US2982373A - Method and device for replacing rungs on a ladder - Google Patents

Description

May 2, 1961 H. HOPFELD 2,982,373

METHOD AND DEVICE FOR REPLACING RUNGS ON A LADDER Filed Nov. 17, 1958 a 9 2 22 l9 l9 INVENTOR. HENRY HOPFELD ATTORNEY.

U ited States Patent METHOD AND DEVICE FOR REPLAING RUNGS ON A LADDER Thiszinvention pertains to method and device for replacing rungs on'a ladder. l

The primary object of the invention is to provide a method and device whereby a broken rung on a ladder can be replaced so that the replacement rung is integrally united with the rails of. the ladder without the necessity of dismantling or disassembling the ladder.

Particularly-it iscan object of the invention to provide a method anddevice whereby a rung can be extended into the sockets of the old rung in the rail so as to be suitably cemented therein or integrally united by the same type of fiberglass plastic from which the rails are made.

I am "aware that some changes may be made in the general arrangements and combinations of the several devices and parts, as well as in the details of the construction thereof without departing from the scope of the present invention as set forth in the following specification, and as defined in the following claim; hence I do not limit my invention to the exact arrangements and combinations of the said device and parts as described in the said specification, nor do I confine myself to the exact details of the construction of the said parts as illustrated in the ac- Fig.2 is a sectional view of said ladder, the section being Itaken on lines Z-Z of Fig. l.

. Fig. 3 -is a fragmental sectional view showing the socket in the ladder bored and the end of the replacement rung in position adjacent to the socket.

Fig. 4 is a fragmental perspective view of the ladder and of the adjacent end of the replacement rung.

Fig. is a developmentview of the fastening elements in the end of the'replacement rung.

Fig. 6 is a partly sectional view showing the assembly of the replacement rung and the installing structure in position, and; p l

Fig. 7 isa fragmental, sectional view of the replacement rung secured in position.

The type of ladder on which my method and device could be most effectively utilized is illustrated herein as a ladder the rails of which are made in part or wholly out of fiberglass. In the presentillustration the rails are made of an outer fiberglass channel 1 and an inner fiberglass channel 2. The inner channel 2 fits into the outer channel 1 andthe channels 1 and Z are integrally united together. At spaced points or locations, where the rungs 3 are placed, are provided rail sockets 4 for receiving the reduced ends 5 of the rungs 3' as shown in Fig. 1. These rail sockets 4 are formed in this illustration in wooden blocks 6 which are fillers in the hollow or cavity inside of the united opposite channels 1 and 1.

When a rung 3* breaks, then it is removed. In my method the socket 4 is reamed or bored so as to re- 2,982,373 i atented May 2, 1961 move from the same the remains of the reduced end 5 of the broken rung 3 and form a clear rail socket.

'A replacement rung 7 is produced with cylindrical sockets 8 in the opposite ends thereof. In each end socket 8 is driven an end plug 9. Each plug 9 is formedwith a reducedouter end 11 which fits into the rail sockets 4. The plug 9 is driven into the end socket 8 of the replacement rung.7 so that the reduced end 11 of the plug 9 is concealed within, the end socket 8 and the outer end thereof is flush with the-end of the replacement rung 7. In the reduced end 11 of the plug 9 is an axial threaded hole 12 into which fits a pull screw 13. 1

After the opposite rail sockets -4 are rebored, or cleared, the replacement rung 7 with the plugs 9* inside each end is placed in registry with the rebored rail sockets 4. A central hole 14 is drilled through the outer channel 1 into the center of the bottom 16 of each rail socket 4 through which the pull screw 13 is inserted and screwed into the threaded hole 12 in the reduced end 11 of the plug 9. Then the screw 13 is turned while its head 17 bears against the outside face 18 of the rail either directly or through a bearing plate 19 so as to pull the tightly fitting plug 9' out of the end socket 8 and to pull its reduced end 11 into the rail socket 4. The reduced end 11 of each plug 9' is of a length generally corresponding to the depth of each rail socket 4 so that the shoulder 21 thereof will be flush with the adjacent end of the replacement rung 7 when the reduced end 11 is completely pulled into the rail socket. 4, and will bear against the adjacent face of the rail. i

As a preliminary step, the cleared rail socket 4 is filled with suitable plastic cement such as a cold setting plastic,

pands during the insertion ofjthe reduced end in the socket and during setting, so as to positively integrate the plug with the cylindrical end socket of the replacement rung as well as the reduced end with the rail socket.

Thebearing plate 19 protects the outer face of the rail around the drilled hole. After the replacement rung is in place the bearing plates and the pull screws are removed and the remaining cavity is filled with the same plastic cement, and the plastic cement sets in the rail socket and around the reduced ends and in the ends of the rung and thereby a firm integrated connection is achieved between the new rung and the rail of the ladder.

I claim:

1. The method of replacing a rung in the rails of a ladder comprising, forming sockets in the rails for the opposite ends of the rung, tightly driving into each end of the rung a plug longer than the depth of the adjacent rail socket, filling the rail sockets with plastic cement capable of integrating the plugs with the rail sockets, placing the rung in the leadder with the ends of the rung in registry with the respective sockets, and partly withdraw ing said plugs axially from said rung and into the respective rail sockets for integration with said rail sockets.

2. The method of replacing a rung in the rails of a ladder comprising, forming opposite sockets in the rails, completely concealing in each end of a rung a plug formed so that said rung fits between the rails of the ladder when the outer end of the plug is in registry with the adjacent socket, filling the sockets with plastic cement capable of integrating the outer ends of the plugs with the respective sockets, placing said rung in said ladder in registry with said opposite sockets, and partly withdrawing said plugs axially from said rung and into the respective sockets so as to force part of said plastic cement into the ends of said rung and around said plugs for integrating said plugs with said sockets and with the ends of said rung.

3. The method of replacing a rung in opposite rails of a ladder comprising, forming opposite sockets in said rails, forming a rung with plugs in its opposite ends with passage for plastic cement about each plug, driving each plug into the adjacent end of the rung so as to completely conceal the plug, filling each socket with plastic cement capable of integrating each plug with the adjacent socket and with said rung, placing said rung between the opposite rails of said ladder in registry with said sockets and partly withdrawing each plug axially from the rung and into the adjacent socket so as to force part of said plastic cement into said passage about said plug for integrating said plugs with the respective sockets and with said rung.

4. The method of replacing a rung in opposite rails of a ladder, comprising forming sockets in the rail, driving into each end of the rung a plug so that the ends of the plugs are flush with the respective ends of the rung, forming an access hole in the bottom of each socket, aligning the rung with said sockets, filling said sockets with a plastic cement capable of integrating the plugs with the sockets, engaging said plugs through the respective access holes and drawing the plugs into the respective sockets so that a portion of each plug remains in the rung and part of said plastic cement.is forced around each plug into the rung, and allowing said plastic cement to set.

5. A replacement rung for a ladder having rail sockets in the rails thereof comprising a rung body having a cavity in each end thereof, a plug tightly fitting and concealed within each cavity, the outer portion of each plug fitting into the adjacent socket when pulled thereinto, and cement receiving means at the peripheries of said plugs for receiving plastic cement forced from said sockets along the plug peripheries for integrating said plugs with said rail sockets and with said rung in said cavity.

6. A replacement rung for the rails of a ladder having opposite rail sockets, comprising a generally cylindrical rung, a rung socket in each end of the rung, a plug forced completely into said rung socket so that the outer end of the plug is substantially flush with the adjacent end of the rung, said rung being of a length substantially equal to the distance between said rails, engagement means in the end of each plug for pulling the plug adapted to be engaged and axially pulled into a adjacent rail socket in said rails for integrating with said rails.

7. A replacement rung for the rails of a ladder having opposite rail sockets, comprising a generally cylindrical rung, a rung socket in each end of the rung, a plug forced completely into said rung socket so that the outer end of the plug is substantially flush with the adjacent end of the rung, said rung being of a length substantially equal to the distance between said rails, engagement means in the end of each plug for pulling the plug adapted to be engaged and axially pulled into an adjacent rail socket in said rails for integrating with said rails, said end of said plug being reduced and said reduced end being substantially the same length as the depth of the rail socket.

8. A replacement rung for the rails of a ladder having opposite rail sockets, comprising a generally cylindrical rung, a rung socket in each end of the rung, a plug forced completely into said rung socket so that the outer end of the plug is substantially flush with the adjacent end of the rung, said rung being of a length substantially equal to the distance between said rails, engagement means in the end of each plug for pulling the plug adapted to be engaged and axially pulled into an adjacent rail socket in said rails for integrating with said rails, said end of said plug being reduced and said reduced end being substantially the same length as the depth of the railsocket, and said reduced end and said plug having grooves on the outer peripheries thereof for receiving cementing material for uniting said plug respectively with said rail socket and with said socket in said replacement rung.

9. A replacement rung for the rails of a ladder having opposite rail sockets for rungs, comprising a generally cylindrical rung, a rung socket in each end .of the rung, a plug forced completely into said rung socket so that the outer end of the plug is substantially flush with the adjacent end of the rung, said rung being of a length substantially equal to the distance between said rails, a threaded hole in the end of each plug adapted to be engaged for pulling the plug axially into an adjacent rail socket in said rails for integrating with said rails, and a pull member engageable with said threaded hole through said adjacent rail socket and with said rail for pulling said plug into the adjacent rail.

10. A replacement rung of the rails of a ladder having opposite rail sockets for rungs, comprising a generally cylindrical rung, a rung socket in each end of the rung, a plug forced completely into said rung socket so that the outer end of the plug is substantially flush with the adjacent end of the rung, said rung being of a length substantially equal to the distance between said rails, a threaded hole in the end of each plug adapted to be engaged for pulling the plug axially into an adjacent rail socket in said rails for integrating with said rails, and a pull member engageable with said threaded hole through said adjacent rail socket for pulling said plug into the adjacent rail, a head on said pull-member, and a bearing element between each head and the adjacent rail.

References Cited in the file of this patent UNITED STATES PATENTS 925,105 Kaufman June 15, 1909 1,644,694 Rowe Oct. 11, 1927 FOREIGN PATENTS 468,382 Germany Nov. 12, 1928 362,382 Great Britain Dec. 2, 1931 100,807 Australia Apr. 14, 1937 940,732 Germany Mar. 22, 1956

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