US 3139155 A
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June 30, 1964 LE ROY C. SKEELS LADDER HANDRAIL Filed Feb. 14, 1963 INVENTOR.
LeReyQSkeeha United States Patent 3,139,155 LADDER HANDRAIL Le Roy C. Slreels, R0. Box 66, Alburnett, Iowa Filed Feb. 14, 1963, Ser. No. 258,525 4 Claims. (Cl. 182106) This invention relates to handrail equipped stepladders and in particular to a stepladder with a retractable guard rail (or safety handrail) which automatically locks in the raised, open, or unfolded position and to manually actuated means for unlocking the handrail when the handrail is to be lowered from the raised and locked position.
Various safety handrail devices have been employed for giving guidance and support to those using a stepladder. Some of the devices have been of the type that unfold and fold as a stepladder of the folding type is opened and closed. Others employ rail position friction clutch holding devices, and others employ positively fastened rail structures that are not retractable. These fall short, how ever, in providing the flexibility of use desired in a safety handrail, such as independent raising, retracting, and positive position locking for the raised position, and further for ease in removing the lock and retraction.
It is, therefore, a principal object of this invention to provide a retractable safety handrail for a stepladder having an automatic raised position lock and easy lock release when the handrail is to be lowered from the raised position to the retracted position.
Another object is for operation of a retractable handrail to be independent of folding and unfolding of a foldable stepladder.
A further object is to provide a stepladder retractable safety handrail having automatic raised position locking for two depending side rails and for easy simultaneous lock release.
Features of the invention, useful in accomplishing the above objects, include a retractable handrail for a foldable stepladder, automatic locking means for positively and safely locking the handrail in the topmost raised position, and a manually activated lock releasing device. The automatic locking means has opposite side spring loaded and cam actuated latch members, and the lock releasing device has a pivotally mounted lever with two offset crank action plunger rods extending to the respective opposite side latch members.
A specific embodiment representing what is presently regarded as the best mode of carrying out the invention is illustrated in the accompanying drawing.
In the drawing:
FIGURE 1 represents a perspective view of a foldable stepladder equipped with a retractable safety handrail utilizing the raised position lock and lock release of this invention;
FIGURE 2, a side view of the stepladder of FIGURE 1 in the folded state with the safety handrail retracted;
FIGURE 3, a partial transverse section taken on the line 3-3 of FIGURE 2 with, however, cam lock actuating handrail mounting links in raised lock position as in FIG- URE 1, and showing lock release detail; and
FIGURE 4, a fragmentary enlarged section view of a portion of FIGURE 3, with the lock release actuated and a side latch member resiliently displaced from the latched lock link retaining position.
3,139,155 latented June 30, 1964 Referring to the drawing:
Stepladder 10, conforming to the invention, is constructed primarily of wood although it could be entirely of metal. It includes two opposite side upright members 11 with transversely extended steps 12 mounted between. A top platform 13 is rigidly mounted to the upper ends of side members 11 and two rear props 14. The rear props 14 are connected together by member 15 and cross framing 16, and are pivotally mounted, together as a folding unit, with pivot pins 17 extended through top side frame members 18, the top ends of props 14, and into top transverse member 19.
The upper ends of side members 11 are received between top side frame members 18 and a mounting frame member of the respective side. Opposite ends of transverse member 19 are mounted to the rear bottom of respective frame members 20 by nails or rivets 21, and a forward transverse member 22 is mounted to the forward bottoms of frame members 20 by nails or rivets 23. A rearwardly extended hand actuated lever 24, described in greater detail hereinafter, is pivotally mounted by pivot pin 25 to the transverse center of member 22.
A retractable safety handrail 26 having a left depending side rail 26a and a right depending side rail 26]) is mounted by pivot pins 27 and brackets 28 on the outer ends of upper links 29 and lower links 30. A link 29 and a link 30 are in turn pivotally mounted on the outer side of each side member 11 by pivot pins 31. This facilitates raising and lowering of retractable handrail 26 between the topmost raised position of FIGURE 1 and the lowered retracted state of FIGURE 2. Bearing plates 32 aid in pivoting of links 29 and 30 between the depending state of FIGURE 2 and the upright state of FIGURE 1. The links 29 and 30 are so shaped and the depending side rails 26a and 26b so spaced that the outer ends of links 29 freely move into overlapping relation to the inner ends of links 30 as the handrail 26 is lowered to the retracted state of FIGURE 2.
Cam and latch members 33a and 33b are mounted on the outer sides of respective frame members 18 to project forwardly beyond the forward edges of the members 18 and the respective upright side members 11. Latch members 33a and 33b, as mounted by respective anchor pivot pins 34 and bolt assemblies 35, also angle downwardly from back to front. The anchor pivot pins 34 each have a head so spaced as to permit pivoting movement of the respective latch members 33a and 33b about the anchor point in order that the forward ends of the latch members may be displaced through an outward arcing range of movement. The bolt assemblies 35 extend through openings in the latch members 33a and 33b to outer end spaced heads 36 and include resiliently compressed springs 37 mounted on the bolt shanks and confined between the bolt heads 36 and the outer sides of the latch members 33a and 33b. Thus, the latch members 33a and 33b are continually resiliently biased to the inward positions in side by side engagement with the outer sides of the frame members 18, as shown in FIG- URES 1 and 3.
Latch members 33a and 33b are provided with outwardly curved cam portions 38a and 38b. These are shaped to present cam surfaces engaged by upper edges of upper links 29 as handrail 26 is being raised and upper links 29 are being pivoted to the raised and locked position of FIGURE 1. When upper links 29 engage the cam surfaces of latch cam portions 38a and 38b, respectively, continued upward pivoted movement of the links 29 by cam action pivots the latch members 33a and 33b outwardly to as far as the deflected latch member 33a position of FIGURE 4 against the resilient compressive force of springs 37. Then as the upward pivotal movement of links 29 is being completed and the bottom edges of the links 29 pass beyond cam portions 38a and 38b the resilient force of springs 37 snap the latch members 33a and 3312 back to the inward positions of FIG- URES l and 3. Latch surfaces 39a and 39b of latch members 33a and 3312 are then in latch link 29 locking alignment and safety handrail 26 is in the raised and locked state. Grooved brackets 40 are mounted on the forward edge of top platform 13 for receiving the upper edges of links 29 to give additional support to links 29 and handrail 26 in the raised position. It should be noted that depending side rails 26a and 26b are spaced to freely move into outside overlapping relation with the latch cam portions 38a and 38b, respectively, as handrail 26 is lowered to the retracted state of FIGURE 2.
An easy lock release, including lever 24, is provided for moving the latch members'33a and 33b from the lock positions of FIGURES l and 3, with latch surfaces 39:: and 39b in locking link 29 restraining alignment, to positions as shown for latch member 33a in FIGURE 4 to permit outward and downward pivoting movement of the links 29 and lowering of safety handrail 26 to the retracted state of FIGURE 2. Two crank action plunger rods 41a and 41b are pivotally connected at inner ends by crank pins 42a and 42b to lever 24 at points spaced outwardly and inwardly, respectively from pivot pin 25. Each plunger rod 41a and 411) extends from the lever 24 to and through guide openings through the respective side members 11 and frame members 18 to end 43a and 43b abutting contact with the inner side of the latch members 33a and 33b, respectively. End abutting contact transmits thrust for moving latch members 33a and 33b outwardly, as indicated in FIGURE 4 for latch member 33a, particularly when lever 24 is manually moved in a clockwise direction as viewed in FIGURE 3. Such lever 24 clockwise movement about pivot pin 25 acting through crank pins 42a and 42b in a crank action thrusts plunger rod 41a outwardly to the left, and simultaneously plunger rod 41b outwardly to the right as viewed in FIG- URE 3. It should be noted that the resilient force of springs 37 acting through latch members 33a and 33b returns the lever 24 to the latch lock position when manual lock release force is removed from lever 24 except when the latch members 33a and 33b may be deflected outwardly by their cam action With upper links 29. Thus, easy simultaneous lock release is provided for the two opposite depending side handrails having automatic raised position locking in a folding stepladder having a retractable safety handrail.
A foldable linkdevice 44 is provided at each side of stepladder 10 extending between a side member 11 and a prop 14 for limiting and locking the unfolded position of the prop 14 ladder back relative to the front of the ladder as shown in FIGURE 1. Each link device 44 includes a rear link 45 pivotally mounted by a pivot pin 46 on a prop 14 and front link 47 pivotally mounted by a pivot pin 48 on a side member 11. Each set of links 45 and 47 are pivotally connected together by a pin 49. Each link 47 is also provided with a resilient snap and cam action engaged clip 50 that interacts with its companion link 45 between the pins 46 and 49 for locking the straight link 45 and 47 longitudinally aligned unfolded state. Each lip 50 is also provided with a stop extension 51 that engages the top edge of the companion link 45 to prevent reverse link 45 and 47 folding. The clips 50 may be manually deflected outwardly for lock release when it is desired to fold the link devices 44 and the stepladder to the compact folded state of FIGURE 2.
Thus, from. the foregoing description it becomes apparent that, an improved foldable stepladder is provided that features an independently retractable and extendable safety handrail. Further, the automatic locking mechanisms for safely holding the handrail in the topmost raised position is provided with an easy manually activated lock release that simultaneously releases the handrail position lock of both sides.
Whereas this invention is here illustrated and described with respect to a single embodiment thereof, it should,
be realized that various changes may be made without departing from the essential contribution to the art made by the teachings hereof.
1. In a safety handrail equipped stepladder having two opposite side upright members with steps mounted between, a top platform, and two rear props: a depending handrail; multiple links pivotally connected to said depending handrail and pivotally mounted on one of said upright members in order that the handrail may be pivotally raised and lower between a topmost raised position and a lowered retracted state; latch means mounted on said stepladder; mounting means adapted for deflection of the latch means between a first position and a deflected position; means resiliently urging the latch means from the deflected position to the first position; a cam portion of said latch means positioned to be engaged by one of said multiple links and, by cam riding action with the link, for deflection of the latch means from the first position toward the deflected position and to permit the link to pass as the handrail is being raised to the topmost raised position; a latch step surface between the cam portion and the mounting means of said latch means; said latch step surface being positioned for resiliently biased movement into link locking alignment as the link engaging the latch means passes the cam portion and the latch step surface and the handrail is attaining the topmost raised position; manually actuated latch lock release means mounted on the stepladder and constructed for deflecting said latch,
means from the first position to said deflected position against the force of the means acting resiliently on'the latch means for removing the latch means from link locking alignment to permit handrail lowering from the topmost raised and locked position to the retracted state; and wherein the mounting means adapted for deflection of the latch means between a first position and a deflected position includes: an anchor member extending through stepladder structural means and through a pivot end of the latch means opposite from the cam portion end, and bolt means extending through stepladder structural means and the latch means to an outwardly spaced head; and the means resiliently acting on the latch means being resiliently compressed spring means supported on the shank of said bolt means and confined between the head of the bolt and said latch means.
2. The safety handrail equipped stepladder of claim 1, wherein an additional depending handrail is pivotally mounted on the other side of the stepladder by additional multiple links pivotally connected to the other upright member; additional latch means having features duplicating those recited for said latch means, mounted by duplicate mounting means, resiliently biased in the same manner by duplicate resilient biasing means; and with said manually actuated latch lock release means being constructed for simultaneously deflecting both said latch means from the respective first positions outwardly to said deflected positions to' permit lowering of both depending handrails from the respective topmost raised and locked positions to the retracted state.
3. The safety handrail equipped stepladder of claim 2, wherein the latch means of each side is mounted for cam action deflection by, and locking of, the topmost handrail mounting link of each side; and said manually actuated latch lock release means includes: a hand lever pivotally mounted by pivot means mounted beneath said top platform; first and second plunger rods pivotally connected at inner ends by first and second crank pins, respectively we J References Cited in the file of this patent UNITED STATES PATENTS Meisel Ian. 29, 1889 Mead May 18, 1909 Boggs May 9, 1950 Seigneur July 3, 1951 Haltenberger Mar. 5, 1957 FOREIGN PATENTS Germany Oct. 27, 1930