US2036529A - Passenger chair for airplanes - Google Patents

Description

April 1936- J. H. KINDELBERGER'ET AL PASSENGER CHAIR FOR AIRPLANES Filed Oct. 18, 1933 4 Sheets-Sheet l Br v do! A TTORJVEV.

April 7, 1936. J.YH. KINDELBERGER ET AL 2,036,529

PASSENGER CHAIR FOR AIRPLANES Filed OCL. 18, 1933 4 Sheets-Sheet 2 A TTORNEY.

A ril 7, 1936. J. H. KINDELBERGER ET AL 2,036,529

' PASSENGER CHAIR FOR AIRPLANES Filed Oct. 18, 1933 4 Sheets-Sheet 3 I h [/vvtI/vTo/as: 95 04 I/Z z/amec. H. K [ride/be rye; /o 5 /O6 Arf/zur 5/541 mend,

dd 'wi z April 1936. J. H. KINDELBERGER ET AL 2,036,529

PASSENGER CHAIR FOR AIRPLANES Filed Oct. 18, 1933 4 Sheets-Sheet 4 f/vv /vroes (/amea HK/nde/ber yer;

Arf/zur 5.8a mend 5y we mum? m w M/ 6 O g n w w w w P Q w ?atented Apr. 7, 1936 UNITED STATES PATENT OFFICE 2,036,529 PASSENGER CHAIR roa AIRPLANES Application October 18, 1933, Serial No. 694,084.

4 Claims.

Our invention relates to an improved chair construction especially suitable for use in airplanes.

Owing to the length of continuous flights by airplane consideration of the personal comfort of the passengers becomes important. It is accordingly an object of our present invention to provide a chair having a plurality of adjustments and having means whereby the cooperating parts thereof may be easily and quickly adjusted without the exercise of any great force to accomplish the same. In this seat structure the seat member is supported in such a manner that the weight of the person sitting therein produces substantially no resistance to adjusting movement of the sea A further object of the invention is to provide a chair of the character described having a simple means for adjusting the back thereof entirely independently of the adjustment of the seat, the improved results obtained by the invention being contributed to by the simple back and seat adjusting mechanisms which we have provided. 4

A further object of the invention is to provide a chair of the above general character having a back which is reversible relative to the seat so that the passenger may ride either forwardly or rearwardly. In conjunction with the reversible back we have provided a simple reversible connecter for connecting an end of the back member to an end of the seat member.

Further objects and advantages of our invention are concerned with the provision of an improved form of securing. means for the passenger occupying'the seat which may be readily secured in operative position, adjusted and released. Straps for'holding passengers in chairs are employed with attachment hooksor buckles at the ends thereof, the lengthof the strap or belt being adjustable to suit the passenger, "and generally requiring adjustment for each passenger. In our I present securing means the strap does not require length adjustment but the effective length thereof is controlled by the position in which its free end portion is connected to the seat structure by means of a simple form of clamp. The chair is provided with cushion supporting means for se-' curing it to a carrying structure, such as the walls of an airplane fuselage. These cushion supporting means have resilient load carrying elements adapted to absorb small shocks, with positive stop means for limiting the deflection of the resilient elements, one value of the stop means being to resist any tendency for the chair to set up a periodic-vibrating or swaying motion. Operative between the seat member and. the supporting structure therefor we provide stop means interengaging in a manner to restrain side sway of the seat member relative to its support. 5

In the invention the back member is provided with a simple means for limiting the downward movement of the back member, such means consisting of a dog-leg connecting an end of the adjustable linkage with the supporting structure of 10 the chair in such a manner that the lower end of the linkage is held in an offset position and that a stop for limiting the downward movement of the back member is provided.

Additional advantages and further objects of 5 our invention will be brought out in the following part of the specification. I

Referring to the drawings, which are for illustrative purposes .only,

Fig. l is a partly sectioned side elevation of a 20 preferred embodiment of the invention.

Fig. 2 is a sectional view taken on the plane represented by the line 2-2 of Fig. 1.

Fig. 3 is an enlarged fragmentary section of the mechanism within the dotted circle 3 of .Fig. 2.

Fig. 4 is a fragmentary section taken as indicated by the line 44 of Fig. 2 for showing details of the adjusting means for the seat member.

Fig. 5 is an enlarged fragmentary section showing details of the construction of the latch means forming a part of the adjusting means for the back member.

Fig. 6 is a view taken as indicated by the line 6-6 of Fig. 1.

Fig. l'is an enlarged section on a plane represented bythe line 1-1 of Fig. 2 for showing de tails of construction and the manner of operation of the releasable connection for the back member 40 and the seat member.

Fig. 8 is an enlarged fragmentary section taken. as indicated by the line 8-8 of Fig. 1 showing the simple strap securing means of the passenger anchoring device.

Fig. 9 is a fragmentary view cooperating with Fig. 8 to show the manner in which the opposite end of the strap is secured to the opposite side of the seat member.

Fig. 10 is an enlarged fragmentary section on the plane represented by the line Ill-40 of Fig. 1.

Fig. 11 is an enlarged fragmentary section on the plane represented by the line I I-l I of Fig. 1.

Fig. 12 is an enlarged fragmentary section taken as indicated by the line l2l2 of Fig. 6.

As shown in Figs. 1 and 2, the main elements of the invention are a seat structure l5 consisting of a seat member l6 and its supporting means l1, and a back structure |8 comprising a back member 20 and its adjustable securing means 2|. The seat member I6 is comprised of a seat designated by the numeral l6a, from which there extends upwardly from each side thereof suspension means |6b. In Fig. 2 we have shown a floor line 22 and a side wall member 23 representing the floor and side of a vehicle cabin, such as the fuselage of an airplane. The seat member 6 includesa bottom plate 24 having a pair of tubular members 25 and 26 respectively secured to the forward and rearward ends thereof, these tubular members, as shown in Fig. 12, consisting of a sheet 21' of thin metal bent to tubular form and so that the edge portions 28 of the sheet 21 extending outwardly in parallel relation, provide flanges in position to overlie the edge 38 of the bottom plate 24 and to be secured thereto by means of rivets 3|. By using tubes, of this characterit is possible to combine a light weight tubular wall structure with a flange means for securing the tube to a flat wall member such as the plate 24, thereby maintaining ample strength and rigidity in conjunction with light weight.

Secured in the ends of the tubes 25 and 26 are tubular elbows 32, the outer end portions 33 of which are directed vertically upwardly so as to fit into the lower ends of vertical tubes 34 and 35 disposed at the ends of side plates 36 which are disposed vertically along the edges of the bottom plate 24. The vertical tubes 34 and 35 may be of the same formation as the tube 25, a cross section of which is shown in Fig. 12, or, alternatively, the tubes 34 and 35 may be rolled up from the end portions of the side plates 36. The upper edges of the side plates 36 are reinforced by angle members 31, each of which has a web 38 in a vertical plane and a web 39 in a horizontal plane, the web 3.9 serving as an arm rest and having a tube 4| rolled up along the outer edge thereof. The supporting structure|1 comprises a pairof side members 42and 43 adapted to lie along the outer faces of the sidewalls or side plates 36 of the seat member l6, the'side members of the supporting structure being respectively shown as a leg structure 42 which is of such vertical dimension that it will rest upon the floor 22, and a bracket member 43 which may be secured to the side wall 23, as shown in Fig. 2. i

The leg structure 42 is fabricated from tubular members 44 and 45 of the same type as the tube 25 shown in Fig. 12. In cooperating pairs as shown, the lower ends 46 and 41 of the tubular members are secured to fittings 48. The tubular members 44 converge upwardly to engage pin members 56 which project downwardly from a hinge fitting 5 I, and the tubular members 45 converge upwardly to join with a bearing plate 52 disposed vertically below the hinge fitting 5|. An approximately A-shaped plate 53 of thin metal is placed in the area enclosed by the four tubular members 45 and. the edges of this plate 53 are secured to the flanges 28 which extend relatively inwardly from the tubular members 44 and 45. The hinge member 5| has a laterally disposed horizontal bore 54 therein which cooperates with a bore 55 formed in the upper part of the bracket 43 .to provide pivot means for the seat member, which pivot means also includes pin members 56 secured tothe outer faces and near the upper edges of the side walls or plates 36, cotter pins 51 being provided in the ends of the pin members 56 to hold them in the bores 54 and 55.

The bracket 43 comprises a vertical leg 58 having a bearing structure 60 near the lower end thereof for receiving an end pin 6| of a shaft member 62 which extends horizontally and laterally under the seat member l6, and near the bottom plate 24 thereof, the central portion of the shaft member 62 consisting of a tube 63, the leftward end of which carries the member 6|, as shown in Fig. 2, and the rightward end of which receives a tubular extension 64 adapted to project through a bearing bore 68 in the bearing plate 52. Below the bearing means 66 thereof the bracket 43 includes a bifurcated extension 10 adapted to engage a cushion block 1| which is secured to the side wall 23. The upper part of the bracket 43 has a lateral extension 16 which engages another cushion block 1| which is also secured to the wall 23. The members 6| and 64 have gears 12 formed thereon which rest in close proximity to the ends of the tube 63 and in such position are adapted to engage gear segments or curved legs 13 mounted on the sides of the seat member l6 below and concentric with the pivot means represented by the pin members 56; consequently, rotation of the gears 12 will move the leg members 13 and swing the seat member |6 relative to the horizontal lateral axis defined by the pin members 56.

For driving the-gears 12 we provide a lever 14, the inner end 15 of which extends across a collar 16 moimted, as shown in Fig. 3, on the outer end of the member 68 and being hinged at 11 so as to swing outwardly a limited distance as indicated by dotted lines 18. I mally held leftward and inward by means of a tension spring 88, the inner end of which is connected to a. bar or rivet 8| extending diametrically across the inner end of the member 68 and the outer end of which connects at 82 to the lever 14. Adjacent the collar 16, opposite the hinge means 11, the lever 14 is provided with a pin 83 adapted to selective engagement with holes 84 formed in the bearing plate 52 concentric with the bore thereof. The seat member 6 is supported in suspension. The side plates 36 together with the pin members 56 form suspension means for the bottom plate 24 of the seat member l6. A's viewed in Fig. 1, the pivot means represented by the member 56 are disposed toward the rightward or rearward end of the seat member 5 and at a material distance above the bottom plate 24 thereof. In this position the pivot means is above the approximate center of gravity of a person occupying the chair, the result being that the weight of the person occupying the chair does not resist a relatively free swinging of the seat member l6 by rotation of the gears 12 which is acomplished by moving the lever 14 outwardly into its dotted line position 18, Fig. 3, and then rotating the same. As clearly illustrated in Fig. 4, the angle or tilt, as into the position indicated by dotted lines 86, of the seat member |6 on an arc concentric with the pin members 56 may be readily accomplished.

At this point it may be noted that we have, bythe specific manner of suspension and operation shown, provided a means for seat adjustment which may be operated with such ease as to encourage the use thereof, by making it possible for the passenger to obtain greatest comfort throughout the entire journey.

In conjunction with the seat structure |5 we provide a back structure l6 adjustable independently of the seat member 6. This back structure I 8 includes a back member 20 including a web 81 of vertically elongated shape out- The lever 14 is " noraoeaeao frame members 88, 98 and 9I are of a tubular construction similar to the tube 25 shown in cross-section in Fig. 12 and have relatively inwardly projecting flanges 92 which are secured to the edge portions of the web 81 by use of rivets 93. The adjacent ends .of the frame mem-' bers 88, 98, and 9I are connected by tubular elbow-type fittings-94, each of which has a projecting lug or relatively outer wallmember 95 with a lateral opening 96 therein. The projecting lugs 95 are so formed on the fittings 94 that when they are installed as shown in Figs. 2 and 6 they project in cooperating pairs from the upper and lower ends of the back member 28 which in certain claims is referred to as a primary member.

The lugs or bodies 95 on the lower and upper ends of the back member 28 form part of a connecting means 91 for securing the lower end of the back member 28 to the rearward end of the seat member or secondary member I6, as shown in full lines in Fig. 1, and for securing the upper end of the back member 28 to the forward edge of the seat member I6 when the back member 28 is in reversed position, as shown by broken lines 98 in Fig. 1. To complete the connecting means 97 we employ projecting members or relatively inner wall members I88 forming walls or bodies adapted to extend into the space between the lugs 95, as shown in Fig. 6. The enlarged sectional view, Fig. 7, shows the manner in which engagers I8I are carried by the projecting members I88 in a manner to engage the openings 96 in the projections 95 of the back member, together with means which may be quickly and easily operated to retract the engagers IN. The bodies I88 are provided with openings or bores I82 aligned with the openings 96, and the engagers I8I are made in cylindrical form to slide in the bores I82 and have rounded outer ends for guiding them readily into engagement with the openings 96. The facing or relative inner ends of the bodies -I 88 are constricted by inwardly projecting flange portions I83so as to produce small openings I84 at the relative inner ends of the bores I82. Each engager IN is provided with a bore I85 to receive a compressionspring I86 which bears against the flange portion I83, this spring I86 urging the engager I8I outwardly. To limit outward movement of the engagers I8I relative to the bores I82, we provide a flexible member or operating member I8'I, the endsof which are connected to the engagers I8I, as for instance by securing such ends in axial openings I 88 formed in'the outer ends of the engagers I8 I. Near the extremities of the flexible member I8'i, which is preferably a cord or cable, stop members H8 are securedin such position that they will engage the flange portions I83 when the engagers I8I are in extended position, as shown in full lines in Fig. 7. To detach the connecting means 91 theintermediate portion III of the flexible member ml is manually engaged and moved or pulled in lateral direction toward the position indicated by broken lines II2. This action pulls the end portions of the flexible member I8? through the openings I84 and likewise pulls the engagers I8I into the bores I82, thereby disengaging the members I8I from the openings 96 of the projections 95. It will be noted that theends of the projections 95 are chamiered at H3 and that they may be channeled, as shown by dotted lines lit in Fig. 1. for the purpose of guiding the engagers I8I readily into engagement with the openings 96. 1

In order that the connecting means 91 may be of pivotal character the openings 96 and the engagers "II are axially aligned. The back member 28 may swing around the pivotal connecting means 91 through various positions of inclination relative to the seat member I6, as indicated by broken lines II 6 in Fig. 4, and to accomplish and expedite this adjustment of 'the back member 28 the adjustable securing means 2I are provided. The adjustable securing means 2I constitutes an extensible linkage between the back member and a part. of the seat structure I5, the means 2| being preferably connected to the supporting means II of the seat structurel5. Adjustable link means 2I comprises preferably a U-shaped member II'I having a central portion II 8 which extends laterally across the back member 28 and tubula arms or struts I28 disposed perpendicular t and on the ends of the central portion II 8. The U-shaped member II'I may be readily bent from a length of metal tubing. Slidable within the tubular end portions or struts I28 are cooperating strut members i2i which may be also tubular and the outer ends I22 of which are connected to dog-leg brackets I23 which project leftwardly or forwardly, as shown in Fig. 1, and are plvotally connected at I24 to hinge means I25 formed on the hinge fitt ngs 5|. The seeming or link means 2i, by being extended or shortened, control the slope or position of the back member 28.

To urge the siidably disposed strut members I28 and I2I tension coil springs I26 are disposed within the members I28 and I2 I, the lower end of each spring I26, as shown in Fig. 1, being secured to a rivet I21 employed for securing a bracket I23 to the lower end of a tube I2 I, and the upper ends of which spring I26 are secured to pins I28 extending across the tubular strut members I28 above the upper ends of the members I2I. For securing the adjustable link means 2I in various positions of extension, we provide a simple latch means I38 which may be readily operated by a person seated in the chair. This latch means, as best shown in Fig. 5, employs a pin I3 I carried by the lower portion I32 of an inverted pan-shaped lever member I33 which is intermediately pivoted on a pin I34 carried in a lug I35 projecting from a fitting I36, one each of which is secured to-the lower end of a tubular strut member G28. A

openings I38 and I48 respectively in the iiting- I36 and the strut I28 into engagement with a selected one of a plurality of openings Ifii in the strut member I2 I, such engagement being shown in Fig. 1. For pivotally connecting the link means 2I to the back member 28 cooperating hinge parts I42 and I43 are respectively mounted on the frame members 88 and the end portions of the central part II8 of the U-shaped member II'I, these members I42 and I43 being connected by hinge pins I44 permitting a suificient rotation of the back member 28 relative to the extensible link means 2i to realize a desired opera ion of these cooperating parts. In Fig. I the back member 28 is shown in upright position. Should it be desired to lower the back member. the upper portions of the lever members I33 are manually depressed to withdraw the pins I3I into positions such as indicated in Fig. 5. A rightward or rearward force upon the back member wiil then cause the tubular struts I20 to move outwardly on the cooperating strut members iZI as the back member 20 is moved into the desired new position.

I When such new position is reached, the lever members I33 are released so that the pins I3I may enter cooperating openings MI in the cooperating strut members I2I. An outward movement of the back member 20 is limited by the stop means provided by the dog-leg brackets I23 which engage the supporting means I1 of the seat structure I5, as shown by broken iines I45 in Fig. 1, the result being that a fully lowered position for the back member 20, such as indicated by broken lines I45, is established. The seat member 96 and the back member 20 being separately and independently adjustable contribute to the general effect of providing maximum comfort for the passenger. As indicated in broken lines 86 in Fig. 4 the seat member 56 may be readily adjusted through a variety of positions relative to horizontal and, as shown in Figs. 1 and 4, the back member 20 may be adjusted independently of the adjustmentof the seat member I6, through a variety of positions between upright and fully lowered. A further important feature of our chair is that the back member 20 is reversed relative to the seat member I6 to enable the passenger to ride backward should he desire. This reversal of the back member is accomplished as follows:

The connecting means 91 between the lower end of the back member and the rearward or rightward end of the seat member I6, as shown in Fig. 1, is released in the manner previously described. The back member 20 is then rotated in anti-clockwise direction on the hinge pins I44 and the extensible link means I2i is swung leftwardly or in anti-clockwise direction toward the position indicated by broken lines I41. clockwise rotation of the back member 20 will accordingly bring the upper end I48 of the back member 20 into conjunction with the forward edge of the seat i I6 whereupon the lugs 95 of the proper extension of the link means '2I a position of the back member 26, such as indicated in broken lines 98, may obtained. It will be recognized that during the reversed position of the back member 20 the seat member I6 and such reversed back member 20 may be readily independently adjusted. An important element of our invention employed in conjunction with the hereinbefore disclosed manner of supporting the seat member I6 in suspension from pivot means disposed above the bottom plate 24 thereof, consists in the means for limiting side-sway of the seat member between the leg structure 42 and the bracket member 43. This rneansconsists of a projection or lug I5ii extending from the leg structure 42 to ward the lower portion of. the seat member, and a lug or projection I5I extending from the bracket 43. These members I50 and I5i are preierably so placed as to very nearly bear against the side faces of the rack members 13, thereby limiting sideward motion of the lower portion of the seat member I6.

The fittings 58 at the lower end of the leg structur'e 42 form parts of.cushion supporting members I52 which function to produce a limited resilient supporting of the leg structure 42 whereby to absorb high frequency vibration but to limit An antithe movement of the cooperating parts thereof when the cushion element of the supporting member I 52 is subjected to excessive strain. The cushion supporting means 1| for securing the bracket 53 to the sidewall 23 are of the same construction as the cushion'means I52 shown in Fig. 1, and accordingly the description relating to the supporting means I52 also applies to the supporting means I I. The fitting 48 comprises a horizontal plate I 53 from the edges of which walls Q54 downwardly extend, as shown in Fig. 10. The horizontal wall I 53 is also provided with projecting pins I55 and I56-angularly disposed so as to enter the lower ends'of the members 44 and 45. The walls I54 are of rounded configuration, as shown in Fig. 1, and are of reduced length as compared to the horizontal wall I53 so that they will project into spaces I51 formed between ears or walls I58 which project upwardly near the ends and from the sides of a bottom plate I60 having openings therein through which securing screws !59 may be passed, the parts I58 and I66 forming a receiver or channel i6l for a rubber or resilient body I62 of rectangular prismoidal form having side plates I63 along'the side faces l64 thereof. The ends of the plates I63, as shown in Fig. 11, are provided with holes I64 for receiving bolts I65 which pass through the ears I58 and also through the rubber body I62. The intermediate portions of the plates I63 are provided with enlarged openings I66 through which bolts I51 pass in concentric relation. The bolts i61 pass through the central portion of the rubber body I62 and through openings 158 formed in the walls I54, the bolts I61 being closely fitted in the openings I68. The resilient bodies I62 rest upon the bottom walls I60 of the receivers I6I and the upper faces I10 of the bodies I62 are in engagement with the horizontal walls I53 of the fittings 48 so that the weight and forces received from the chair structure are transmitted directly to therubber bodies I62. Accordingly, the resilent members I52 form resilient supporting means for the chair structure which will deflect and will absorb vibrations under ordinary loads. The movement of the fittings 48 relative to the receivers I6I is limited by the side bars I 63 and the pins I61 which pass through the over-sized openings I66 therein. Should an excessive force be applied, for instance in a downward direction, the rubber bodies I 62 will deflect or compress downwardiy under such force until the bolts I61 occupy the positions indicated by dotted lines I12.

To avoid the present difliculty of adiusting and securing straps forholding the passenger in a chair, we provide the improved securing means shown in Figs. 1, 8, and 9. The side plate 36 of the seat member I6, presented to view in Fig. 1 and shown in Fig. .8, has an opening I13 therein which is of rectangular form and disposed atan position of engagement with a fiat strap member I82, as shown in full lines. On the outer face of the side plate 36 a guard and guide plate IE3 is secured in the position of the opening I13 and slopes downwardly and outwardly so that when the end of the flexible securing member or strap I82 is passed into the opening in the general diopposite side of the seat member I6 and is looped around a flat bar I8'I secured by bolts I88 to the outer face of this last named plate 36.

The passenger securing means disclosed in Figs. 8 and 9 avoids all of the previous difficulties found in the operation of the commonly used adjustable straps for holding passengers in their seats in an .airplane. The strap I82, instead of being itself adjustable in length and having a hook or snap on the end thereof, ,consists .of a single piece of flexible flat material, such as leather, which may be secured across the lap of the passenger with a proper degree of tightness merely through a selection of the point of engagement of the cam I18 with the free end portion of the strap I82. Accordingly, the strap member remains of constant over-all length but the effective length thereof between the sides 01' the seat is readily varied to meet the individual needs of the passenger. I

Although we have herein shown and described our invention in simple and practical form, it is recognized that certain parts or elements thereof are representative of other parts, elements, or mechanisms which may be used in substantially the same manner to accomplish substantially the same results; therefore, it is to be understood that the invention is not to be limited to the details disclosed herein but is to be accorded the full scope of the following claims.

We claim as our invention:

1. An attachment device of the character described for connecting a primary member to a secondary member, including: relatively outer wall members projecting from said primary member having facing openings; relatively inner wall members projecting from said secondary member into the space between said relatively outer members; engagers mounted on said relatively inner wall members so as to project into said openings in said relatively outer wall members; means for yieldably urging said engagers into positions of engagement with said openings; and a flexible member having the end portions thereof connected to said engagers and adapted through a transverse pull on said flexible member to retract said engagers into positions of non-engagement with said openings. I

2. An attachment device of'the character described for connecting a primary member to a secondary member, including: relatively outer wall members projecting from said primary member having facing openings; relatively inner wallmembers projecting from said secondary memher into the space between said relatively outer members; engagers mounted on said relatively inner wall members so as to project into said openings in said relatively outer wall members; means for yieldably urging said engagers into positions of engagement with said openings; and

an operating member normally stretched substantially tight and having the end portions thereof connected to said engagers and adapted through a transverse pull on said guide member to retract said engagers into positions of nonengagement with said openings.

3. A chair of the character described, including: a seat structure comprising a seat and supporting means therefor; link means having the inner end thereof pivotally secured to said seat structure; a back member secured to the outer end of said link means and being adapted to swing on said link means from a position of cooperation with the rearward end of said seat to a position of cooperation with the forward end of said seat; and detachable means for pivotally securing said back member selectively to said forward and rearward ends of said seat, said detachable means comprising a pair of relative outer bodies and a pair of relative inner bodies adapted to project into the space between said relative outer bodies, one pair of said bodies being in projecting position on the forward and rearward ends of said seat and the other of said bodies being in projecting position on said back member, there being inwardly facing openings in said relative outer bodies and engagers slidably mounted on said relative inner bodies to enter said openings, means for urging said engagers outwardly toward positions of engagement with said openings, and a flexible retracting member extending between said engagers and having the end portions thereof secured to said engagers so that a lateral pull on said flexible member will move said engagers from said openings.

4. A chair of the character described, including: a supporting structure having a pair of pivot -members in laterally spaced relation; 2. seat member having a bottom and upstanding suspension means aligned with the sides thereof, the upper parts of said suspension means being pivotally secured to said pivot members of said supporting structure; a pair of curved rack members secured in downwardly projecting relation to the opposite sides of said seat member; a shaft extending laterally across said supporting structure under said seat member, said shaft having a tubular end portion; a pair of gears secured to said shaft in positions to engage said rack members; a lever member hinged on the end of said shaft in radially extending position, there being handle means on the outer end of said lever member; stationary engagement means around said shaft in position to be traversed by said lever member; and an engager carried by said lever member in a position between the end of said shaft and said handle means adapted to engage said stationary engagement means, there being a spring, having its inner end connected to said shaft at a point within said tubular end portion and having its outer end connected to said lever member, for urging said lever member toward said stationary engagement means.

JAMES H. KINDELBERGER. ARTHUR E. RAYMOND.

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