Retractable castors
Retractable castors mechanism for attachment to an article of furniture or other heavy object including a castor shank that is rotatably received by a socket of a retaining member. A mainspring biases the retaining member and the castor downwardly, and a latch pin is engageable with the retaining member to latch the castor against the force of the spring in an inoperative retracted position. The latch is operated by a releasing lever having a foot portion that rests against the floor, so that a slight push of the article across the floor causes the latch pin to disengage the retaining member, allowing the castor to descend to an operative position.
A retractable castor mechanism for mounting on a movable article so that the article can be rolled along a floor comprising:
a housing;
a retaining member slidably received by said housing for vertical reciprocation therein and including an outer sleeve and an inner socket;
a castor having a shank inserted in said socket and movable with said retaining member between an extended operative position and a retracted inoperative position;
a spring disposed within said sleeve and biasing said caster toward said operative position;
latching means for latching said castor in said inoperative position against the force of said compression spring;
said latching means including a latch pin movable into a retaining member engaging position;
a releasing lever pivotably mounted on the outside of said housing and connected to said latch pin;
said releasing lever having a foot portion positioned with respect to said housing to frictionally engage said floor when said castor is in said inoperative position; and
latch spring means for urging said foot portion toward said floor and simultaneously urging said latch pin toward said socket engaging position, whereby said retaining member and said castor can be released by said latch pin to move said castorfrom said inoperative position to said operative position by moving said article relative to said floor.
The retractable castor mechanism of claim 1 wherein said foot portion includes a movable tip for frictionally engaging said floor and a tip spring engaging said lever and urging said tip against said floor.
A retractable castor mechanism for mounting on a movable article so that the article can be rolled along a floor comprising:
a housing;
a castor movable relative to said housing between an extended operative position and a retracted inoperative position;
said castor including a shank received within said housing for substantially vertical reciprocation;
resilient means for biasing said castor downwardly toward said operative position; and
means for releasably latching said castor in said inoperative position against the force of said resilient means, said latching means comprising a releasing lever movable between a castor latching position and a castor unlatching position and alatch spring biasing said lever toward said castor latching position, said lever having a foot portion oriented with respect to said housing to frictionally engage said floor when said lever is in said castor latching position, whereby said lever can bemoved from said castor latching position to said castor unlatching position by moving said article relative to said floor.
The retractable castor mechanism of wherein:
said latching means further comprises an opening in said housing, and a latch pin connected to said lever and extending through said opening; and
said mechanism further comprises retaining means within said housing for transmitting the force of said resilient means to said castor, said retaining means being engageable by said latch pin to latch said castor in said inoperative position.
The retractable castor mechanism of, wherein said foot portion of said releasing lever includes a movable tip for engaging said floor and means for biasing said tip against said floor when said lever is in said latched position.
The retractable castor mechanism of, further comprising a retaining member including a socket in which said castor is received, said retaining member being slidably received by said housing for vertical reciprocation therein.
The retractable castor mechanism of, wherein said latching means furhther includes a horizontally movable latch pin connected to said lever for engaging said retaining member when said lever is in said castor latching position.
A retractable castor mechanism for mounting on a movable article so that the article can be rolled along a floor comprising:
a housing;
a castors movable relative to said housing between an extended operative position and a retracted inoperative position;
sais castor including a shank received within said housing for substantially vertical reciprocation;
resilient means for biasing said castor downwardly toward said operative position; and
means for releasably latching said castor in said inoperative position against the force of said resilient means, said latching means comprising a releasing lever mounted on said housing having a foot portion positioned with respect to saidhousing to frictionally engage said floor when said castor is in said inoperative position, said latching means releasing said castor from said inoperative position in response to movement of said releasing lever, whereby said castor can be caused tomove from said inoperative position to said operative position by moving said article relative to said floor.
The retractable castor mechanism of, wherein said latching means further includes latch spring means connected to said housing, urging said foot portion against said floor.
The retractable castor mechanism, wherein said foot portion includes a movable tip and spring means for urging said tip against said floor for frictional engagement therewith when said castor is in said inoperative position.
A retractable castor mechanism for mounting on a movable article so that the article can be rolled along a floor comprising:
a housing;
a castor movable relative to said housing between an extended operative position and a retracted inoperative position;
said castor including a shank received within said housing for substantially vertical reciprocation;
means for releasably latching said castor in said inoperative position against the force of said resilient means; and
a retaining member having a socket within which said shank is rotatably received for vertical reciprocation therewith, said socket being engaged by said resilient means and urged downwardly within said housing by said resilient means.
Description
BACKGROUND
The present invention relates to castors, and more particularly to a castor mechanism that permits a castor to be moved from an operative position to an inoperative position.
Articles of furniture and other heavy objects are often provided with castors so that they can be moved more easily. The castors do not, however, provide a base for the article that is as solid as the legs or bottom surface of the articleitself. It is desirable, therefore, that the castors be made retractable to provide better support and to lower the article to its normal height when it is not being moved.
Retractable castor mechanisms that have been proposed previously are often difficult to operate. Many require that the article be lifted off the castor which is then secured in a retracted position. This arrangment is unsatisfactory because thedesired to avoid lifting the article is often the reason for providing castors in the first place. Even if the article is not heavy, it is usually difficult for one person to simultaneously lift it and operate the castor mechanism. Other difficultiesarise because a single person cannot operate more than one such mechanism at a time, while most articles require four or more castors for adequate support.
Some previously known castor mechanisms have included jacks by which the article can be raised and lowered, but such mechanisms are often unduly complex and difficult to use, especially in a confined area. Moreover, most previously known castormechanisms required that the user be able to reach the mechanism to extend or retract it, and the location of the mechanism under the article and near the floor is often not conveniently accessible.
A principal object of the present invention is to provide an improved castor mechanism that can be operated conveniently by forces applied to the article on which the castor is mounted, without direct access to the castor mechanism itself.
SUMMARY
The present invention comprises a retractable castor mechanism for attachment to items of furniture such as chairs, sofas, desks, tables and beds, and to other relatively heavy objects, such as home appliances and industrial machines. Themechanism can be latched in a retracted inoperatve position to allow the article to rest on its own legs by simply pressing downwardly on the article. It can be unlatched, so that the article is raised by a spring and rides on the castors by simplypulling the article a very short distance along the floor.
The mechanism includes a castor of conventional construction having a vertical shank that may be rotatably received by a socket in a retaining member. A mainspring engages the retaining member and biases the castor downwardly toward the bottomof a housing causing it to extend beneath the article in an operative position.
When the retaining member is moved upwardly in the housing retracting the castor into an inoperative position, a latching mechanism holds the retaining member and the castor against the force of the spring. The latching mechanism can include alatch pin that projects through the housing to engage the retaining member and a pivotable releasing lever that operates the latch pin. A latch spring biases the lever and pin toward a latching position.
The releasing lever may have a foot portion that frictionally engages the floor when the castor is retracted. In response to a slight pull of the article along the floor, the drag produced by the foot causes the lever to pivot against the forceof the latch spring, and the movement of the lever withdraws the latch pin from engagement with the retaining member. The mainspring, acting through the retaining member, then returns the castor to its operative position.
Other features and advantages of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings which illustrate, by way of example, the principles of the invention.
The castor mechanism can be included as an original part of the article, or it can readily be added to a pre-existing article. In either case, the housing is simply positioned on the inside surface of the leg or other member so thatthe castor 14 is even with the bottom of the article when retracted. Wood screws 62 are then used to secure the housing to the leg.
The mechanism 10 is small and compact, of simple construction, and is easily manufactured, but provides convenient movement of the castor 14 between its operative and inoperative positions by simply pressing down on the article or pulling thearticle a short distance along the floor.
While a particular form of the invention has been illustrated and described, it will be apparent that various modifications can be made without departing from the spirit and scope of the invention.