Abstract:
A telescoping extension chute has a first semicircular section with an inlet end for pivotal connection to a main chute on a mixer truck and a pair of tubular tracks attached along upper longitudinal edges. An intermediate section with a semicircular cross-section of larger radius telescopes over the first section and has a pair of tubular tracks attached along upper longitudinal edges which extend through slots formed in the bottom walls of the first section tracks. A third section with a semicircular cross-section of still larger radius telescopes over the intermediate section and has a pair of bars attached along upper longitudinal edges which extend through slots formed in the bottom walls of the intermediate section tracks. Rollers attached to the tracks cooperate to provide relative telescoping movement and a locking mechanism prevents relative movement in any extended position.

Description:
BACKGROUND OF THE INVENTION 
     In general, the invention relates to a discharge chute for a concrete mixer vehicle and, in particular, to a telescopic extension chute for such discharge apparatus. 
     Typically, concrete mixer vehicles have a discharge chute mounted beneath the discharge opening of the mixer for directing the concrete or other mix material from the vehicle to the desired deposit point. One end of the chute is pivotally mounted at the opening of the mixer for pivoting about a vertical axis for swinging from side to side, and for pivoting about a horizontal axis for changing the angle of inclination of the chute to achieve the appropriate elevation of the discharge end. 
     In most conventional concrete mixer trucks, a section of the discharge chute is permanently mounted with its upper end at the mixer outlet and its lower end supported by an extendable element such as a hydraulic piston and cylinder for varying the angle of inclination. A second shorter section of chute is pivotally mounted on the extending first end to fold over on top of the first section for storage. In the folded condition, the chutes are in sufficiently compact relationship for both on and off highway operation of the vehicle. Normally, the vehicle carries one or more additional sections of discharge chute which may be hooked onto the extending end of the second chute to provide the desired length. Due to the extreme weight of the concrete handled and the rough conditions of use, these chutes must be of necessarily heavy construction. 
     Furthermore, it is not uncommon for the position of discharge to change during the pouring of a load of concrete such that the length of the discharge chute must be varied. This requires the operator to manually add and remove the discharge chutes that are carried on the vehicle with the associated delay and substantial effort required. Moreover, the plurality of chute sections can not be left assembled in their extended condition during transit since they would extend beyond practical and legal limits. Thus, the sections must be removed from the permanently attached chute and mounted at some other location on the vehicle. 
     SUMMARY OF THE INVENTION 
     The present invention involves a telescoping extension chute which can be utilized to replace the shorter second permanent chute section and removable sections of the prior art discharge chutes. At least two semi-circular sections of different diameter are utilized with one end of the first or smaller diameter section adapted to be pivotally attached to the extending end of the first permanent chute section on the mixer truck. If an intermediate telescoping section is utilized, it is slightly larger in diameter than the first telescoping section and is fitted over the outside thereof. The discharge end or last telescoping section is the largest in diameter. The first telescoping section and any intermediate sections have generally rectangular tubes attached along both upper edges and the outer or last section has rectangular steel bars welded along the upper edges thereof. The tubes are open along the bottom and function as tracks or rails for the intermediate tubes or the bars. Thus, the tubes of the first section telescope over the tubes of any intermediate sections and over the bars of the last extension section. 
     Rollers are attached to the ends of the telescoping sections away from the pivotal connection to the main chute to engage the rails or bars and support the next outermost section. Furthermore, locking mechanisms are provided to hold the chute sections in the fully telescoped position. Also, a support brace and springs tend to maintain the telescoped and folded chutes in their stored position during travel. 
     It is an object of the present invention to provide a telescoping discharge chute extension for a concrete mixing truck which is permanently attached to the truck and easy to extend and store. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The above as well as other objects of the invention will become apparent to one skilled in the art from reading the following detailed description of a preferred embodiment of the invention when considered in light of the attached drawings in which: 
     FIG. 1 is a side elevational view of a discharge chute and a telescoping extension chute in accordance with the present invention; 
     FIG. 2 is a fragmentary side elevational view of the telescoping chute of FIG. 1 shown in the extended position; 
     FIG. 3 is a fragmentary enlarged view taken as if in cross-section through the telescoping chutes of FIG. 1 to show the supporting rail; 
     FIG. 4 is an enlarged fragmentary view showing a supporting wheel and a locking mechanism of the invention shown in FIG. 1 with the locking mechanism in cross-section; 
     FIG. 5 is an enlarged fragmentary plan view of one of the wheels used in the invention of FIG. 1; 
     FIG. 6 is an enlarged fragmentary plan view of another type of wheel used in the invention of FIG.1; and 
     FIG. 7 is a side elevational view of a discharge chute and a telescoping extension chute in accordance with an alternate embodiment of the present invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     There is shown in FIG. 1 a conventional main chute 11 which is typically semi-circular in cross-section. The main chute 11 has a closed inlet end 13 which can be connected to a mixing vehicle by a bracket 14 attached to the main chute 11. Opposite the closed inlet end 13 is an open outlet end 15 of the main chute. The bracket 14 cooperates with a conventional mechanism on the mixing vehicle to allow the outlet end 15 to rotate about a vertical axis located at the inlet end 13 and also permit vertical positioning of the outlet end 15. 
     The outlet end 15 of the main chute 11 has a flange 16 formed about its peripheral edge. As will be discussed below, the flange 16 cooperates with an abutting end of the telescopic extension chute assembly 12. A pivot mechanism 17 is connected between the upper edge of the outlet end 15 and the upper edge of the abutting end of the telescopic extension chute assembly 12. The pivot mechanism 17 can be of any conventional type such as a shaft and sleeve bearing. Extending generally vertically upwardly from the side of the main chute 11 is a support arm 18 having a support pad 19 attached to an upper end thereof. A supporting surface of the support pad 19 is angled between horizontal and vertical to engage an upper edge of the telescopic extension chute assembly in the folded position as shown in FIG. 1. An helical hold down spring 20 has one end attached to the support arm 18 adjacent the main chute 11. The other end of the spring 20 is connected to a locking hook 21 which releasably engages an eye 22 attached to the telescopic extension chute assembly 12. When the assembly 12 has been folded into engagement with the support pad 19, the hook 21 is engaged with the eye 22 to prevent the assembly 12 from jumping off the support pad 19 and falling over center when the mixing vehicle goes over a bump. 
     A mounting bracket 23 is attached to an upper edge of the chute assembly 12 near the pivot mechanism 17. One end of a helical spring 24 is pivotally attached to the bracket 23. The other end of the helical spring 24 is attached to one end of a turnbuckle 25 having its other end attached to the support arm 18. The helical spring 24 is a tension spring which aids in lowering and raising the chute assembly 12 about the pivot mechanism 17. The turnbuckle 25 can be utilized to adjust the tension of the spring 24. Although only one side of the main chute 11 and chute assembly 12 have been shown in FIG. 1, the bracket 14 and the elements 17 through 25 can be duplicated along the opposite edges of the main chute 11 and chute assembly 12. 
     In FIG. 2, the telescopic extension chute assembly 12 is shown in the lowered and extended position. The chute assembly 12 has been lowered by pivoting about the pivot mechanism 17 in a counterclockwise direction until a flange 26, formed at the peripheral edge of an inlet end 27 of a first chute extension section 28, abuts the flange 16. Typically, the chute assembly 12 is lowered into position with all of the extension chutes telescoped together as shown in FIG. 1. During the lowering of the chute assembly 12, the helical spring 24 will be extended as shown in FIG. 2 thereby assuming some of the load or weight of the chute assembly 12 as it is being lowered into position. When the flange 26 abuts the flange 16, the chute assembly 12 can be extended to its full length or any intermediate position. 
     A second or intermediate extension chute or section 29 is slightly larger in diameter than the first extension section 28. Thus, an outlet end 30 of the section 28 extends inside an inlet end 31 of the section 29. This configuration tends to prevent the material being discharged from the mixer vehicle from flowing between the extension chutes 28 and 29 without the necessity for a seal. Similarly, a third or discharge extension section 32 has a slightly larger diameter than the section 29. Thus, an outlet end 33 of the chute 29 extends inside an inlet end 34 of the extension chute 32. The section 29 can have a flange 35 formed about the peripheral edge of its inlet end 31 and the section 32 can have a flange 36 formed about the peripheral edge of its inlet end 33 and a flange 37 formed about the peripheral edge of an outlet end 38. 
     As best shown in FIG. 3, the extension chute sections 28, 29 and 32 are of different diameters to enable them to nest or telescope together in the stored position shown in FIG. 1. FIG. 3 is an enlarged fragmentary view taken as if in cross-section to show the nesting of the tracks or rails of the chute assembly 12. The first extension section 28 has a generally tubular track 39 attached to an upper edge thereof. The track 39 has a slot 40 formed along the entire length of a bottom wall 41. The slot 40 is formed adjacent an inner side wall 42 such that the bottom edge of the side wall 42 abuts and is attached to an upper edge 43 of the section 28. 
     The second or intermediate extension section 29 extends about the outside of the section 28 and an upper edge 44 of the section 29 extends upwardly through the slot 40. A track 45 of generally rectangular tubular cross-section is attached to the chute 29 and is enclosed by the track 39. The track 45 has a slot 46 formed in a bottom wall 47 thereof which slot 46 extends along the entire length of the track 45. The slot 46 is formed adjacent an inner side wall 48 of the track 45 and a lower end of the side wall 48 abuts and is attached to the upper edge 44 of the section 29. The upper edge of the third or discharge extension section 32 extends through the slots 40 and 46. A strip of bar stock 49 of generally rectangular cross-section is attached to an outer surface of the upper edge of the section 32. The bar stock 49 is surrounded by the track 45 which in turn is surrounded by the track 39. 
     Typically, the chute sections 28 and 29 are formed of a twelve gage steel material and the chute section 32 is formed of a lighter fourteen gage steel material. The track 39 can be a length of 11/2&#34;×21/2&#34;×1/8&#34; steel tubing. The track 45 can be a length of 1&#34;×2&#34;×1/8&#34; thick steel tubing. The bar 49 can be a 3/8&#34;×1&#34; bar. Each of the chute sections 28, 29 and 32 can be approximately four feet long. 
     As shown in FIGS. 1 and 2, the extension chutes 29 and 32 are supported by roller assemblies 50 and 51 respectively which are attached to the outlet ends of the extension chutes 28 and 29 respectively. The roller assembly 50 is shown in greater detail in FIG. 4 and is representative of the roller assembly 51. Typically, the roller assemblies 50 and 51 are duplicated on the opposite sides of the chutes. The roller assembly 50 includes an arm 52 having one end attached to an outwardly facing side wall of the track 39. The arm 52 is attached at the outlet end 30 and extends beyond the outlet end of the chute 28 at a downward angle. The other end of the arm 52 has a roller 53 pivotally connected thereto by a conventional fastener 54. The roller 53 engages the bottom wall 47 of the track 45 to position the track 45 centrally within the track 39. Similarly, the roller assembly 51 is attached to the track 45 to engage a lower surface of the bar 49 and support the bar 49 centrally within the track 45. If necessary, the roller 53 can be mounted on bearings (not shown) of the ball or roller type. 
     Also shown in FIGS. 1 and 2, are locking mechanisms 55 and 56 mounted on the extension chutes 28 and 29 respectively. The locking mechanism 55 is shown in more detail in FIG. 4 and is representative of the locking mechanism 56. Although the locking mechanisms 55 and 56 are shown as positioned on the tops of the tracks 39 and 45 respectively, they could also be mounted on the sides of such tracks and similar locking mechanisms could be provided on the opposite edges of the chutes 28 and 29. 
     The locking mechanism 54 includes a threaded base 57 which is attached to an upper surface of the track 39 by any conventional means such as by welding. The base 57 includes a threaded aperture 58 extending therethrough and oriented with its longitudinal axis in a generally vertical direction centered over an aperture 59 formed in an upper wall 60 of the track 39. A threaded rod 61 has one end attached at the center of a generally disk-shaped handle 62. The other end of the rod 61 extends through the base 57 and the aperture 59. When it is desired to lock the chutes 28 and 29 in position relative to one another, the handle 62 is turned to thread the rod 61 into engagement with an upper surface 63 of the track 45 thereby trapping the track 45 between the end of the threaded rod 61 and the roller 53 to prevent relative longitudinal movement between the chutes 28 and 29. The locking mechanism 55 is released by a rotating handle 62 in the opposite direction to move the end of the threaded rod 61 out of engagement with the upper surface 63. 
     The inlet ends 31 and 34 of the extension sections 29 and 32 respectively are also supported on rollers. As shown in FIG. 2, a roller assembly 64 is attached to the inlet end 31 and a roller assembly 65 is attached to the inlet end 34. The roller assembly 65 is shown in more detail in FIG. 5. The bar 49 stops short of the peripheral edge of the inlet end 34 of the extension chute 32. A mounting plate 66 can be attached to the outer surface of the extension chute 32 between the end of the bar 49 and the edge of the inlet end 34. A roller 67 is pivotally mounted on a shaft 68 which extends through and is attached to the mounting plate 66 and the extension chute 32. The roller 67 is positioned to engage the inner surface of an upper wall 69 (FIG. 3) of the track 45. Thus, it can be seen that the roller assembly 51 and the roller assembly 65 cooperate with the track 45 and the bar 49 to permit relative movement between the chutes 29 and 32. 
     As shown in FIG. 6, the peripheral end of the upper wall 69 of the track 45 is cut out to form a recess 70 for accepting a roller 71. The roller 71 is rotatably mounted on a shaft 72 which extends between and is retained in the side walls of the track 45. As shown in FIG. 3, the roller 71 extends above the upper wall 69 of the track 45 and engages an inner surface of an upper wall 73 of the track 39. Thus, the roller assembly 50 and the roller assembly 64 cooperate with the track 39 and the track 45 to permit the extension sections 28 and 29 to move relative to one another. Of course, the roller assemblies 64 and 65 are typically duplicated on the other side of the extension chute assembly 12. 
     As an aid in extending and retracting the sections 29 and 32, a downwardly extending handle 74 can be attached to the track 45 adjacent the roller assembly 51 and a downwardly extending handle 75 can be attached to the bar 49 adjacent the flange 37. The handles 74 and 75 make it easier to exert force to extend and retract the extension sections 29 and 32 respectively. 
     There is shown in FIG. 7 an alternate embodiment of the present invention in which elements similar to those shown in FIG. 1 are labeled with the same reference numbers with a prime added thereto. A main chute 11&#39; has a closed inlet end 13&#39; which can be connected to a mixing vehicle 80 by a bracket 14&#39; attached to and downwardly extending from the main chute 11&#39;. The bracket 14&#39; is pivotally attached to an outer end of a generally horizontally extending arm 81 affixed to the mixing vehicle 80. An outlet end 15&#39; of the main chute 11&#39; is attached to an abutting end of a telescopic chute assembly 12&#39;. 
     Also attached to the mixing vehicle 80 is another arm 82 generally horizontally extending and spaced above the arm 81. A hoist or winch 83 is attached to an outer end of the arm 82 and includes a pulley or a drum 84 driven by an electric motor (not shown) and connected to a power source (not shown) by an electrical cable 85. The winch 83 is reversible to lower the chute assembly to the fully extended position shown in the solid lines and to raise the chute assembly to the retracted or storage position shown in phantom lines. The pulley 84 is attached to one end of a cable 86 which extends through a pulley 87 and has its other end attached to a clevis 88. Typically, the pulley 87 is mounted along an upper edge near the discharge end of the first chute extension 28&#39;. Typically, the clevis 88 is mounted along an upper edge near the discharge end of the third or discharge extension section 32&#39;. 
     In the retracted position shown in the phantom lines in FIG. 7, a chain 89 has one end attached to the extension chute section 28&#39;. The other end of the chain is attached to a locking hook 90 which engages an eye 91 on the support arm 18&#39; for supporting the telescopic extension chute assembly 12&#39;. When it is desired to lower the extension chute 12&#39;, the locking hook 90 is released from the eye 91 and approximately eight to ten inches of winch cable 86 is released by the winch 83. This action enables the main chute 11&#39; to be lowered to an operating position as shown by the solid lines in FIG. 7. The main chute 11&#39; is retained in its lowered position by any suitable means (not shown) such as stop means on the bracket 14&#39;. Next, the winch 83 is run in reverse to release the winch cable 86 from the pulley or drum 84 thereby lowering the telescopic chute section assembly 12&#39; to an approximately horizontal position. Next, the lock 55&#39; is unlocked to release a second extension chute section (not shown). Finally, the lock 56&#39; on the second chute extension is unlocked to release the third chute extension 32&#39;. The telescoping extension chute according to the present invention is now in its fully extended position. 
     To retract the chute, the main chute 11&#39; and extension chute 12&#39; sections should be thoroughly cleaned. Both of the locks must be in the unlocked position and then the winch is operated to retract the cable 86. The third extension chute section 32&#39; will retract first followed by the next chute section 29&#39; and finally the three extension chute sections will be retracted and rotated about the pivot mechanism 17&#39; to rest upon the support bracket 18&#39;. The safety chain 89 and locking hook 90 are then attached to the eye 91 and the winch 83 is operated to raise the main chute 11&#39; about the bracket 14&#39;. 
     In accordance with the provisions of the patent statutes, the present invention has been described in what is considered to represent its preferred embodiment. However, it should be noted that the invention can be practiced otherwise than as specifically illustrated and described without departing from its spirit or scope.