Adjustable connection for tool heads and operating handles

March 29, 1938. e. f. schumacher 2,112,349

ADJUSTABLE CONNECTION FOR TOOL HEADS AND OPERATING HANDLES

Filed June 16, 1936

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Patented Mar. 29, 1938

2,112,349

UNITED STATES PATENT OFFICE

2,112,349

ADJUSTABLE CONNECTION FOR TOOL HEADS AND OPERATING HANDLES

Elroy F. Schumacher, North Olmsted, Ohio, assignor to The Cleveland Formgrader Company, Cleveland, Ohio, a corporation of Ohio

Application June 16, 1936, Serial No. 85,548

Claims. (Cl. 306—10)

This invention relates to an adjustable connection for connecting various tool heads to the operating handles.

For the purposes of illustration the use and 3 desirability of such a device is best illustrated by describing its application to road building tools such as brushes, floats, straight edges and the like which are operated from an extremely long operating handle, its use for window cleaning or other 10 devices being apparent therefrom.

In various States the statutes require that the surface of cement pavements be of a brushed finish so as to break up the surface and light floating material as upon failure to do so this 15 material forms a light scale which pits and chips out of the finished surface. Experience has proven that a stiff bristle brush is most satisfactory for this purpose. However, in using such a· brush, it is necessary that the brush be in,_?0 clined slightly toward the operator inasmuch as if the brush is disposed with the bristles too nearly vertical there is tendency to splatter the material. On the other hand, if the brush is inclined at too great an angle, many of the bristles 9,- are not effective as a brush but act more or less as a solid board or drag which drags the surface too heavily or renders it uneven-. A few trials, however, demonstrate the most effective angle for the particular brush. Other tool heads like30 wise can be utilized efficiently only when disposed at the proper angle relative to the operating handle.

Since all such tools are often used at various times by different workmen or operators it is 33 desirable that the angular relation of the handle and brush be capable of being varied according to the physical characteristics of the particular operator and the position from which the tool must be operated. It is also highly necessary that •10 a very firm and rigid connection between the brush and other tool heads and the handle is maintained and that such connection can be varied conveniently when desired.

With these problems in mind it is one of the ,15 principal objects of the present invention to provide an adjustable connection for connecting a tool head and handle which connection can be operated to provide any required angular relation between the brush or tool head and the handle 50 and which will retain the brush firmly in the adjusted position.

Another object is to provide a connection in which the adjustment can be set without unduly stressing any of the working parts and without 55 requiring undue clamping pressure, yet which, if occasion demands, may be stressed into engagement without damage to the working parts.

Still another object resides in the provision of a device of this character in which the parts may be readily broken loose after having re- 5 mained in use in one position for a long period of time.

A more specific object is to provide a means by which the handle may be secured firmly to the adjustable connection. 1;)

Other objects and advantages will become apparent from the following specification wherein reference is made to the drawing.

In the drawing:

Fig. 1 is a diagrammatic illustration showing .15 the manner of using a roadway brush incorporating the principles of the present invention;

Fig. 2 is an enlarged side elevation of the adjustable connection;

Fig. 3 is a front elevation of the connection, part thereof being shown in section for clearness in illustration;

Fig. 4 is a plan view of the connection;

Fig. 5 is a side elevation illustrating a modified form of the connection; 35

Fig. 6 is a plan view of the modified structure shown in Fig. 5;

Fig. 7 is a diagrammatic illustration of the stresses and reactionary forces therefor in a structure of the present invention; and 30

Fig. 8 is a diagrammatic view showing the stresses and reactionary forces in one of the commonly used prior structures comparable in size to the present structure.

Referring to Figs. 1 to 4, the adjustable con- 85 nection comprises a body member ! adapted to be secured to a suitable operating handle 2. The body is preferably a cylindrical shell open at both ends so as to receive the handle endwise and slotted longitudinally along one portion, as 4!) indicated at 3, so that the shell can. be contracted tightly about the handle. Aligned passages are provided transversely of the shell in a position for alignment with a passage extending through the handle 2 so that a suitable bolt 5 ^;4° may be passed therethrough and through the handle and secured tightly In place, thus directly securing the handle against endwise movement out of the body and also drawing the shell ₅θ tightly thereabout to provide a tight fit between the two.

Near the outer end of the body member means are provided which have an abutment surface extending transversely of the body and handle. 55

2,112,349

The most suitable manner of providing such means is clearly illustrated in Figs. 2 and 3.

As there illustrated, laterally extending fins 6 are provided on opposite sides of the body mem5 ber, each of these Uns preferably being arcuate in cross section so as to provide an arcuate abutment surface Ί, the axis of which extends transversely of the axis of the handle and is spaced beyond and on the opposite side of the axis of 10 the handle from the fins. The fins 6 are likewise preferably arcuate on the upper surface, as shown, for a purpose later to be described.

Suitable elements adapted for engagement with the particular tool head being used are also 15 provided. For example, in the case of a brush, these elements may comprise a pair of brackets, each bracket preferably comprising a body I δ having downwardly depending yoke arms ί f adapted to receive and snugly embrace there20 between the brush head 12, a bolt 13 or other securing device being provided for securing each pair of yoke arms and brush or tool head firmly together. If desired, an equivalent single bracket may be used, however. Surmounting the body 25 ! 8 is a fin or flange 14, the upper abutment surface 15 of which is arcuate and complementary to the surface I of the fin 6 and preferably of greater length circumferentially. The bracket body ! 8 is so positioned relative to the fin 14 30 that when the surfaces ΐ and !5 are moved circumferentially relative to each other while in contact the body ί 2 and the fin ! 4 of each bracket will clear the end of the body member I or protruding end of the handle 2. The fins 6 and 35 !4 are each provided with openings extending through the respective abutment surfaces and aligned axially thereof with each other so as to permit passage of a suitable clamping screw '3 therethrough.

In the form illustrated, the passage in the fin S is preferably of sufficient size only to receive the screw, the passage in the fin 14 being elongated so as to permit relative rotation of the two fins clamping thereof in face to face relationship in various adjusted rotated position. Suitable lock washers, such as indicated at Π, may be provided for insuring a firm bearing between the locking screw IS and its locking nut and the respective fins.

By making both the fins 8 and arcuate in cross section it is possible to warp the same into stressed engagement when the occasion demands though under normal working conditions this is not necessary for obtaining a sufficient degree of 55 clamping. It is apparent that by loosening the locking nut !8 the bracket 5 8 may be swung to different positions by sliding the surface ! 5 along the surface 1 and that the fins may be secured in firm face to face abutting relationship in various 60 relatively ro tated positions as required.

Referring to Figs. 5 and 6, there is illustrated a modified form of the apparatus having some of the advantages above pointed out but which differs from the structure above described in that 65 instead of the arcuate fins 6, laterally extending cylindrical fins 20 are provided on the body, and instead of the arcuate fins ifl, cylindrical fins 2i are provided on the brackets ί 0', the fins 2 ί being adapted to fit ever the outside of the fins 29. 70 Axially aligned circumferential passages may be provided in the fins 20 and 21 respectively, and suitable locking screws 22 inserted therethrough for clamping the fins 20 and 21 with their complementary surfaces in firm face to face contact. 75 Referring to Figs. 7 and 8 the advantages of the structure illustrated in Figs. 2 to 4 are more clearly illustrated. In Fig. 8 the usual manner of securing a tool head to an operating handle is shown. This customary practice constitutes providing a rigid body secured to the tool head and 5 carrying at the top or some convenient position a fiat circular pad 38 adapted to lie in face to face contact with, a suitable surface on the handle supporting body so that the clamping faces of the pad and such surface are disposed vertically 10 instead of horizontally as in the present structure. These abutment surfaces are drawn into firm contact by passage of a suitable pivot transversely of the axis of the stem and centrally through the abutment surfaces, as at O2. 15

In Fig. 7 a tool and handle made in accordance with the present invention and comparable in size to that shown in Fig. 8 is diagrammatically illustrated. Upon comparing the two it is apparent that abutment surfaces used for clamping may be 20 of the same area in both cases. In Fig. 8, however, since the pivot extends through the flat pad 30, a high degree of clamping pressure cannot be obtained except through that portion of the pad surface close to the screw, the outer marginal 25 portions of the pad not being drawn as firmly into contact with the surface on the body. In the present structure, however, since both fins are arcuate in outline and the locking screw or washers extend a considerable distance to each side 30 of the screw, the pressure between the abutment surfaces may be more evenly distributed. Again, also because the fins are arcuate in cross section, each may be more rigid and drawn together over their full contact surfaces by a single centrally 35 disposed screw, as illustrated in Fig. 2.

More important however is the manner in which the force F, resulting from operation of the brush is overcome. Assuming the forces Fi and F2 to be the same in both instances in Figs. 40 7 and 8, in the prior structure of Fig. 8 the force F2 is directly effective to rotate the brush about the pivotal axis O2. In Fig. 7 the force Fi is effective radially of the clamping screw and tends to pinch a portion of the abutment surfaces more 45 tightly together. As above described, however, the abutment surfaces in the present structure are curved about an axis disposed above the body preferably on the opposite side of the handle axis from the fins. Thus the force Fi which is effective ₅₀to cause relative rotation of the fins 6 and 14 must rotate them about their axis of curvature. This force must be resisted by a resistance force Ri which is effected by the clamping or abutment surfaces. In Fig. 8 the resisting force R2 is 55 necessarily close to the pivotal center O2 while in the present structure the force Ri acts about the same axis of curvature about which the fins are curved. Tire reacting force R2 in Fig. 8 would act at a distance Y2 from the pivotal axis O2, 60 while the force F2 would act at a distance X2 from the pivotal axis O2. Consequently, F2CX2) must equal R2(Y2), or R2 equals F(X2)/Y2. Due to the fact that Y2 is so much less than X2, a tremendous resisting force is 65 required. Referring to Fig. 7 the reacting force Ri is distant Yi from the pivotal axis Oi and the force Fi at a distance Xi and Yi therefrom. Therefore Ri equals Fi(Xi plus Yi) /Yi. By scaling the dimensions of the illustrations of struc- 70 tures which are comparable in size, Xi equals X2 equals 6 units, Y2 equals 1 unit, and Yi 5 units. If, as stated Fi equals F2 therefore Ri equals F(6 plus 5) /5 equals 2F. R₂ equals F(S/1) equals 6F. Obviously, therefore the reacting force which 75

2,112,349 3 must be provided by friction between the abutment surface is much smaller in the present structure than in the structure illustrated in Fig. 5, in fact, only one third as great. Obviously, it can be made still smaller relative to the force Fi by decreasing the degree of curvature of the surface of the fins 6 and 14, which step results in an increase in the radius of curvature Yi. This can be accomplished without increasing the bulk and weight of the connection, a matter to be considered when operating a tool from the end of a long handle, whereas in the prior structures, any change in the pad 30 to obtain more effective results must be accompanied by an increase in weight.

It is apparent therefore that the present invention has many advantages over the structures heretofore used, not only in that it may be made more conveniently and can be taken apart readily after a long use but also because actually the working parts thereof are subjected to a more uniform stress and each individual part to less stress for a given degree of clamping resistance than in prior structures.