CA1281201C - Vibratory screed including a spreading device for levelling and distributing plastic concete in front of the screed - Google Patents
Vibratory screed including a spreading device for levelling and distributing plastic concete in front of the screedInfo
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- CA1281201C CA1281201C CA000522479A CA522479A CA1281201C CA 1281201 C CA1281201 C CA 1281201C CA 000522479 A CA000522479 A CA 000522479A CA 522479 A CA522479 A CA 522479A CA 1281201 C CA1281201 C CA 1281201C
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- screed
- concrete
- blade
- auger
- plastic
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Abstract
ABSTRACT OF THE DISCLOSURE
A vibratory concrete screed includes a frame and a sub-stantially horizontal screed blade. A pair of end-mounted winches advance the screed along concrete forms into an area of unfinished plastic concrete. A concrete spreading device is translated back and forth along the length of the screed to partially level the unfinished concrete before engagement by the screed blade. The concrete spreading device includes grading means having distributing means in the form of an auger and metering means in the form of a plow. The auger initially levels and redistributes the plastic concrete while the plow receives the plastic concrete from the trailing edge of the auger and regulates the level of plastic concrete discharged from the concrete spreading device and intercepted by the screed blade.
A carriage maintains the grading means at a predetermined eleva-tion in front of the screed blade and translates the spreading device along the length of the screed frame. The concrete spreading device operates on the unfinished plastic concrete to feed a partially finished, constant height charge of concrete to the screed blade.
A vibratory concrete screed includes a frame and a sub-stantially horizontal screed blade. A pair of end-mounted winches advance the screed along concrete forms into an area of unfinished plastic concrete. A concrete spreading device is translated back and forth along the length of the screed to partially level the unfinished concrete before engagement by the screed blade. The concrete spreading device includes grading means having distributing means in the form of an auger and metering means in the form of a plow. The auger initially levels and redistributes the plastic concrete while the plow receives the plastic concrete from the trailing edge of the auger and regulates the level of plastic concrete discharged from the concrete spreading device and intercepted by the screed blade.
A carriage maintains the grading means at a predetermined eleva-tion in front of the screed blade and translates the spreading device along the length of the screed frame. The concrete spreading device operates on the unfinished plastic concrete to feed a partially finished, constant height charge of concrete to the screed blade.
Description
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BACKGROUND OF THE INVENTI(~IY
1. Field of the lnven~ n This invention relates to vibratory concrete screeds, and more particularly, to vibratory concrete screeds which include a laterally translatable concrete spreading device positioned in front of the screed blade to partially level and distribute plastic concrete before the screed blade engages the concrete.
BACKGROUND OF THE INVENTI(~IY
1. Field of the lnven~ n This invention relates to vibratory concrete screeds, and more particularly, to vibratory concrete screeds which include a laterally translatable concrete spreading device positioned in front of the screed blade to partially level and distribute plastic concrete before the screed blade engages the concrete.
2. Description of the Prior Art A concrete screed is a device for simultaneously leveling and fi.nishing -the entire wid-th of the surface of freshly poured plas-tic concre-te. :[n order -to achieve greater production rates, modern concrete screeds typically incorporate vibration generating mechanisms for vibrating the screed blade which actually engages, levels and finishes the upper surface of the concrete. rl'r:iangular -truss concrete screeds incorpora-ting spaced apart front and rear blades have become increasingly popular during -the last few years for a number of reasons. A -triangular truss screed is strong yet li.ght and can be assembled in a vari.e-ty of lengths from a plurality of separate, shorter leng-th screed frame sec-tions.
Concre-te is -typically poured between opposing side forms that also support the ends of the screed. Before the screed can be advanced into the area of freshly poured concrete, several workers with shovels must fill in any low places in the plastic concrete and mus-t redistribute the concrete so that the screed blade will initially engage -the plastic concrete surface only approximately slightly above the concre-te surface. If the upper surface of the ~28~201 plastic concrete is not properly manually leveled and distributed, an excess amount of concrete will come in contact with the screed blade and will ultimately prevent further forward movement of the screed into the unfinished concrete. 'rhese manual prefinishing operations must be accomplished promptly to preven-t premature setting of the freshly poured concrete before the screed finishing operation has been completed.
The Bid-Well Division of CMI Corporation of Canton, S. Dak.
presently manufactures a spinning tube concrete finishing device that utilizes an elevated support bridge which spans the width of an unfinished concrete surface. See U.S. Pat. No. 4,320,9~7. A
laterally -translatable spinning tube finishing device is suspended beneath -the elevat;ed bridge and is transla-ted from side to side beneath the bridge by an engine driven hydraulic system that engages and displaces a continous chain. A large horizontally oriented dual-auger assembly is coupled to the front of the laterally translatable spinning tube finishing device. The two coun-ter rota-ting augers engage the upper surface of the concrete and both level and distribute plastic concrete as the finishing unit is translated from side to side below the support bridge. After an out and back finishing pass has been cornp:Leted, the support bridge is moved forward on -the concrete side forms to reposi-tion the spinning tube finishing rollers for -the next ou-t and back finishing pass.
The Bid-Wel] roller finisher also may include a spud vibrator attachment which can be coupled to -the la-terally translatable finishing device in fron-t of the auger to consolidate the plastlc concrete before contact by the augers. The bridge is supported by four spaced apart corner roller assemblies. Each roller assembly includes a jacking device for independently adjus-ting each of the four corners of the support bridge. Each roller assembly can be positioned at a variable location along the length of the suppor-t bridge to permit the roller assemblies to engage concrete forms having variable spacing. Hydraulic motors drive rollers coupled to ~Z8~L2~
selected ones of the roller assemblies in order to -transla-te the Bid-Well roller finisher along the concre-te forms.
In the Bid-Well device, finishing is accomplished by interaction of the srnooth rotating surface of the paired spinning tubes as they are laterally translated back and forth across the upper surface of the concrete. As explained above, a vibratory concrete screed utilizes either a single or two spaced apar-t vibrating blades to leve] and smoothly finish the upper surface of the plastic concrete. The screed is continuously advanced into the unfinished plastic concrete surface. The Bid-Well roller finisher accomplishes its finishing operation by la-terally translating a pair of spaced apart spinning -tubes beneath an eleva-ted bridge deck while the bridge deck is maintained in a fixed posi-tion along the concrete side forms.
The Miller Formless Company of McHenry, III. manufactures a 30,000 pound directiona] paver machine which includes an oscillating screed blade and a variable height strike-off auger. This fixed position auger is oriented parallel to the oscillating screed blade.
Rotation of the auger spreads concrete along -the width of the screed blade.
U.S. Pat. No. 4,335,976 (Morr-i.son) discloses a triangular truss screed having an engine driven vibratory shaft which extends along the entire ],ength of the screed for imparting vibratory motion to the front and rear screed blades. Morrison fur-ther discloses a hydraulically powered wi.nch system whi.ch incorporates a hydraulic pump which is belt driven by the rotary motion of the screed vibratory shaft. The -two spaced apart hydraulic winches are therefore powered by a single internal combustion engine mounted on the screed frame.
U.S. Pat. No. 3,377,933 (Dale) discloses a winch prop~lled road laying machine having a reciprocating, rear-mounted screed and a front-mounted spreading auger which spans the distance between the concrete forms.
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U.S. Pat. No. 2,583,108 (Lewis) discloses a concrete spreader having t~o spaced apart spreading augers ~ounted on a carriage and laterally translatable with respect to -the machine fra~e. A ver-tical distributing plate is mounted on the carriage between the augers to laterally distribute plas-tic concrete.
Both the Dale and Lewis patents were cited as references against U.S. Pat. No. 4,320,987 referred to above.
SUMMARY OF THE INVENTION
United States Patent No. 4,466,757 which issued to Allen Engineering Corpora-tion on August 21, 1984 disc]oses a preferred embodiment of the invention including grading means in the form of a rotating auger. In that embodiment of the invention, the partially levelled, redistributed plastic concrete exits the trailing edge of the auger and is immediately intercepted by the advancing front blade of the screed. One improvement of that invention is disclosed and claimed herein and includes metering means which forms a part of the grading means of the present -` ~8120~ f 1 invention. The metering means recei~es the partially levelled 2 plastic concrete from the distributing means which forms the 3 initial portion of the grading ~eans. The metering means 4 functions to regulate the height of the charge of plastic concrete discharged from the concrete spreading means and inter-6 cepted by the screed blade. This improved grading means including 7 both distributing means and metering means sequentially operates 8 on the unfinished plastic concrete to feed a partially finished, 9 constant height charge of concrete to the screed blade as the carriage means of the present invention translates the grading 11 means in first and second directions along the length of the 12 screed frame.
14 United States Patent No. 4,466,757 also discloses an oscillating strike-off concrete finishing mechanism which is 16 coupled to a screed frame in front of the front screed blade.
17 The oscillating strike-off is either coupled between the concrete lB spreading means and the front screed blade and operates as an 19 intermediate finishing device or may be coupled in a similar position to a screed which does not include concrete spreading 21 means. The improved oscillating strike-off disclosed herein 22 includes means for adjusting the vertical spacing between the 23 oscillating strike-off blade and the screed blade. When used as 24 a concrete finishing device without the concrete spreading means o~ the present invention, a plurality of spaced apart pneumatic 26 vibrators may be mounted directly on the oscillating strike-off 27 blade to improve the concrete finishing capabilities.
29 The imprDved invention disclosed herein also includes 30 ¦¦ a paving train consistlng of a primary finishing screed including 31 concrete spreading means followed in spaced apart relationship 3Z by a secondary finishing screed including an oscillating strike-of .
DESCRIPTION OF THE DRAWINGS
__ _ The invention is poin-ted out with particularity in the appended claims. Elowever, other objects and advantages together with the operation of the invention may be better understood by reference to the following detailed description taken in connection with the following illustrations, wherein:
FIG. 1 is a partial perspective view of the primary structural elements of the vibratory concrete screed of the present invention. For the purpose of clarity, several subsidiary structures of the screed are not depicted in FIG. 1.
FIG. 2 is an exploded perspective view of the primary elements of the auger and auger drive assembly.
FIG. 3 is a schema-tic diagram representation of the hydraulic system of the concrete spreading device.
FIG. 4 is a partial perspective view showing the manner in which a hydraulic motor is coupled to the oscillating s-trikeoff attachment of the present invention to reciprocate the oscillating strikeoff.
FIG. 5 is a partially cutaway, elevationa] v:Lew indicating the manner in which the hydraulic drive motor for the carriage is coupled to the frame of the concrete screed.
FIGS. 6-9 comprise a series of illustrations depicting the structure and operation of the carriage directional control switch.
FIG. 10 :Lllustrates the utilization of a pneumatically powered vibrator for imparting vibratory motion to the screed blades.
FIG. 11 is an enlarged perspective view of one end of the vibratory concrete screed of the present invention, particularly illustrating the winch and its hydraulic power system and the screed guide means.
F'IG. 12 is a plan view of the first and second units of the screed guide means.
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FIG. 13 is a partially cutaway perspective view of a pneumatically powered version of the oscillating strikeoff attachment for the vibratory concrete screed of the present invention.
FIG. 14 is a partially cutaway perspective view particularly illustrating the manner in which the carriage is coupled to the screed frame.
FIGS. 15A and B are partially cutaway plan views of the carriage depicting the manner in which the concrete grading blade is repositioned between the first and second trailing positions as a result of reversal of the direc-tion of travel of the concrete spreading device.
FIG. 16 is a schematic diagram representation of the self-contained hydraulic system of the oscillating strikeoff attachment.
FIG. 17 is a partially cutaway sectional view of the vibratory concrete screed of the present invention.
FIG. 18 is a partially cutaway perspective view depicting concrete spreading means of the present invention which includes only a "V"-shaped grading blade.
FIG. 19 is a simplified plan view of the present invention depicting concrete spreading means having a "V"-shaped grading blade, particularly illustrating the manner in which the grading b:Lade is displaced between first and second positions as the direction of travel of the carriage changes.
FIG. 20 is a simplified plan view of the present invention depicting a single fixed grading blade coupled to the front face of the carriage.
FIG. 21 depicts the manner in which a wheel unit of the screed guide means of the present invention can be configured to permit a range of movement to accommodate varying spacing between concrete forms.
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FIG. 22 illustrates the manner in which the screed guide means of the present invention can be configured to permit the screed to be skewed.
FIG. 23 is a simplified plan view of the present invention depicting the manner in which the screed guide means, of the present invention permits the screed to travel along curved concrete forms.
FIG. 24 is a partially cutaway perspective view of an alternative embodiment of a vibratory concrete screed including a modified concrete spreading device and a modified end support structure.
FIG. 25 is a partially cutaway elevational view of the end support structure oE the screed depicted in FIG. 24, particularly illustrating the manner in which the screed guide unit can be vertically adjusted.
FIG. 26 is an enlarged, partially cutaway perspective view of the end support member hinge structure depicted in FIG. 25.
FIG. 27 is a partially cutaway, enlarged view of the hinge clamp depicted in FIG. 26.
FIG. 28 is a partially cutaway sectional view of the modified roller assembly utilized on the screed depicted in FIG. 2~.
FIG. 29 is an exploded perspective view of the lateral adjustment device for the horizontally oriented roller depicted in FIG. 28.
FIG. 30 is a simplifi,ed view from above of the horizontally oriented roller support structure depicted in FIG. 28.
FIGS. 31A-D illustrate the excessive build-up of plastic concrete on the blade of a vibxating screed which receives an excessive charge height of plastic concrete.
FIG. 32 is a view from above of the blade spill-over problem illustrated in FIG. 31.
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FIG. 33 is a view from above illustrating the metering Imeans of the present invention coupled to the concrete spreading ¦means.
FIG. 34 illustrates the relative position of the metering means of the present invention with respect to the front screed blade and the distributing means of the present invention.
FIG. 35 depicts the grading means detached from the carriage means of the present invention to illustrate structure permitting relative vertical adjustment between the grading means and the carriage means.
FIG. 36 illustrates the grading means of the present ,/
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~2812~ ' 1 invention including both distributing means and metering means 2 and its relative position with respect to a front screed blade 3 having both forward and rear facing blade sections.
FIG. 37 illustrates the grading means of the present 6 invention including both distributing means and metering means 7 with an oscillating strike-off positioned between the grading 8 means and the screed blade.
FIG. 38 illustrates the improved oscillating strike-off 11 includiny vertical strike-off blade adjustment means and a 12 plurality of pneumatic vibrators coupled to the strike-off blade.
14 FIG. 39 is a sectional view of the oscillating strike-off support structure depicted in FIG. 38, taken along section 16 line 39-39, particularly illustrating the structure which couples 17 ¦the oscillating strike-off blade to the screed.
lg FIG. 40 represents a sectional view of the oscillating strike-off illustrated in FIG. 38, particularly depicting the 21 roller structure which maintains a predetermined fixed spacing 22 between the oscillating strike-off blade and the screed blade.
24 FIG. 41 depicts a paver train comprising a primary finishing screed including concrete spreading means followed 26 in spaced apart relationship by a secondary finishing screed 27 including an oscillating strike-off system.
29 FIG. 42 represents a view from above of the paver train depicted in FIG. 41.
32 ...
' - 10 -! (_ 1 DESCRIP~ION C)F' 'rHE PREFERR~D EM~3ODIMENT
3 In order to better illustrate the advantages of the 4 invention and its contributions of the artl a preferred hardware embodiment of the invention will now be described in detail.
7 The preferred embodiment of the initial version of the invention is fully disclosed in ~nited States Patent No. 4,466, 9 757 and illustrated in prior art Figs. ] to 30. In certain circumstances, that initial embodiment of the invention encountered 11 blade spill over problerns of the type illustrated in FIGS. 31 12 and 32. In the embodiment of the invention as illustrated in 13 FIGS. 1 and 17, the trailing edge of auger 84 was immovably 14 secured to carriage 76 precluding relative vertical adjustments between the trailing edge of auger 84 and front screed blade 16.
16 As the screed advanced forward into an area of unfinished plastic 17 concrete, concrete could spill over the top of screed blade 16 18 disturbing the finished concrete surface designated by reference 19 number 300 as illustrated in FIG. 31D.
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21 In order to overcome this problem, the structure il-2 lustrated in FIGS. 33-35 has been created. The grading means 23 302 of the present invention has now been improved to incorporate 24 distributing means and metering means. In the depicted preferred embodiment of the invention, the distributing means takes the 26 form of an auger 304 and the metering means takes the form of a 27 plow 306. Plow 306 inclucles a horizontally oriented, continuous 29 lower surface 308 joining together a pair of wedge-shaped end sections 310 which each include a vertically oriented cutting edge 312. Plow 306 is coupled to the horizontally oriented lower 31 surface of chain box 314 which houses the drive chain coupling auger drive motor 92 to auger 304.
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1 ¦ To optimize operation of the metering means of the 2 ¦ present invention,vertical adjustment means is provided to 3 ¦ permit precise adjustment of the spacing between the lower 4 ¦ surface 308 of plow 306 and the horizontally oriented surface 5 ¦ 316 of front screed blade 16. The inner face 318 of auger 6 ¦ support bracket 320 includes four spaced-apart, vertically 7 ¦ oriented oval apertures 322 which may be mated with either an 8 ¦upper group 324 or a lower group 326 of apertures in the face 9 ¦of auger carriage 76. A set of four bolts (not shown) are 10 ¦inserted through vertically oriented channels 328, through each 11 ¦of the oval apertures 322 and into either the upper or lower group 12 ¦of apertures 324 or 326 as necessary to achieve the desired 13 ¦spacing between the lower surface 308 of plow 306 and the upper 14 ¦surface 316 of front screed blade 316. When the appropriate 15 ¦vertical spacing has been achieved, each of the four spaced 16 ¦apart mounting bolts is tightened to maintain auger support 17 ¦bracket 320, auger 304 and plow 306 in the desired vertical 18 position. For example, for low slump concrete including one and 19 one half inch stones, the spacing between the lower surface 308 of plow 306 and the upper surface 316 of blade 16 might be ad-21 justed to approximately one and one quarter inches. For higher 22 slump concrete, the distance between the plow and the screed blade Z3 is typically decreased. The particular plow/screed blade vertical 24 spacing which optimizes performance of the present invention with Z5 any particular type of plastic concrete can be readily determined 26 by persons of ordinary sklll in the art.
28 In operation, the metering means of the present invention, 29 including both plow 306 and the above-described vertical adjust-~0 ment means, is translated back and forth along the length of the 31 screed and as illustrated in FIGS. 33 and 34 intercepts and moves 32 plastic concrete forward into the trailing edge of auger 304.
12~1~01 1 The rotating blade of auger 304 intercepts and moves the plastic 2 concrete forward and laterally redistributes it to produce a 3 substantially level surface. In addition, the metering means 4 of the present invention regulates the charge height of plastic concrete fed to the advancing screed blade 16 by stripping off 6 and moving forward excess height plastic concrete into the 7 trailing edge of auger 30~. The elevation of the lower surface 8 308 of plow 30~ determines the charge height of the plastic 9 concrete fed to screed blade 16. The interrelated operation of the distributing means and metering means of the present 11 invention feeds a partially finished, constant height charge of 12 concrete to screed blade 16 as the carriage 76 translates the 13 grading means of the present invention back and forth along the 14 length of the screed frame as the screed simultaneously advances into the unfinished plastic concrete.
17 FIG. 34 depicts the concrete spreading means of the 18 present invention operating in connection with a single forward-19 facing screed blade 16. As indicated, the spacing between the lower surface 308 of plow 306 and the upper surface 316 of screed 21 blade 16 may be made quite small. In FIG. 36, screed blade l6 22 includes both forward facing and rear facing L-shaped blade 23 elements while the spacing between the lower surface 308 of 24 plow 306 and the upper surface 316 of blade 16 has been increased to a distance slightly less than the concrete stone size. The Z6 rear edge of plow 306 is situated approximately halfway between 227 the front and rear edges of the front L-shaped section of screed blade 16. In FIG. 37, screed blade 16 includes only a 29 single, rear facing L-shaped blade section and an oscillating strike-off 330 has been coupled to the screed frame between 31 the rear surface of plow 306 and the front surface of screed 32 blade 16. In the particular embodiment illustrated in FIG. 37, lZB5~01 1 the lower blade surface o~ oscillating strike-off 330 is positioned 2 slightly above the lower surface of screed blade 16 znd approxi-3 mately even with the lower surface 308 of plow 306. In operation, 4 the laterally reciprocating motion of oscillating strike-off 330 accomplishes an intermediate consolidating and finishing operation 6 on the partially finished plastic concrete discharged from the 7 trailing edge of the grading means of the present invention before 8 the plastic concrete is intercePted by screed blade 16. The 9 differential elevation between the lower surface of oscillating strike-off blade 330 and the lower surface of screed blade 16 11 ay be controlled to regulate the height of the charge of plastic 12 concrete fed to screed blade 16. In practice, the lower surface 13 of the blade of oscillating strike-off 330 will typically be 14 adjusted to be even with the lower surface of screed blade 16 or as high as approximately 3/8 of an inch above the lower surface 16 ¦f screed blade 16. Proper adjustment of the oscillating strike-17 ¦off 330/screed blade 16 height differential can be regulated 18 by a person of ordinary skill in the art to achieve the desired 19 concrete finishing characteristics.
21 Referring now to FIGS. 38-40, screed 332 includes an 22 oscillating strike-off 330 having both a plurality of pneumatically 23 powered, high frequency air vibrators 334 as well as vertical blad~
24 adjustment means 336 for controlling the height differential 2~ between the lower surface 338 of the oscillating strike-off 330 26 and the lower surface of screed blade 16. ~IGS. 38 and 39 il-27 lustrate the structure of vertical blade adjustment means 336.
29 A plurality of vertically oriented brackets 340 are coupled to the vertically oriented face of screed blade 16 and 31 1 include a centrally located, vertically oriented oval aperture 32 ~ 342 for accommodating vertical adjustments of oscillating strike-l off blade support units 344. A bolt 346 extends through the lt~81;201 1 ¦various elements of support unit 344 and is secured to a vertical 2 ¦adjustment clamp 348 which interfaces with the rear surface of 3 ¦bracket 340. When bolt 346 is loosened, the rotation of bolt 4 1350 regulates the vertical position of strike-off support unit 5 1344 with respect to bracket 340 to control the relative elevation 6 ¦of the lower surface 338 of oscillating strike-off unit 330 with 7 ¦respect to the lower surface of screed blade 316.
8 l 9 ¦ As illustrated by FIGS. 38 and 40, a plurality of spaced 10 ¦apart rollers 352 are coupled by brackets 354 to the interior 11 ¦face of the blade of oscillating strike-off 330. The comparatively 12 ¦long rolling interface between rollers 35Z and the vertical face 13 ¦of screed blade 16 maintains the blade of oscillating strike-off 14 ¦330 parallel to the vertical face of screed blade 16 as the 15 ¦screed is advanced i.nto the unfinished plastic concrete.
17 Continuous , reciprocating motion of the oscillating 18 strike-off 330 is provided by reciprocating means in the form of 19 a dual-action pneumatic ram 356 and the associated connecting linkage 358 depicted in FIG. 38. As illustrated in FIG. 4 of 21 United States Patent No. 4,466,757, oscillating strike-off 330 22 may also be driven by reciprocating means in the form of hydraulic 23 motor 64 and the associated reciprocation linkage depicted.
When the oscillating strike-off 330 is operated without 26 the concrete spreading means of the present invention as depicted 26 in FIG. 38, single or dual paired air vibrators 334 may be coupled as shown to vibrate the blade of the oscillating strike-29 off. When the oscillating strike-off 330 is configured as indicated in FIG. 37 and positioned between the trailing edge of 31 plow 306 and screed blade 16, the air vibrators 334 will 32 typically be removed to minimize the space occupied by strike-off 330.
lZ~3lZOl 1 ¦ Referring now to FIGS. 41 and 42, a paving train con-2 ¦sisting of a primary finishing screed 360 and a secondary finishing 3 ¦screed 366. Screed 360 includes concrete spreading means 362 4 ¦while screed 366 includes oscillating strike-off 370. Screed 5 ¦366 trails screed 360 by a predetermined time or distance 6 Ito allow the partially finished concrete existing screed 360 7 ¦to reach a semi-equilibrium condition prior to engagement by 8 ¦screed 366. Screed to screed spacing on the order of twenty to 9 ¦forty feet is typical although other spacing variations would 10 ¦be apparent to one of ordinary skill in the art.
12 ¦ It has been found that use of the disclosed two-unit 13 paving train incorporating primary and secondary screeds including 14 concrete spreading means 362 and oscillating strike-off 370 pro-duces a superior concrete finish. Since screeds 360 and 366 16 typically include precisely controllable, hydraulically actuated 17 winches, the screed translation velocity and screed to screed 18 spacing can easily be regulated.
It will be apparent to those skilled in the art that 21 the disclosed vibratory concrete screed and paver train system 22 may be modified in numerous ways and may assume many embodiments 23 other than the preferred forms specifically set out and described Z4 above. For example, various aifferent plow configurations other than the disclosed configuration would function effectively 26 as metering means. Distributing means such as a V-shaped grading Z7 blade or a spinning tube finisher could be used as a substitute 28 for the disclosed rotating auger distributing means. Accordingly, 29 it is intended by the appended claims to cover all such modifica-tions of the invention which fall within the true spirit and 31 scope of the invention.
Concre-te is -typically poured between opposing side forms that also support the ends of the screed. Before the screed can be advanced into the area of freshly poured concrete, several workers with shovels must fill in any low places in the plastic concrete and mus-t redistribute the concrete so that the screed blade will initially engage -the plastic concrete surface only approximately slightly above the concre-te surface. If the upper surface of the ~28~201 plastic concrete is not properly manually leveled and distributed, an excess amount of concrete will come in contact with the screed blade and will ultimately prevent further forward movement of the screed into the unfinished concrete. 'rhese manual prefinishing operations must be accomplished promptly to preven-t premature setting of the freshly poured concrete before the screed finishing operation has been completed.
The Bid-Well Division of CMI Corporation of Canton, S. Dak.
presently manufactures a spinning tube concrete finishing device that utilizes an elevated support bridge which spans the width of an unfinished concrete surface. See U.S. Pat. No. 4,320,9~7. A
laterally -translatable spinning tube finishing device is suspended beneath -the elevat;ed bridge and is transla-ted from side to side beneath the bridge by an engine driven hydraulic system that engages and displaces a continous chain. A large horizontally oriented dual-auger assembly is coupled to the front of the laterally translatable spinning tube finishing device. The two coun-ter rota-ting augers engage the upper surface of the concrete and both level and distribute plastic concrete as the finishing unit is translated from side to side below the support bridge. After an out and back finishing pass has been cornp:Leted, the support bridge is moved forward on -the concrete side forms to reposi-tion the spinning tube finishing rollers for -the next ou-t and back finishing pass.
The Bid-Wel] roller finisher also may include a spud vibrator attachment which can be coupled to -the la-terally translatable finishing device in fron-t of the auger to consolidate the plastlc concrete before contact by the augers. The bridge is supported by four spaced apart corner roller assemblies. Each roller assembly includes a jacking device for independently adjus-ting each of the four corners of the support bridge. Each roller assembly can be positioned at a variable location along the length of the suppor-t bridge to permit the roller assemblies to engage concrete forms having variable spacing. Hydraulic motors drive rollers coupled to ~Z8~L2~
selected ones of the roller assemblies in order to -transla-te the Bid-Well roller finisher along the concre-te forms.
In the Bid-Well device, finishing is accomplished by interaction of the srnooth rotating surface of the paired spinning tubes as they are laterally translated back and forth across the upper surface of the concrete. As explained above, a vibratory concrete screed utilizes either a single or two spaced apar-t vibrating blades to leve] and smoothly finish the upper surface of the plastic concrete. The screed is continuously advanced into the unfinished plastic concrete surface. The Bid-Well roller finisher accomplishes its finishing operation by la-terally translating a pair of spaced apart spinning -tubes beneath an eleva-ted bridge deck while the bridge deck is maintained in a fixed posi-tion along the concrete side forms.
The Miller Formless Company of McHenry, III. manufactures a 30,000 pound directiona] paver machine which includes an oscillating screed blade and a variable height strike-off auger. This fixed position auger is oriented parallel to the oscillating screed blade.
Rotation of the auger spreads concrete along -the width of the screed blade.
U.S. Pat. No. 4,335,976 (Morr-i.son) discloses a triangular truss screed having an engine driven vibratory shaft which extends along the entire ],ength of the screed for imparting vibratory motion to the front and rear screed blades. Morrison fur-ther discloses a hydraulically powered wi.nch system whi.ch incorporates a hydraulic pump which is belt driven by the rotary motion of the screed vibratory shaft. The -two spaced apart hydraulic winches are therefore powered by a single internal combustion engine mounted on the screed frame.
U.S. Pat. No. 3,377,933 (Dale) discloses a winch prop~lled road laying machine having a reciprocating, rear-mounted screed and a front-mounted spreading auger which spans the distance between the concrete forms.
2~
U.S. Pat. No. 2,583,108 (Lewis) discloses a concrete spreader having t~o spaced apart spreading augers ~ounted on a carriage and laterally translatable with respect to -the machine fra~e. A ver-tical distributing plate is mounted on the carriage between the augers to laterally distribute plas-tic concrete.
Both the Dale and Lewis patents were cited as references against U.S. Pat. No. 4,320,987 referred to above.
SUMMARY OF THE INVENTION
United States Patent No. 4,466,757 which issued to Allen Engineering Corpora-tion on August 21, 1984 disc]oses a preferred embodiment of the invention including grading means in the form of a rotating auger. In that embodiment of the invention, the partially levelled, redistributed plastic concrete exits the trailing edge of the auger and is immediately intercepted by the advancing front blade of the screed. One improvement of that invention is disclosed and claimed herein and includes metering means which forms a part of the grading means of the present -` ~8120~ f 1 invention. The metering means recei~es the partially levelled 2 plastic concrete from the distributing means which forms the 3 initial portion of the grading ~eans. The metering means 4 functions to regulate the height of the charge of plastic concrete discharged from the concrete spreading means and inter-6 cepted by the screed blade. This improved grading means including 7 both distributing means and metering means sequentially operates 8 on the unfinished plastic concrete to feed a partially finished, 9 constant height charge of concrete to the screed blade as the carriage means of the present invention translates the grading 11 means in first and second directions along the length of the 12 screed frame.
14 United States Patent No. 4,466,757 also discloses an oscillating strike-off concrete finishing mechanism which is 16 coupled to a screed frame in front of the front screed blade.
17 The oscillating strike-off is either coupled between the concrete lB spreading means and the front screed blade and operates as an 19 intermediate finishing device or may be coupled in a similar position to a screed which does not include concrete spreading 21 means. The improved oscillating strike-off disclosed herein 22 includes means for adjusting the vertical spacing between the 23 oscillating strike-off blade and the screed blade. When used as 24 a concrete finishing device without the concrete spreading means o~ the present invention, a plurality of spaced apart pneumatic 26 vibrators may be mounted directly on the oscillating strike-off 27 blade to improve the concrete finishing capabilities.
29 The imprDved invention disclosed herein also includes 30 ¦¦ a paving train consistlng of a primary finishing screed including 31 concrete spreading means followed in spaced apart relationship 3Z by a secondary finishing screed including an oscillating strike-of .
DESCRIPTION OF THE DRAWINGS
__ _ The invention is poin-ted out with particularity in the appended claims. Elowever, other objects and advantages together with the operation of the invention may be better understood by reference to the following detailed description taken in connection with the following illustrations, wherein:
FIG. 1 is a partial perspective view of the primary structural elements of the vibratory concrete screed of the present invention. For the purpose of clarity, several subsidiary structures of the screed are not depicted in FIG. 1.
FIG. 2 is an exploded perspective view of the primary elements of the auger and auger drive assembly.
FIG. 3 is a schema-tic diagram representation of the hydraulic system of the concrete spreading device.
FIG. 4 is a partial perspective view showing the manner in which a hydraulic motor is coupled to the oscillating s-trikeoff attachment of the present invention to reciprocate the oscillating strikeoff.
FIG. 5 is a partially cutaway, elevationa] v:Lew indicating the manner in which the hydraulic drive motor for the carriage is coupled to the frame of the concrete screed.
FIGS. 6-9 comprise a series of illustrations depicting the structure and operation of the carriage directional control switch.
FIG. 10 :Lllustrates the utilization of a pneumatically powered vibrator for imparting vibratory motion to the screed blades.
FIG. 11 is an enlarged perspective view of one end of the vibratory concrete screed of the present invention, particularly illustrating the winch and its hydraulic power system and the screed guide means.
F'IG. 12 is a plan view of the first and second units of the screed guide means.
~2~3~2~
FIG. 13 is a partially cutaway perspective view of a pneumatically powered version of the oscillating strikeoff attachment for the vibratory concrete screed of the present invention.
FIG. 14 is a partially cutaway perspective view particularly illustrating the manner in which the carriage is coupled to the screed frame.
FIGS. 15A and B are partially cutaway plan views of the carriage depicting the manner in which the concrete grading blade is repositioned between the first and second trailing positions as a result of reversal of the direc-tion of travel of the concrete spreading device.
FIG. 16 is a schematic diagram representation of the self-contained hydraulic system of the oscillating strikeoff attachment.
FIG. 17 is a partially cutaway sectional view of the vibratory concrete screed of the present invention.
FIG. 18 is a partially cutaway perspective view depicting concrete spreading means of the present invention which includes only a "V"-shaped grading blade.
FIG. 19 is a simplified plan view of the present invention depicting concrete spreading means having a "V"-shaped grading blade, particularly illustrating the manner in which the grading b:Lade is displaced between first and second positions as the direction of travel of the carriage changes.
FIG. 20 is a simplified plan view of the present invention depicting a single fixed grading blade coupled to the front face of the carriage.
FIG. 21 depicts the manner in which a wheel unit of the screed guide means of the present invention can be configured to permit a range of movement to accommodate varying spacing between concrete forms.
~28120~
FIG. 22 illustrates the manner in which the screed guide means of the present invention can be configured to permit the screed to be skewed.
FIG. 23 is a simplified plan view of the present invention depicting the manner in which the screed guide means, of the present invention permits the screed to travel along curved concrete forms.
FIG. 24 is a partially cutaway perspective view of an alternative embodiment of a vibratory concrete screed including a modified concrete spreading device and a modified end support structure.
FIG. 25 is a partially cutaway elevational view of the end support structure oE the screed depicted in FIG. 24, particularly illustrating the manner in which the screed guide unit can be vertically adjusted.
FIG. 26 is an enlarged, partially cutaway perspective view of the end support member hinge structure depicted in FIG. 25.
FIG. 27 is a partially cutaway, enlarged view of the hinge clamp depicted in FIG. 26.
FIG. 28 is a partially cutaway sectional view of the modified roller assembly utilized on the screed depicted in FIG. 2~.
FIG. 29 is an exploded perspective view of the lateral adjustment device for the horizontally oriented roller depicted in FIG. 28.
FIG. 30 is a simplifi,ed view from above of the horizontally oriented roller support structure depicted in FIG. 28.
FIGS. 31A-D illustrate the excessive build-up of plastic concrete on the blade of a vibxating screed which receives an excessive charge height of plastic concrete.
FIG. 32 is a view from above of the blade spill-over problem illustrated in FIG. 31.
8~
FIG. 33 is a view from above illustrating the metering Imeans of the present invention coupled to the concrete spreading ¦means.
FIG. 34 illustrates the relative position of the metering means of the present invention with respect to the front screed blade and the distributing means of the present invention.
FIG. 35 depicts the grading means detached from the carriage means of the present invention to illustrate structure permitting relative vertical adjustment between the grading means and the carriage means.
FIG. 36 illustrates the grading means of the present ,/
/
~2812~ ' 1 invention including both distributing means and metering means 2 and its relative position with respect to a front screed blade 3 having both forward and rear facing blade sections.
FIG. 37 illustrates the grading means of the present 6 invention including both distributing means and metering means 7 with an oscillating strike-off positioned between the grading 8 means and the screed blade.
FIG. 38 illustrates the improved oscillating strike-off 11 includiny vertical strike-off blade adjustment means and a 12 plurality of pneumatic vibrators coupled to the strike-off blade.
14 FIG. 39 is a sectional view of the oscillating strike-off support structure depicted in FIG. 38, taken along section 16 line 39-39, particularly illustrating the structure which couples 17 ¦the oscillating strike-off blade to the screed.
lg FIG. 40 represents a sectional view of the oscillating strike-off illustrated in FIG. 38, particularly depicting the 21 roller structure which maintains a predetermined fixed spacing 22 between the oscillating strike-off blade and the screed blade.
24 FIG. 41 depicts a paver train comprising a primary finishing screed including concrete spreading means followed 26 in spaced apart relationship by a secondary finishing screed 27 including an oscillating strike-off system.
29 FIG. 42 represents a view from above of the paver train depicted in FIG. 41.
32 ...
' - 10 -! (_ 1 DESCRIP~ION C)F' 'rHE PREFERR~D EM~3ODIMENT
3 In order to better illustrate the advantages of the 4 invention and its contributions of the artl a preferred hardware embodiment of the invention will now be described in detail.
7 The preferred embodiment of the initial version of the invention is fully disclosed in ~nited States Patent No. 4,466, 9 757 and illustrated in prior art Figs. ] to 30. In certain circumstances, that initial embodiment of the invention encountered 11 blade spill over problerns of the type illustrated in FIGS. 31 12 and 32. In the embodiment of the invention as illustrated in 13 FIGS. 1 and 17, the trailing edge of auger 84 was immovably 14 secured to carriage 76 precluding relative vertical adjustments between the trailing edge of auger 84 and front screed blade 16.
16 As the screed advanced forward into an area of unfinished plastic 17 concrete, concrete could spill over the top of screed blade 16 18 disturbing the finished concrete surface designated by reference 19 number 300 as illustrated in FIG. 31D.
ZO
21 In order to overcome this problem, the structure il-2 lustrated in FIGS. 33-35 has been created. The grading means 23 302 of the present invention has now been improved to incorporate 24 distributing means and metering means. In the depicted preferred embodiment of the invention, the distributing means takes the 26 form of an auger 304 and the metering means takes the form of a 27 plow 306. Plow 306 inclucles a horizontally oriented, continuous 29 lower surface 308 joining together a pair of wedge-shaped end sections 310 which each include a vertically oriented cutting edge 312. Plow 306 is coupled to the horizontally oriented lower 31 surface of chain box 314 which houses the drive chain coupling auger drive motor 92 to auger 304.
lZ81Z~lL ¢
1 ¦ To optimize operation of the metering means of the 2 ¦ present invention,vertical adjustment means is provided to 3 ¦ permit precise adjustment of the spacing between the lower 4 ¦ surface 308 of plow 306 and the horizontally oriented surface 5 ¦ 316 of front screed blade 16. The inner face 318 of auger 6 ¦ support bracket 320 includes four spaced-apart, vertically 7 ¦ oriented oval apertures 322 which may be mated with either an 8 ¦upper group 324 or a lower group 326 of apertures in the face 9 ¦of auger carriage 76. A set of four bolts (not shown) are 10 ¦inserted through vertically oriented channels 328, through each 11 ¦of the oval apertures 322 and into either the upper or lower group 12 ¦of apertures 324 or 326 as necessary to achieve the desired 13 ¦spacing between the lower surface 308 of plow 306 and the upper 14 ¦surface 316 of front screed blade 316. When the appropriate 15 ¦vertical spacing has been achieved, each of the four spaced 16 ¦apart mounting bolts is tightened to maintain auger support 17 ¦bracket 320, auger 304 and plow 306 in the desired vertical 18 position. For example, for low slump concrete including one and 19 one half inch stones, the spacing between the lower surface 308 of plow 306 and the upper surface 316 of blade 16 might be ad-21 justed to approximately one and one quarter inches. For higher 22 slump concrete, the distance between the plow and the screed blade Z3 is typically decreased. The particular plow/screed blade vertical 24 spacing which optimizes performance of the present invention with Z5 any particular type of plastic concrete can be readily determined 26 by persons of ordinary sklll in the art.
28 In operation, the metering means of the present invention, 29 including both plow 306 and the above-described vertical adjust-~0 ment means, is translated back and forth along the length of the 31 screed and as illustrated in FIGS. 33 and 34 intercepts and moves 32 plastic concrete forward into the trailing edge of auger 304.
12~1~01 1 The rotating blade of auger 304 intercepts and moves the plastic 2 concrete forward and laterally redistributes it to produce a 3 substantially level surface. In addition, the metering means 4 of the present invention regulates the charge height of plastic concrete fed to the advancing screed blade 16 by stripping off 6 and moving forward excess height plastic concrete into the 7 trailing edge of auger 30~. The elevation of the lower surface 8 308 of plow 30~ determines the charge height of the plastic 9 concrete fed to screed blade 16. The interrelated operation of the distributing means and metering means of the present 11 invention feeds a partially finished, constant height charge of 12 concrete to screed blade 16 as the carriage 76 translates the 13 grading means of the present invention back and forth along the 14 length of the screed frame as the screed simultaneously advances into the unfinished plastic concrete.
17 FIG. 34 depicts the concrete spreading means of the 18 present invention operating in connection with a single forward-19 facing screed blade 16. As indicated, the spacing between the lower surface 308 of plow 306 and the upper surface 316 of screed 21 blade 16 may be made quite small. In FIG. 36, screed blade l6 22 includes both forward facing and rear facing L-shaped blade 23 elements while the spacing between the lower surface 308 of 24 plow 306 and the upper surface 316 of blade 16 has been increased to a distance slightly less than the concrete stone size. The Z6 rear edge of plow 306 is situated approximately halfway between 227 the front and rear edges of the front L-shaped section of screed blade 16. In FIG. 37, screed blade 16 includes only a 29 single, rear facing L-shaped blade section and an oscillating strike-off 330 has been coupled to the screed frame between 31 the rear surface of plow 306 and the front surface of screed 32 blade 16. In the particular embodiment illustrated in FIG. 37, lZB5~01 1 the lower blade surface o~ oscillating strike-off 330 is positioned 2 slightly above the lower surface of screed blade 16 znd approxi-3 mately even with the lower surface 308 of plow 306. In operation, 4 the laterally reciprocating motion of oscillating strike-off 330 accomplishes an intermediate consolidating and finishing operation 6 on the partially finished plastic concrete discharged from the 7 trailing edge of the grading means of the present invention before 8 the plastic concrete is intercePted by screed blade 16. The 9 differential elevation between the lower surface of oscillating strike-off blade 330 and the lower surface of screed blade 16 11 ay be controlled to regulate the height of the charge of plastic 12 concrete fed to screed blade 16. In practice, the lower surface 13 of the blade of oscillating strike-off 330 will typically be 14 adjusted to be even with the lower surface of screed blade 16 or as high as approximately 3/8 of an inch above the lower surface 16 ¦f screed blade 16. Proper adjustment of the oscillating strike-17 ¦off 330/screed blade 16 height differential can be regulated 18 by a person of ordinary skill in the art to achieve the desired 19 concrete finishing characteristics.
21 Referring now to FIGS. 38-40, screed 332 includes an 22 oscillating strike-off 330 having both a plurality of pneumatically 23 powered, high frequency air vibrators 334 as well as vertical blad~
24 adjustment means 336 for controlling the height differential 2~ between the lower surface 338 of the oscillating strike-off 330 26 and the lower surface of screed blade 16. ~IGS. 38 and 39 il-27 lustrate the structure of vertical blade adjustment means 336.
29 A plurality of vertically oriented brackets 340 are coupled to the vertically oriented face of screed blade 16 and 31 1 include a centrally located, vertically oriented oval aperture 32 ~ 342 for accommodating vertical adjustments of oscillating strike-l off blade support units 344. A bolt 346 extends through the lt~81;201 1 ¦various elements of support unit 344 and is secured to a vertical 2 ¦adjustment clamp 348 which interfaces with the rear surface of 3 ¦bracket 340. When bolt 346 is loosened, the rotation of bolt 4 1350 regulates the vertical position of strike-off support unit 5 1344 with respect to bracket 340 to control the relative elevation 6 ¦of the lower surface 338 of oscillating strike-off unit 330 with 7 ¦respect to the lower surface of screed blade 316.
8 l 9 ¦ As illustrated by FIGS. 38 and 40, a plurality of spaced 10 ¦apart rollers 352 are coupled by brackets 354 to the interior 11 ¦face of the blade of oscillating strike-off 330. The comparatively 12 ¦long rolling interface between rollers 35Z and the vertical face 13 ¦of screed blade 16 maintains the blade of oscillating strike-off 14 ¦330 parallel to the vertical face of screed blade 16 as the 15 ¦screed is advanced i.nto the unfinished plastic concrete.
17 Continuous , reciprocating motion of the oscillating 18 strike-off 330 is provided by reciprocating means in the form of 19 a dual-action pneumatic ram 356 and the associated connecting linkage 358 depicted in FIG. 38. As illustrated in FIG. 4 of 21 United States Patent No. 4,466,757, oscillating strike-off 330 22 may also be driven by reciprocating means in the form of hydraulic 23 motor 64 and the associated reciprocation linkage depicted.
When the oscillating strike-off 330 is operated without 26 the concrete spreading means of the present invention as depicted 26 in FIG. 38, single or dual paired air vibrators 334 may be coupled as shown to vibrate the blade of the oscillating strike-29 off. When the oscillating strike-off 330 is configured as indicated in FIG. 37 and positioned between the trailing edge of 31 plow 306 and screed blade 16, the air vibrators 334 will 32 typically be removed to minimize the space occupied by strike-off 330.
lZ~3lZOl 1 ¦ Referring now to FIGS. 41 and 42, a paving train con-2 ¦sisting of a primary finishing screed 360 and a secondary finishing 3 ¦screed 366. Screed 360 includes concrete spreading means 362 4 ¦while screed 366 includes oscillating strike-off 370. Screed 5 ¦366 trails screed 360 by a predetermined time or distance 6 Ito allow the partially finished concrete existing screed 360 7 ¦to reach a semi-equilibrium condition prior to engagement by 8 ¦screed 366. Screed to screed spacing on the order of twenty to 9 ¦forty feet is typical although other spacing variations would 10 ¦be apparent to one of ordinary skill in the art.
12 ¦ It has been found that use of the disclosed two-unit 13 paving train incorporating primary and secondary screeds including 14 concrete spreading means 362 and oscillating strike-off 370 pro-duces a superior concrete finish. Since screeds 360 and 366 16 typically include precisely controllable, hydraulically actuated 17 winches, the screed translation velocity and screed to screed 18 spacing can easily be regulated.
It will be apparent to those skilled in the art that 21 the disclosed vibratory concrete screed and paver train system 22 may be modified in numerous ways and may assume many embodiments 23 other than the preferred forms specifically set out and described Z4 above. For example, various aifferent plow configurations other than the disclosed configuration would function effectively 26 as metering means. Distributing means such as a V-shaped grading Z7 blade or a spinning tube finisher could be used as a substitute 28 for the disclosed rotating auger distributing means. Accordingly, 29 it is intended by the appended claims to cover all such modifica-tions of the invention which fall within the true spirit and 31 scope of the invention.
Claims (10)
1. A vibratory concrete screed for finishing the surface of an area of unfinished plastic concrete lying between first and second spaced apart, generally parallel forms, the spacing between the first and second forms defining the width of the plastic concrete, said screed comprising:
a. a frame having first and second ends with a length equal to or greater than the width of the plastic concrete;
b. a screed blade coupled to said frame and including a substantially horizontal blade surface and a leading edge;
c. means coupled to said frame for advancing said screed along the length of said forms into the unfinished plastic concrete;
d. means for vibrating said screed blade; and e. concrete spreading means coupled to said screed for partially levelling the unfinished plastic concrete and for regulating the charge height of the concrete intercepted by the leading edge of said screed blade, including i. an auger having a longitudinal axis, a leading edge and a trailing edge;
- Page 1 of Claims -ii. carriage means for maintaining said auger at a predetermined elevation in front of said screed blade with the longitudinal axis of said auger inclined at an angle to said screed blade with the leading edge of said auger extending outward from said screed blade and in front of the trailing edge of said auger, for translating said auger in either a first or a second direction along said screed frame, and for rotating said auger to laterally redistribute said plastic concrete, to displace said concrete forward and away from said screed blade and to thereby form an intermediate, partially levelled concrete surface; and iii. metering means coupled to said carriage means to maintain a gap between said metering means and said screed blade, said metering means having a lower surface maintained below the intermediate concrete surface formed by said auger and above the horizontal blade surface of said screed blade for regulating the charge height of plastic concrete fed to the leading edge of said screed blade and for moving excess height plastic concrete forward into the rotating trailing edge of said auger where said excess height concrete is intercepted and displaced forward toward the leading edge of said auger and away from said metering means and is laterally redistributed by said auger as said carriage means translates said metering means and said auger in first and second directions along the length of said screed frame.
- Page 2 of Claims -
a. a frame having first and second ends with a length equal to or greater than the width of the plastic concrete;
b. a screed blade coupled to said frame and including a substantially horizontal blade surface and a leading edge;
c. means coupled to said frame for advancing said screed along the length of said forms into the unfinished plastic concrete;
d. means for vibrating said screed blade; and e. concrete spreading means coupled to said screed for partially levelling the unfinished plastic concrete and for regulating the charge height of the concrete intercepted by the leading edge of said screed blade, including i. an auger having a longitudinal axis, a leading edge and a trailing edge;
- Page 1 of Claims -ii. carriage means for maintaining said auger at a predetermined elevation in front of said screed blade with the longitudinal axis of said auger inclined at an angle to said screed blade with the leading edge of said auger extending outward from said screed blade and in front of the trailing edge of said auger, for translating said auger in either a first or a second direction along said screed frame, and for rotating said auger to laterally redistribute said plastic concrete, to displace said concrete forward and away from said screed blade and to thereby form an intermediate, partially levelled concrete surface; and iii. metering means coupled to said carriage means to maintain a gap between said metering means and said screed blade, said metering means having a lower surface maintained below the intermediate concrete surface formed by said auger and above the horizontal blade surface of said screed blade for regulating the charge height of plastic concrete fed to the leading edge of said screed blade and for moving excess height plastic concrete forward into the rotating trailing edge of said auger where said excess height concrete is intercepted and displaced forward toward the leading edge of said auger and away from said metering means and is laterally redistributed by said auger as said carriage means translates said metering means and said auger in first and second directions along the length of said screed frame.
- Page 2 of Claims -
2. The screed of Claim 1 wherein the longitudinal axis of said auger is oriented substantially perpendicular to the lengthwise axis of said screed frame.
3. The screed of Claim 2 wherein said metering means is centered about the longitudinal axis of said auger and includes a lower rear edge oriented parallel to the leading edge of said screed blade.
4. The screed of Claim 3 wherein said metering means includes a flat, horizontally oriented lower surface.
5. The screed of Claim 4 wherein said metering means includes first and second symmetrical end sections extending laterally outward beyond said auger, wherein each end section includes a wedge having a cutting tip including a vertical edge oriented perpendicular to the longitudinal axis of said auger.
6. The screed of Claim 3 wherein said concrete spreading means further includes first means for adjusting the vertical spacing between said metering means and the horizontal surface of said screed blade to control the charge height of the concrete discharged from said metering means and intercepted by said screed blade.
7. The screed of Claim 6 wherein said concrete spreading means further includes second means for adjusting the vertical spacing between said auger and the horizontal surface of said screed blade.
- Page 3 of Claims -
- Page 3 of Claims -
8. The screed of Claim 3 wherein said concrete spreading means further includes means for simultaneously adjusting the vertical spacing between the horizontal surface of said screed blade and both said auger and said metering means.
9. The screed of Claim 1 further including an oscillating strike-off coupled to said screed between said concrete spreading means and said screed blade for smoothing and compacting the plastic concrete discharged from said metering means before engagement by said screed blade wherein said oscillating strike-off includes a lower surface positioned at an elevation above the elevation of the horizontal blade surface of said screed blade and below the level of plastic concrete discharged from said metering means.
10. The screed of Claim 9 further including means for reciprocating said oscillating strike-off with respect to said screed blade.
- page 4 of Claims -
- page 4 of Claims -
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000522479A CA1281201C (en) | 1986-11-07 | 1986-11-07 | Vibratory screed including a spreading device for levelling and distributing plastic concete in front of the screed |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000522479A CA1281201C (en) | 1986-11-07 | 1986-11-07 | Vibratory screed including a spreading device for levelling and distributing plastic concete in front of the screed |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1281201C true CA1281201C (en) | 1991-03-12 |
Family
ID=4134309
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000522479A Expired - Fee Related CA1281201C (en) | 1986-11-07 | 1986-11-07 | Vibratory screed including a spreading device for levelling and distributing plastic concete in front of the screed |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1281201C (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8360681B1 (en) | 2011-08-18 | 2013-01-29 | 9168-8168 Quebec Inc. | Portable concrete striking device with auger |
-
1986
- 1986-11-07 CA CA000522479A patent/CA1281201C/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8360681B1 (en) | 2011-08-18 | 2013-01-29 | 9168-8168 Quebec Inc. | Portable concrete striking device with auger |
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