Abstract: A playpen includes four posts, four rails installed between the posts, at least two stems attached to one of the rails and at least two positioning devices each attached to one of the posts for cooperating with the stems for movably installing the rail on the posts. Each of the related posts includes a groove for receiving one of the stems and a dent in communication with the groove. Each of the positioning devices includes a button movable across the detent and a latch including a first portion connected to the button and a second portion. The button is operable so as to move the latch between a locking position where the second portion thereof restrains the stem in the groove and a releasing position where the second portion thereof retreats from the groove.

Abstract: A playpen includes four posts, four rails installed between the posts, at least two stems attached to one of the rails and at least two positioning devices each attached to one of the posts for cooperating with the stems for movably installing the rail on the posts. Each of the related posts includes a groove for receiving one of the stems and a dent in communication with the groove. Each of the positioning devices includes a button movable across the detent and a latch including a first portion connected to the button and a second portion. The button is operable so as to move the latch between a locking position where the second portion thereof restrains the stem in the groove and a releasing position where the second portion thereof retreats from the groove.

Abstract: A automatic multi-function testing machine for electric appliances includes an oval annular testing table, carriers moving around on the table for carrying electrical appliances to be tested, various testers and meters fixed on a gauge panel located on an oval support base located inside the table, a first electric rail annularly located near the peripheral edge of the oval support base and insulatingly separated into five stages. Each stage is electrically connected with one of the testers and the meters on the gauge panel. Each carrier has two brushes contacting and sliding under the first rail and a socket to connect with a plug of an appliance thereon. So the appliances are tested separately by all the testers and measured by the meters in a flowing system, when moved around with the carrier on the table for one round.