Search Images Maps Play YouTube News Gmail Drive More »
Sign in
Screen reader users: click this link for accessible mode. Accessible mode has the same essential features but works better with your reader.


  1. Advanced Patent Search
Publication numberUS418867 A
Publication typeGrant
Publication dateJan 7, 1890
Filing dateAug 21, 1889
Publication numberUS 418867 A, US 418867A, US-A-418867, US418867 A, US418867A
InventorsPatrick Francis Dundon
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Discharge-door for steam digesters and retorts
US 418867 A
Abstract  available in
Previous page
Next page
Claims  available in
Description  (OCR text may contain errors)

(No Model.)


Patented Jan. '7, 1890.




SPECIFICATION forming part of Letters Patent No. 418,867, dated January 7, 1890.

Applicationfiled August 21, 1889. Serial No. 321,509. (No model.)

To (ZZZ whmn it may concern:

Be itknown that I, PATRICK FRANCIS DUN- DON, of the city and county of San Francisco, State of California, have invented an Improvement in Discharge-Doors for Steam Digesters and Retorts; and I hereby declare the following to be a full, clear, and exact description of the same.

My invention relates to a drop bottom or door for discharging the contents of digesters or steam-tanks which are used for rendering lard, tallow, and other like matters.

7 It consists of a door or bottom suitably fixedto the bottom of the digester, a leverarm, and a supplemental eccentric-lever for locking the same and the door when closed, and a screw which acts against the door to produce any desired compression upon it after the lever is locked in place, together with certain details of construction.

Referring to the accompanying drawings for a more complete explanation of my invention, Figure 1 is a view showing a section of the bottom of thetank or digester with the drop bottom or door,.the lever, eccentric, and screw by which it is held in place. Fig. 2 is a bottom view of the same. Fig.3 is a perspective View of a part of the lever, link, and eccentric.

The tank or digester may be made in any suitable or desirable shape to suit the work to be done, the bottom being preferably slightly depressed or concave, as shown atA, and terminating in a conical discharge-opening B. Around the bottom of this opening is a suitably-shaped projecting bead 0, against which the door or bottom D is fitted to close. A groove or channel is cut in this bottom corresponding with the projecting bead G, and within this is fitted a gasket of lead or other suitable soft material, which maybe melted in, and the upper surface afterward faced off so as to make a joint with the projecting bead when the door is closed against it.

E is a curved arm or bar, hinged at one side to the bottom of the digester, as shown atF, and curving from this point downward below the door D and extending straight across beneath said door, being provided at its outer end with a'suitable handle G, by which to move it.

H is a link hinged to the opposite side of the digester, as shown at I, and having its lower end adapted to receive an eccentric J, which is pivoted to the link, or, if preferred, between the two straps H, which may be used in place of the single one. The eccentric J has an arm or extension K, whichserves as a lever by which to turn it. The link H, swinging on its pivot I, is swung beneath the leverarm E after the latter has been brought up into position beneath the door D. Through the center of the arm E extends a scrcwL, the point of which is adapted to press against the central portion of the door D, and this .screw holds the door in place when the arm E has been brought up to the proper position, so that the link H is swung beneath it. The arm K of the eccentric J is turned so as to present the lowest portion of the eccentric beneath the arm E, and after the link H is in place the lever K is turned so as to cause the eccentric to act upon the arm E and force it upward, so that acting upon thebottom D it will force the latter into close contact with the bottom of the tank or digester. This bottom may be forced as tightly against the bead O as maybe desired by turningthe screw L after the bar E has been locked in place by the eccentric J, thus providing a simple and rapid means for closing and locking the bottomof the digester.

When the work has been completed Within -the digester and it is necessary to discharge it, this is effected without loosening the screw L or any necessity of going beneath the digester by simply drawing the lever-arm K backward, so that the eccentric will be turned and release the bar E, the eccentric being slipped away so as to allow the bar E and the drop-bottom D to fall away, thus allowing the contents of the digester to be discharged.

The door D is secured to the bar E by,

means of a bracket M, which is bolted to the door' and extends down around the bar E, as.

shown, the screw L passing through an open ing in the bracket and through the bar E, as above described, so that the whole may drop and may be lifted together without being separated from each other. Pins 0 prevent the bracket and door from moving out of place, and guides P, projecting down from the bottom flange, keep the door in the proper position when being closed.


Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is

1. The digester or tank having the conical or tapering discharge with the projecting bead, in combination with the door and gasket fitting against the said head, a lever-arm hinged to one side of the digester, extending 'across and beneath the door, and having a it, a screw passing through an arm so as to bear against the center of the door, and a yoke or bracket whereby the door is loosely connected with the arm, a swinging link attached to the opposite side of the digester, and an eccentric journaled in said link and adapted to swing beneath the front end of the leverarm, said eccentric having an arm or extension whereby it may be turned so as to lock or release the lever-arm and the door when closed, substantially as described.

In witnesswhereof I have hereunto set my hand.




Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4367768 *Feb 19, 1980Jan 11, 1983Heraeus Quarzschmelze GmbhRefractory protective tube for the heat treatment of semiconductor components
US5064089 *Mar 8, 1990Nov 12, 1991Salco Products Inc.Vented hatch cover
US5960980 *Jun 3, 1997Oct 5, 1999Zeftek, Inc.Vented hatch cover
Cooperative ClassificationF16J13/20