Abstract: An elastic overshoe has an outer layer through which extend a plurality of protrusions. The protrusions are preferably carried on an inner layer, which is sandwiched between the outer layer and the shoe upon which the overshoe is placed. Inner layer segments can run the length of the overshoe, or more preferably include only a ball region of a toe region. The openings can have any practical size, shape, orientation and arrangement of openings, although of course at least some of the openings must be aligned with at least some of the protrusions, and ideally the protrusions will fit snugly within the openings to avoid tearing of the openings. The inner and outer layers can advantageously have different chemical compositions. The inner layer, for example, can be tougher, while the outer layer could be more stretchable.

Abstract: A utility knife has a protective guard that moves from a locked position to an unlocked position. Preferred mechanisms utilize a pawl that cooperates with a stop to reduce movement of the guard while the guard is in a locked position, and a simple latching mechanism that allows the pawl to bypass the stop. The pawl is disposed with respect to other elements of the mechanism such that the blade guard can only pulled back to a retracted position after operation of a trigger or other actuator, and then only for a single use. Both the stop and the catch can advantageously be carried in a fixed special relation to one another by operation of a trigger or other actuator.