US1711357A - Ladder and adjusting mechanism - Google Patents

Description

April 30, 1929. F. A. LUNDAHL y LADDER AND ADJUSTING MECHANISM Filed 001,.v 8, 1925 2 Sheets-Sheet 1 'EA/TOR wia/NZ l ATTORNEY I I l \||Ill.l ||||||II|||I April, 30, 1929 F. A. LUNDAHL 1,711,357

LADDER AND DJUSTING MECHANISM Filed om. 8, 1925 2 sheets-sheet 2 INVEN TOR WTORNEY Patentes Apr. 3o, i929..A

UNITED STATES.

FRED A. LUNDAHL OF MOLINE, ILLINOIS.

.- LADDER AND ADJUSTING IMECHAN'ISlVI.

Application filed October 8i, 1925. Serial No. .61,262.

While the present invention relates primarily to the construction of ltoys which are sufliciently durable to stand considerable usage and unusual wear, I desire 1t understood that certain yfeatures thereof are capable of use in similar articles for use other than astoys. The present invention relates to adjusting means whereby ladders may be adjusted in various directions.

Among the objects of my invention are to orovide improved mechanism for the horizontal adjustment of ladders; to provide improved mechanism vfor the vertical adjustment of ladders; to provide an improved mechanism for the extension and shortening of'ladders; and such further obj ects,v advan- Jtages, and capabilitiesfas will hereafter more fully appear and as are inherent Vin the mechanism disclosed. My invention further re sides in the combination, construction and arrangement of parts illustrated and, while I have disclosed herein a specific embodiment of my invention, ldesire the same tov Vbe 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 shown in outline by dotted lines. Fig. 1.A is a broken plan view of the construction shown in Fig. 1, with the ladder extended; Fig.` 2 is a longitudinal section of my construction vdetached from the truck and showing* the Vladder in elevated yand extended position, sections of the ladderbeing broken outfor the purpose of shortening lthe same; Fig. 3 is a cross section in front of the winding drum, looking rearward and showing the arrangementl of the cables on thewqinding drum and the spacingineans between said cables; Figs. 3A

and 3B are similar views showingthe posi-.

tions of the parts when the ladder is fully extended and fully retracted; Fig. 4 is a cross sect-ion of winding drum just, inside of one of the supporting `arms therefor and showing Ameans cables are secured to the winding drum; Fig. 5 isa sectionI through the flange ofv the supporting member 9, looking upwardly, and showing the relative positions of the gears 5 and 8, pivots 6 and 10, .and the lmeshing of the teeth 3 and 4; Fig. 6 is a cross section through the ladder, fully collapsed Aas;v shown in Fig. 1, said section showing more" clearly :the interitting of the ladder j sec,

by which the ends of thek 4turning tions shown in Figs. 1 and 2; Fig. 7 is a ver-V tical section through the turn table and the supporting means for the lower end of the ladder. Y

Referring more in detail -to the `annexed drawing, numeral l-designates a supporting body of any suitable type, herein shown as an .automobile truck, while numeral 2 denotes a disc secured to the' supporting body. As shown in Fig. 2, said d-isc 2 has a plate 8, carrying gear teeth 43, rigidly secured thereto, the saine being'engaged by the cooperating teeth 4 yon apinion ofcarried by the rod 6 provided witlra wheel 7. 'It will be understood, of course, that this mechanism may be varied asv desired to produce the results intended.

A. supporting member `9 is mounted upon the disc 8 and pivoted thereon by means of a .king pin 10 extending axially through the disc 2.y This king pin is herein shown as being secured in place by means of nuts ybut 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 pivot/ed at 12 a bracket 14. The bracket has Va ladder 13 secured Athereto in any desired manner, as by bolts 17 lt comprises .opposite side 'members connected by cross bars 16 and has upwardly extending arms 15 which are perforated for the reception Vof the pivots 12. j Other supporting means rises fromthe upper surface of thek supporting means or table 9, said other supporting means being y designatedby the numeral 18, in the present instance being shown as a pair of brackets. To these brackets are pivotally connected at 19 a pairof arms 20, the extremities of said arms being bent upwardly `as shown at 21 to enga-ge the sides of the ladder 13. The arms 20 have their ends 20a extending into the channels 48 of the lower ladder section 47 as shown in Fig. '6, these arms also being provided Vwith lugs '2Ob formed in the reinforcing flanges along the edges of these arms, shown in Fig. 1. The

lugs 2()h are received in channels formed byk bending inwardly the edges of 'ladder section 47 as shown at 49. It will therefore be seen that as the 4arms 20 are raised by the wheel v.29 the ends y20a will slide in the channels 48 and will lift the ladder.

In turning thewheel 29 in the opposite direction, the lugs 20 pull downwardly uponv the flanges 49, thus overcoming any tendency toward sticking of the laddei` in elevated position (shown in Fig. 2). -A cross-bar 22 extends between the arms 20 and is pivotally secured thereto, said arms being secured together by a plate 23 which has edges thereof bent transversely to serve as stilfening means, the entire structure being reinforced in this manner, so far as practicable. The cross-bar 22 is perforated and screw-threaded for the reception of a correspondingly screw-threaded adjusting rod 24, the upper end of which passes through a cross-bar 25 which is pivoted on the pivots 12. Longitudinal play of the shaft 24, with respect to the cross-bar 25 is prevented by the sleeves 25 and 27 the latter of which is secured to the shaft by the crosspin 28. The shaft is operated by means 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 of the wheel 29 it will move longitudinally through the cross-bar 22, thus causing relative motion between the shaft and the arms 20. Since the upper end of the shaft can not move longitudinally with respect to the wings l1 it results in the arms 20 moving and these, in turn, cause the bracket 14 to move about its pivots l2. As indicated, the lowest rung 3l of the ladder acts as a stop so that when the ladder reaches a substantially vertical position the shaft 24 will engage said rung 3l and it will be impossibleto move the ladder any farther.

The winding drum 32 is mounted in perforations in the extremities 33 of the bracket 14, said extremities being offset laterally at 34 to get the ends of the winding drum beyond the sides of the ladder (see Fig. 1^). 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 38 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 for all of the cable which is needed in operating the ladder.

In the present construction, the cable 38 extends from the winding drum 32 to a fastening means 39 at the outer extremity of the upper section 40 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 4() of the ladder is a securing means 41 to which the extreme end of the cable 37 is secured. From here the cable passes over a pulle 42 at the outer end of section and from thence under a pulley 43 and over the pulley 44. These pulleys 43 and 44 are carried by the near end of the intermediate section 45 of the ladder. From the pulley 44 the cable passes over the pulley 46 near the outer end of the lower section of the ladder and down tor the drum 32, its end being secured to one of the securing means 35, 3G. 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 l sections 45 and 40 upwardly to extend the ladder at its lower part. Due to the friction in the pulleys 42, 43 and 44 the upper section of the ladder will not be extended until the lower part has reached its limit. This occurs when the stop 50 engages the stop 51. Motion 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, 43 and 44 that the sections 40 and 45 will come down together to the lower limit before upper section 40 begins to travel. It will thus be seen that in extending the la'dder the two upper sections will remain collapsed and will move together until the lower section has reached maximum extension and then the upper section will move outwardly. In reverse action, the upper sections will remain extended until the lowerI section has been collapsed and then movement of the extreme outer section will take place.

It is believed that the operation of this device will be understood from the foregoing description but a brief statement will now 1 be given. The rear end of the truck is provided laterally of the ladder with upwardly extending projections 55 which prevent Vthe ladder from swinging sidewise until it has been elevated sufficient to cause all parts thereof to clear 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 lthe crank 56 connected with the winding drum 32 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 the operations are the reverse of those given above. A spacing member, such as a washer 60, separates cables 37 and 38 as shown in Fig. 3 and prevents them from coming in contact and interfering with each other during the winding operation.

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

HavingV now described my invention, I claim l. I'n a structure of the character described, a ladder comprising a plurality of integral interconnected relatively slidable sections, some of said sections having cross bars secured to .the proximate ends thereof, the ends of the cross bars projecting transversely along the sides of the sections into a position to cooperate with stop means on the next section, and stop mea-ns projecting outwardly adjacent the remote end of the next section in a position to be engaged by said projecting ends, whereby the outward movement of the sections of the ladder may be limited.

2. In a structure of the character indicated, a ladder section, a base upon which said ladder section may be pivotally mounted, said ladder section having a bracket at its proximate end, the bracket extending across the face of the ladder and along the lateral sides thereof, said bracket having ears extending in planes substantially parallel with the lateral faces of the ladder and beyond the surface thereof across which the bracket extends, said ears beingV pivotally connected to the base.

f 3. In a structure of the character indicated, a ladder section, a base upon which said ladder section may be pivotally mounted, said ladder section having a bracket at its proximate end, the bracket extending across the face of the ladder and along the lateral sides thereof, said bracket having ears extending in planes substantially parallel with the lateralfacesof the ladder and beyond the surface thereof `across which the bracket extends, said ears being pivotally connected to the base, said bracket having ears offset laterally from the sides of the ladder section and extending beyond the ladder section in a direction opposite to that of the first named ears, and a winding drum mounted in said second mentioned ears.

In witness whereof, I hereunto subscribe.

my name.l

. FRED A. LUNDAI-IL.

Images