTION, THE FIRST AND SECOND PIVOT ELEMENTS COOPERATING TO MOUNT THE MIDPORTION AND THE TERMINAL END PORTION FOR VERTICAL SWINGING MOVEMENT, (E) SECOND PIVOT MEANS INCLUDING A THIRD PIVOT ELEMENT ASSOCIATED WITH THE MIDPORTION AND A FOURTH PIVOT ELEMENT ASSOCIATED WITH THE OUTER END PORTION, THE THIRD AND FOURTH PIVOT ELEMENTS COOPERATING TO MOUNT THE MIDPORTION AND THE OUTER END PORTION FOR VERTICAL SWINGING MOVEMENT RELATIVE TO EACH OTHER, (F) MEANS ASSOCIATED WITH ONE OF THE PIVOT MEANS FOR ALLOWING MOVEMENT OF THE PIVOT ELEMENTS OF SAID ONE OF THE PIVOT MEANS RELATIVE TO ONE ANOTHER IN A SUBSTANTIALLY HORIZONTAL PLANE, (G) GROUND-ENGAGING SUPPORT MEANS FOR THE OUTER END PORTION RIDIGLY CONNECTED TO THE BASE MEANS OF THE OUTER END PORTION, (H) THE SUPPORT MEANS FOR THE OUTER END PORTION INCLUDING MEANS FOR RAISING AND LOWERING THE OUTER END PORTION, (I) MEANS CONSTRAINING THE OUTER END PORTION SUPPORT MEANS TO MOVEMENT IN A STRAIGHT VERTICAL LINE, (J) MEANS ASSOCIATED WITH AT LEAST ONE OF PIVOT MEANS (D) AND PIVOT MEANS (E) FOR RESISTING ROTATION OF THE MIDPORTION A LONGITUDINAL AXIS PASSING THROUGH THE MIDPORTION CAUSED BY LATERAL FORCES DIRECTED AGAINST THE MIDPORTION, (K) MEANS ASSOCIATED WITH THE OUTER END PORTION SUPPORT MEANS MAINTAINING THE FLOOR MEANS OF THE OUTER END PORTION HORIZONTAL AT ALL TIMES, (L) MEANS ASSOCIATED WITH THE OUTER END PORTION CONSTRAINING THE CONVEYANCE ENGAGING PORTION OF THE OUTER END PORTON TO HORIZONTAL MOVEMENT TOWARD AND AWAY FROM A CONVEYANCE IN A STRAIGHT LINE PATH WHICH IS FIXED RELATIVE TO THE OUTER END PORTION BASE MEANS, AND (M) MEANS MOUNTING THE VESTIBULE FOR HORIZONTAL SWINGING MOVEMENT RELATIVE TO THE REMAINDER OF THE OUTER END PORTION ABOUT A VERTICAL AXIS, THE VESTIBLE BEING HORIZONTALLY SWINGABLE BETWEEN EXTREME POSITIONS IN WHICH THE VESTIBULE IS DISPOSED AT NEGATIVE AND POSITIVE ACUTE ANGLES TO A VERTICAL PLANE PASSING THROUGH SAID UPRIGHT AXIS AND PERPENDICULAR TO THE LENGTH OF THE MIDPORTION.