US2199074A

US2199074A - Concrete placement apparatus

Info

Publication number: US2199074A
Application number: US234918A
Authority: US
Inventors: Jackson Corwill
Original assignee: Individual
Current assignee: Individual
Priority date: 1938-10-14
Filing date: 1938-10-14
Publication date: 1940-04-30
Anticipated expiration: 1957-04-30

Description

A ril 30, 1940. Q JAgKsoN 2,199,074

CONCRETE PLACEMENT APPARATUS Filed Oct. 14, 1938 5 Sheets-Sheet 1 w $3 g? ill INVENTOR. L I m BY Jaw/W Vac/16017 ATTORNEYS Ap 30, 1940. c. JACKSON I CONCRETE PLACEMENT APPARATUS Filed 001:. 14, 1938 5 Sheets-Sheet 2 Q m QM/Q R% Ma "iv Y A TTORNEYS April 30, 1940.

c. JACKSON 2,199,074

CONCRETE PLACEMENT APPARATUS Filed Oct. 14, 1938 5 Sheets-Sheet 3 INVENTOR flaw/w efamsm BY @mw 4 A ORNEYS P 30, 1940- c. JACKSON 2,199,074

CONCRETE PLACEMENT APPARATUS Filed Oct. 14, 1938 5 Sheets-Sheet 4 IN VENTOR. Coma/H 4/270/160/7 BY 6%? QL/6VK4M ATTORNEYS April 30, 1940. c. JACKSON CONCRETE PLACEMENT APPARATUS 0 M mwww N w MJ/m .M. MA t e M W. s M 5 Filed Oct. 14, 1938 Patented Apr. 30, 1940 UNITED STATES PATENTOFFICE.

Application October 14,

: 22 Claims.

improvements in of relatively wide pavements or paving slabs in which the concrete is effectively subjected to vibrations throughout the width of the slab.

Third, to provide a machine of this character which is readily adapted for the placement of pavements and the like having a substantial crown.

Fourth, to provide a machine of the character described which may be very easily manipulated to submerge or lift the vibratory element from the mass of concrete and automatically stop and start the vibrating means at predetermined points in the lowering and elevating movements thereof.

Fifth, to provide in a machine of the character described means for preventing the imparting of excessive or undesirable vibrations to the forms.

Sixth, to provide a machine of this class which is of very large capacity and capable of adjustment and adaptation to a. very wide range of conditions. Seventh, to provide a machine of the class described in which the moving parts are effectively housed and protected from injury and from clogging or loading up with the concrete being treated.

Further objects and objects pertaining to de-- tails and economies of construction and operation will appear from the description to follow. The invention is defined in, the claims. Preferred embodiments of my invention are illus- -57 trated in the accompanying drawings, in which:

Fig. 1 is a fragmentary front elevation of a machine embodying the features of my invention, certain parts being omitted and others being shown conventionally and no attempt having i i been made to show the parts in their relative proportions or dimensions.

Fig. 2 is a plan view of a preferred form of one of the vibratory elements, the same being shown in relation to a form and one of the form shields or guards being shown in section.

1938, Serial No. 234,918

Fig. 3 isa fragmentary plan view partially in horizontal section on line 3-3 of Fig. 1.

Fig. 4 is a side elevation of a machine embodying certain features of my invention in operative relation to a form which is partially broken away to disclose the material being treated therein, certain of the parts being shown conventionally. v

Fig. 5 is an enlarged fragmentary view partially in longitudinal section on line 5-4 of Fig. 2. l

Fig. 6 is a fragmentary view partially in vertical section on the broken line 6--6 of Fig. 3.

Fig. 7 is an enlarged detail partially in section on line 1-4 of Fig. 1, showing details of the switch control mechanism and also details of the raising and lowering mechanism.

Fig. 8 is a sectional view on line 88 of Fig. 9, showing details of the vibratory element supporting means. I

Fig. 9 is a fragmentary elevation looking from the right or the direction of the arrow in Fig. 8. Fig. .10 ,is'a fragmentary section showing a modified form of the vibratory element supporting means.

Fig. 11 is a fragmentary view partiallyin vertical section showing another modification or embodiment of the vibratory element supporting means.

' Fig. .12 is a diagrammatic illustration showing the relation of the vibratory element to the mass of concrete being worked and to the screed with which itis operatively associated.

Fig. 13 is a diagrammatic view showing the relation of the vibratory element to the form 3 and the form shield or guard.

Fig. 14 is a diagrammatic illustration of the machine in operative relation to a. pavement joint and further illustrating one advantage of the mounting for the vibratory element.

In the accompanying drawings, no attempt has been made to illustrate the parts in their rela-v tive proportions and certain parts have been conventionalized to simplify the drawings. The structure shown in the preferred embodiment, however, is a commercial structureas is also the embodiments or modifications thereof.

l represents the frame of a main carriage which in this instance is a paving machine provided with a screed 2 having face plate 3 adapted to support a substantial mass of concrete, as is more particularly illustrated in Figs. 12 and 14. The mounting for the screed on the carriage l is not illustrated as that forms no part of this invention and the screed may be mounted r either to be reciprocated transversely of the slab being laid or not, as may be desired. Indeed, my particular improvements are designed to be readily mounted or associated with the paving machines of different manufacturers. I do, however, preferably modify the ordinary screed by providing forwardly projecting end wings t which are adapted not only to retain. the treated mass that may be piled up in front of the screed, but also to wipe off the longitudinal form memhere as the machine is advanced.

The frame of my machine in the embodimen illustrated comprises a pair of push bars 6 which are pivotally mounted at 1 on the attaching plates 8 which are designed to be bolted to some appropriate part of the carriage I The frame end members 9 are provided with split clamps i0 adapted to receive or be sleeved uponthe front end of the push bars 6 and to beclar'nped thereon These end. members I by means of the bolts H. of the frame are adapted to receive the ends of the tubular cross or transverse member, 12 and are fixedly secured thereto by welding or other suitable means. In this embodiment the parts are secured together by welding, and bracing plates l3 extend between the transverse frame member and the inner of the forwardly projecting pairs of arms I 3. These pairs of arms carry the wheel supports !5, thewheel supports being disposed between the pairs of arms'a'nd pivoted thereto at E6. The wheels I! are designed to travel upon the forms 55 as are also the wheels it of the main carriage. The wheel 'forks or supports iii are provided with laterally projecting arms I9 to which operating means are connected for swing- I provide a rock shaft 20 which is journaledv within the tubular member at 2! so that it is housed andprotected as'well as provided with an eifective support. This rockshaft is provided with arms 22 which project downwardly through openings 23 in the under side of the cross member, the rockshaft arms 22 being connected to the arms l9 of the wheel support by the links 24., so that when the rockshaft is actuated the.

wheelsupports are simultaneously actuated to raise or lowerthe carriage frame and thereby raise or lower the vibratory element carried thereby, as will be hereinafter described.

In the preferred embodiment illustrated, the raising and, lowering is effected by a hydraulic engine, the cylinder 25 of which is pivoted on the bracket 26 at 27, the bracket being of the split type and adjustably clamped to the push rods 6. The plunger rod 2% is connected to one of the rockshaft ar'm's'22 as illustrated in Fig. 6. These partsare conventionally shown, the connections 29 and 38 being adapted to admit fluid under pressure to cylinders at opposite sides of the piston, the pump or power'means being conventionally indicated at 3|, see Fig. 4.

It will be understood that considerable weight is involved inthe machine and by means of this hydraulic engine the framemay be adjusted to raise or lower the vibratory element as desired with comparative ease and also there is the ad-v vantage of there being no mechanical parts which would become obstructed by exposure to the concrete, it being extremely difiicult to prevent concrete from falling upon or being dropped upon the machine while it is in use. 1

LI r ie m lr 'er a p vibrat y a e:

ments designated generally by the numeral 32. As these are duplicates, a description of one will suffice and it should be understood that in the placement of slabs or pavements of the narrower widths, single vibratory elements are entirely sufficient. One of the advantages of the pair of vibratory elements is that pavements are frequently laid with a crown and I have provided means for mounting my pair of vibratory elements so that they may be adjusted and operated in an oppositely inclined relation to each other to accommodate the crown. A further point of advantage is that Where the vibratory element is of substantially 20 ft. length, as is necessary in laying a 29 ft. pavement with a single vibratory element, there is a tendency, unless the vibratory element be made very heavy and rigid, for the vibrations to, dampen out or minimize toward the ends of the vibratory element. Also the structure must be made very rigid in order to prevent low amplitude nodes being set up in certain zones in the length of the element. It

should be borne in mind that I do not rely upon large amplitude vibrations but desire to secure high frequency, low' amplitude vibrations, and, in the most desirable condition, to' supportthe vibratory element so that it can vibrate at high frequency in an orbital path and under such conditions the relatively low amplitude vibrations are not only sufiicient but are desirable. In my pending application Serial No. 101,607, filed September 16, 1936, I have disclosed one manner of supporting the vibratory element to permit vibrations in an orbital path and the invention of this application is in some respects an adapta tion of and an improvement upon the structure there shown.

In the embodiment shown in Figs' 1-9 inclusive, vibratory elements designated generally by the numeral 32 are suspended from the transverse frame member !2 and adjustably mounted thereon by means of brackets 33 which are secured to the transverse frame member 42 by means of U-bo'lts 341' Clip pieces 35 are providedto form seats for the brackets. The brackets are vertically slotted'at 36 so that they may be vertically adjusted on the bolts and clamped in their adjusted positions. This not only permits longitudinal tilting adjustment of the vibratory elements to accommodate the crown. of a pavement, but the. pavement slab foundation 3? is sometimes formed with a crown, as shown in Fig. 1, this crown and the foundation being formed so that there is a heavier mass of concrete at the edges of the pavement than there is at the center. It may be desired to support the vibrating element so that it is submerged more deeply adjacent the sides of the pavement than at the center and this adjustment makes it possible to meet all conditions.

The vibratory element is provided with clamps 38, which may be adjusted longitudinally thereof as desired. The clamps are conformed, as shown in Fig. 8, to surround and fit the tubular part as well as the reinforcing channel to be hereinafter described. The forked hanger coupling 39 is secured to this clamp by means of the bolts 4t, the hanger coupling being provided with a cross pin M receiving one end of the link-like flexible non-extensible member 42, and the other end surrounding the pin 43 on the bracket 33. These features are shown in detail in Figs. 8 and 9.

, The brackets are provided with forwardly projecting arms 44 to which the flexible non-extensible draftmembers it are connected, the rear ends of these draft members being clamped between the coupling 39 and the clamps 38. This provides a very effective supporting means and permits a vibrating movement of the element in an orbital path and also serves to absorb the vibrations so that they are not transmitted to the carriage and other mechanism. It will be appreciated that any supporting means that team substantial degree transmits vibration to the supporting carriage or frame reduces the efliciency of the apparatus to the degree of such transmission, as the vibratory element is imparting that much energy to. the machine rather than to the material treated.

I also provide an improved vibratory element which is highly efficient. This comprises a motor or rotor housing 46 preferably made up of two

sections

41 and 48 connected by the bolts 49'for convenience in assembling the parts therein. An electric motor 50 is mounted in this housing, the shaft 5| thereof being supported in suitable bearings indicated at 52 at the ends of the housing. The shaft is provided with unbalancing weights "The motor isconventionally illustrated and While I prefer an electric motor, other means might be'utilized for driving the rotor shaft 5|, the disposition of which in connection with the longitudinal axis of the vibratory element is an important feature of this invention. The

end members

54 and 55 are in this preferred embodiment formed of tubing, the inner ends of which areinserted into outwardly tapered coupling members or housing extensions 56.' These parts are adapted to be a close fit, inner sockets 51 beingprovided to receive the ends of these extensions. The outer ends of the bearing supports are closed by the caps 58 secured to the ends of the motor housing proper.

The extensions or coupling members 56 are detachably securedto the motor housing proper by means of bolts 59,.

' To reinforce the

vibratory end members

54 and 55, I secure inwardly facing channels 60 thereto,-

these channels being arranged on the rear sides of: the

members

54 and 55 as best shown in Figs. 2 and 8 and their flanges 6| are welded thereto throughout the length, making substantially a one-piece structure. The ends of the channels are preferably welded as indicated at 62 to the ends of the couplingv members 56. It will be noted that these coupling members are outwardly tapered.

'- The rotor'shaft 5| is disposed longitudinally of the vibratory element and in alignment with the end extensions thereof. Owing to the necessary dimensions where a motor is housed in the vibratory element as in this case, the axis of the rotor is slightly off-center of the longitudinal axis of the vibratory element. It is, however, sufficiently close tothe center so that there are substantially no distortion movements resulting from the axis of the rotor being somewhat offcenter and in that respect this'structure is a substantial improvement over the structure shown in my pending application for patent referred to where the motor housing is mounted on-top of thevibratory'element. It is also to be observed that the end-extension 54 is sub- 'stantially shorter than the extension 55 and this brings the vibrating means closer to that part of the pavement where more work is required.

I The vibratory elements are preferably provided at their ends with outwardly inclined end plates 63 disposed transversely of the vibratory elements, soas to insure an effective vibration of vibratory the concrete along the forms as isindicated at 54 in Fig. 13. However, to prevent imparting excessive vibration to the forms, I provide shields ".65 which are mounted on the machine to travel along the forms in opposed relation to the vibratory elements as shown in Figs. 2 and113, gBy

providing the end plates. at the inner spaced,

ends of the .vibratory elements, they are effective in imparting vibrating movement to the mass lying between the adjacent fective where longitudinal parting both sides of these parting strips.

With this arrangement ofparts, I provide a machine which has a very wide range of adaptae bility and is highly efiicient. The motors are con nected by the cables 66 to a control switch designated generally by the numeral 61 housed within the switch box 58. The control switch'cona trols the currents from the lead circuits indl-= that the switch is automatically closed at 'a piedetermined point in the lowering movement of the vibratory elements and'automatically opened at a predetermined point in the lifting or elevating movement thereof. The mechanism. is shown'in detail in Fig. '7 and it will be noted that the arm 22 is provided with a tappet H acting upon the push pin 12 which inturn engages the lever I3 pivoted at 14 and connected by the'link '15 to an arm 16 on the switch. i 1 With this arrangement of parts, all the operator is required to do is to control the raising and lowering which, as described in this embodiment, is by means of a hydraulic engine and the motor is automatically turned on on the lowering movement and automatically turned off'on the elevating movement. This automatic turning on of the motor is of very great practical importance because of the fact that when the vibrating tube is being vibrated as itis lowered into the mass to be treated, it readily enters, whereas if it is not vibrating it is very difficult to cause the elongated member to penetrate the mass, the apparatus being specially designed for the placement of concrete of very low water content. The same is true on the lifting'or retracting movement, that is, it can be retracted quite easily while the vibratory element is vibrating. It is also desirable not to waste current unnecessarily when the vibratory element is in fully retracted position.

In Figs. 12, 13 and 14, I have conventionally illustrated the operative relation of the vibratory ends and also are efstrips are laid in the pavement in vibrating the material on element to the mass treated and to the screed.

It will be understood that I have not attempted to show these parts in exact relation or in proportion. The imparting of the vibrations to the mass resulting fro-m the high frequency vibration in an orbital path is indicated by the dotted circles 11 in Figs. 12 and 14. r

In Fig. 14, I show at 18 a transverse parting or joint strip. The slab dowels are indicated at 19. It will be understood that when a joint is reached it is necessary to raise the vibratory element to pass over the joint strip. Therefore an effective mounting or support forvertical adjustment is of great importance and I have provided a very efiicient means for this. purpose. Also the vertical position of the vibratory element relative to the surface of the finished pavement or slab being laid is important, some times dict d b t e p cem ntpf, r in orcing. ale-V.

ments' in the pavement and some times by the engineersspecifications.

My improvements provide for an eificient and practical means for raising and lowering the vibratory element and its operation in its vertically adjusted position, except, of course, at a point where the motor is cut oil and then it would be entirely out of the concrete.

In Fig. 10, I illustrate a modified form of support for the vibratory element. This consists of the supporting bracket 80 having forwardly projecti'ng arm 8! on the vibratory element being secured to the link-like hanger 83 which is sup:- ported with its vertical reaches in substantially spaced relation to receive the cylindrical holder 84 for the buffer 85. A thrust member 85 is carried by the vibratory element. This buffer receives the upward thrust of the vibratory element should there be a tendency for it to lift in the mass being treated, but when it is vibrated while entering the mass, it effectively enters without buffers, as is shown in Figs. 8 and 9. The nonextensible flexible draft member 45 is provided in this embodiment.

- In the embodiment shown in Fig. 11, the bracket 81 is adjustably mounted on the cross member of the frame for vertical adjustment and is pro vided with a curved seat 88 for the adjustable arm 89, the arm being secured or clamped in this seat by means of the bolts at which may be adjusted to tilt the arm and thereby tighten or loosen the flexible non-extensible hanger 9! which is secured to the vibratory element by the clamp 92. The ends of the hanger 9| are clamped to a seat 93 provided therefor on the bracket 8'! and to a seat 94 provided therefor on the arm 89 by means of the clamps 95. A thrust bar 96 is provided for the bracket 14 and is secured to bracket 91 on the push bar 6,

While both the embodiments shown in Figs. 10 and 11 are practical, the embodiment shown in Fig. 8 has the advantage of being somewhat more economical and is a highly desirable structure.

I have illustrated and described my improvements in commercially practical embodiments thereof. I have not attempted to illustrate or describe various modifications and adaptations which I contemplate or which are possible, as it is believed that this disclosure will enable those skilled in the art to adapt my improvements as may be desired. The structure illustrated is highly efficient for the purpose intended and has a very wide range of adaptability.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. In a machine of the class described, the combination with a main carriage adapted to travel on parallel form members, of a carrying frame comprising push bars pivotally mounted on said main carriage to project forwardly therefrom, frame end members mounted on said push bars, wheel supports pivotally mounted on said frame end members, wheels on said supports, a tubular transverse frame member extending between. said frame end members and having openings in the underside thereof, a rockshaft disposed longitudinally within said transverse frame member and provided with arms extending through said openings, links connecting said rockshaft arms to said wheel supports, means for actuating said rockshaft, an elongated submersible vibratory element, means for supporting said vibratory element on said transverse frame member permitting vibratory movement thereof, and means for vibrating said vibratory element.

2. In a machine of the class described, the combination of a carrying frame comprising a pair of pivotally mounted push bars, frame end members mounted on the forward ends of said push bars, wheels provided with supports pivotally mounted on said end members, a transverse frame member extending between said frame end members, a rockshaft disposed longitudinally of said transverse frame member, means connecting said rockshaft to said wheel supports, a manually controlled means for raising and lowering said frame, an elongated submersible vibratory element, and means for supporting said vibratory element on said transverse frame member permitting vibratory movement thereof.

3. In a machine of the class described, the combination of a carrying frame, Wheels provided with supports mounted on said frame for vertical adjustment, a rockshaft, operating connections for said rockshaft to said wheel supports, a manually controlled means operatively associated with said rockshaft, an elongated submersible vibratory element, means for supporting said vibratory element on said frame permitting vibratory movement thereof, and means for vibrating said vibratory element.

4. In a machine of the class described, the combination of a carrying frame supported for vertical adjustment, means for elevating and lowering said frame, a horizontally disposed elongated submersible vibratory element mounted on said frame to permit vibratory movement of the vibratory element independently of the frame, an electrically driven means for vibrating said vibratory element, electrical connections for said electrically driven means including a control switch, and means for automatically actuating said switch operatively associated with said raising and lowering means to open the switch at a predetermined point in the elevating movement of said frame and to close the switch at a predetermined point in the lowering movement of said frame.

5. In a machine of the class described, the combination of a carrying frame, a submersible v1- bratory element supported for vibratory movement independently of the frame, means for raising and lowering said vibratory element, means for vibrating said vibratory element, and control means for said vibrating means operatively associated with the same for raising and lowering the vibratory element to stop said vibrating means at a predetermined point in the elevating movement of the vibratory element and to start the same at a predetermined point in the lowering movement of the vibratory element.

6. In a machine of the class described, the combination of a supporting frame, a submersible vibratory element mounted on said frame for adjustment into and out of the mass to be treated, an electric motor-driven means for vibrating said vibratory element, manually controlled means for loweringsaid vibrating element into the mass to be treated and for raising it therefrom, electrical connections for supplying current to said vibrating means, a control switch therefor, and means for automatically closing said switch on the lowering movement of said vibratory element and opening the switch on the retracting movement of said vibratory element.

7. In a machine of the class described, the combination of a supporting frame, a submersible vibratory element mounted on said frame for adjustment into and out of the mass to be treated, means for vibrating said vibratory element, man- "ually" controlled hydraulic means for lowering said vibrating element-into the mass to be treated and forraising it therefrom, and means for-automatically starting said vibrating means at a predetermined point on the lowering movement of said vibratory element andstopping on the retra'cting movement of said vibratory element.

8. In a -machine of the "class described, the combination of a supporting frame, a submersible vibratory element mounted on'said frame for adjustment into and out of the mass to be treated,'means for vibrating said vibratory 'elen'ient, means for lowering said vibratingelementinto the to be't'r'eat'ed' and for raising it therefrom, and means for automatically starting said vibrating means at a predetermined point on the lowering movement of said vibratory element and stopping on the retracting movement of said vibratory element.

9. In a machine of the class described, the combination of a supporting and propelling member, means for raisingand lowering said member, an elongated submersible vibratory element, flexible non-extensible hangers for said Vibratory element carried by said member, a flexible nonextensible draft member for said vibratory element carried by said member, power means for vibrating said vibratory element, and means for automatically controlling said power means operatively associated with the said raising and lowering means to start the power at a predetermined point in the lowering movement of the vibratory element and to stop the power means at a predetermined point in the elevating movement of the vibratory element.

10. In a machine of the class described, the combination with a carriage comprising 'a cross member, of'a plurality of elongated submersible vibratory elements disposed horizontally in end to end relation, a vibrating means for each of said vibratory elements carried thereby, vibratory element supporting brackets having forwardly projecting arms mounted on said cross member for independent vertical adjustment, there being a plurality of said supporting brackets for each vibratory element, flexible non-extensible hangers for said vibratory elements carried by said brackets, and flexible non-extensible draft members connected to the forward ends of said arms on said supporting brackets and to said vibratory elements.

11. In a machine of the class described, the combination of a carriage, elongated submersible vibratory elements disposed horizontally in end to end relation and each comprising a rotor housing, and end extension members for said housing, the inner end extension members being substantially longer than the other, supporting means for said vibratory members permitting vibration thereof in an orbital path and permitting independent vertical adjustment thereof, and rotors arranged within said rotor housings with their axes disposed longitudinally of the vibratory elements and provided with unbalancing weights.

12. In a machine of the class described, the combination of a carriage, elongated submersible vibratory elements disposed horizontally in end to end relation and each comprising a rotor housing, and end extension members for said housing, supporting means for said vibratory members permitting vibration thereof in an orbital path and permitting independent vertical adjustment thereof, and rotors arranged within said rotor housings with their axes disposed longitudinally of" the vibratory element's and' provided with unbalancing weights.

13. In a machine of the class described,-the

combination of a carriage, elongated'submersible vibratory elements disposed horizontally in end to end relation and provided at'their outer ends with transversely disposed outwardly'inc1in'ed end plates-supporting means'for said vibratory members permitting vibration thereof and permitting independent vertical adjustment thereof," :and

means for vibrating said vibratory members.

; 14. In'a'machine of the class'desc'r ibed, the combination of a carriage, an elongated submersible vibratoryelem'ent "comprising a rotor Housing and end extension members for said rotor housing, said rotor housing being provided with coupling members receiving said end extension members, and a rotor arranged within said housing with its axis disposed longitudinally thereof, said/ rotor being provided with an unbalancing weight.

15. In a machine of the class described, the

combination of a carriage, an elongated submersible vibratory element comprising a rotor housing and end extension members for said rotor;

housing, said rotor housing being provided with coupling members receiving said end extension members, and a rotor arranged within said housing with its axis disposed longitudinally thereof and in alignment with said end extensions, saidv rotor being provided with an unbalancingweight.

16. In a machine of the class described,the combination with a carriage adapted to travel on the longitudinal members of a form, of a screed provided with forwardly projecting winglike end members, and a submersible elongated horizontally disposed vibratory element mounted on said carriage in front of said screed and provided with an outwardly inclined end plate and a shield mounted on said carriage in front of said screed end members to depend within a formmember in opposed relation to said vibratory member.

17. In a machine of the class described, the combination with a carriage adapted to travel on the longitudinal members of a form, of a submersible elongated horizontally disposed vibratory element mounted on said carriage for vibratory movement and provided with an outwardly inclined end plate, and a shield mounted on said carriage to depend within the form in opposed relation to said end plate on said vibratory member. I

18. In a machine of the class described, the

combination with a carriage adapted to travel on the longitudinal members of a form, of a submersible elongated horizontally disposed vibratory element mounted on said carriage for vibratory movement, and a shield mounted on said carriage ,to depend within the form in opposed relation to the end of said vibratory member.

19. In a machine of the class described, the combination of a vibratory element comprising a cylindrical tubular member, an inwardly facing channel disposed upon the rear side of said clamps, and flexible non-extensible hanger members secured by said clamps .at the ends thereof and said vibrating element being secured to said hanger members intermediately of said securing combination with the carriage, of a plurality of elongated submersible vibratory elements disposed horizontally in end to end relation, means for vibrating each of said vibratory elements, a means on said carriage common to said vibratory elements for supporting them and vertically adjustable for raising and lowering them relative to the work, and means for supporting said vibratory elements on said common supporting means adjustable for independent vertical adjust- 1 ment whereby the vibratory elements may be individually tilted or inclined relative to a horizontal plane.

CORWILL JACKSON.