US 12,440,718 B2
Portable and variable exercise device
Dawn T. Gulick, Spring City, PA (US); Zachary John Pelli, Philadelphia, PA (US); and Thomas D. Kauffman, Glenside, PA (US)
Assigned to Blix Strength LLC, Spring City, PA (US)
Filed by Blix Strength LLC, Spring City, PA (US)
Filed on Oct. 2, 2022, as Appl. No. 17/937,451.
Application 17/937,451 is a continuation in part of application No. 17/568,864, filed on Jan. 5, 2022, granted, now 11,458,346.
Prior Publication US 2023/0211202 A1, Jul. 6, 2023
This patent is subject to a terminal disclaimer.
Int. Cl. A63B 21/00 (2006.01); A63B 21/02 (2006.01); A63B 21/04 (2006.01)
CPC A63B 21/154 (2013.01) [A63B 21/023 (2013.01); A63B 21/0435 (2013.01)] 19 Claims
OG exemplary drawing
 
1. An exercise device comprising:
a cable;
a force modulating pulley around which the cable is wound; and
a constant force spring engaged to the force modulating pulley, wherein the constant force spring provides a constant resistance against rotation of the force modulating pulley when a force is applied to the cable;
wherein the force modulating pulley varies the force that must be applied to rotate the force modulating pulley when the force is applied to the cable
wherein the force modulating pulley has an hourglass profile extending between ends of the force modulating pulley along an axis thereof, wherein a minimum diameter of the hourglass profile is at a midpoint between the ends of the force modulating pulled along the axis, wherein the hourglass profile provides a low-to-high-to-low force relationship to a muscle being worked when using the exercise device.