US3655012A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Universal folding ladder
Assignee: Individual
•
Filing: 1970-07-30
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Granted: 1972-04-11
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Expires: 1990-07-30
Abstract
Abstract A folding ladder is formed of several pairs of ladder sections connected by a joint. The joint includes on one section a circular locking disc concentric with the joint axis and with recesses about its periphery corresponding to the different positions of the ladder sections, and a stop member on the other section engageable in the recesses. A releasing lever is provided which lift the locking member out of the recesses. An arresting device associated with the releasing lever locks the releasing lever in its releasing position during movement of the ladder sections with respect to each other in one direction and disengages the releasing lever at the end of such movement.
Inventors
- 👤 Helmut Hoffman
- 👤 Walter Hoffman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 07:37
CPC Classifications
E; E06; E06C; E06C1/00; E06C1/02; E06C1/32
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
292 words
A universal folding ladder comprising several pairs of ladder sections which are interconnected by joints and which can be locked in the straightly extended position and in at least one service position, each of said joints connecting two ladder sections and comprising a first joint member connected to either of the said two ladder sections and having at least one circular locking disk arranged concentrically with the joint axis, with recesses provided about its periphery which are associated to The straightly extended position and to different service positions, respectively, and further comprising another joint member which is rigidly connected to the other one of the said two ladder sections and further connected with the locking disk of the said first joint member so as to be pivotable about a joint pin, a stop member provided and guided on the said second joint member which snugly fits into the different individual recesses, respectively, when the said ladder sections are in any of the pre-determined positions and which is released from its engaged position and secured in its disengaged position by a single releasing lever which is pivoted on the said second joint member and is to be operated from the outside and which can be pivoted to and fro at will between an engaged position and a disengaged position and with the aid of which the stop may be lifted off the recesses when in its engaged position, wherein to the said releasing lever there is associated an arresting device engaging with, and locking, the releasing lever in its operative position during movement of the sections with respect to each other in one direction and disengaging from, and releasing, the releasing lever again when the joint members reach the end of such movement.
Claim 2
Dependent Claim
292 words
A universal folding ladder comprising several pairs of ladder sections which are interconnected by joints and which can be locked in the straightly extended position and in at least one service position, each of said joints connecting two ladder sections and comprising a first joint member connected to either of the said two ladder sections and having at least one circular locking disk arranged concentrically with the joint axis, with recesses provided about its periphery which are associated to The straightly extended position and to different service positions, respectively, and further comprising another joint member which is rigidly connected to the other one of the said two ladder sections and further connected with the locking disk of the said first joint member so as to be pivotable about a joint pin, a stop member provided and guided on the said second joint member which snugly fits into the different individual recesses, respectively, when the said ladder sections are in any of the pre-determined positions and which is released from its engaged position and secured in its disengaged position by a single releasing lever which is pivoted on the said second joint member and is to be operated from the outside and which can be pivoted to and fro at will between an engaged position and a disengaged position and with the aid of which the stop may be lifted off the recesses when in its engaged position, wherein to the said releasing lever there is associated an arresting device engaging with, and locking, the releasing lever in its operative position during movement of the sections with respect to each other in one direction and disengaging from, and releasing, the releasing lever again when the joint members reach the end of such movement.
Claim 3
Dependent Claim
141 words
The universal folding ladder set forth in claim 1, wherein the said arresting device retains the said releasing lever both in its operative and in its inoperative position, wherein, further, the releasing lever can be transferred into its operative position corresponding to the disengaged position of the stop member against the action of the arresting device only by hand and into its inoperative position corresponding to the engaged position of the stop member against the action of the arresting device only by cooperating with one of the cams associated with the different individual positions of the ladder sections, and wherein, further, the shape and arrangement of the cams and their coordination with the releasing lever are such that they will become effective only when the ladder sections are being unfolded while remaining ineffective when the ladder sections are being folded together.
Claim 4
Dependent Claim
94 words
The universal folding ladder set forth in claim 1, wherein to the said releasing lever having the form of an angular lever there is associated a spring member which is movably connected with the said releasing lever and which retains and locks it both in its operative and in its inoperative position, the said spring member acting in the manner of a snap acting means so that the lever, once it has been removed from one end position and pivoted beyond its dead-center position, will snap into its other end position, and vice versa.
Claim 5
Dependent Claim
80 words
The universal folding ladder set forth in claim 3, wherein the one end of the said releasing lever is the operating end and the other end thereof is loaded by the spring member, wherein, further, the releasing lever is movably supported in about the middle area between its ends by means of pins and oblong holes and wherein, finally, the counterface of the said releasing lever cooperating with the cams is provided on the lever side opposite the joint member.
Claim 6
Dependent Claim
72 words
The universal folding ladder set forth in claim 1, wherein to the said recesses in the said locking disk there are associated guide slots provided in another disk connected coaxially to the said other joint member which hold and guide the stop member, the said stop member engaging the recesses in the radial direction from the periphery towards the center of the disk when the stop member is in its engaged position.
Claim 7
Dependent Claim
171 words
The universal folding ladder set forth in claim 1, wherein the stop member passes through opposing recesses provided, on the one hand, in the releasing lever between the latter''s support portion and the end associated with the spring member and, on the other hand, in the associated joint member, in such a manner that the stop member may be movable on the one hand along a straight line between its engaged position and its disengaged Position and, may, on the other hand, perform a relative movement between the stop member and the releasing lever when the latter is pivoted, this being done by making the recesses in the associated joint member to have the form of oblong holes the length of which corresponds approximately to the height of the stop member plus the path travelled by the stop member between the engaged and the disengaged position, while the recesses in the releasing lever have the shape of rectangular holes with a width considerably greater than the width of the stop member.
Claim 8
Dependent Claim
155 words
The universal folding ladder set forth in claim 1, wherein cams, which are provided at approximately equal intervals along the circumference consist each of a projection provided on that side of the locking disk carrying the recesses which faces the releasing lever, the said projections having when viewed from above, the form of a quadrant with the arc facing the periphery of the locking disk, while one of the two straight boundary lines are directed radially to the center of the locking disk and the other one of the straight boundary lines on the corresponding point extends parallely to the tangent to the circumference of the locking disk, the counterface of the releasing lever cooperating with the cams being, when viewed from the operating end, curved towards the cams and interrupted at about the middle of its length by a step facing the other side and ending towards the spring member in a flat curve.
Claim 9
Dependent Claim
68 words
The universal folding ladder set forth in claim 1, wherein a spring acting on the stop member is arranged excentrically and bears on the one hand against an abutment arranged approximately diametrically opposite the said stop member and forming an integral part with the said second joint member, and on the other hand in directly against the side of the stop member facing away from the releasing lever.
Claim 10
Dependent Claim
235 words
The universal folding ladder set forth in claim 8, wherein the releasing lever comprises two portions which can be flexibly moved towards and away from each other, while maintaining the rotatable support provided by the journal pin mounted to each of the portions, the said two portions of the said releasing lever having one recess each essentially in the region of the journal pin, the said recess cooperating with an associated stop member provided on the inner surface of the associated circular disk, such cooperation taking place in such a manner that rotating of the releasing lever and displacing of the stop member into the or disengaged position, when the stop member of the joint is engaged in any of the service positions, will cause the stop member of each circular disk to engage into the associated recess in the releasing lever and thereby arrest and lock the latter in this position, while in the case of any subsequent relative movement of the joint the journal pins will be moved away from the inner surface of the associated circular disk, through the recesses provided in the locking disk, so that the recess of the releasing lever will disengage from the associated stop member in a direction rectangular to the circular disk, thus releasing the stop member of the joint for another automatic engagement or locking movement when the joint is rotated into another service position.
Claim 11
Dependent Claim
87 words
The universal folding ladder set forth in claim 1, wherein the cross-section of the rungs has the shape of a polygon with two sides inclined in relation to each other, one of them corresponding to the opposite surface and wherein, further, the arrangement of the rungs in relation to the ladder beams is such that the tread surface, which is comprised in an approximately horizontal plane and which extends over substantially the whole stringer width, is inclined in relation to the longitudinal edges of the respective stringer.
References Cited (Backward Citations)
FR1531014A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-04-11 | 1975-10-11 | 1976-04-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-04-11 | 1979-10-11 | 1980-04-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-04-11 | 1983-10-11 | 1984-04-11 | $7700.00 | Window Closed / Lapsed |