US2662681A - Foldable ladder and hinge members therefor - Google Patents

Description

Dec. 15, 1953 B. E. STAPLETON 2,662,681

FOLDABLE LADDER AND HINGE MEMBERS THEREFOR Filed July 31. 1948 3 Sheets-Sheet l Brzucz E. STAPLETON INVENTOR.

{ITTUENEY Dec. 15, 1953 B. E. STAPLETON FOLDABLE LADDER AND HINGE MEMBERS THEREFOR 3 Sheets-Sheet 2 Filed July 61. 1948 BRUCE E. STAPLETON INVENTOR.

BY a a llu-llllll:

Aime/w Dec. 15, 1953 STAPLETON 2,662,681

FOLDABLE LADDER AND HINGE MEMBERS THEREFOR Filed July 51, 1948 s Sheets-Sheet s 5e BRUCE E. STAPLETON INVENTOR.

12 BY. M444 ATTORNEY Patented Dec. 15, 1953 FOLDABLE LADDER AND HINGE MEMBERS THEREFOR Bruce E. Stapleton, Dallas, Tex.

Application July e1, 1948, Serial No. 41,776

6 Claims.

This invention relates to new and useful improvements in ioldable ladders and h n e members therefor.

One object of the invention is to provide an improved ladder which is substantially rigid when extended and which may be folded in a plurality of sections into a small space for storage or transportation.

An important object of the invention is to provide a foldable ladder having sections thereof joined by a novel combination hinge and latch for hingedly interconnectin the sections of said ladder, said latch being constructed and arranged to releasably maintain the ladder in an extended position or in a folded position, as desired.

Another object of the invention is to provide a ladder of the character described wherein the hin e members are so constructed and arranged on the ladder that the full strength of the side rails of the ladder is utilized for maintaining rigidity of the ladder.

A further object of the invention is to provide in a ladder of the character described hinge members which are so constructed and arranged that the ladder may be folded in sections, all hinge members breaking or opening in the same direction, whereby when the ladder is extended with the opening side of the hinges upwardly the ladder will be maintained rigidly in such extended position.

A still further object of the invention is to provide in a ladder of the character described reinforcing means at the abutting ends of the rail sections or" the ladder for preventin undue compression of the material from which the rail sections are made and for reinforcing the side members of the hinge member which are under tension when the ladder is extended.

A particular object of the invention is to provide a novel combination hinge and latch by means of which two movable parts or members may be hin edly connected so as to be swingable to folded and extended positions, said hinge mem bers having resiliently actuated means restraining said two movable parts or members in either an extended or folded position.

Still another object of the invention is to pro vide hinge members of the character described which are simple in structure and capable of manufacture in quantities by stamping machines or die presses, whereby the hinge members are economical to manufacture and simple to install and use.

Additional objects and advantages of the invention will readily be apparent from the reading of the following description of a device constructed in accordance with the invention, and reference to the accompanying drawings thereof, wherein:

Figure 1 is an isometric view of a ladder constructed in accordance with the invention and showing the same in an extended position,

Figure 2 is a side elevation of the ladder of Figure 1 showing the same in folded position,

Figure 3 is a side elevation of one of the hinge members of the ladder,

Figure l is a bottom plan view of the hinge member of Figure 3,

b Figure 5 is a top plan view of the hinge mem- Figure 6 is a view, similar to Figure 3, showing the hinge member open permitting the sections of the ladder to be folded,

, Figure '7 is an isometric view of the hinge membe'r'and' showing the ladder in an extended position, andalso showing a rung plate for carrying a'rung adjacent the hinge,

Figure 8 is a transverse vertical sectional view taken on the line 8-8 of Figure 7, through the center of the joint,

Figure 9 is an isometric view of a modified form of the invention, showing the ladder in extended position,

Figure 10 is a side elevation of the ladder of Figure 9 showing the same in folded position,

' Figure 11 is an enlarged side elevation of one of the modified hinge members showing the same partially folded.

Figure 12 is a transverse vertical sectional view of the hinge member taken on the line i 2--l2 of Figure 11, and

Figure 13 is a side elevation of a further modification, showing the ladder folded.

In the drawings, the numeral it designates a ladder having side bars or rails Ii and cross members or rungs I2. The side rails of the ladder are formed in sections it which are hingedly connected together by hinge members I4, the details of which will be hereinafter more fully explained, whereby the sections of the ladder may be folded at the hinge members through an angle of degrees. The sections of the side rails of the ladder are progressively shorter from the lower end of the ladder toward the upper end, whereby the ladder may be folded in the square spiral or rolled form shown in Figure 2 to occupy a reduced space and permit the folded ladder to be readily stored or transported.

Each of the hinge members i i includes four hinge sections or hinge plates 15, and a pair of the hinge plates is secured on each side of the side rails of the sections :3 by means of bolts extending through said side rail sections. Each hinge plate is preferably formed of flat sheet metal in substantially a T-shape having an upright section It and an elongate cross-piece section ll. Bolt openings are formed at the extreme outer ends of the cross piece section, at the intersection of the upright and cross piece, and at the lower or outer end of the upright section. The hinge plates are secured to the side rail sections 13 in such a manner that the extreme outer or lower end of the upright l8 of the hinge plate is positioned adjacent the upper abutting corners of the side rail sections and the cross piece sections ii are disposed so as to extend downwardly at an angle and position the bolt opening at the outer end of one of the arms of the cross piece of each hinge plate below and in alignment with the plane of abutment between the two adjacent side rail sections. Thus, the openings at the outer end of this lower arm of the cross pieces ll of the hinge plates are positioned in alignment, and a pivot or cross bolt l8 extends through said openings in all four of the hinge plates. A spacer sleeve is is disposed between the pairs of hinge plates to hold the same in alignment with the sides of the side rail, as clearly shown in Figures 4 and 8. Bolts 21! extend through the opening at the opposite end of the cross piece H and through the side rail sections I3 to the corresponding opening in the hinge plate on the pposite side of said side rail. A similar bolt 28 likewise extends through the opening at the center of the cross piece and through the side rail and corresponding central opening in the hinge plate on the opposite side of the side rail. A rivet or pin it extends through the opening at the lower or outer end of the upright of the hinge plates on each side rail section for securing such upright portion of the hinge plate to the ears of U-shaped upper reinforcing clamp members 22 which are disposed in recesses formed in the upper surface of the side rail sections corresponding to the shape of the reinforcing clamps. The reinforcing clamps are held in place on the side rails by means of bolts 23 which extend vertically through said side rail sections and through openings in correspondingly shaped lower reinforcing clamps 24 on the lower surface of the side rail sections. The arms of the lower reinforcing clamps 2d are turned outwardly away from the bottom of the side rail sections and are connected by means of rivets or bolts 25 to the hinge plate cross piece arms extending below each side of said side rail.

It will be seen, therefore, that the side rail sections i3 arehingedly connected together and may be swung about the pivot bolts 13 to fold the sections with respect to each other.

In order to hold the side rail sections of the ladder in an extended position or in a folded position, it is necessary that some restraining, securing or latching means be provided. One form of restraining or securing means is clearly illustrated in the drawings, Figures 1 through 8, wherein an arm link 39 having an opening at each end is swingably mounted at one end on each pin or rivet 2| on the inner side of the side rail of the ladder, said arm link being spaced from the upright section of the hinge plate by means of a washer 3i mounted on said pin or rivet and interposed between the hinge plate and the arm link. The outer free end of each arm link of the pair at each hinge is connected by t means of a rivet 32 or other suitable means to a tie link 33, which limits the movement of the arm links 39, as will be hereinafter described.

A guide bar 35 having a pivot hole at one end and an elongate slot 38 at other end is mounted on the rivet 32 between the arm link 3 31 and the tie link 33, and has the slotted portion of its arm slidably engaging the bolt 2% which also connects one arm of the lower reinforcing clamp to the projecting portion of the cross piece of the inner hinge plate. A spacer washer 3i threaded on the bolt 25 is interposed between the guide bar and the hinge plate for holding the guide bar in proper alignment parallel to the surface of the side rail section, whereby the guide bar may move longitudinally on the bolt 2:5. A helical. coiled spring 38 surrounds the guide bar and is confined thereon between washers -33 abutting against the head of the bolt 25 and the spacer washer 3'! at the lower end of the guide bar and against downwardly facing shoulders formed at the upper portion of the guide bar by an enlargement of the upper end of said guide bar.

The length of the tie link 33 is such that the arm links 39 are limited in their movement and prevented from moving into a position 180 degrees apart. The tie link is thus slightly less in length than the combined lengths of the arm links 33 when the side rail sections 13 are in an extended position shown in Figures 3 and 'l. The guide bars 35 also limit the arm links against movement into a straight line, since the lower end of the slot 3'5 engages the bolt '25 to stop upward movement of the arm links before such links travel. to such straight line position. The springs 38 constantly exert their force to the guide bars 35 upwardly, thus constantly urging the swingable arm links 33 upwardly toward the position shown in Figures 3 and *7 whereby the side rail sections is are resiliently locked or secured in an extended position, are restrained against folding or swinging to the position shown in Figure 6.

However, when the side rail sections are folded or swung about the bolt H! of the hinge member,

0 the arm links 39 may swing downwardly and inwardly toward each other through an arc of less than 180 degrees to permit the side rail sections to move through an angle of approximately degrees. In this extended position the arm links are disposed at an obtuse angle with respect to the tie links, as clearly shown in Figure 6, said arm links being limited against movement to a straight line position by the engagement of the lower end of the slot in the guide bar 35 with the bolt 25. Also, when the side rail sections are folded about the pivot bolt IE to the position shown in Figures 2 and 6, the springs 38 constantly urge the guide bars 35 upwardly to resiliently maintain the swingable arm links 33 and the tie links 33 in the extended position, whereby the ladder sections are resiliently restrained in folded position.

Since the arm links 30 may only swing through an arc of less than degrees, and so never move into a straight line position with respect to each other and the tie link 33, it will be seen that the links cannot attain a position wherein they will not swing from folded position to extended position when the ladder sections are folded. However, since the links approach a straight line position in both the folded and extended position, it will be seen that they will, when aided by the springs 38, restrain the hinged ladder sections in folded or extended position, as desired.

When the ladder is in an extended position, such as is shown in Figures 1 and '7, the abutting ends of the side rail sections it are placed under compression when a weight is applied to the ladder, as when a person mounts the rungs oi the ladder. Such compression of the upper edge of the side rail causes the reinforcing or U-clamps 22 to abut each other and reinforce such upper edge portion of the side rail sections to prevent splintering or splitting of the side rail sections, it the same are made of wood or the like. Similarly, due to the weight applied to the side rail, as aforesaid, the downwardly projecting cross piece section I! undergoes a force attempting to swing such projecting portion of the hinge plate upwardly, and this swinging movement is resisted by the lower reinforcing clamp 24, which conmeets the projecting cross piece portions of the hinge plates and presses against the underside of the side rail.

Should a rung [2 on the ladder be spaced so as to be positioned adjacent the hinge member it, the rung may be mounted on a rung plate which has an elongate central portion at and a pair of spaced ears 46 arranged to be mounted on the bolts 2!! so that the rung plate will extend axially of the side rail sections. The rung plate has a plurality of axial openings 4? formed therein by means of which a rung cup 48 may be secured to the rung plate for receiving the rung 2. The rung plate is spaced to clear the links 3% and 33, the guide bar 35, and the spring 38 by means of spacers at which are mounted on the bolts 2% between the hinge plate It and the rung plate 45, as clearly shown in Figures '1 and 8. Therefore, the rung l2 may be positioned at any desired point with respect to the hinge member and will not interfere with the operation of the hinge member, since it is spaced inwardly from the side rail to clear all moving parts of the hinge member.

The securing or restraining linkage for each hinge member is provided on only the inner pair of hinge plates of each hinge member, whereby the securing mechanism does not project out wardly from the ladder and interfere with the normal use of the -ladder or catch upon shrubbery, wires and the like. Furthermore, the positioning of the securing or restraining means on the inner sides of the rails of the ladder provides for more pleasing appearance.

From the foregoing, it will be seen that an improved ioldable ladder has been provided which is substantially rigid when it is extended and which may be folded in a plurality of sections into a small space for storage or transportation. Obviously, the ladder may be formed with any desired number of sections joined by the hinge members to provide a ladder of any desired length. Further, the improved ladder has a plurality of sections having their side rails each joined by a novel combination hinge and latch for hingedly interconnecting the sections of the ladder and constructed and arranged to releasably maintain the ladder in a folded position or in an extended position, said hinge members being so constructed and arranged on the ladder that the full strength of the side rails of the ladder is utilized for maintaining rigidity of the ladder. It will also be seen that the hinge members of the ladder are so constructed and arranged that the sections of the ladder are all folded in the same direction, whereby the ladder may be rolled into a substantially square spiral, and when the ladder is extended with the opening side of the hinge upwardly the ladder will be maintained rigidly in such extended position, any weight applied to the ladder positively maintaining the ladder in open extended position. Weight applied to the ladder when it is in the extended position acts to more firmly abut the ends of the side rails together and render the ladder still more rigid.

The ladder has been provided with reinforcing means at the abutting ends of the rail sections of the ladder for preventing undue compression or deformation of the material from which the rail sections are made and for reinforcing the side members or plates of the hinge which are under tension when the ladder is extended.

it will particularly be noted that an improved novel combination hinge and latch has been provided, by means of which two movable parts or members may be hingedly connected so as to be swingable to folded or extended positions, said hinge members having resiliently actuated means restraining the two movable parts or members in either an extended or folded position. It is also believed manifest that the hinge members are simple in structure and capable of manufacture by punch press, or stamping or the like, whereby the hinges are economical to manufacture and simple to install and use.

A modified form or" ladder is illustrated in Fig ures 9 through 12, wherein the ladder is folded in a slightly different manner from that form first described. In this form, the side rails of the ladder are formed with a short central section having a pair of hinge members it at each end connecting such short section with a pair of elongate ladder sections 52 on each end of the short central section. Each section of each pair of the elongate ladder sections 52 has its side rails connected to the side rails of the other section of the pair by means of hinge members 2-3 positioned at the joint between the pair of elongate ladder sections, as clearly shown in Figures 9 through 12, said hinge members being constructed and arranged to permit the sections to be folded through an angle of approximately 189 degrees.

Each hinge member 53 includes four hinge sec-' tions or hinge plates 5t, which are illustrated being formed of flat sheet metal in substantially a T-shape having an upright section and an elongate cross piece section identical to the hinge plates of the form first described. Bolt openings are formed at the extreme outer of the cross piece section, at the intersection of the upright and cross piece, and at the outer or lower end of the upright section, and the hinge plates are secured to the side rails of the ladder sections 52 by bolts 5? in such a manner that the extreme outer end of the upright 55 is posi tioned adjacent the upper abutting corner of the side rails and is connected by the rivet or pin iii to the reinforcing clamp 23 in the same main nor as the previous form. The cross pieces 56 are disposed so as to extend downwardly at an angle and position the bolt opening at the outer end of one of the arms of each cross piece below and in alignment with the plane or. abutment be tween the two adjacent side rail sections. A pivot or cross bolt 58 extends through the openings in the downwardly projecting arm ends of the four hinge plates, and a spacer sleeve 55 is disposed between the pairs of hinge plates on each side of the side rail to hold the same in alignment with the sides of' said side rail, as clearly shown in Figure 12. Other parts of the hinge are the same as those of the form first described. It will be seen, therefore, that the elongate ladder sections 52 may swing about the pivot bolts 58 to move said ladder sections into longitudinal alignment, or to fold thee same upon each other through an angle of 180 degrees so that said elongate sections lie parallel and are substantially coextensive, as clearly shown in Figure 10.

For holding the elongate ladder sections 52 in an extended position, a pair of spring catch members til are mounted on the inner hinge plates 56, as clearly shown in Figures 11 and 12, and are positioned so that their upper ends lie in the plane of abutment of the two side rail sections. The catch members are secured to the hinge plates by means of the bolts at the lower end or" the catch members and by means of an auxiliary bolt i5! near the upper ends or" said catch members. One of the catch members 69 is provided with a recess 55 which is arranged to receive a spherical segment projection 65 formed on the upper projecting end of the other catch member. Engagement of the projection 66 in the opening '55 releasably restrains or maintains the sections of the ladder in an extended position, but due to the resiliency of the latch members permits the spherical segment projection to be moved out of the opening 235 whereby the ladder sections may be folded to the position shown in Figure 10. The catch or latch members so are spaced inwardly from the inner hinge plates 55 means of spacer sleeves 6'! mounted on the bolts 5'5 and Bl between the catch members and the hinge plates.

The length of the central section 5% of the ladder is such that the two folded half sections of the ladder may be folded through an angle of approximately 90 degrees with res set to such central section to position four elongate ladder sections 52 parallel to each other and SLlbStii1 tially coextensive, as clearly shown in Figure 10. This permits the ladder to be readily folded. into a small space for storage or transportation.

All of the advantages of the ladder of the form first described are present in this form of the ladder, there being merely a slightly different form of hinge employed to permit the ladder to be folded in a slightly different manner.

Obviousiy, other combinations of hinges and ide rail sections be ern loyed to form a v oldable ladder in accordance with the invention, nol @Ifl'iIJlOE/ZAQ the hinge members oi the invention.

Another form of ladder is iliustrated in Figure 13, which shows the ladder in ioldecl position and is believed to be self-explanatory Hinge members l l are empioyed between the various inner sec ions of the rails, and hinge mem- 53 are employed between said inner sections and the two end sections of the side rails, as clearly shown in F gure 13, the other features or the ladder be" g the same as those of the forms already described.

The foregoing description of the invention is explanatory only, and changes in the details of the construction illustrated may be made by those skilled in the art, within the scope of the appended claims, without departing from the spirit of the invention.

What I claim Patent is:

l. A foldable and desire to secure by Letters ladder having a plurality of ladder sections having side rails and cross rungs, and hinge means connecting the ends of the side rails of adjacent sections and having their pivot points on the under side of the side rails whereby the ladder sections may be swung from folded to rigid extended position, each of said hinge means including, a hinge plate secured on the outer side of each side rail section, an identical hinge plate secured on the inner side of each side rail section, said hinge plates having projections extending below the lower edge of the side rail sections, a pivot pin connecting the ex tending projections of the hinge plates in the plane of each side rail end, a reinforcing member extending between and secured to the hinge plates and to the associated side rail section, each reinforcing member being disposed below the lower edge of its associated side rail section to resist movement of the projections of the hinge plates toward the associated side rail section and resilient means for releasably restraining the hinge side plate members in position holding the side rails of the ladder section in extended position.

2. A foldable ladder including, a plurality of ladder sections having side rails and cross rungs, hinge means connecting the side rails of adja cent ladder sections whereby said ladder sections may be swung from folded to extended position and back, part of said hinge means hav ing releasable restraining means carried thereby for releasably restraining the hinge members in position holding the ladder sections connected by said hinge members extended, said releasable restraining means including elongate resilient catch members secured to the inner side of the side rails of the adjacent hinged sections and spaced from the hinge members, said catch members being so disposed that their outer ends engage each other in the plane of the ends of the side rails, said catch members having releasable catch means at their engaging positions for releasably holding the members engaged.

3. As a subcombination in a foldable ladder, a hinge member for hingedly connecting the ends of the side rails of adjacent sections of the ladder together and including, a hinge plate secured on the outer side of each side rail section, an identical hinge plate secured on the inner side of each side rail section, said hinge plates each having projections extending below the lower edge of the side rail section and intersecting the plane of the end of said side rail section, means extending through the side rail section securely clamping the inner and outer hinge plates together and to the side rail section, a substantially U-shaped reinforcing strap having its arms connected to the hinge plates on each side of the side rail section and extending across the upper edge of the side rail section at the end thereof, a second substantially U-shaped reinforcing strap having its arms connected to the hinge plates below the side rail section and extending across the lower edge of the side rail section, a bolt extending through the side rail section and connecting the central portions of the reinforcing straps, said reinforcing straps resisting deformation of the hinge plates and the side rail ends, and a pivot pin connecting the hinge plates of adjacent ends of side rail sections in the plane of the ends of the side rail sections below and spaced from the lower edges of said rail sections whereby said adjacent side rail sections may be swung from folded to extended position, the ends of said side rails when extended abutting each other.

4. As a subcombination in a foldable ladder, a hinge member for hingedly connecting the ends of the side rails of adjacent sections of the ladder together and including, an outer hinge plate adapted to be secured on the outer side of a first side rail section, an inner hinge plate adapted to be secured on the inner side of said side rail section, said hinge plates each having a projection extending below the lower edge of the side rail section and intersecting the plane of the end of said side rail section, securing means connecting the hinge plates for securely clamping the hinge plates to the side rail section, a complementary outer hinge plate adapted to be secured on the outer side of a second siderail section, av complementary inner hinge plate adapted to be secured on the inner side of a second side rail section, said complementary hinge plates each having a projection extending below the lower edge of said second side rail section and intersecting the plane of the end of said side rail section, securing means connecting the complementary hinge plates for securely clamping said hinge plates to the second side rail section, means pivotally connecting the projections of the two outer hinge plates together at a point in the planes of the ends of the side rail sections and pivotally connecting the two inner hinge plates together at a point in the planes of the ends of the side rail sections, and a pair of complementary resilient means mounted on a pair of adjacent pivotally connected hinge plates and coacting to yieldably hold the rail sections in extended positions against pivotal movement in one direction about said pivotal connecting means, said resilient means being yieldable to allow pivotal movement of said rail sections in the opposite direction about said connecting means when a force which tends to move said sections in said opposite direction about said connecting means and which exceeds a predetermined value is applied to move said rail sections to folded position.

5. As a subcombination in a fcldable ladder, a hinge member for hingedly connecting the ends of the side rails of adjacent sections of the ladder together and including, an outer hinge plate adapted to be secured on the outer side of a first side rail section, an inner hinge plate adapted to be secured on the inner side of said side rail section, said hinge plates each having a projection extending below the lower edge of the side rail section and intersecting the plane of the end of said side rail section, securing means connecting the hinge plates for securely clamping the hinge plates to the side rail section, a strap connecting the hinge plates and bearing against the upper edge of the side rail section, a strap connecting the hinge plates and bearing against the lower edge of the side rail section, means connecting the straps for clamping the end of the side rail section therebetween, the end of the side rail section being thus clamped between the hinge plates and straps whereby deformation of the hinge plates and the side rail end is resisted, a complementary outer hinge plate adapted to be secured on the outer side of a second side rail section, a complementary inner hinge plate adapted to be secured on the inner side of said second side rail section, said complementary hinge plates each having a projection extending below the lower edge of said second side rail section and intersecting the plane of the end of said side rail section, securing means connecting the complementary hinge plates for securely clamping said hinge plates to said second side rail section, a. strap connecting the complementary hinge plates atnd bearing against the upper edge of said second side rail section, a strap connecting the complementary hinge plates and bearing against the lower edge of said second side rail section, means connecting the straps for clamping the end of said second side rail section therebetween, the end of said second side rail section being thus clamped between the hinge plates and straps whereby deformation of the complementary hinge plates and said second side rail end is resisted, and means pivotally connecting the projections of the two outer hinge plates together at a point in the planes of the ends of the side rail sections and pivotally connecting the two inner hinge plates together at a point in the planes of the ends of the side rail sections, the pivotal connections being in axial alignment below and spaced from the lower edges of said rail sections.

6. As a subcombination in a foldable ladder, a hinge member for hingedly connecting the ends of the side rails of adjacent sections of the ladder together and including, an outer hinge plate adapted to be secured on the outer side of a first side rail section, an inner hinge plate adapted to be secured on the inner side of said side rail section, said hinge plates each having a projection extending below the lower edge of the side rail section and intersecting the plane of the end of said side rail section,'securing means connecting the hinge plates for securely clamping the hinge plates to the side rail section, a strap connecting the hinge plates and bearing against the upper edge of the side rail section, a strap connecting the hinge plates and bearing against the lower edge of the side rail section, means connecting the straps for clamping the end of the side rail section therebetween, the end of the side rail section being thus clamped between the hinge plates and straps whereby deformation or the hinge plates and the side rail end is resisted, a complementary outer hinge plate adapted to be secured on the outer side of a second side rail section, a complementary inner hinge plate adapted to be secured on the inner side of said second side rail section, said complementary hinge plates each having a projection extending below the lower edge of said second side rail section and intersecting the plane of the end of said side rail section, securing means connecting the complementary hinge plates for securely clamping said hinge plates to said second side rail section, a strap connecting the complementary hinge plates and bearing against the upper edge of said second side rail section, a strap connecting the complementary hinge plates and bearing against the lower edge of said second side rail section, means connecting the straps for clamping the end of said second side rail section therebetween, the end of said second side rail section being thus clamped between the hinge plates and straps whereby deformation of the complementary hinge plates and said second side rail end is resisted, means pivotally connecting the projections of the two outer hinge plates together at a point in the planes of the ends of the side rail sections and pivotally connecting the two inner hinge plates together at a point in the planes of the ends of the side rail sections, the pivotal connections being in axial alignment below and spaced from the lower edges of said rail sections, and means carried by the inner hinge plates for releasably holding said hinge plates in position holding the side rails of the adjacent 11 ladder sections extended, said last-mentioned means including elongate resilient catch members secured to a pair of adjacent connected hinge plates and spaced from the hinge plates, said catch members being so disposed that their outer ends engage each other in the planes of the ends of the side rail sections, said catch members having releasable catch means at their engaging positions for releasably holding the members enaged.

BRUCE E. STAPLETON.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 216,777 Barry June 24, 1879 269,126 Shupe Dec. 12, 1882 320,692 Ready June 23, 1885 437,936 OBrien Oct. 7, 1890 439,361 Stupp Oct. 28, 1890 494,073 Necker Mar. 21, 1893 513,012 Hall Jan. 16, 1894 689,315 Krueger Dec. 17, 1901 960,085 Giles May 31, 1910 Number Number 12 Name Date Howard May 28, 1912 Wright et a1 Nov. 4, 1913 Fernald Feb. 17, 1914 Simonich July 24, 1923 Sunde et a1. Sept. 4, 1923 Seger Jan. 1, 1924 Stockstrom Aug. 3, 1926 Wattawa Apr. 19, 1927 Singley Aug. 16, 1927 Hammond et a1. Sept. 25, 1928 Schulz Nov. 27, 1928 Busch Sept. 12, 1933 Burke Sept. 18, 1834 Ulfving July 21, 1942 Low Oct. 20, 1942 Peglow Jan. 8, 1946 FOREIGN PATENTS Country Date Great Britain 1901 Austria Feb. 2, 1912 Great Britain Apr. 6, 1933 Germany Mar. 18, 1929

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