US1711358A - Ladder and adjusting mechanism - Google Patents

Description

April 30, 1929.

1 F. A. LUNDAHL LADDER AND ADJUSTING MECHANISM Filed June 20, 1927 3 Sheets-Sheet 1N VENTbR wfx nwunwwmmw hu A 4. 4 amok/a.

ATTORNEY April 30, 192 9. LUNDAHL 1,711,358

LADDER AND ADJUSTING MECHANISM Filed, June 20, 1927- a Sheets-Sheet 2 A TTORNE Y April 30,1929. LUNDAHL I 1,711,358

LADDER AND ADJUSTING MECHANISM Filed June 20, 1927 3 Sheets-Sheet 3 514, lU/VDAI/L I INIVENTOR ATTORNEY Patented Apr. 39, 1929.

PATENT oFFIcE.

FRED A. LUNDAHL, OF MOLINE, ILLINOIS.

LADDER AND ADJUSTING MEOHAN ISM.

Application filed June 20, 1927. Serial No. 199,908.

lVhile the present invention relates primarily to the construction of toys which are sufficiently durable to stand considerable usage and unusual wear, 1 desire it understood that certain features thereof are capable of use in similar articles for use other than as toys. The present invention relates to a new ladder.construction and adjusting means whereby ladders may be adjusted in various directions.

Among the ob'ects of my invention are to provideimproved mechanism for the horizontal adjustment of ladders; to provide improved mechanism for the vertical adjustment of ladders; to provide an improved mechanism for the extension and shortening of ladders; to provide improved mechanism for the separation on the winding drum of the ladder extending and retracting cables;

to provide an improved construction of lad-' der; and such further ob ects, advantages, and capab1hties as will hereafter more fully appear and as are inherent in the mechanism disclosed. My invention further re sides in the combination, construction and arrangement of parts illustrated in the accompanying orawings and, while I have discloserl'therein a specific embodiment of my invention, I desire the same to be understood as illustrative only and not as limiting said invention.

In the drawings annexed hereto and forming a part hereof, Fig. 1 is an elevation of my invention mounted upon a suitable support, the latter being shownin outline by dotted lines; Fig. 2 is a broken plan view of the construction shown in Fig,1, with the ladder extended; F 3 is a longitudinal section of my construction detached from the truck and showing the ladder in elevator and extended position, sections of the ladder being broken out for the purpose of short ening the same; Fig. 4 is a crosss'ection in front of thewinding drum, looking rearward and showing the arrangement of the cables on the winding drum and the spacing means between said cables; Figs. 5' and (3 are similar views showing the positions of the in the upper part of the disc 2.

ts when the ladder is fully extendedand I member 9, looking upwardly, and showing the relative positions of the gears 5 and 8, pivots 6 audit), and the meshing of the teeth 3 and d; Fig. 9 is a cross section through the ladder, fully collapsed as shown in Fig. 1, said section showing more clearly the inter-fitting of the ladder sections shown in. Figs. 1 and 3; Fig. 10 is a cross section substantially along the plane indicated by the line 10-10, Fig. 3; Fig. 11 is a fragmentary elevation of a portion of my device showing another type of lifting mechanism for the ladder; Fig. 12 is a similar view with the ladder shown in elevated position; Fig.

13 is a fragmentary transverse section substantially along the plane indicated by the line.13-13, Fig. 11. I

Referring more in detail to the annexed drawing, numeral 1 designates a supporting body of any suitable type, herein shown as an automobile truck, while numeral 2 denotes a discsecured to the supporting body. Said disc 2, has gear teeth 3 rigidly secured thereto, the same being engaged by the cooperating teeth 4; on a the rod 6 provided with a Wheel 7. It will be understood of course, that this mechanism maybe varied as desired to produce the results intended. For example, the upper part of the disc 2 may be perforated at intervals to provide teeth taking the place of the teeth'i'l, herein shown as formed upon the edge of a disc 8 which is secured to the disc 2. In such a construction the teeth 4: of the pinion 5 would be located enough lower than. herein shown so that they would engage and cooperate with the teeth formed Various other constructions will suggest themselves from the foregoing and it is therefore not considered necessary to disclose these in detail. 7 V I Asupporting member -9 is mounted upon the disc and pivoted thereon by means of a kingpin 10 extending axially through the disc 2. This kingpin is herein shown as being secured in place by means of nuts but any other suitable fastening means may be employed for this purpose.

Rising from the upper surface of the supporting means 9 are wings 11 to which is pinion 5 carried by ception of the pivots 12. The bracket l t comprises opposite side members connected by cross-burs 16 and is secured to the ladder in any desired manner, as by bolts 17.

Other suppo: means rises from the upper surface ol: tne supporting means or table 9, said other supporting means being designated by the numeral 13, in the present instance being shown as apair of brackets. To these brackets are pivotally connected at 19 a pair of arms 20, the ex tremitics (it said arms being); bent upwardly as showi'i at 21 to engage the sides of the ladder 13. A. crossbar 22 extends between the arms 20 and is pivotally secured thereto, said arms being}; sceured together by a plate 23 which has the ed es thcrcot bent transvercel y to.serve as stihcning means, the entire structure being reinforced in this manner, so tar as practicable. The crossbar 22 is perforated and sci'ew-threaded for the reception of a ciurrespondingly screwthreaded adjusting rod 21-, the upper end oi which passes through a cross-bar 25 which is pivoted on the pivots 12. Longitiuliual play of the shaft 24, with respect to the cross-bar 25 prevented by the sleeves 26 and 27, the latter of which is scurcd to the shaft by the cross-pin 28. The shaft operated by nieans of a wheel 29, in the present instance shown. as provided with a handle 30. It will be seen that as the shaft 24 is rotated by means oi the wheel 29 it will move loi'igitudinally through the cross-bar 22, thus causii relative motion between the t and the arms 20. Since the upper end he sl'ia'tt can not move longitudinally with respect to the wings 11 it results in the arms 20 moving and these, in turn, cause the hulder 13 to move about its pivots 1.2. A stop 31 is provided so that when the ladder reaches a substanti 'ly vertical position the shaft will cng g'age said. stop 3i and it will be impossible to move the ladder any i'arther. V

llt will be noted that the sections of the ladder are bent so as to have grooves formed along one edge thereof and other grooves formed along the sides thereoit so that the ladder sections will fit together and slide on each other freely but without undue looseness. The lower section H, like the other sc-ction has its edge bent inwardly as indicated at it) to term a groove along the edge thereof. The arms 20 have their e):- trcmitics bent outwardly indicated at 20" to slide i n the eve {it ot section t? andv an edge oil each arm 20 has iorn'ied thereon an angular projection 20" to slide in the groove formed by the flange 49. It will thus be seen that as the arms are raised by operation out the wheel 29 the end 20, sliding in the groove 48 elevates the section l7 to a more or less inclined position or even a nearly vertical position. In turning the part has reached its limit.

wheel 29 in the opposite direction the arms 20 swing downwardly and the projections 20 engage and slide along the flange 49 to pull the ladder downwardly toward a horizontal position, in event there is any resistance to such motion on the part of the ladder.

The winding drum 32 is mounted in perforations in the extremities 33 oi? the bracket 14;, said extremities being oll'set laterally at 34- to get the ends of the winding drum beyond the sides of the ladder (see Fig. 2). In the present instance, the winding drum 32 is provided with fastening means 35 and 36 to which the ends of the cables 37 and 33 may be secured. These securing means 35 and 36 are located outside of the ladder, though this is not necessary. In the present instance it is desirable in order to make room on the winding drum.

In the present construction, the cable 38 extends from the winding drum 32 to a fastei'iing means 39 at the outer extremity of the upper section tO of the ladder. By this means, when the cable 38 is wound upon the drum 32 the ladder sections will be pulled downwardly into collapsed position. Adjacent the near end of the section 40 of the ladder is a securing means 41 to which the extreme end oi the cable 37 is secured. From here the cable passes over a pulley 4L2 at the outer end of section 41-5 and from thence under a pulley 43 and over the pulley 4A. These pulleys 43 and l -l are carried by the near end of the intermediate section 45 of the ladder. From the pulley i l the cable passes over the pulley 46 near the outer end of section 4? and down to the drum 32, this end being secured to one of the securing means 35, 36. From this it will be apparent that when the cable 37 is wound upon the drum 32 it will be pulled. over the pulley 46, thus moving the sections 45 and l0 upwardly to extend the ladder at its lower part. Due to the friction in the pulleys 42, 43 and l l the upper section of the ladder will not be extended until the lower This occurs when the stop 50 engages the stop 51. M0- tion of the upper section of the ladder is limited by the stop 52 engaging stop 53.

When collapsing the ladder the friction in pulley 46 is so much less than that in 42, t3 and 44; that the section 45 will come down to its lower limit before upper section 40 begins to travel. It will thus be seen that in extending the ladder the two upper sections will remain collapsed and will move together until the middle section has reached maximum extension and then the upper section will move outwardly. In re separates cab] is It is believed that the operation of this device will be understood from the foregoing descriptionbut a brief statement will now be given. The rear end of the truck is provided laterally of the ladder with upwardly extending projections which prevent the ladder from swinging sidewise until it has been elevated suiiiciently to cause all parts thereof toclear all parts of the truck. When the wheel '29 has been operated to raise the ladder to the desired inclination, the wheel 7 will be next operated to turn the table 9 and with it the ladder 13 to the desired direction. Having gotten the ladder in the desired direction the crank 56 connected with the winding drum is operated to extend the ladder to the desired amount. This having been done, the latch 57 engages the notches in the ratchet wheel 58 to hold the ladder in extended position. When it is desired to restore the ladder to its position upon the truck and operations are the reverse of those given above.

A spacing member, such as a washer 60, 87 and 38 as shown in Fig. 4' and prevents them from coming in contact and interfering with each other during the winding operating. lVhen the parts are in the position shown in Fig. 5 the ladder is fully extended as shown in Fig. 2. As the crank 56 is turned counter-cloclnvise the cable 37 is unwound from and the cable 38 is wound on the drum 32, the spacer 60 be ing gradually moved along the drum until the ladder is fully collapsed as shown in Fi 1, the position of the winding parts being shown in Fig. 6. Fig. 4 shows the parts in an intermediate position.

In the construction shown on Sheet 3 of the drawings a different type of' lifting mechanism is provided for the ladders. In this construction an elongated supporting member 61, substantially U-shaped incross section, is secured. to the supporting member 9 in any suitable manner'as, for example, by

spot-welding. Within this supporting member 61 is a cylinder62 which extends from near the forwardend of supporting me1nher 61 back nearly to the slots 63 in opposite sides of the rearward prolongation of the supporting member 61, which is shown as being flattened on the top and bottom at (i l. A piston mounted on the forward end of the piston rod 65 is slidable in the cylinder 62 and has a yoke 66 at its rearward end pivoted. at 67 to the links 68. The endsof the yoke 66 are slidable in the opposite slots the yoke being forced rearwa-rdly by means of a spring 69 located in the cylinder 62 and causing motion of the piston and piston rod in that direction. When the ladder is free to move, the spring, through the piston, piston rod, yoke and links causes the ladder to be elevated to the position shown in Fig. 12 or any desired intermediate position between those shown in Figs. 11

the under side of one of the cross bars 16.

The links 68 are pivotally connected at 72 with these arms of the bracket and therefore transmit motion to the ladder. A sector 7 3 provided with notches 74 is rigidly secured to the arms 15 and therefore moves with the ladder as shown in Figs. 11 and 12. A bracket 75 is secured to the supporting member 9 and one of the wings 11 and has pivoted therein the'lend 76 of the lever 77. A locking pawl. or dog. 78 is secured to the arm 76 of the lever and the forward end thereof engages any desired one of the notches 7a in order to stop and hold the ladder in any desired position of vertical adjustment. A'stop or stops 80, integral with the bracket 14, serve to limit the downward motion of the movable ladder sections.

From the foregoing it will be understood that the ladder 13 is manually lowered into the position shown in Fig. 11 and the lever 77. turned from the position shown in Fig. 12 to that shown in Fig. 11 wherein the pawl 78 engages one of the notches 74 to hold the ladder in lowered position. The ladder will then be maintained in this position until the lever 77 is turned forwardly to disengage the pawl 7 8 from the notches. When this is done, the spring 69 forces the piston backwardly in. the cylinder 62 and causes the links 68 to lift the ladder into an ele vated position. If it is desired, the lever canbe left in the forward position shown in Fig. 12 and the ladder will then rise to the vertical position as here shown. If it is desired to stop it at any intermediate position, the lever is turned backward while the ladder is rising and eiiiga-gcs one of the notches 74 tostop the ladder in such intermediate position. It will be understood that the shaft 6 may pass'thru the end of the cylinder 62 or not, as desired, butI prefer to'secure thecyiinderin place'by passing the shaft through the end of .it and thus avoid the not ssity' of using any other means to fasten the cylinder in place;

The present application'is a continuation in part of my prior application Serial No. 61,262, filed October 8, 1925 in which the examiner has held that the movability of the spacer 60 was not disclosed in the application as filed. Since this is one of the important elements of'my construction I consider it advisable to file this additional application clearly disclosing and claiming that which was apart of my original invention and was invented before the filing of 'my prior application though the same was not stressed therein.

While I have disclosed herein preferred embodiments of my construction, I desire the same to be understood as illustrative only and not as limiting said invention.

Having now described my invention, I claim:

1. In a truck, a sheet metal supporting body, a separate disc secured thereto, gear teeth rigid with said disc, an inverted cupped supporting member mounted upon said disc and carrying an operating member provided with a toothed member, the teeth of which. engage with the aforesaid gear teeth, said stupporting member being adapted to carry a ladder and to enclose the gears.

2. In a construction of the character indicated, a horizontally rotatable support, a cylinder secured thereon and having a piston therein, a spring to actuate said piston, a ladder pivoted on the support, a link connecting the ladder and piston, and pawl and ratchet means connecting the support and the ladder to hold the latter in various positions of vertical adjustment.

3. In a structure of the character described, a support, a partially tubular support mounted thereon, a cylinder within the last named support having a movable piston therein, a piston rod extending longitudinally of the cylinder beyond the end thereof, a ladderpivoted on the first named support, apart of the tubular support projecting be yond the cylinder having a slot therein, a yoke in said slot having connection with the piston rod, and a link connecting the yoke with the ladder.

i. In a structure of the character described, a support, a partly tubular support mounted thereon, a cylinder within the last named support having a movable piston therein, a piston rod extending longitudinally of the cylinder beyond the end thereof, a ladder pivoted on the first named support, a part of the tubular support projecting beyond the (Lydindei' having a slot therein, a yoke in said slot having connection with the piston rod, a link connecting the yoke with the ladder, and means comprising a latch and sector connected respectively with the first named support and the ladder whereby the latter may be stopped and held in any desired position of vertical adjustment.

5. In a ladder, a support, a ladder section pivoted upon said support to turn in a substzmtially vertical directioi'i, said huldor section being grooved along its under and inner faces for the reception of an actuating means, an actuating arm having a lateral projection to engage a groove in the inner face of the ladder section and having its end engaging the groove in the under face thereof to swing the same about its pivot.

6. An extensible ladder comprising a plurality of similar sections slidably connected with each other, each section being formed from sheet metal cut and pressed to form a pair of side rails and a plurality of rungs, integrally formed, the side rails having substantially parallel longitudinal ridges so that the rails, in cross section, comprise a series of alternating ridges and grooves, the ridges of one section inter-fitting with the grooves of the next.

7 In a ladder, a support, a ladder section pivoted upon said support to turn in a substantially vertical direction, said section being grooved for the reception of actuating means, actuating arms having lateral projections to engage grooves in the ladder section to swing same about its pivot, other similar sections slidably connected with each other and w'th the first named section, each section being formed from sheet metal cut and pressed to form side rails and rungs connecting them, the rails and rungs being integrally connected, the side rails having substantially parallel longitudinal ridges so that the rails in cross section comprise a series of alternating ridges and grooves, the ridges of one section interiitting with the grooves of the next.

8. In structure of the character indicated, a support, an extensible ladder pivoted thereon, a notched sector connected to and traveling with the ladder about its pivotal point, a locking dog cooperating with said sector to stop the ladder and hold it in relatively fixed relation with respect to the support, resilient means connected with the support for raising the ladder, and connections between the resilient means and the ladder for raising the latter from a lowered to an elevated posit-ion.

9. In an extension ladder, a supporting member, a ladder section pivotally mounted upon the supporting member, the side rails of said section having depending flanges and being longitudinally grooved, a pair of lifting arms pivoted adjacent one end for actuation of the ladder about its pivot, each of said arms havine a lateral projection to engage a groove of each of said side rails of said ladder so that when the arms are actuated about their pivots they may transmit force to the ladder to turn it about its pivot;

In witness whereof, I hereunto subscribe my name to this specification.

FRED A. LUNDAHL.

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