The invention relates generally to an automatic lubrication system for an impact tool or the like, and more particularly to a system which includes a pump component for delivering lubricant from a lubricant storage container to a location on the tool where the lubricant is to be applied, the lubricant being transported either by its own flow characteristics and/or by means of pressure to the delivery chamber of the pump component, and means for producing a pump stroke of the pump component with each actuation of the impact tool to deliver lubricant to the point of lubrication.
EP-A-0 430 024 describes an automatic lubricating system for the tool of a hydraulic impact mechanism. The system comprises a delivery unit connected to a lubricant storage container for delivering lubricant to the chisel guide supporting the chisel of the impact mechanism. In that case, the lubricant storage container, filled with lubricating grease, features a movable separating component which acts under the bias of a compression spring to force lubricant grease to the delivery chamber of the delivery unit. Here, the delivery pressure of the delivery unit is generated by the same hydraulic operating pressure that drives the impact mechanism, so that each time operating pressure is applied to the impact mechanism, the delivery unit produces a predetermined delivery stroke of adjustable magnitude. Such a lubricating system requires expensive hydraulic and/or pneumatic connecting lines as well as the pertinent control and command installations.
is an object of the present invention to create a simpler and more reliable lubricating system of the type mentioned at the outset.
This task is achieved by an oscillatory mass to which is transferred the impact motion of the tool, and by means which converts the oscillating motion of this mass into a pump pressure for driving the pump component.
In a first embodiment of the invention, the oscillatory mass for actuating the pumping component is either slidably supported on a fixed rod element or is affixed to a movable rod element supported in an axially sliding fashion, so that on each actuation (vibration) of the impact tool the oscillatory mass is deflected from its rest position. In this embodiment, the rod element is preferably aligned with the direction of impact. At least one slide bearing is provided for the oscillating mass. This bearing may consist of a bearing housing in which the mass oscillates back and forth. In the case where the oscillating mass is slidable on a fixed rod element, the slide bearing may comprise the walls of the bearing housing; where the mass is affixed to a movable rod element, the slide bearing for the rod element may comprise the lids of the bearing housing.
To ensure that the oscillating mass returns to its starting point or home position after each oscillation, the mass may be supported on opposite sides by compression springs. The compression springs in turn may react against the end walls or lids of the bearing housing.
A further defining feature of the invention consists of the fact that the rod element comprises, at least in part, a gear rack which is engageable with a gear to drive the pump component. In this embodiment, the gear rack drivingly engages the toothed rim of the gear as the rod element moves through a forward stroke; during a reverse stroke the gear rack slides, ratchet-fashion, over the appropriately inclined teeth of the gear rack. This ensures that the gear that actuates the delivery piston of the pump component moves only in one direction. In this embodiment, the gear rack is preferably attached to one end of the rod element for pivotal movement relative to the axis of rotation of the gear. The rack pivots away from the axis during a reverse stroke of the rod element and is urged by a spring toward the axis during a forward stroke to ensure that the gear rack drivingly engages the gear to drive the pump component.
According to a further aspect of this invention, a cam is used to transfer the motion of the gear to the delivery piston of the pump. The cam has a cam surface which engages the piston to drive it through a forward pumping stroke. A spring is used to move the piston back through a return stroke.
In another aspect of this invention, the range of movement of the oscillating mass, and thus the stroke of the delivery piston, can be varied by an adjustable stop. This stop permits adjustment of the amount of lubricant to be delivered to the lubrication site with each impact.
In another embodiment of this invention, the oscillatory mass is supported on a shaft element by first and second one-way clutches. In this case the axis of the shaft element is preferably oriented crosswise relative to the impact direction of the impact mechanism. Movement of the oscillating mass in one direction causes the first one-way clutch to engage the shaft to rotate it and thus drive the piston of the pump through a forward pumping strike. The second one-way clutch is disengaged from the shaft during this rotation. As the oscillating mass moves in the opposite direction, the first one-way clutch disengages the shaft and the second one-way clutch engages the shaft to prevent reverse rotation of the shaft. In this fashion the impact (vibrating) motion of the tool is converted into a directional rotating movement of the shaft element.
The rotary movement of the shaft is transferred to the piston of the delivery pump by means of a cam having a cam surface which is engageable with the delivery piston of the pump component. Rotation of the eccentric drives the piston through a forward stroke to deliver lubricant to the point of lubrication. The piston is moved through a reverse stroke by a return spring.
In this embodiment, an adjustable stop is provided at the bearing housing to vary the stroke of the delivery piston. This enables the amount of lubricant delivered to be adjusted.
In general, a lubrication system for a vibratory apparatus of the present invention comprises a lubricant pump for pumping lubricant from a supply thereof to one or more points of lubrication of the apparatus. A drive for the pump is powered in response to the vibration of the apparatus.
In another aspect, a lubrication system of the present invention is for a hydraulic striking device, the device being vibratory in operation. The system comprises a base for attachment to the device for vibration therewith and a lubricant pump for pumping lubricant from a supply to one or more points of lubrication of the device. The pump comprises a cylinder and a plunger reciprocable in the cylinder through a stroke between a retracted position for intake of lubricant into the cylinder and a forward position for delivery of the intake from the cylinder. A weight is mounted on the base for oscillation in response to the vibration of the device when the base is attached to the device, oscillation of the weight effecting reciprocation of the plunger through a stroke.
Additional objectives, features and application possibilities of the present invention are found in the description of examples of embodiment, below, based on the drawing. In so doing the defining features, described and/or illustrated in figures, constitute, per se or in any desired combination, the object of this invention, independently of their summarization into individual claims or their back-references.