Wall crane

Abstract

The wall crane is used to raise a wall from a horizontal to a vertical position. The crane has a base, a telescopic post pivotally connected to the base and a pulley connected adjacent to the top of the post. A hook is used to connect the crane to the wall and a cable extends from the hook, over the pulley and terminates at a winch. By reeling the hook toward the winch, the wall is raised. A catch is connected to the post and engages the wall when it has been raised to a vertical position to prevent the wall from toppling over backward away from the crane.

Description

[0001] This invention relates to equipment used in the construction of housing and more particularly to a hand-powered wall crane for raising a preformed wall to a vertical position.

[0002] The usual practice in the construction of the walls of a house is to assemble the frames for the walls on a level horizontal surface such as a floor or the ground. The frame is then raised from the horizontal to vertical position and connected in place by wood braces, bolts or the like. The frame is then prepared for wall boards such as dry wall panels and finally the wall boards are attached to the frame.

[0003] The frames for walls are heavy, particularly when the frames are long. It is conventional for a crew of men to raise the frames from the horizontal to vertical positions. When the frame is vertical it is braced to prevent it from toppling over.

[0004] I have invented a wall crane which does away with the need for a crew of men to raise a wall frame. The crane is powered by hand and can be operated by one individual. The crane is portable and can be assembled by hand where needed and dismantled and removed, again by hand.

[0005] Briefly the wall crane of the invention serves to raise a wall to a vertical position comprising: a base having means by which the base can be made stationary; a post pivotally connected to the base; a pulley connected to the post at a point spaced apart from the base, a hook for securing a wall; a winch; and a cable extending from the winch to the hook. The wall crane has stop means for selectively preventing pivotal movement of the post relative to the base such that the post can be made immovable relative to the base. The wall crane further may have a catch connected to the post for engaging the wall and preventing further raising thereof. In addition the post may be telescopic.

[0006] The wall crane of my invention is described with reference to the accompanying drawings in which:

[0007] FIG. 1 is a perspective view of the wall crane in conjunction with the frame of a wall resting on the ground;

[0008] FIG. 2 is a perspective view of the wall crane in enlarged scale;

[0009] FIG. 3 is a side view of the wall crane and a wall resting on the ground;

[0010] FIG. 4 is a perspective view of the crane and the wall raised to an angle of about 45 degrees from the ground;

[0011] FIG. 5 is a perspective view of the crane and the wall raised to a fully upright position.

[0012] Like reference characters refer to like parts throughout the drawings.

[0013] With reference to FIG. 1, the wall crane, generally 10, comprises a post 12 and a pulley 14 adjacent to the upper end of the post. A base 16 is at the opposite end of the post. The crane is anchored to a stationary floor 17 on which the frame of a wall 18 rests.

[0014] With reference to FIG. 2, the base has a bottom wall 20 and a pair of side walls 22, 24 which extend normally upward from the bottom wall and which are disposed on opposite sides of post 12. A pair of braces 25 is provided for supporting each side wall.

[0015] The bottom wall has a number of apertures 26 formed in it for receipt of nails so that the base an be anchored to floor 17 or to some other stationary object.

[0016] Side walls 22, 24 are connected to the post by two bolts; a lower bolt 28 and an upper bolt 30. Both bolts pass through apertures formed in the plates and the post. The apertures in the post are larger than the cross sectional area of the lower bolt so that the post may pivot relative to the walls. The upper bolt 30 is held in place by means of nut 31. Other means may also be used for maintaining the bolt in place such as a cotter pin. Whatever means is used, it must allow the upper bolt to be removed easily so that the post can pivot relative to the base when that is required.

[0017] Upper bolt 30 serves as a stop means for selectively preventing pivotal movement of the post relative to the base such that the post can be made immovable relative to the base.

[0018] A hook 32 is located on the side of the post opposite the bottom wall. The hook has a lower face 34 and inner faces 36 and an outer lip 38 bent back at right angles from the lower wall. The lower face is sufficiently wide to receive the top plate of a wall as described below. An aperture 39 is formed in the lip for receipt of a nail for a purpose to be described below.

[0019] A crampon 40 is connected to the upper end of the inner face and serves to connect the hook to cable 41. The cable extends along the length of the post to its upper end, around pulley 14 and terminates at a winch 42 on the opposite side of the post.

[0020] The upper end of the post is bifurcated into two branches 12a, b and the pulley is mounted for rotation in bearings in the two branches. The two branches terminate above the pulley and a retaining rod 43 extends between the two branches and adjacent to the upper edge of the pulley. The retaining rod has an enlarged head (not illustrated) at one end and a cotter pin 44 at the other end to ensure that it remains connected to the post. The rod may however be removed from the post by removing the cotter pin, from the retaining rod.

[0021] The retaining rod ensures that the cable remains in the groove of the pulley when the wall crane is in use. When the crane is being stored, the rod may be removed so that the cable can be removed from the pulley.

[0022] The winch is of conventional construction and is mounted to the post on the side opposite the clasp. The winch has a handle 45 (FIG. 1) for winding and unwinding the cable. Winding the winch causes the hook to move along the post toward the pulley and unwinding the winch causes the hook to move in the opposite direction and to resume the position illustrated in FIG. 2.

[0023] The post is hollow and is composed of two segments, a lower segment 12c and an upper segment 12d. Preferably the segments are of equal length. The latter segment has a smaller cross-sectional area than the former so that it fits into the lower segment. A conventional connecting pin 50 fits though apertures in the two segments to interconnect them and a cotter pin (not illustrated) is provided to prevent removal of the connecting pin rom the apertures unless the cotter pin is removed.

[0024] The post is thus telescopic in the sense that it can be lengthened or shortened. A number of apertures 51 through which the connecting pin may be inserted can be formed in the upper segment to allow for adjustability in the length of the post. The post can accordingly be adjusted to the height of the wall which the wall crane is used to raise.

[0025] A catch 52 is connected to the upper segment 12d of the post. With reference to FIGS. 3 and 4, the catch has a pair of interconnected inner and outer arms 52a,b. Inner arm 52a extends outwardly from the post and terminates at the outer arm 52b. The purpose of the catch is described below.

[0026] The operation of the wall crane is described with reference to FIGS. 1 and 3 to 5. With reference first to FIG. 1, two wall cranes are mounted beside the top plate 64 of the frame of a previously constructed wall or partition. The bottom wall 20 of the base of each wall crane is anchored to floor 17 so that the bottom walls are stationary.

[0027] The hook of each wall crane is then attached to the top plate and is held in position be means of nails driven through apertures 39 in the outer lip of each hook. The hooks are then raised by means of the winches of each crane. As the hooks rise the wall pivots upwardly about its lower plate 70.

[0028] With reference to FIG. 4, as the wall pivots, the top plate moves horizontally away from the wall crane in the direction of arrow 69. The upper bolt 30 which connects the base to the post of each crane is then removed to allow the post to pivot forward to accommodate this movement.

[0029] With reference to FIG. 5, when the wall is vertical, the inner arm 52a of the catch is above the wall and outer arm 52b is in contact with the upper edge of the wall. The catch prevents the wall from pivoting past the vertical. In the absence of the catch, the wall might pivot past that point and if it did, the wall would topple over in the opposite direction. The wall crane is not capable of preventing that in the absence of the catch.

[0030] To ensure that the catch is in the correct position the height of the wall is measured while it is resting on the floor and before it is lifted by the wall crane. The effective length of the post is adjusted by means of connecting pin 50 so that the catch will be in the required position when the wall is upright.

[0031] Once the wall is vertical it is braced by conventional means to prevent it from moving. The hook is then raised by the winch to remove it from contact with the wall and the post is swung back to the vertical position and out of contact with the wall.

[0032] The angle between the outer arm 52b of the catch and the outer face 66a of the wall, marked 80 in FIG. 5, should be in the range of about 45 degrees to 60 degrees, preferably 50 degrees. If the angle is less than that, the weight of the wall against the catch will make it difficult to disengage the wall from the catch even though the wall is vertical. If the angle is more than about 60 degrees, the catch may not be effective to firmly contact the wall to prevent the wall from toppling over backward.

[0033] It will be understood of course that modifications can be made in the structure of the wall crane illustrated and described herein without departing from the scope and purview of the invention.

Claims

1. A hand-powered wall crane for raising a wall to a vertical position comprising: a base having means by which said base can be made stationary; a post pivotally connected to said base; a pulley connected to said post at a point spaced apart from said base; a hook for securing the wall; a cable extending from said winch, over said pulley and to said hook; and a winch for winding and unwinding said cable.

2. The wall crane as claimed in claim 1 further including stop means for selectively preventing pivotal movement of said post relative to said base such that said post can be made immovable relative to said base.

3. The wall crane as claimed in claim 1 further including a catch connected to said post for engaging said wall when in a vertical position and preventing further pivoting of said wall past said position.

4. The wall crane as claimed in claim 1 wherein said post is telescopic.

5. The wall crane as claimed in claim 1 further including means for preventing said cable from separating from said pulley.

6. The wall crane as claimed in claim 1 wherein said post extends from said base and terminates at an upper end, said upper end being bifurcated into two spaced apart branches, said pulley being rotatably disposed between said branches, said wall crane further including a retaining rod extending between said branches adjacent to said upper and preventing said cable from separating from said pulley.

7. The wall crane as claimed in claim 6 wherein said retaining rod is separable from said branches to permit removal of said cable from said pulley.

8. The wall crane as claimed in claim 3 wherein said catch has a pair of interconnected inner and outer arms, said inner arm extending outwardly from said post and terminating at said outer arm, said inner arm being disposed above said wall and said outer arm being disposed at an angle in the range of about 45 degrees to 60 degrees from said wall when said wall is in a vertical position.

9. The wall crane as claimed in claim 8 wherein said angle is about 50 degrees.

10. A hand-powered wall crane for raising a wall to a vertical position comprising: a base having means by which said base can be made stationary, a post pivotally connected to said base; a pulley connected to said post at a point spaced apart from said base; a hook for securing the wall; a cable extending from said winch, over said pulley and to said hook; a winch for winding and unwinding said cable; stop means for selectively preventing pivotal movement of said post relative to said base such that said post can be made immovable relative to said base; and a catch connected to said post for engaging said wall when in a vertical position and preventing further pivoting of said wall past said position.

11. The wall crane as claimed in claim 10 wherein said post is telescopic.

12. The wall crane as claimed in claim 10 further including means for preventing said cable from separating from said pulley.

13. The wall crane as claimed in claim 10 wherein said post extends from said base and terminates at an upper end, said upper end being bifurcated into two spaced apart branches, said pulley being rotatably disposed between said branches, said wall crane further including a retaining rod extending between said branches adjacent to said upper end and preventing said cable from separating from said pulley.

14. The wall crane as claimed in claim 13 wherein said retaining rod is separable from said branches to permit removal of said cable from said pulley.

15. The wall crane as claimed in claim 10 wherein said catch has a pair of interconnected inner and outer arms, said inner arm extending outwardly from said post and terminating at said outer arm, said inner arm being disposed above said wall and said outer arm being disposed at an angle in the range of about 45 degrees to 60 degrees from said wall