US3480315A - Reciprocal door latch for laundry washing machine - Google Patents

Description

Nov. 25, 1969 K. H. WOLVERTON RECIPROCAL DOOR LATCH FOR LAUNDRY WASHING MACHINE Filed July 21, 1967 2 I 3 n :1 L' l J FIG 3 INVENTOR KEN/V577! ff h/oz Venn/u ATTORNEYS United States Patent 3,480,315 RECIPROCAL DOOR LATCH FOR LAUNDRY WASHING MACHINE Kenneth H. Wolverton, Moline, Ill., assignor to Ametek, Inc., New York, N.Y., a corporation of Delaware Filed July 21, 1967, Ser. No. 655,205 Int. Cl. Ec 1/04; D06f 39/14 US. Cl. 292175 5 Claims ABSTRACT OF THE DISCLOSURE The present invention relates to a reciprocable door latch for the inner cylindrical drum of a laundry washing machine, and more particularly to such a door latch which will automatically be locked in the event the inner drum begins to rotate when the latch has been left in the open position.

A conventional form of laundry washing machine comprises an outer cylindrical shell in which is rotatably mounted a cylindrical drum. The outer shell is provided with a door or other access through which the articles to be washed are introduced into a door formed in the wall of the inner shell. After the articles have been placed in the inner drum, the door is locked by a suitable latching mechanism which must be dependable so as to maintain the door locked throughout the rotary move ment of the drum. Various forms of latching assemblies have been proposed for this purpose. However, on occasion, the latches have been left unlocked and operation of the laundry machine commenced by rotating the inner drum. Under these conditions, the door was open and the laundry machine damaged, with possible loss or destruction of the articles being washed. While several forms of electrical safety circuits and interlocks have been devised, these have not been successful since extensive modifications of the laundry machines were required for their installations. Further, the complexity of these safety arrangements added unduly to the cost of the laundry machines.

It is therefore an object of the present invention to provide a novel and improved reciprocable door latch.

Another object of the invention is to provide a reciprocable door latch particularly adapted for the inner rotatable drum of a laundry washing machine.

A further object of the invention is to provide a latch assembly for the door of the inner drum of a laundry machine which will automatically move to the locking position on rotation of the inner drum.

In one aspect of the invention, there may be provided a bracket having a bore therethrough and mounted upon the outer surface of the inner drum door adjacent to the door edge. A keeper element is mounted on the drum so as to lockingly cooperate with the latch. A guide sleeve is attached to the bracket and is coaxial with the bracket bore. A latch bolt having a forward end and an outer end is slidably mounted in the bracket and guide sleeve and is urged outwardly into the locking position by a spring mounted within the guide sleeve. A handle is mounted on the outer end of the latch bolt 3,480,315 Patented Nov. 25, 1969 "ice for free pivotal movement in a plane perpendicular to the reciprocable movement of the latch bolt. Extending outwardly from the guide sleeve away from the bracket is a longitudinal plate having an arcuate cross section. The longitudinal edges of this plate guide the movement of the handle when the handle is pivoted to a position substantially parallel to the door surface so that the latch bolt is movable to the locking position. On the outer end of the longitudinal plate there is formed a shallow notch which can releasably receive the handle when the handle is pivoted to a position perpendicular to the door surface after the latch bolt has been moved to its unlocked position. In the unlocked position, the handle extends radially outwardly into the path of projecting structure on the outer drum so as to be pivoted from this position when the inner drum begins to rotate. When the handle is released from this unlocked position, the latch bolt will be moved to the locking position under the action of the spring in the guide sleeve.

Other objects, features and advantages of the invention will be apparent from the following description taken in conjunction with the accompanying drawings which are exemplary.

In the drawings:

FIG. 1 is a partial transverse sectional view of the laundry washing machine incorporating the present invention;

FIG. 2 is an enlarged top plan view of the latch bolt according to the invention in the locking position and taken along line 22 of FIG. 1;

FIG. 3 is a front elevational view of the latch bolt of FIG. 2, showing the bolt and handle in the unlocked position;

FIG. 4 is an end view of the latch illustrated in FIG. 3; and

FIG. 5 is a sectional view taken along the line 5-5 of FIG. 3.

Referring to the drawings wherein like reference symbols indicate the same parts throughout the various views, a specific embodiment of the invention will be described in detail.

As may be seen in FIG. 1, the stationary outer shell or drum of a conventional side loading washing machine is indicated at 10 and is provided with the usual door .11 which is closed in regular use of the machine and which may be of the sliding type or of the swinging hinge type. An inner drum 12 is rotatably mounted within the shell 10 with both the shell and the drum being of the cylindrical type. The inner drum 12 is also provided with a door 13 which may be of the sliding or hinge type. The inner door 13 is provided with a latch bolt assembly generally indicated at 14 which is essential since the inner door must be positively locked during the operation of the machine.

Such a latching arrangement for the outer door may be 7 optional. 7

Referring to FIGS. 2 to 5, the latch assembly 14 comprises a latch bolt assembly indicated generally at 15 and a keeper 16. The keeper is in the form of a bracket having a bore 17 therein and is mounted on the outer surface of the inner drum 12 adjacent the door opening. The latch bolt assembly comprises a bracket 18 having a bore 19 therein, the bracket being mounted on the outer surface of the inner door 13 for cooperation with keeper 16. A cylindrical guide sleeve 20 is attached to bracket 18 and has a bore 21 which is coaxial with the bore 19. A latch bolt 22 is slidably mounted in the guide sleeve 20 and bracket 18, and has a forward end 23 and an outer end 24. The for-ward end 23 may be slightly tapered and has a notch 25 therein. There is an annular shoulder 26 on the latch bolt 22 and a spring 27 seated against this shoulder and against a retaining member 28 mounted on the outer end of the guide sleeve 20.

On the outer end 24 of the latch bolt, there is mounted a handle 29 which is freely pivotable in a plane perpendicular to the direction of reciprocable movement of the latch bolt. The handle 29 is retained in position by a nut 30 and a cotter pin 31.

Welded to the upper surface of the guide sleeve 20 is a longitudinally extending guide plate 32 which may be arcuate in cross section, as seen in FIG. 5, and has longitudinal guide edges 33. The outer end of plate 32 is provided with a shallow notch 34 having a configuration to conform to the cross section of handle 29 so as to releasably retain the handle therein.

A guide block 35 is mounted on the latch bolt 22 adjacent handle 29 by means of a set screw 36. The guide block 35 has a groove 37 in its upper surface and receives the longitudinal edges 33 of the guide plate therein.

The latch bolt 22 is slidably mounted for reciprocable movement between a locked position as illustrated in FIG. 2 and an unlocked position as shown in FIG. 3. When the latch bolt is withdrawn to the unlocked position, the handle 29 is pivoted upwardly to a radial position with respect ot the inner drum 12 and seated into the notch 34 on the end of the guide plate 32. The latch assembly is thus retained in the unlocked position.

When it is desired to commence the laundering operation and to lock the inner drum door, it is only necessary for the operator to hit the handle 29 downwardly toward the door 13. With very little force, the handle will become unseated from notch 3 and will be pivoted downwardly to a position substantially parallel to the door 13 where the handle will be guided along one of the longitudinal edges of the guide plate 32. While under the action of the guide spring, the latch bolt 22 is moved to the locked position.

The length of the bolt handle 29 is such that when the handle is retained in the unlocked position, it is engageable with either the edges in the door 11 in the outer shell or some other structure located on the inner surface of the outer shell. Thus, in the event that the operator inadvertently commences operation of the laundry machine without first latching the door 13 on the inner drum, the rotating inner drum will cause the handle to contact some part of the outershell and the handle will be pivoted downwardly. The spring will then move the latch bolt to the locked position.

Thus, it can be seen that the present invention has disclosed a simple yet effective structure for a latch bolt assembly which is particularly adapted for the door of the inner drum of a laundry washing machine. The latch bolt assembly has a built-in safety feature in that the operating handle extends radially outwardly of the inner drum when the latch is unlocked. When the handle is in this position, it may contact a portion of the outer drum so as automatically to lock the latch as soon as the inner drum begins to rotate. The latch structure comprises a minimum of components so that maintenance problems are considerably reduced.

It is to be understood that changes in various details of construction and arrangement of parts may be made without departing from the spirit of the invention.

What is claimed is:

1. A latch bolt for a door of a washing machine drum, comprising a bracket having a bore therethrough mounted upon a surface, a guide sleeve attached to said bracket and coaxial with said bore, a latch bolt having a forward end and outer end slidably mounted in said bracket and guide sleeve, a spring within said guide sleeve urging said latch bolt outwardly of said bracket to the locking position, a handle freely pivotable on the outer end of said latch bolt in a plane perpendicular to the slidable movement of said latch bolt, a longitudinal plate on said guide sleeve and extending outwardly therefrom away from said bracket for guiding the movement of said handle when pivoted to a position substantially parallel to said surface so that the latch bolt is movable to the locking position, and a notch on the outer end of said longitudinal plate for releasably receiving said handle when the latch bolt is moved to its unlocked position and the handle is pivoted to a position substantially perpendicular to said bracket mounting surface, and guiding means on said bolt for slidably engaging said longitudinal plate during the slidable movement of said bolt.

2. A latch bolt as claimed in claim 1, further comprising a guide plate mounted on said latch bolt adjacent said handle and slidably mounted on the longitudinal edges of said longitudinal plate.

3. A latch bolt as claimed in claim 1, further comprising an annular shoulder on said latch bolt, retaining means on the end of said guide sleeve, said spring being between said shoulder and said retaining means to urge said latch bolt into the locking position.

-4. In a laundry washing machine, the combination of a stationary outer cylindrical shell having an access opening therein, a rotary cylindrical drum rotatably mounted within said outer shell, a door in the wall of said cylindrical drum, a keeper element on said drum adjacent said door, a latch on said door having a reciprocable latch bolt lockingly engageable with said keeper element, a handle on said latch bolt freely pivotable thereon in a plane perpendicular to the movement of said latch bolt, and means on said latch for releasably retaining said handle in a position substantially perpendicular to said door when the latch is in the unlocked position, said handle extending radially outwardly of said drum a sufficient distance to engage an edge of said access opening when said drum is rotated, whereby the handle will be pivoted out of engagement with said retaining means to permit the locking of the latch.

5. A laundry washing machine as claimed in claim 4 wherein said latch comprises a bracket having a bore therethrough mounted upon said door, a guide sleeve attached to said bracket and coaxial with said bore, said latch bolt having a forward end and outer end and slidably mounted in said bracket and guide sleeve, a spring within said guide sleeve urging said latch bolt outwardly of said bracket to the locking position, said handle being freely pivotably mounted on the outer end of said latch bolt, and means on said guide sleeve for guiding the movement of said handle when pivoted to a position substantially parallel to said door so that the latch bolt is movable to the locking position.

References Cited UNITED STATES PATENTS 2,438,597 3/1948 Batina 292- X 2,490,707 12/1949 Piltz 292-173 FOREIGN PATENTS 344,249 3/ 1931 Great Britain. 570,762 7/1945 Great Britain.

RICHARD E. MOORE, Primary Examiner O U.S. Cl. X.R. 68139, 143

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