US3028929A

US3028929A - Ladder attachment

Info

Publication number: US3028929A
Application number: US13473A
Authority: US
Inventors: Howard L Chubbs
Original assignee: Individual
Current assignee: Individual
Priority date: 1960-03-08
Filing date: 1960-03-08
Publication date: 1962-04-10
Anticipated expiration: 1979-04-10

Description

April 10, 1962 H. CHUBBS 3,028,929

LADDER ATTACHMENT Filed March 8, 1960 4 Sheets-Sheet l INV EN TOR.

0% BR 'M April 10, 1962 H. L. CHUBBS 3,028,929

LADDER ATTACHMENT Filed March 8, 1960 4 Sheets-Sheet 2 April 10, 1962 H. L. CHUBBS 3,028,929

LADDER ATTACHMENT 4 Sheets-Sheet 3 Filed March 8, 1960 hiya/Z w M I @MM fi 44 25.1 M 7 April 1962 H. L. CHUBBS 3,028,929

LADDER ATTACHMENT Filed March 8, 1960 4 Sheets-Sheet 4 WWWZZZQ B Y.

3,028,929 Patented Apr; 10, 1962 3,028,929 LADDER ATTACHMENT Howard L. Chubbs, 736 Hanley St, Gary, ind. Filed Mar. 8, 1%0, Ser. No. 13,473 4 Claims. ((11. 182-206) The present invention relates to ladder attachments and, more particularly, pertains to devices adapted to space the upper portions of a ladder from a vertically disposed supporting member, to safely engage a vertical support where that member is of a slim, elongated configuration, such as a tree, post or pole, and to provide means for supporting a scaffold platform and safety rail on the ladder.

This invention is well adapted for incorporation into attachments such as those disclosed in United States Letters Patent 2,903,086, issued to me on September 8, 1959.

In the use of an ordinary ladder for working on a tree, vertical post, pole or the like, difficulties are encountered in safely positioning and supporting the top end of the ladder. The top crosspiece (top step of a step ladder or top rung of an extension ladder) engages the upright post only for a short transverse distance or, in the case of a round pole, only at one point. The result is that the top of the ladder tends to tip or slide to one side or the other, even off of the post, resulting in an unstable, unsafe support.

It is often desirable to use ordinary ladders for constructing or supporting a catwalk or scaffolding platform, often at the very top of the ladders. Such platforms should be firmly and safely supported whether the ladders are supported against a flat, vertical surface or against vertical posts or poles. For the convenience and safety of workmen, these platforms should be supported in spaced relation to the surface against which the top of the ladder rests. If such a platform is dis posed directly against the supporting surface, little room for walking, maneuvering and working is provided unless an unduly wide platform is utilized. Further, it is highly desirable that a safety rail be provided to lend support to persons utilizing the elevated scaffold platform and to serve as a safety device to guard against persons falling from such a platform to their serious injury.

It is an object of this invention, therefore, to provide a ladder attachment which spaces the upper end portion of a ladder from a supporting member and which will firmly and safely engage the supporting member even where such member is of a slim, elongated vertical configuration.

It is another object of this invention to provide a ladder attachment which spaces the upper end portion of a ladder a. desired distance from a vertical supporting member and which is adapted to safely support a scaffold platform upon the ladder.

It is a further object of this invention to provide a ladder attachment which is adapted to engage a slim, vertical elongated member and to safely support the upper end of a ladder thereagainst.

It is a still further object of this invention to provide a ladder attachment which, when contacting a vertical elongated member, engages that member with greater tenacity as a load is placed upon the ladder.

It is another object of this invention to provide a ladder attachment adapted to effectively engage vertical elongated members, which vary in size and shape over a wide range, in such a manner that tilting, sliding or rocking of a ladder supported thereagainst is eliminated or minimized materially.

It is yet another object of this invention to provide a ladder attachment for positioning and supporting a scafiold platform and/or a safety rail upon a ladder.

It is a still further object of this invention to provide a ladder attachment which is adapted for use with vertical supports formed of metallic, fibrous, or plastic material.

It is an additional object of this invention to provide a ladder attachment meeting the aforementioned objects and which is of simple, compact and sturdy construction, readily assembled or disassembled, readily mounted on and dismounted from a ladder, and which is inexpensive to produce.

The above and other objects will become more apparent upon proceeding with the following discussion when read in light of the accompanying drawings and appended claims.

in one embodiment of the attachment, an elongate, rigid crosspiece is provided having a pair of spaced parallel projecting arms secured to and extending generally transversely of the crosspiece. Securing means are provided in association with the crosspiece for detachably securing the attachment to a stepladder or to the stiles of an extension ladder. A pair of supports are provided, each having one portion secured to a projecting arm, and a second portion secured to the segment of the crosspiece disposed between the projecting arms. A pair of gripper levers are pivotally mounted on the two supports, each of the levers being pivoted between its ends and having an outer end outwardly disposed relative to the crosspiece and angularly disposed relative to an inner end adjacent said crosspiece. Gripper means are provided on the pivoted levers for engaging a vertical pole-like support. A platform support member is secured to the crosspiece and is provided with upright studs for laterally positioning and supporting a platform mend-I ber thereupon. An upright post is secured to the platform support member and is disposed transversely with respect to such support member and the crosspiece. The post is provided with a safety rail receiving member dis posed a substantial distance above the platform support member. A brace means entends from one side of the platform support member and is adapted to be secured to a portion of the accommodated ladder spaced from the area of securement of the crosspiece to the ladder.

For a more complete understanding of this invention, reference should now be had to the drawings wherein:

FIG. 1 is a fragmentary perspective view of one'foriii of the improved ladder attachment;

FIG. 2 is a fragmentary perspective view in reduced scale of the ladder attachment of FIG. 1 shown assembled on a stepladder;

FIG. 3 is similar to FIG. 2 with a safety rail and support therefor shown in assembled relation therewith;

FIG. 4 is an enlarged perspective view of one of. the platform and safety rail support assemblies sliown in FIG. 3;

FIG. 5 is a fragmentary perspective view of one form of ladder attachment without the platform support shown assembled on an extension ladder; I

FIG. 6 is similar to FIG. 5 but showing the ladder atf tachment secured to the top step of a stepladder accorn: modating a vertical pole, indicated by dashed lines;

FIG. 7 is an enlarged top plan view of'FlG. 6 with the ladder and vertical pole shown in dashed lines, and with the gripper mechanism shown in changed positions to accommodate poles of different diameters;

FIG. 8 is a sectional view taken along line 8-4; of FIG. 7; I

FIG. 9 is a top plan view or" a modified gripper mechanism;

FIGS. 10, ll and 12 are similar to FIGS. 6, 7 and 8, respectively, but show a modified ladder attachment;

FIG. 13 is an enlarged sectional view taken along line 13-13 of FIG. 11; and

FIG. 14 is an elevation VIQV'! of the pole-engaging surface of one of the gripper shoes shown FIG. 11.

FIGS. and 16 are similar to FIG. 7 but show a modified ladder attachment in two positions.

FIG. 17 is a perspective view of a modified gripper mechanism.

FIG. 18 is a top plan view of a support gripper memher.

As the ladder attachment of the present invention is intended for attachment to a ladder such as is generally vertically disposed when in normal use, and as the attachment is intended to be generally horizontally disposed when in such normal use, the attachment and its use will be discussed, in some instances, in terms of vertical and horizontal disposition. It is to be understood that this is the normal use only and such terminology is utilized primarily for convenience and clarity of description and is not intended to in any way limit the modifications of structure and the various uses to which the attachment may be adapted within the spirit and scope of the present invention.

Referring now to the drawings, and more particularly to FIGS. 1-3, one embodiment of an improved attachment 10 is illustrated. In FIGS. 2 and 3 the improved attachment is shown attached to a closed conventional type of stepladder 11 which includes opposing stiles 12, a plurality of steps as indicated at 13 and a top step 14 disposed generally transverse to the stiles 12.

The attachment 1% comprises an elongate frame member 16 formed of rigid sturdy material such as, for example, a piece of angle iron or channel. The frame member 16 serves as a crosspiece normally extending generally horizontally and transverse to the stiles 12 of the ladder to which it is attached by means of a vise clamp device indicated generally at 17 or by U-bolts 18 extending through wedge-shaped blocks 19 (see FIG. 5), depending upon whether the attachment is to a stepladder or an extension ladder. A pair of relatively spaced, substantially parallel,

elongate arms

29 and 21 are secured to and extend transversely from opposite end areas of frame member 16. The

arms

20 and 21 are generally horizontally disposed, extending from the frame member on the side opposite the securing means 17 and 18, and each of the arms is provided with rubber caps 22 on their distal ends. Further details of the structure so far described are amply set forth in the aforenoted U.S. Patent No. 2,903,086.

Disposed between the

parallel arms

20 and 21, and secured to these arms and to the crosspiece 16 is a support-engaging apparatus, indicated generally at 25, including a pair of

arcuate supports

26 and 27 and levers 28 and 29 pivotally mounted on the supports and adapted to engage an elongated slim upright support member such as a tree, pole or post.

Removably mounted on the upper side of frame member 16 is a pair of

platform support structures

31 and 32, both of which are of substantially the same construction, and each includes a platform support member 33 disposed generally transverselyto the frame member 16, parallel to the

support arms

20 and 21 and secured to the upper side of frame member 16 by bolts 34. Each of the members 33 is provided with a plurality of longitudinally spaced holes 35 adapted to overlie one of a plurality of holes 36 provided in the upper portion of frame member 16. By suitably selecting the

holes

35 and 36 to receive bolt 34, lateral and longitudinal adjustments of members 33 are obtained for fitting to ladders of various sizes and configurations. A pair of up

right studs

37 and 38 are mounted on, and extend transversely upwardly from, each of members 33 for laterally positioning a platform member or plank 39 supported upon the upper surfaces of the platform support members. Extending outwardly and downwardly from the end of each of the platform support members disposed opposite from the direction of extension of

arms

20 and 21 is a brace 42. The lower ends of braces 42 are secured to the stiles 12 of' the ladder 11 at points 45 and 46 (see FIG. 2); the latter points are vertically spaced from

members

17 and 18 to effect adequate bracing of the attachment when mounted upon a ladder. While two platform supports are provided on one attachment in FIGS. 2 and 3, one support on each of two attachments disposed on spaced ladders may be utilized in supporting longer platforms.

Referring now to FIGS. 3 and 4, a safety rail unit 50 is provided on each of the

platform support members

31 and 32 for supporting an elongate rail 51 above the platform support member and in substantially parallel relation to plank 39. The two disclosed rail-supporting units are the same except that one is for right-hand sccuremcnt and the other is for left-hand securement to the opposite platform supports 31 and 32. Each unit consists of an upright post 52 secured adjacent its lower end to the respective platform support member 33 as by a bolt 53, and to the respective brace 42 at a point therebelow as by a bolt 54. The post 52 is provided at its upper end with a U-shaped safety rail receiving member 55. Disposed transversely of platform support member 33 and post 52 is a brace 57 suitably secured to the post 52. Diagonaliy extending elements 53 interconnect the end portions of brace 57 with the post 52, see FIG. 4. Each transverse brace 57 is spaced above the upper edge of the respective platform support a distance substantially equal to the thickness of the plank 39 to insure a close fit of the member 39 therebetween. The rail posts are of sutficient height that the rail 51 supported thereby will serve as a safety rail for persons standing on plank 39. A pair of rail supports may be placed on one attachment as in FIG. 3 or single supports may be disposed on attachments on separate spaced ladders.

FIG. 5 illustrates the mode of sccurement of the ladder attachment to an extension type ladder 60 wherein the stiles thereof are engaged by U-bolts 18. Platform supports 33 and safety rail supports 50 may, if desired, be utilized with ladder 60 in substantially the same manner as shown in FIGS. 1-3.

The details of the engaging apparatus 25 and its general mode of operation are further illustrated in FIGS. 6-8.

Supports

26 and 27 are each suitably secured at one end to one of

arms

20 and 21, respectively, at a point thereon spaced outwardly from frame member 16, and extend in generally arcuate fashion toward one another and toward the frame member, being secured at their opposite ends to the frame member. Each of the

levers

28 and 29 includes an arcuate midportion 63 pivotally mounted on the respective support via a pivot pin 62. Extending outwardly from the midportions, in the direction of extension of the

supports

26 and 27 from frame member 16, are outer free end portions 64, each having a pointed terminus 65. In this embodiment, gripper means 65 comprises one or more sharp points or spikes, on each lever, particularly adapted for engaging and penetrating a wooden upright such as the poles or posts indicated by the dashed lines 66 and 67. The opposite ends of each of the

levers

28 and 29 comprise inner free straight portions, as at 68, the latter portions being of sufficient length to overlap one another when the pivot levers are positioned in a generally open position as shown in solid lines in FIG. 7.

Referring further to FIGS. 6 and 7, the operation of the upright member gripping structure is illustrated in conjunction with a pole, it being understood that the operation is the same when a post, tree, or other slim, elongated support, either circular or polygonal in crosssection, is encountered. A ladded 70, to which the present ladder attachment has previously been secured, is positioned so that the opening between

levers

28 and 29 is aligned with the pole. As the ladder is inclined toward the pole, the elfect is tourge the pole between the levers toward the frame member and thus toward the ladder. As the pole passes between the first ends of the levers, which have previously been spread, one of two general types of actions will take place depending on the particular size relation of the opening between the levers and the diameter of the pole. Referring first to the pole 66 and the position of the

levers

28 and 29 shown in solid lines in FIG. 7, a comparatively large-sized pole will first engage the inner or first ends 68 of the levers and, by pressure against these ends, will force the outer or second ends into a position wherein the grippers 65 will engage the pole. Further pressure or force exerted upon the attachment, toward the pole, such as would be created by a person or weight placed upon the ladder, will further urge the pole between the levers against inner ends 68, tending to rotate the levers, and will thus cause increased tightening of the grippers on the pole. The levers will also operate on a pole of a diameter too small to engage the inner lever ends 68 as illustrated in dashed lines in FIG. 7. In the latter instance, the levers are pre-positioned with the grippers spaced apart a distance less than the diameter of the pole 67 and the attachment is then moved toward the pole. The grippers engage the pole 67 and are urged into ever tighter engagement with the pole by further loads applied to the ladder or platform. Due to the position of the pivot pins 62, which are each outside of the outer diametral limits of the engaged poie, an effective lever arm of a length indicated at L in FIG. 7 is created which, in combination with the applied load, tends to further rotate the outer ends of each of the levers inwardly toward the post, thus tightening the engagement of the grippers on the post 67. It should be noted that a similar but shorter effective lever arm may occur even with a pole 66 which is large enough to contact inner ends 68.

Ladder 70 is similar to one-half of a conventional stepladder, having a fiat top step upon which vise clamp 17 may be secured. The attachments illustrated in the various embodiments are all adapted to be attached to a stepladder as in FIGS. 2 and 3, an extension-type ladder as in PEG. 5, or various other ladders such as that shown in FIG. 6.

One alternative form of gripper particularly adapted for use on metal poles or posts is shown in FIG. 9. In this modification an arcuate member or shoe 72 is pivotally mounted on the outer free end of each lever as by a further pivot pin 73. Member 72 is preferably of a size and configuration to match the circumferential periphery of poles upon which it is to engage. A liner 74 of rubber, plastic, abrasive or other suitable non-slip gripping material and of suitable configuration is preferably secured to the concave surface of member 72 as by riveting or by a suitable adhesive.

In FIGS. -12 there is illustrated another form of engaging means adapted for use on slim, elongated supports and which includes a linkage means to provide added stability, thus further preventing rocking or tilting of the attachment and related ladder about the points or area of engagement of the engaging means with such supports. The linkage means includes a pair of

links

76 and 77 each pivoted at one end to the inner end portion of the

respective levers

28 and 29 as by

pivot bolts

78 and 79, see FIG. 11. The two

links

76 and 77 are pivotally interconnected at their opposite ends as at 31. A further pivot link or leg 82 is pivotally joined at one end to the two links at 81 and has its opposite end pivotally joined to one of the arms and 21 as at 83. This linkage assembly may be utilized with the various gripper means and provides an additional point of support for each of the lever arms, thus aiding in the prevention of rocking of the attachment unit about an upright with which it is engaged. Use of the link-age assembly is particularly desirable when the attachment is utilized in cooperation with smaller diameter supports which do not engage the inner ends of the levers.

FIGS. 10 through 12 also illustrate a further form of gripper in which a band-type unit 84 is provided on each lever. Each unit 84 includes

loops

85 and 86 integral with or secured to each end of a flexible strip 87. The

port.

loops engage pins 88 which, site ends of each of the levers. The strips 87 should be flexible but must possess considerable tensile strength and may be formed of metallic stock. A liner, similar to liner 74, may be applied to the concave face of each of the units 84; however, I prefer to utilize the gripping means illustrated in FIGS. 11 and 14 wherein rubber disks 89 are disposed in a line running diagonally across the face of each strip 84. The disks 89 may be secured to the units 84- by various means such as riveting or by the use of a suitable adhesive.

FIG. 13 illustrates the pivotal connection of the

levers

28 and 29 to the

supports

26 and 27. Bolt 62 is countersunk into support 26, passes through lever 28 and is engaged on the opposite end by a burr 62a. Interposed between support 26 and lever 28 and between lever 28 and burr 62a are washers 90 and )1 which act as bearing surfaces to permit relative rotation between the lever 28 and support 26.

In FIGS. 15 and 16 there is illustrated another form of engaging means somewhat similar to the device of FIGS. 10-12 but with added engaging structure and brace means. This structure provides for improved gripping of a support member and added stability of the supported ladder by providing a further support engaging member 92 including a support gripper 93. Member 92 is a straight rigid member, similar to links 76 -77, extending forward from a pivotal mounting at 81a. The forward portion of member $2 is pivotally connected to a pivot link or leg 94, similar to and generally parallel with member 82. Link 94 is also pivotally connected to the same arm as the corresponding end of link 82. Thus, a parallelogram is formed of member 92,

links

82 and 94, and a portion of arm 20, which results in the maintenance of member 92 in a predetermined relation to arms 26-21 and assures proper presentment of support gripper 3 in all positions of the engaging mechanism. The disclosed support gripper 93 comprises an angularly formed back plate 95 with a plurality of rub.- ber disks 8% disposed on the forward face thereof.

The grippers 65a shown in FIGS. 15 and 16 represent a multi-point variation of grippers 65. In FIG. 15 the modified engaging mechanism is shown expanded for engaging a large support member, while FIG. 16 illustrates the position of the grippers when engaging a smaller sup- This modified engaging mechanism, in use with any of the disclosed gripper means, provides a third or additional engaging point for grippinga vertical support and thus enhances the operation and stability of the attachment.

FIG. 17 illustrates a further modification of gripper 'suitable for use on wooden or metal supports. This gripper comprises a right-angle back plate or shoe 96, pivotally mounted on a lever 28 via one leg of the back plate 96, and grippers such as rubber disks 89b secured on the exposed face of the other leg.

FIG. 18 illustrates one modification of member 92 wherein the gripper 93 of FIGS. 15 and 16 is replaced by a sharp point gripper 93a similar to grippers 65a. This modification is particularly well adapted for use in conjunction with wooden supports.

The dimensions of the various members may, of course, be varied to adapt the disclosed attachment for various specific uses. Notably, the length of

arms

20 and 21 and supports 26 and 27 may be varied to accommodate platforms of various widths in conjunction with the various types of ladders.

It will be appreciated that applicant has provided an improved ladder attachment which will firmly and safely engage various vertical members, even where the vertical member is of a slim, elongated vertical configuration such as, for instance, a tree, pole, or post. Further, the attachmerit Will engage such vertical members with greater tenacity as additional loads are placed upon the supported ladder. The attachment is adapted for use with wide ranges of sizes of support members and it safely supports in turn, pass through oppoa a scaffold platform in a desired position spaced from the support member. Further, the improved attachment provides support for a safety rail, and is in addition of simple, sturdy, and safe construction and is adapted for ready use on the various types of ladders.

While several embodiments of this invention are shown above, it will be understood, of course, that the invention is not to be limited thereto, since many modifications may be made in light of the foregoing disclosure. It is contemplated, therefore, by the appended claims to cover any such modifications as fall within the true spirit and scope of this invention.

I claim:

1. An attachment for supporting a ladder against a slender support element comprising: a frame member removably mountable on such ladder, support means including spaced arms and support members bifurcately fixed thereto and mounted on and extending laterally from said frame member, a pair of levers pivotally mounted on said support members in opposed relation, said levers each having a free first end disposed generally toward said frame member from the respective pivot point and a free second end disposed generally away from said frame member, one of said free first ends overlapping the other of said free first ends for engaging such element upon movement of said frame member toward such element, said second end of each lever being angularly disposed relative to said first end, and gripper means on said levers for engaging such element upon pivotal movement of said levers.

2. An attachment for supporting a ladder against a support element comprising frame means removably mountable on such ladder, support means mounted on and extending laterally from said frame means and spaced gripper levers pivotally mounted on said support means in opposed relation, a gripper member disposed between said spaced levers, a parallelogram linkage system connecting said gripper member to said support means, and linkage means interconnecting said levers and said gripper member for coordinated movement.

3. An attachment for supporting a ladder against a support element, which ladder is generally vertically oriented when in normal use comprising, a frame member, securing means for securing said frame member to said ladder in a normally horizontal position, spaced projecting arms secured to and extending generally horizontally from one side of said frame member, supports secured to each of said arms and extending to and secured to said frame member between said arms, spaced opposed gripper levers pivotally mounted on said supports, pivotally interconnected links pivotally secured one to each of said gripper levers, and a pivot member pivotally connected to said links and to one of said arms.

4. An attachment as in claim 3 and including a gripper member disposed between said gripper levers, parallel to said one of said arms and pivotally connected to said links and said pivot member; and a further pivot member generally parallel to and spaced from the first-named pivot member, said further pivot member pivotally connected to said one of said arms and to said gripper member.

References Cited in the file of this patent UNITED STATES PATENTS 1,195,740 Samuelson Aug. 22, 1916 1,915,715 Bodenieck June 27, 1933 2,903,086 Chubbs Sept. 8, 1959 2,910,135 Moore Oct. 27, 1959 FOREIGN PATENTS 239,473 Germany Oct. 13, 1911 461,822 Italy Jan. 31, 1950 848,245 Germany Sept. 1, 1952 1,121,612 France May 7, 1956 OTHER REFERENCES Popular Mechanics Magazine, page 148, August 1958.