Audio load indicator

Abstract

The load indicator hereof, comprises a device useful in conjunction with pressure operated mechanism which device includes means to respond to the pressures developed in said mechanism by completing an electrical circuit with contacts under the influence of a diaphragm, which is acted on by pressure developed in the mechanism, different signals being provided by a contact unit for different conditions encountered, and means to prevent signal operation when conditions desirably require that none be given.

Parent Case Text

This application is a continuation in part of application Ser. No. 304,210 filed Nov. 6, 1972, now abandoned.

Description

OBJECTS OF THE INVENTION

It is a principal object of this invention to provide an indicator which, by audible signal, will indicate the status of a load condition existing in pressure operated mechanism, since a pressure responsive device is availed of which includes therein certain contacts for electrical operation of a signal, all the same being incorporated in a small unit which is attachable to known and presently used devices as well as those contemplated for future applications.

A further object of the invention is to provide a pressure responsive device which includes a signal and means in the device connected to and operable by the mechanism for actuating movement, the movement operating the signal member to provide a warning when predetermined operating pressure is reached in the mechanism to which the device is attached, or in which the same is incorporated.

Another object of the invention is to provide a device which may be incorporated in a small unitary housing, in which a load cell is provided, this load cell including a diaphragm to which the operating pressure in the basic mechanism is directed, the diaphragm in turn actuating a contact unit which, together with a power source and circuitry, in turn operates a signal for audible indication that certain pressure conditions in the mechanism have been or are being exceeded.

A still further object of the invention is to provide a contact unit in which a circuit may be completed at different times so as to provide two different signals at least for two different conditions being encountered, or to provide a first signal as an initial indication of conditions existing, followed by a second signal when a dangerous condition exists, all under the control of the pressure developed in the pressure operated mechanism.

Another object of the invention is to provide a mechanism of the class described, in which the different signals may be provided by completion of the circuit in which the conditions encountered are different as by those encountered in the tipping operation for example, where a boom is being raised and lowered by pressure operated mechanism, and in addition a load condition of the boom may be indicated as having been exceeded under other positions thereof.

Another object of the invention is to incorporate a pressure responsive device in a pressure operated mechanism and system related thereto of the hydraulic piston and cylinder type, wherein pilot compensating means are supplied to assist in lowering the piston and cylinder instrumentalities or returning the same to their initial condition since it is required by safety considerations that a check valve be supplied for use in the extending or load lifting operation of a piston and cylinder unit and yet the same must be returned to its initial condition, additional pressure being required and no signals being desired to be given.

Other and further objects of the invention will be understood from a consideration of the specification appended hereto and disclosed in the drawing wherein:

FIG. 1 is a fragmentary perspective view, showing a pressure operated mechanism of the boom type which is mounted for rotation and in which the boom may be raised and lowered by hydraulic piston and cylinder instrumentalities, and in which the device hereof is incorporated.

FIG. 2 is an enlarged fragmentary view, showing generally the relationship of the device hereof in the system disclosed in FIG. 1.

FIG. 3 is a fragmentary sectional view, incorporating in a diagrammatic manner the specific mechanism hereof with a general mechanism which the same is desired to be associated with, and the general method of operation and relationship of parts being illustrated.

FIG. 4 is a sectional view of a form of check valve used in this construction.

DESCRIPTION OF THE INVENTION

Referring now to FIG. 1 initially, the pressure operated mechanism of this invention is shown as being incorporated in a boom unit in which a boom designated 1 is pivotally mounted at 2 on a turret 3, which turret 3 is in turn supported on a base 4 for rotation thereabout.

The boom 1 may be generally classified as a lifting means and certain hydraulic piston and cylinder instrumentalities generally designated 5, including the cylinder unit 6 thereof and the piston 7 mounted therewithin for reciprocation back and forth, the lower end of the cylinder 6 being pivotally mounted at 8 and the upper end at 9 on the boom 1.

It will therefore be understood that by introducing fluid suitably in the lower end of the cylinder 6, the piston rod 7 may be extended to raise the boom 1 about the pivot 2.

Suitable hydraulic motor and storage instrumentalities indicated at 10 are provided to supply the piston and cylinder unit 5 with fluid as may be required to effect the operation of the lifting means so called.

Since it is desired by the present invention to provide a warning means which will be actuated when the lifting means capacity may be exceeded or when the direction of lifting is improper so that tipping of the same might result, the mechanism shown in FIG. 2 is applied to the disclosure.

In FIG. 2, the pressure responsive device of this invention is generally designated at 12, suitably connected by piping such as 13 to a distribution member 14 which in turn facilitates the directing of hydraulic fluid from the pump unit 10 for example through the device 12 by the pipe 13, a pilot compensating connection at 15 being provided and connected to a pipe 16 extending to the outer end of the cylinder 6 as indicated in FIG. 1 at 17.

With the foregoing general understanding of the location of the device, FIG. 3 is referred to at this point for the specific description of the parts thereof and the system in which the same may be incorporated, with the basic piston and cylinder unit 5 being indicated in diagrammatic manner as incorporating the piston and rod 7 therein mounted in a cylinder 6 as previously described, the pump and storage portion of this hydraulic operated device being indicated at 10 likewise in fragmentary manner.

The specific device hereof includes, as indicated in the sectional portion of FIG. 3, a housing 18 which for the sake of this description may be a metal die casting having a hollow interior in which certain of the parts hereof are mounted as will be more particularly set forth hereinafter.

On one surface, or in one side of the housing 18 is a load cell denoted 19 which is mounted in a boss 20 formed integrally with the housing 18 as by the threaded portion 21 on the cell 19, which is threadedly engaged with mating threads in the boss 20 as shown.

The threads 21 are formed on a vertical member 22 which is in turn provided with threads 23 interiorly thereof to receive a connection member 24 likewise threaded exteriorly thereof, and having the lower surface 25 thereon adapted to position a diaphragm 26 which is of flexible sealing nature having the peripheral enlargement 27 therearound engaged by the surface 25 so as to position the same against an inner surface 28, the diaphragm having a pin 29 extending downwardly therefrom through an opening 30 formed in the part 19 at the center of a cavity 31.

A suitable opening 32 is formed in the part 24 and threads 33 are provided therewithin for connection of the same in a manner to be more specifically described hereinafter.

It will therefore be seen that the load cell now having been heretofore described is one which incorporates therewithin the diaphragm 26 and by connection with the pressure from the line 13 which is in the system extending to the hydraulic piston and cylinder unit or instrumentalities 5, will obviously receive the same amount of pressure thereon as is necessary to move the piston and rod 7 in the instrumentalities 5.

The load cell now having been described and indicated at 19, is arranged to cooperate with a contact unit including a contact element 35 which is a spring-like element mounted in a cavity 36 formed in the boss 20 previously mentioned, so that the pin 29 of the diaphragm 26 may impinge thereagainst and as viewed in the figure against the upper surface thereof so as to force the same to bend downwardly somewhat as pressure is applied through the opening 32 for that purpose.

This contact element 35 is arranged to coact with the first contact part 37 which is mounted by threaded engagement with a spring 38, the spring 38 in turn being connected at one end at 39 to a contact part support member 40 which is itself an insulated member and generally speaking may be described as an elongated flat strip, which is suitably fastened by fastenings such as 41 to the housing 18 and is intended to lie at about the angle or a similar angle to that illustrated in the disclosure, for purposes which will appear hereinafter.

A second contact part 42, mounted in spring 43 substantially identical to the spring 38, previously mentioned, and alongside of the spring 38 is similarly fastened alongside the fastening 39 illustrated.

It will therefore be understood that by suitable manipulation of the contact parts 37 and 42 as by inserting a screw-driver in the slots 37a and 42a respectively, adjustment of the ends of the respective parts with respect to the contact element 35 may be accomplished.

It should be noted that the spring 43 is shown in an exaggeratedly different position from the spring 38 for illustrative purposes only and will generally lie directly alongside of and be at all times parallel to the spring 38, although the contact parts 37 and 42 themselves may be relatively differently adjusted with respect to the contact element 35.

The contact part support member 40 previously mentioned, extends as indicated and includes at its outer end an opening 44 to which a support adjusting unit part is directed, the support adjusting part being designated 45 and comprising a headed bolt with a piston-like head 46 thereon, and the other end of the bolt 45 being threaded at 47 so as to receive a nut 48 thereon for adjustment purposes as will appear.

The piston-like head 46 is arranged for movement in a cylindrical section 48, there being a spring 49 and a seal 50 arranged as indicated, with the head 46 at the lower end of a threaded opening 51 to which the pressure line 15 is connected, this being generally designated as a support adjusting unit so that the aspect of the contact part support member 40 may be varied as suggested by the dotted line 53.

It will also be understood that by application of pressure on the head 46, acting as a sort of piston-like arrangement, the spring 49 will be compressed and the contact part support member 40 will move downwardly about the mounting screw 41 in a manner and according to the description of the operation of the device that will be set forth subsequently.

Referring now again to the first contact part 37, the same is in turn connected to the negative terminal of a horn or signal member 55 by wire 37b.

The second contact part 42 is connected by a wire 42b to the negative terminal of the horn signal member 55 likewise, but in this case a resistor 56 is interposed, the entire system being supplied with suitable power by means of three small batteries generally denoted at 57 wherein the positive terminal 58 thereof is connected to the signal member 55 and the negative terminal 59 is grounded to the housing 18, completing a circuit with the contact element 36 as will be set forth shortly.

Inasmuch as a check valve is necessarily required in the hydraulic system involving the piston and cylinder unit 5, such check valve being denoted at 60, it is appropriate to describe the check valve as one which is arranged to prevent inadvertent lowering of the boom by the hydraulic piston and cylinder unit 7.

In other words, when the lifting means, including the boom 1 is operated initially for example to raise the same to the position of FIG. 1, the check valve 60, specifically the valve member 60a therein, will prevent the boom 1 from moving back to its initial position irrespective of the release of the control therefor, the controls being suggested as mounted in a control panel at 61 involving levers such as 62, 63 and 64 perhaps.

In order to overcome the action of the check valve and to permit return of the piston and cylinder unit to its initial position, the pilot compensating means including the check valve 60 being part of that means and the line 16 being directed to the upper part of the piston cylinder unit. By suitable application of fluid pressure to that line, which fluid pressure will in turn be transferred to the top of the piston and thereby move the same downwardly and the check valve 60 will be actuated by the fluid beneath the piston, unseating the ball 65 therein, in the check valve to permit fluid to flow through the valve causing the lowering operation to take place, and thus be completely controlled by the operator against inadvertent dropping of any load.

Since one of the basic objects of this invention is to signal when loads are either too great or approaching a condition in which they are too great, or that a tipping condition of the mechanism in which the same is incorporated, the method of operation of the device is now described as one in which the initial pressure to the lifting means 1 by the piston and cylinder instrumentalities 5 may be applied as for example by a lever 63 from the source of hydraulic fluid under pressure at 10, being directed through the line 13 to the pressure responsive device, and specifically to the load cell 19 therein.

Since this pressure through the line 13 will act on the diaphragm 26, it will therefore be apparent that when the load may become too great upon the lifting means, requiring that the pressure in line 13 is greater than a predetermined value, the diaphragm 26 will be deflected downwardly, carrying the pin 29 therewith and in turn operating the contact element 35. If the overload or load pressure is great enough, the contact element 35 will cause a completing of a circuit with the contact part 37 for example, and by means of this contact part carry through the circuit involving the line 37b and sound the signal member 55 accordingly. The operator is thus warned of the probable overload and should immediately take steps to counteract potential damage.

The device is arranged in such a manner that if the condition continues to exist and further load is imposed on the lifting means, further deflection of the contact element 35 will take place, and the second contact part 42 will complete another circuit through the line 42b, and to the resistor 56, and by reason of the resistor 56 sound a different tone in the signal member 55.

Thus, the operator is warned of a condition existing and can take the necessary steps to alleviate the same.

Since the construction of the lifting mechanism is such as to require that additional pressure be applied through a pilot compensating line 16 to overcome the resistance of the check valve 60 to normal return of fluid through the lines to the pump and storage tank 10, the application of such additional pressure to the line 16 for the purposes of returning the lifting means to its original position would normally cause additional signalling to take place, or a signal to be sounded irrespective of whether an overload was being imposed on the equipment.

Since it is not desired to have the signal sound when the device is returning to initial position, it is contemplated that the contact part support member as adjusted in such a manner as to move he contact parts 37 and 42 sufficiently far away from the contact element 35 that no circuit will be completed.

Thus application of the additional pressure through the line 16 will in turn pass through the line 15 to the support adjusting unit previously described in detail as including the piston-like head 46, pushing the same downwardly, compressing the spring 49 and carrying the contact part support member 40 downwardly and the contact parts 37 and 42 therewith.

When the lifting means have returned to the initial condition or pressure is removed from the pilot compensating line 16, the contact part support member 40 will return to its normal attitude and support the contact parts 37 and 42 in the desired pre-adjusted position, which adjustment will provide for various loads as will be readily apparent in accordance with the deflection of the contact element 35.

Since it may be desired to provide an indication of a tipping action of the entire machine, the part of FIG. 3 including the top view of the boom 1 mounted on the turret and base 4, discloses a mounting tube such as 68 which may rotate for example with the boom of the lifting means and with the provision of segments or cam-like members 69 thereon, causing the segments 69 to move therewith and if the dotted line position 70 of FIG. 3 is reached for example, the cam 69 will coact with a micro switch 71 which is designated as a means to complete a second circuit, and close such second circuit through the lines 72 and 73 to complete connection of the line 42b with the line in which the resistor 56 is located thereby by-passing the resistor. Thus, when the load is impressed on the lifting means 1, in the dotted line position 70 for example, which load is exceeding that desired since the circuit is completed, the horn or signal member 55 will sound by reason of the completing of the circuit through the contact element 35 and contact part 42.

It is thus noted that both an overload in a tipping position and a normally impressed overload so to speak in the straight-ahead position are both accommodated for and signalling given in response thereto.

Claims

I claim:

1. In pressure operated mechanism, in combination, a pressure responsive device including a signal member and means in the device connected to and operable by the pressure operated mechanism for actuating movement in response to operating pressure changes therein, the movement aforesaid in turn operating the signal member to provide a warning when a predetermined increase in operating pressure takes place in the mechanism, said device comprising a housing, a load cell comprising a diaphragm to which the operating pressure is directed, the device further comprising a contact unit actuated by the diaphragm, and in alignment therewith for actuation by said diaphragm, a power source and circuitry connecting the contact unit, signal member and power source for operating the signal member for warning as stated, the pressure operated mechanism further comprising hydraulic piston and cylinder instrumentalities connected to lifting means, said instrumentalities including pilot compensating means operable to facilitate return movement of the instrumentalities to initial position, the pressure responsive device including a load cell connected to the piston and cylinder instrumentalities, and a contact unit having means to complete a circuit to produce a signal by the signal member when the predetermined operating pressure is reached, said unit having means to prevent signal operation during the return movement aforesaid.

2. Mechanism as claimed in claim 1 wherein the contact unit comprises a contact support member and a contact part carried thereby, said load cell being adjacent the contact unit, said cell including a diaphragm, the contact element is operable by the diaphragm to engage the contact part to complete the circuit as stated, and the support adjusting unit coacts with the support member responsive to increased pressure in he compensating means to move the support member and contact part out of position to complete the said circuit.

3. Mechanism as claimed in claim 1, wherein the pressure responsive mechansim comprises hydraulic piston and cylinder instrumentalities connected to lifting means, the pressure responsive device includes a load cell having a diaphragm therein to which the pressure in the instrumentalities is directed to operate the diaphragm in response to changes in pressure in the piston and cylinder instrumentalities, said diaphragm being arranged to operate a contact element to engage a first contact part in the device, the signal member on the device being actuated when the contact part and element are in engagement in consequence of a predetermined pressure in the instrumentalities, the contact element is arranged to engage a second contact part in the device at a different pressure from the first contact part to produce distinct signals in response to different pressures in the piston and cylinder instrumentalities, the piston and cylinder instrumentalities include pilot compensating means operable to facilitate the return movement of the instrumentalities to initial position, and the pressure responsive device includes means connected to the compensating means to vary the position of the contact parts to prevent actuation of the signal member during the return movement aforesaid.