GB2200522A

GB2200522A - Cultivator blade mounting

Info

Publication number: GB2200522A
Application number: GB08729339A
Authority: GB
Inventors: Charles Vernon Roge Dowdeswell
Original assignee: Individual
Current assignee: Individual
Priority date: 1986-12-17
Filing date: 1987-12-16
Publication date: 1988-08-10
Anticipated expiration: 2007-12-16
Also published as: GB2200522B; GB8729339D0; GB8630126D0

Abstract

Each cultivator blade (28,30) has a handle or shank (24, 26) secured in a rotatable support member (12) by a corresponding wedge (32, 34) having a toothed engagement with the handle (24, 26). The toothed engagement may be of symmetrical tooth form or preferably of ratchet form as shown to resist end movement of the blade (28, 30) relative to the support member (12) and facilitate blade adjustment. The wedges (32, 34) are releasably retained or tightened by a screw operated clamp (36). <IMAGE>

Description

Adjustable Cultivator Mounting The present invention relates to agricultural cultivators and in particular to cultivator blade mounting assemblies.

One known type of rotary cultivator comprises two cultivator blades each having a handle which is secured by a wedge in a respective slot at each end of a cultivator blade support. The support has an upwardly extending axle which is splined to a gear which in turn meshes with the gears of adjacent supports so that each support and therefore the associated blades is rotatably driven about a s,ubstantially vertical axis in the opposite direction to each adjacent support. In another type of known cultivator each blade handle is again wedged in a slot in a blade support, the support being secured to a horizontal shaft which is rotatably driven about its horizontal axis. The support members are spaced axially along the shaft with adjacent support members being angularly offset to provide a helical formation on the shaft.

One disadvantage of the above two forms of cultivator is that during use the continual impact of a cultivator blade with the soil can drive the handle further through the slot, thus shortening the blade's effective length. This problem also shows itself when a blade becomes worn. When the wedge is removed to extend the blade it is often difficult or impossible to tighten the wedge sufficiently to prevent the blade being pushed back into the aperture during use.

The present invention seeks to provide an improved form of cultivator mounting.

Accordingly, the present invention provides a cultivator blade mounting assembly comprising a cultivator blade having a blade portion and å handle, a support member having a slot therein for receiving said blade handle, and a wedge means engageable with said handle in said slot and movable in a direction substantially axially of said handle away from said blade portion whereby to wedge said blade handle in said slot; and wherein said handle and said wedge means have cooperating teeth means engageable to inhibit movement of said blade relative to said wedge means.

The present invention is further described hereinafter, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a sid elevation,- partly in section, of a first embodiment of cultivator blade mounting assembly; Figure la shows a modified arrangement of Figure 1; Figure 2 is a diagrammatic plan view of the assembly of Figure 1 mounted with several additional assemblies; Figure 3 is a side elevation, partly in section showing a modification to the assembly of Figure 1; Figure 3a shows a modified arrangement of Figure 3; Figure 4 is a side elevation, partly in section, of a further embodiment of cultivator blade mounting assembly; Figure 5 is a section on the line A-A of Figure 4; Figure 6 is a section along the line B-B of Figure 4;; Figure 7a is a plan view, partly in section, of a further modification to the assembly of Figure 1; Figure 7b is a view similar to Figure 7a of a further modification; and Figure 8 is a side elevation of a cultivator blade.

Referring firstly to Figure 1 this shows an assembly 10 having a horizontally arranged-elongate support member 12 which is rotatably supported by a shaft 14 in a gear housing 16. The shaft 14 is splined to a gear wheel 18 in the gear housing 16, the gear wheel 18 meshing with the gear wheels of adjacent assemblies.

The support member 12 has a respective slot 20, 22 adjacent each end, in which the handle 24, 26 of an associated cultivator blade 28, 30 is wedged by means of a respective wedge 32, 34. Each slot 20, 22 is of a complementary wedge shape and the wedge 32, 34 is inserted from below and clamped in position by means of a clamp 36 formed by a bridge-member 38 which is secured to the support member 12 by means of a bolt 40.

As can be seen from Figure 1 each blade handle 24,26 is formed with a series of serrations or teeth 42, 44 each of which extends transversely of the handle and has its steeper, leading edge facing away from the blade. The associated wedge 32, 34 has complementary serrations or saw teeth which face in the opposite direction to and mate with those on the blade handle.

The effect of the serrations is to prevent the blade handle 24,26 moving upwardly relative- to the associated wedge 32, 34 during use in response to impacts on the blade. Instead, the serrations or teeth serve to carry the associated wedge with the handle, increasing the action of the wedge. This inhibits movement of the blade handle upwardly through the slot and therefore-shortening of the effective length of the blade.

Once the tip of a blade has worn down sufficiently to reduce its effectiveness the above-described mounting assembly allows the blade to be further extended without it being necessary to remove the associated wedge. The shape of the teeth on the blade handle 24, 26 and the wedge 32, 34 allow them to ride over one another when the blade handle is given a sharp rap with a hammer to extend the blade downwardly as seen in Figure 1. If necessary, the clamp 36 can be loosened slightly to facilitate this and then retightened once the blade has been set at its des-ired effective length.

Figure 3 shows a modification to the assembly of Figure I in which the wedge 32' is drawn into the slot 20 from above by means of, for example, a bolt 46.

It desired the teeth 42 may be of symmetrical V-form or similar shape as distinct from the ratchet form shown in Figures 1 and 3 whilst in some applications the direction of the ratchet form of the teeth may be reversed as shown at 42', 44' in Figures la and 3a i.e. to facilitate upward adjustment of the blades 28, 30 relative to the support member 12.

Figures 4 to 6 show a further form of cultivator blade mounting assembly 100 in which a number of blade support members 112 (only one of which is shown in the drawings) are secured, for example by welding, to a horizontal shaft 114 which, in use, is rotatably driven about its longitudinal axis in an anti-clockwise direction as seen in Figure 4. The support members 112 are axially spaced along the shaft 114 and are also angularly spaced by a preselected amount from the next adjacent support members to provide one or more groups which are arranged in a helical formation on the shaft 114.

Each support member 112 has a wedge-shaped slot 120 which receives a handle 124 of a cultivator blade 128 together with a wedge 132. The handle and the wedge are formed with a series of serrations or saw teeth 142 in the same manner as described with reference to the assembly of Fiqure 1 and these saw teeth serve the same function. The wedge 132 is prevented from dropping through the slot 120 by means of a pin or lug 144 in the upper end region of the wedge, the pin abutting the upper surface of the support member 112 should the wedge 132 become loose. in the slot 120.

As an additional feature in this form of assembly the lower portion of the wedge projecting below the slot 120 is provided with a leading edge 146 which is generally V-shaped in section as is shown in Figure 6. This provides a cutting action during rotation of the shaft 114 to reduce the tendency of grass and similar material to wrap around the wedge and support member 112.

Referring to Figures 1 to 3 again, in order to provide each blade 28, 30 with a leading edge which follows a circu]ar path outside the trailing edge during rotation of the cultivator, the blades are normally "handed". That is, the surface of the handle which carries the saw teeth 42, 44 and engages with the wedge 32, 34 lies in a plane at an acute angle to the plane of the blade, the angles being reversed in the left-handed and right-handed versions. This means that three forms of blade have to be stocked by the user, the un-handed blade used in the cultivator of Figures 4 to 6 and the left-handed and right-handed blades for the cultivator of Figure 1.

This problem is overcome by using a "handed" wedge as is shown in Figures 7a and 7b. In Figure 7a the face of the wedge 32" which engages the handle 24" of the cultivator blade 28" lies at an acute angle to the plane containing the longitudinal axis and rotational axis of the support member 12" thus, as can be seen in Figure 7a, although the blade 28" is an un-handed blade the leading edge follows a path outside that of the trailing edge during rotation of the cultivator. If the wedge 32" of Figure 7a is taken as a left-handed wedge for clockwise rotation then Figure 7b shows a right-handed wedge 32"' for anti-clockwise rotation.

Figure 8 shows a side elevation or face view of an unhanded blade 28" having serrations 42" on the handle 24".

Claims

CLAIMS:

1. A cultivator blade mounting assembly comprising a cultivator blade having a blade portion and a handle, a support member having a slot therein for receiving said blade handle, and a wedge means engageable with said handle in said slot and movable in a direction substantially axially of said handle away form said blade portion whereby to wedge said blade handle in said slot; and wherein said handle and said wedge means have cooperating teeth means engageable to inhibit movement of said blade relative to said wedge means.

2. A cultivator blade mounting assembly according to claim 1 wherein the cooperating teeth means is of ratchet or like form.

3. A cultivator blade mounting assembly according to claim 1 wherein the cooperating teeth means is of symmetrical tooth form such as Wform or of similar shape.

4. A cultivator blade mounting assembly according to claim 1, 2 or 3 wherein the wedge means is retained or tightened in position of use or released or permitted to release therefrom by screw mechanism.

5. A cultivator blade mounting assembly according to any of the preceding claims wherein the wedge means is retained against movement out of the slot e.g by means of a pin or lug at the upper region of the wedge and arranged to bear against the upper side of the support member.

6. A cultivator blade mounting assembly according to any of the preceding claims wherein the support member or a plurality thereof is or are carried by a rotary member or shaft which in use is rotatable about a substantially horizontal axis.

7. A cultivator blade mounting assembly according to claim 6 wherein a plurality of said support members are spaced along and about the rotary member or shaft to provide a helical formation of the support members there- about.

8. A cultivator blade mounting assembly according to any of the preceding claims wherein an exposed portion of the wedge means is provided with cutting edge formation for the purpose of reducing the tendency of grass or similar material to accumulate about the wedge and adjacent part of the support member and blade.

9. A cultivator blade mounting assembly according to any of the preceding claims wherein that part or face of the wedge means which cooperates with the blade handle is angled in relation to the support member in order to correspondingly angle the blade handle and blade portion relative thereto.

10 A cultivator blade mountinq assembly when substantially as herein described with reference to any of the embodiments thereof shown in the accompanying drawings.