Patent Application
20130291679
This disclosure relates to a protective device adapted to shield internal elements of a working component from potentially damaging operating force loads otherwise imparted to the component by a structural member of an associated machine, and more particularly to a bracket designed to isolate an attached component from such transient loads.
The protection of operating components, including hydraulic valves, is a common consideration in design and manufacture of machines, including, for example, trucks, construction equipment, excavators, wheel loaders, tractors, motor graders, mining machines and the like, on or in which such components may be secured. For example, a machine may impose transient and/or twisting loads on attached components at a level sufficient to bind or restrict movement of internal parts contained within the components.
In the case of a hydraulic valve component, an internal valve spool normally free to move reciprocally within the valve component may become damaged or bound by machine forces, rendering the component at least sporadically inoperable, i.e. causing desired movement of the valve spool to cease. Prior efforts directed to avoiding such component interference, as especially associated with off-road machines subject to particularly harsh loads, have involved using various isolating devices, including so-called isolation mounts incorporating rubber bushings. Such structures are, however, associated with greater complexity and assembly requirements, considering that, apart from the extra expense, the rubber parts must be separately manufactured and inventoried.
In accordance with one aspect of the disclosure, a protective load isolating device may include a planar body having a plurality of tabs arranged about the body. Each tab may define a peripheral extremity of the body, extending outwardly thereof though substantially situated within the same plane of the body. Each tab may have a particular width, and a neck defined by a fillet having a predetermined radius. Both the tab width and fillet radius may be adjusted for desired amount of deformation of the tab relative to the body.
In accordance with another aspect of the disclosure, the predetermined fillet radius of each neck may be sized and configured to absorb load forces through elastic deformation, such that the tabs may elastically deform and thus minimize any deformation within the planar body of the device.
In accordance with another aspect of the disclosure, the device may be formed of an elastic metal plate, and each tab may have the same thickness as the planar body.
In accordance with yet another aspect of the disclosure, both the tabs and the planar body may comprise a metal material, and the planar body may include a plurality of attachment apertures adapted for direct securement to the housing of a component adapted to be protected or shielded from work machine load forces.
Referring initially to
The bucket 22 may be affixed to and directly operable by hydraulic linkage apparatus 24, as may be controlled by a machine operator (not shown) seated within the cab 18. Thus a seat 26, as well as controls 28 including a steering wheel as shown, may be utilized by such machine operator. The machine 10 may be adapted to perform work tasks, such as the movement of dirt and debris, for example.
Finally, a machine component, such as a spool valve assembly 30 by way of example, may be adapted for manipulation of the bucket 22 via the hydraulic linkage apparatus 24. Such work task movements of the machine 10 may be associated with significant transient operating force loads, particularly during actual digging into soil and/or the raising and lowering buckets of dirt. As such, the spool valve assembly 30 may bind up and become inoperative if not isolated from such transient force loads otherwise imposed thereon during operation of the machine 10.
Referring now to
Referring now more particularly to
Mounting tabs 44a, 44b, and 44c may extend about the boundary of the body 42. The mounting tabs may be adapted to be secured to the main frame 12 (
Each of the mounting tabs 44a, 44b, and 44c may include a neck portion 48a, 48b, and 48c, by which it is connected to the planar body portion 42. Each neck portion 48 may have a pair of fillets 50 of differing sizes about the body 42. In alternate embodiments, and within the scope of this disclosure, a neck portion 48a, 48b, and 48c may be configured with one or more fillets 50. Each fillet 50 may have a predetermined radius and configured to best absorb load forces through elastic deformation. The sizing and configuration of the tabs 44a, 44b, and 44c and fillets 50 may be achieved via finite element analysis, although other methodologies may be employed within the scope of this disclosure.
The tabs may therefore be designed to elastically deform under transient force loads, and in a manner that minimizes deformation of the planar body 42, to protect any component, as the spool valve 30, for example, that may be attached to the mounting bracket 40.
Making continued reference to
The use of only three mounting tabs 44 and three points of attachment as depicted, rather than four or more, for example, may better assure that the connection points will all lie within the same plane. Moreover, the use of three mounting tabs 44, in combination with the spacers 58, may provide for substantial isolation of any component attached to the bracket 40 almost as effectively as the use of isolation mounts utilizing rubber bushings.
Finally, auxiliary tab apertures 60 may accommodate other unrelated connections, including an electrical power supply unit, for example.
The described protective load isolation device may be useful in a variety of machines, including wheel loaders, excavators, tractors, trucks, and other off-road machines. As disclosed, the load isolation mounting bracket 40 may replace isolation brackets that incorporate rubber bushings as part of their mounting structure.
In operation, the mounting bracket 40 may be adapted to protect operational components, such as the spool valve assembly 30, whenever linear, torsional, which or other transient force loads may otherwise be transferred from the main frame 12 of the machine 10 to the component.
A method of isolating a component in accordance with the disclosure may include step of forming a bracket having a planar body and a plurality of machine mounting tabs extending from the body, each of the tabs being substantially within the same plane of the body, the body containing a first set of apertures, the tabs containing a second set of apertures. The method may further include the steps of forming a spacer corresponding to each tab for securement to the machine, attaching the spacer directly to the machine, attaching the bracket to the component utilizing the first set of apertures, and attaching each of the tabs to one of the spacers utilizing the second set of apertures. Further, each of the tabs may be sized and configured to absorb transient force loads that may be imposed from the machine to the component, thereby avoiding binding of or damage to any moving element within the component.
